Advertisement

Relationship between MMP-9 serum levels and tHcy levels and total imaging load and cognitive dysfunction

  • Jianhua Zhao
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Author Footnotes
    1 co-first author
    Qiong Li
    Footnotes
    1 co-first author
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Lifang Meng
    Affiliations
    Neurology, Kaifeng Pepople's Hospital, Kaifeng, Henan 475000,China
    Search for articles by this author
  • Fan Wang
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Qing Li
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Fangli Yang
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Minghua Wang
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Miao Yu
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Jian Zhang
    Affiliations
    Imaging Department, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Shaomin Li
    Correspondence
    Corresponding authors.
    Affiliations
    Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States
    Search for articles by this author
  • Sibei Ji
    Correspondence
    Corresponding authors.
    Affiliations
    Henan Joint International Research Laboratory of Neurorestoratology for Senile Dementia, Henan Key Laboratory of Neurorestoratology, Neurology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453100, China
    Search for articles by this author
  • Author Footnotes
    1 co-first author
Open AccessPublished:October 03, 2022DOI:https://doi.org/10.1016/j.jstrokecerebrovasdis.2022.106759

      Abstract

      Objectives

      To investigate the correlation and predictive value of serum matrix metalloproteinase-9 (MMP-9) level with cognitive dysfunction and total imaging load in patients with cerebral small vessel disease (CSVD).

      Methods

      A total of 80 patients with CSVD who were admitted to the First Affiliated Hospital of Xinxiang Medical University between April 2019 and April 2020 were enrolled. All subjects underwent T1-weighted imaging (T1WI), T2WI, fluid-attenuated inversion recovery (FLAIR), diffusion weighted imaging (DWI), serum sample collection, and assessment of cognitive function at a specific time-point after admission. According to the results of the neuropsychological test, subjects were divided into cognitive dysfunction group (n=40) and normal cognitive function group (n=40). The total imaging load was estimated according to the neuroimaging findings. Serum MMP-9 level was measured by an enzyme-linked immunosorbent assay (ELISA) kit. Beside, serum MMP-9 level and total imaging load were compared between the two groups.

      Results

      Serum levels of MMP-9 and plasma total homocysteine (tHcy) were negatively correlated with cognitive function (P<0.05). Serum MMP-9 level was found as a significant factor for diagnosing cognitive impairment due to CSVD (area under the curve (AUC), 0.756; sensitivity and specificity were 97.5% and 75.0%, respectively). THcy level was also found as significant factor for diagnosing cognitive impairment due to CSVD (area under the curve (AUC), 0.727; sensitivity and specificity were 97.5% and 75.0%, respectively).

      Conclusion

      Serum MMP-9 level and tHcy level were significantly correlated with cognitive function in patients with CSVD. Serum MMP-9 level has a specific correlation with the total imaging load in patients with CSVD. It plays an important role in diagnosing cognitive impairment in patients with CSVD.

      Key words

      Introduction

      Cerebral small vessel disease (CSVD) is the most common, chronic and progressive vascular disease, threatening human health due to its increasing incidence year-by-year. It mainly manifests as cognitive impairment. Previous studies have shown that matrix metalloproteinase-9 (MMP-9) level changes correspondingly before patients have severe clinical symptoms and cognitive impairment .
      • Meng Lifang
      • Zhao Jianhua
      • Liu Junli
      • et al.
      Cerebral small vessel disease and cognitive impairment.
      MMP-9 is secreted by a wide number of cell types, including cardiomyocytes, endothelial cells, neutrophils, macrophages, and fibroblasts. It plays a key role in neuronal damage, inflammation, and cell apoptosis and migration. It can regulate neural synaptic plasticity and affect learning and memory functions. CSVD refers to a spectrum of clinical and imaging findings, resulting from pathological processes of various etiologies, influencing cerebral arterioles. The present study aimed to analyze serum MMP-9 level in subjects by using the total imaging load as the standard to evaluate the severity of CSVD. Additionally, using the Functional Cognitive Assessment Scale (FUCAS), the correlation of serum MMP-9 level with cognitive dysfunction and total imaging load in patients with CSVD was explored.

      Methods

      Subjects

      Patients with CSVD who were admitted to the Neurology Department of the First Affiliated Hospital of Xinxiang Medical University (Urumqi, China) between April 2019 and April 2020 and met the eligibility criteria were included in the present study.
      • liwen Hu
      • Lei Yang
      • xuanting Li
      • yonghua Huang
      Chinese consensus on diagnosis and therapy of cerebral small vessel disease 2021.
      The specific diagnostic criteria for CSVD are mainly based on imaging rather than clinical manifestations. The main imaging features are recent small subcortical infarct(RSSI) (Fig. 1), lacunar infarcts(LIs) (Fig. 2), white matter hyperintensity(WMH) (Fig. 3), cerebral microbleed(CMB) (Fig. 4), enlarged perivascular spaces(EPVSs) (Fig. 5), and cerebral atrophy (Fig. 6). The total imaging load standard is summarized as shown in Fig. 7. The inclusion criteria were as follows: (1) patients who aged 40-80 years old, (2) patients who met diagnostic criteria for cerebral microangiopathy, (3) patients who were willing to undergo neuropsychological tests, and (4) patients who agreed to participate in this researcher. The exclusion criteria were as follows: (1) patients with a history of stroke, (2) non-vascular factors that cause imaging changes, (3) patients with other central nervous system (CNS) diseases, such as dementia, epilepsy, Parkinson's syndrome, and CNS-inflammatory demyelination diseases, (4) patients with serious cognitive dysfunction who could not complete the test, (5) patients with serious cardiac and pulmonary diseases, and (6) patients who disagreed to participate in this researcher. All subjects underwent T1-weighted imaging (T1WI), T2WI, fluid-attenuated inversion recovery (FLAIR), diffusion weighted imaging (DWI), serum sample collection, and assessment of cognitive function at a specific time-point after admission. According to the results of neuropsychological test, subjects were divided into cognitive dysfunction group and normal cognitive function group.
      Fig 1
      Fig. 1Neuroimaging characteristics of recent small subcortical infarct(RSSI). a:DWI;b:T1 FLAIR;c:T2WI;d:T2 FLAIR.
      Fig 2
      Fig. 2Neuroimaging characteristics of Lacunar stroke. a:DWI. b:T1 FLAIR. c:T2WI.
      Fig 3
      Fig. 3Neuroimaging characteristics of white matter hyperintensity(WMH) in magnetic resonance T2 FLAIR(T2 FLAIR). Deep WMHs (DWMHs):a,b,c. Periventricular WMHs (PVWMHs):d,e,f. a and d:grade 1; b and e:grade 2; c and f:grade 3.
      Fig 4
      Fig. 4Neuroimaging characteristics of cerebral microbleeds(CMBs) in MR Susceptibility Weighted Imaging(SWI).
      Fig 5
      Fig. 5Neuroimaging characteristics of enlarged perivascular spaces(EPVSs) in magnetic resonance T2 weighted image(T2WI). a and e:grade 1. b and f:grade 2. c and g:grade 3. d and h:grade 4.
      Fig 6
      Fig. 6Neuroimaging characteristics of cerebral atrophy in Magnetic resonance T2 weighted image(T2WI).
      Fig 7
      Fig. 7A 45-year-old man with CSVD. The main complaint was slurred. a: DWI showed Lacunar stroke, scored 1 point. b:T2 FLAIR showed WMH, and the fazekas score is 4 points, scored 1point. c: T2 FLAIR showed EPVS: scored 1point. d:SWI showed CMBs: scored 1point. So the total imaging load scored 4 points.

      General data collection

      Medical data were collected by professionally trained physicians, including age, gender, educational level, history of hypertension, diabetes, cardiac disease, smoking, and drinking, and serum samples (total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), glucose (GLU), glycosylated hemoglobin (GHb), and homocysteine (tHcy)). Hypertension and diabetes were diagnosed at the first interview, and cardiac disease was either previously diagnosed or at the time of admission. Smoking history was defined as smoking for 5 years with an average of 10 or more cigarettes per day. Drinking history was defined as drinking alcohol for more than 5 years and ethanol intake of 30 g or more per day. The normal range of relevant biochemical indicators was as follows: TC: 0-5.2 mmol/L; TG: 0.7-1.7 mmol/L; HDL; 0.8-1.55 mmol/L; LDL: 1.68-4.53 mmol/L; tHcy: 0-15 mmol/L; GHb: 4-6%. All subjects underwent magnetic resonance imaging (MRI) of the cranial site using a unified MRI instrument. Imaging results were interpreted by two professional radiologists. Neuropsychological test included the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The subjects were all tested in the same conditions.

      Assessment of cognitive function

      According to the 2019 Chinese Expert Guideline for Cognitive Disorders Related to Cerebral Microangiopathy,
      • dantao Peng
      • Wen Shao
      Clinical practice guideline for cognitive impairment of cerebral small vessel disease of China (2019).
      subjects were assigned into cognitive dysfunction group and normal cognitive function group. The bias was corrected according to the years of education. The specific method was to add 1 point to the basic score if a subject had 12 years of education. The standard MMSE score for normal cognitive function was illiterate > 17 points, primary school > 20 points, and middle school and higher levels of education > 24 points.

      Evaluation of the total imaging load

      Total imaging load score was assessed according to the imaging diagnostic standard for CSVD. Four typical imaging manifestations of the LIs,WMH,CMB and EPVS were selected as the evaluation content of the total imaging load. The main scoring items about total imaging load score included 1 point for one lacunar and lacunar infarction, 1 point for one cerebral micro-bleed, 1 point for the Virchow-Robin space in grades 2-4, 1 point for 3 points of high signal in lateral ventricle and 2 points in deep brain. The total score was 0-4 points. Evaluation of the white matter hyperintensity (WMH) was performed using Fazekas classification method, in which WMHs were divided into periventricular WMHs (PVWMHs) and deep WMHs (DWMHs) as follows
      • yifan Ji
      • zhenjie Teng
      • xiangyu Li
      • et al.
      Correlation of total magnetic resonance imaging burden with homocysteine in patients with cerebral small vessel disease.
      : PVWMHs scoring criteria: 0 point: no WMHs; 1 point: caps or pencil-thin lining; 2 points: smooth halo; 3 points: irregular PVWMHs extending into the deep white matter. DWMHs scoring criteria: 0 point: no WMHs; 1 point: punctate foci; 2 points: beginning confluence of foci; 3 points: large confluent areas. Total score: PVWMHs score + DWMHs score. The Virchow-Robin space was evaluated from the imaging level with the highest number of lesions.
      • Doubal FN
      • MacLullich AM
      • Ferguson KJ
      • Dennis MS
      • Wardlaw JM.
      Enlarged perivascular spaces on MRI are a feature of cerebral small vessel disease.
      The main classification standard included grade 0 without perivascular clearance, grade 2 levels of 11-20, grade 3 levels of 21-40, and grade 3 levels of 40 and more.

      Determination of serum MMP-9 level

      Subjects' venous blood was collected and centrifuged at 3000 r/min for 10 min at room temperature. The supernatant was retained, and the serum MMP-9 level was measured using an enzyme-linked immunosorbent assay (ELISA) kit.

      Statistical analysis

      The data were statistically analyzed by SPSS 26.0 software (IBM, Armonk, NY, USA). Measurement data were expressed as mean ± standard deviation. Differences between groups were compared using the independent-samples t-test. The correlation analysis was performed by the Pearson correlation analysis. Categorical variables were described as count and percentage, and compared by the Chi-square test or the Fisher's exact test, as appropriate. The receiver operating characteristic (ROC) curve analysis was used to analyze the diagnostic value of serum MMP-9 level in patients with CSVD. P < 0.05 was considered statistically significant.

      Results

      The general data and total imaging load in the two groups are presented in Table 1. A total of 80 subjects were included, of whom, there were 24 male (60.0%) and 16 female (40%) subjects. The normal cognitive function group and the cognitive dysfunction group equally included 40 (50%) cases (normal cognitive function group (n=40), cognitive dysfunction group (n=40)). The subjects’ mean age in the two groups was 58.3±11.21 and 66.4±7.76 years old, respectively.The proportions of cerebral infarction, hypertension, and coronary heart disease in the cognitive dysfunction group (35%, 67.5%, 15%) were greater than those in the normal cognitive function group (20%, 60%, 2.5%). In terms of biochemical indicators, the levels of TG, tHcy, and MMP-9 (1.69±1.18, 17.35±7.36, and 2.61±0.73 mmol/L) in the cognitive dysfunction group were higher than those in the normal cognitive function group (1.37±0.67, 12.86±4.70, and 1.83±0.87 mmol/L). There were no significant differences in gender, years of education, proportions of hypertension, diabetes, smoking history, drinking history, TG, TC, LDL, HDL, GLU, and GHb between the two groups. However, serum levels of tHcy and MMP-9 varied significantly (P <0.05). In terms of total imaging load, the proportion of 3-4 points (60.0%) in the cognitive dysfunction group was significantly greater than that in the normal cognitive function group (37.5%) (P <0.05).
      Table 1Gender data, biochemical indicators, and total image load.
      Normal cognitive function group (n=40)Cognitive dysfunction group (n=40)Inspection value (t/u)P
      Gender/case (%)-0.2640.791
      Male

      Female
      24 (60.0)25 (62.5)
      16 (40.0)15 (37.5)
      Age (years old)58.3±11.2166.4±7.76-3.7090.000
      Culture level (year)7.9±3.836.93±3.36-1.1960.232
      Cerebral infarction8 (20)14 (35)-1.6830.092
      Cerebral hemorrhage2 (5)0 (0.0)-2.0080.045
      Hypertension24 (60)27 (67.5)-0.8090.419
      Heart disease1 (2.5)6 (15)-2.0680.039
      Diabetes6 (15)3 (7.5)-1.2860.199
      Smoking history12 (30)8 (20)-1.2160.224
      Drinking history10 (25)5 (12.5)-1.7250.085
      Biochemical indicator
      TG (mmol/L)1.37±0.671.69±1.18-1.3810.167
      TC (mmol/L)4.02±0.744.00±0.840.1130.910
      LDL (mmol/L)2.24±0.472.04±0.641.6050.112
      HDL(mmol/L)1.37±0.401.36±0.26-0.4860.627
      tHcy(μmol/L)12.86±4.7017.35±7.36-3.4980.000
      GLU(mmol/L)5.76±2.135.52±1.30-0.0630.950
      GHb(%)5.80±1.125.65±0.94-0.2020.840
      MMP-9 (ng/l)1.83±0.872.61±0.73-4.2650.000
      Total imaging load-2.1300.033
      0-225 (62.5%)16 (40.0%)
      3-415 (37.5%)24 (60.0%)
      TG: triglyceride; TC: total cholesterol; LDL: low-density lipoprotein; HDL: high-density lipoprotein; tHcy: total homocysteine; GLU: glucose; GHb: glycosylated hemoglobin; MMP-9: matrix metalloproteinase-9.
      The results of correlation analysis of serum MMP-9 level with cognitive function and total imaging load are shown in Table 2. The Pearson correlation coefficient of serum MMP-9 level with total MMSE score and total MoCA score was (r= -0.519, P <0.05) and (r= -0.345, P <0.05), respectively, indicating that there was a negative correlation between serum MMP-9 level and cognitive function. The Pearson correlation coefficient of serum MMP-9 level with total imaging load was (r=0.387 and P <0.05), demonstrating that there was a positive correlation between serum MMP-9 level and cognitive function.
      Table 2Results of the correlation analysis of serum MMP-9 level with total imaging load, total MMSE score, and total MoCA score.
      MMP-9 (ng/l)
      RP
      Total imaging load0.4940.001
      Total MMSE score-0.5190.001
      Total MoCA score-0.3450.029
      MMSE: the Mini-Mental State Examination; MoCA: the Montreal Cognitive Assessment.
      The results of the ROC curve analysis of the diagnostic value of serum MMP-9 level and tHcy level in predicting cognitive dysfunction in patients with CSVD are summarized in Table 3 and Fig. 8. It was revealed that serum MMP-9 level and tHcy level were statistically significant in both groups (P <0.05). To further analyze whether the serum MMP-9 leveland tHcy level had diagnostic value in patients with cerebral microangiopathy, ROC curve analysis was performed. The results showed that the area under the curve (AUC) value of MMP-9 in cognitive dysfunction group was 0.756 (0.649-0.863), and the sensitivity and specificity were 0.975 and 0.750, respectively. The area under the curve (AUC) value of tHcy in cognitive dysfunction group was 0.727 (0.615-0.839), and the sensitivity and specificity were 0.975 and 0.750, respectively.
      Table 3Results of the ROC curve analysis of the diagnostic value of serum MMP-9 level and tHcy level in predicting cognitive dysfunction in patients with CSVD.
      AUCSignificanceSensitivenessSpecificity95%CI
      Lower limitUpper limit
      MMP-90.7560.0000.9750.7500.6490.863
      tHcy0.7270.0000.9750.7500.6150.839
      Fig 8
      Fig. 8The ROC curve analysis of the diagnostic value of serum MMP-9 level and tHcy level.

      Discussion

      Cerebral small vessels are crucial to maintenance of adequate blood flow to the sub-surface brain structure. They include small arteries, arterioles, venules, and capillaries.
      • Rost NS
      • Etherton M.
      Cerebral small vessel disease [published correction appears in Continuum (Minneap Minn). 2020 Jun;26(3):826-827].
      CSVD is a syndrome of clinical, imaging, and pathophysiological changes caused by small blood vessel lesions in the brain. Its clinical symptoms are diverse, mainly including cognitive dysfunction, sleep disturbance, movement disturbance, and other manifestations. CSVD is also known as "asymptomatic stroke" or "resting stroke" because of its hidden clinical symptoms. However, due to the lack of specificity in clinical manifestations of CSVD, its diagnosis relies mainly on imaging manifestations. It has six imaging manifestations, such as WHM, new subcortical small infarct, lacunar and lacunar infarction, Virchow-Robin spaces, microhemorrhage, and brain atrophy.
      • Pantoni L.
      Cerebral small vessel disease: from pathogenesis and clinical characteristics to therapeutic challenges.
      To date, clinical researches have shown that CSVD has been the main pathogenic factor of 45% of dementia patients and 20% of stroke patients worldwide. In recent years, it has become a common disease, threatening human health.
      • Joutel A
      • Faraci FM.
      Cerebral small vessel disease: insights and opportunities from mouse models of collagen IV-related small vessel disease and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.
      ,
      • Pantoni L.
      Cerebral small vessel disease: from pathogenesis and clinical characteristics to therapeutic challenges.
      Development of therapeutic approaches for CSVD has markedly attracted scholars’ attention. As for the pathogenesis of CSVD, a previous research demonstrated that its pathogenesis is related to the damaged composition of the blood-brain barrier (BBB), leading to the insufficient supply of local cerebral blood flow.
      • Iadecola C.
      The neurovascular unit coming of age: a journey through neurovascular coupling in health and disease.
      The components of the BBB include vascular endothelial cells, basement membrane, astrocytes, and pericytes. Some studies also suggested that non-familial cerebral small vessel disease starts in vascular endothelial cells. When vascular endothelial cells are damaged, they can affect the entire brain and lead to the dynamic evolution of focal damage.
      • Vinters HV
      • Zarow C
      • Borys E
      • et al.
      Review: vascular dementia: clinicopathologic and genetic considerations.
      ,
      • Arvanitakis Z
      • Capuano AW
      • Leurgans SE
      • et al.
      The relationship of cerebral vessel pathology to brain microinfarcts.
      MMPs are a highly conserved class of proteolytic enzymes. MMPs can disrupt and degrade most of the protein components in the extracellular matrix (ECM). Multiple MMP species are involved in the regulation of the BBB permeability, integrity, and its function, of which MMP-9 plays the most important role. MMPs are a large family divided into 6 classes in total, including gelatinases, collagenases, stromelysins, stromelysins, furin-activated MMPs, and other secreted MMPs. Type IV collagenase is one of the most important types of collagenases. MMP-9 plays a critical role in diverse physiopathological processes. A variety of cells can secrete MMP-9, such as vascular endothelial cells, neutrophils, macrophages, dendritic cells, etc.
      • Dejonckheere E
      • Vandenbroucke RE
      • Libert C.
      Matrix metalloproteinases as drug targets in ischemia/reperfusion injury.
      MMP-9 gene is located in chromosome 20q11.1-13.1, 26-27 kbp, with 13 and 9 genes. Its structure includes hydrophobic signal peptide sequence, propeptide region, catalytic active region, structural domain, etc.
      • Vandooren J
      • Van den Steen PE
      • Opdenakker G.
      Biochemistry and molecular biology of gelatinase B or matrix metalloproteinase-9 (MMP-9): the next decade.
      Inflammation, impaired BBB, and extracellular remodeling are considered as three mechanisms for CSVD. Inflammation and extracellular remodeling can both affect impaired BBB function through MMPs, while the main mechanism has still remained elusive.
      • Candelario-Jalil E
      • Thompson J
      • Taheri S
      • et al.
      Matrix metalloproteinases are associated with increased blood-brain barrier opening in vascular cognitive impairment.
      In the vasculature, MMP-2 and -9 are produced by smooth muscle and endothelial cells, whereas MMP-7 and -12 are mainly secreted from macrophages. Under the action of plasmin, MMP-2 is activated to promote the release of pro-inflammatory factors, such as MMP-9, which in turn affects the BBB function.
      • Lee JY
      • Choi HY
      • Ahn HJ
      • et al.
      Matrix metalloproteinase-3 promotes early blood-spinal cord barrier disruption and hemorrhage and impairs long-term neurological recovery after spinal cord injury.
      In normal physiological conditions, MMP-9 is involved in the remodeling of ECM and regulates cell–cell contacts.
      • Choi JI
      • Ha SK
      • Lim DJ
      • et al.
      S100ß, Matrix metalloproteinase-9, D-dimer, and heat shock protein 70 are serologic biomarkers of acute cerebral infarction in a mouse model of transient MCA occlusion.
      A previous study reported that MMP-9 level increased in human brain tissue after cerebral ischemia,
      • Swetha R
      • Gayen C
      • Kumar D
      • et al.
      Biomolecular basis of matrix metallo proteinase-9 activity.
      suggesting that MMP-9 level is associated with cerebral perfusion. Recent studies found that MMP-9 plays an important role in learning and memory functions by regulating the morphology and function of synapses.
      • Vafadari B
      • Salamian A
      • Kaczmarek L.
      MMP-9 in translation: from molecule to brain physiology, pathology, and therapy.
      ,
      • Tsilibary E
      • Tzinia A
      • Radenovic L
      • et al.
      Neural ECM proteases in learning and synaptic plasticity.
      Previous studies confirmed that MMP-9 has a certain diagnostic value in cognitive dysfunction. In the present study, the results also revealed that the serum MMP-9 level has a certain correlation with cognitive dysfunction, and has a certain diagnostic value as well. The results of a previous research showed that MMP-9 level has a certain correlation with cognitive function, mainly in visuospatial and executive functions.
      • Jianhua Zhao
      • Xue Peng
      • Lifang Meng
      • et al.
      Correlation between serum MMP-9 protein level and vascular cognitive impairment with no dementia in patients with cerebral small vessel diseases.
      ,
      • limin Lu
      • kongliang Zhi
      Effect of matrix metalloproteinase 9 on cognitive dysfunction in patients with ischemic stroke.
      Although the results of the ROC curve analysis in the present study indicated that serum MMP-9 level has a diagnostic value for cognitive dysfunction in CSVD, there are still some shortcomings, including small sample size and insufficient diagnostic value. Therefore, additional studies need to be conducted to eliminate these shortcomings and to confirm our findings. MMP-9 can be implicated in multiple CNS diseases through the inflammatory immune responses, such as stroke, neurodegeneration, epilepsy, etc. Therefore, the specificity of MMP-9 is difficult to be detected. This may be related to the fact that MMP-9 with other neurological factors, as diagnostic markers for CNS diseases, can further improve diagnostic specificity. Several studies have developed new biosensors that can rapidly detect MMP-9 level.
      • Ruiz-Vega G
      • García-Robaina A
      • Ben Ismail M
      • et al.
      Detection of plasma MMP-9 within minutes. Unveiling some of the clues to develop fast and simple electrochemical magneto-immunosensors.
      • Nguyen PD
      • Cong VT
      • Baek C
      • et al.
      Fabrication of peptide stabilized fluorescent gold nanocluster/graphene oxide nanocomplex and its application in turn-on detection of metalloproteinase-9.
      In the future, further technologies will be developed for the treatment of patients with cognitive impairment using serum markers.
      In this study, it was also found that tHcy has a certain correlation with cognitive dysfunction in patients with CSVD, and the ROC curve results show that it has certain diagnostic value for cognitive impairmen. High tHcy levels have been shown to be a risk factor for cerebrovascular disease. Compared with MMP-9, tHcy can be detected in clinical routine test items, which is more convenient. THcy levels can be reduced by supplementing vitamin B12 and methylcobalamin in clinical treatment. It can be used as a secondary prevention indicator of stroke together with hypertension and diabetes. MMP-9 cannot be tested in routine clinical tests at this time. However, previous findings have shown that MMP-9 is associated with the mechanism of cognitive dysfunction in CSVD. Much basic research is still needed to explore the mechanisms involved. Although MMP-9 cannot be directly intervened at present, if the mechanism can be further clarified, it can reduce or even prevent the development of CSVD by influencing the relevant pathways.
      Previous studies showed that CSVD is significantly associated with cognitive function, while these studies only used single imaging as an evaluation index. Lesions may have no obvious clinical symptoms when they appear alone, hindering a comprehensive assessment of the overall influence of CSVD on the brain. However, the increase of a single lesion type and the combination of different lesion types were significantly associated with cognitive dysfunction, affective disorders, and movement disorders.
      • Georgakis MK
      • Duering M
      • Wardlaw JM
      • et al.
      WMH and long-term outcomes in ischemic stroke: a systematic review and meta-analysis.
      Therefore, a great number of scholars have attempted to use the four representative imaging manifestations of WHM, cerebral micro-bleeds, lacunae, and Virchow-Robin space enlargement as the evaluation criteria for the total imaging load to more comprehensively assess the severity of CSVD.
      • Klarenbeek P
      • van Oostenbrugge RJ
      • Rouhl RP
      • et al.
      Ambulatory blood pressure in patients with lacunar stroke: association with total MRI burden of cerebral small vessel disease.
      ,
      • Jiang Y
      • Wang Y
      • Yuan Z
      • et al.
      Total cerebral small vessel disease burden is related to worse performance on the mini-mental state examination and incident dementia: a prospective 5-year follow-up.
      The 2021 Chinese Expert Guideline for Cognitive Disorders also recommended the application of the total imaging load to assess the overall severity of CSVD. In evaluating the comprehensiveness of brain damage in patients with CSVD, the total imaging load combined with multiple imaging manifestations is more effective than the single imaging manifestations. In the present study, the total imaging load was used as the overall evaluation index. The results showed that patients with cognitive dysfunction had higher total imaging load scores, while those with normal cognitive function had lower total imaging load scores. Further analysis of the correlation between serum MMP-9 level and total imaging load showed the existence of a certain correlation. The current study aimed to explore the correlation of serum MMP-9 level with total imaging load and cognitive function, while there are still several deficiencies, hindering analysis of the underlying mechanism. Therefore, the mechanism of influencing cognitive function by MMP-9 has not been assessed in this study, indicating the necessity of conducting further relevant researches.
      In conclusion, the serum MMP-9 level in patients with CSVD was high, and the proportion of high scores in the cognitive dysfunction group was greater than that in the normal cognitive function group. The results of the correlation analysis showed the existence of a negative correlation. Therefore, serum MMP-9 level may be involved in the occurrence and development of cognitive impairment in patients with CSVD. Serum MMP-9 level is of great significance for the diagnosis and treatment of cognitive function in patients with CSVD, while further researches are still required.

      Conflict of interest

      Authors have no conflict of interest to declare.

      References

        • Meng Lifang
        • Zhao Jianhua
        • Liu Junli
        • et al.
        Cerebral small vessel disease and cognitive impairment.
        J Neurorestoratol. 2019; 7: 184-195
        • liwen Hu
        • Lei Yang
        • xuanting Li
        • yonghua Huang
        Chinese consensus on diagnosis and therapy of cerebral small vessel disease 2021.
        Chin J Stroke. 2021; 16: 716-726
        • dantao Peng
        • Wen Shao
        Clinical practice guideline for cognitive impairment of cerebral small vessel disease of China (2019).
        Chin J Geriatr. 2019; 2 (+403): 405-407
        • yifan Ji
        • zhenjie Teng
        • xiangyu Li
        • et al.
        Correlation of total magnetic resonance imaging burden with homocysteine in patients with cerebral small vessel disease.
        Chin J Behav Med Brain Sci. 2020; : 233-238
        • Doubal FN
        • MacLullich AM
        • Ferguson KJ
        • Dennis MS
        • Wardlaw JM.
        Enlarged perivascular spaces on MRI are a feature of cerebral small vessel disease.
        Stroke. 2010; 41: 450-454
        • Rost NS
        • Etherton M.
        Cerebral small vessel disease [published correction appears in Continuum (Minneap Minn). 2020 Jun;26(3):826-827].
        Continuum. 2020; 26: 332-352
        • Pantoni L.
        Cerebral small vessel disease: from pathogenesis and clinical characteristics to therapeutic challenges.
        Lancet Neurol. 2010; 9: 689-701
        • Joutel A
        • Faraci FM.
        Cerebral small vessel disease: insights and opportunities from mouse models of collagen IV-related small vessel disease and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.
        Stroke. 2014; 45: 1215-1221
        • Iadecola C.
        The neurovascular unit coming of age: a journey through neurovascular coupling in health and disease.
        Neuron. 2017; 96: 17-42
        • Vinters HV
        • Zarow C
        • Borys E
        • et al.
        Review: vascular dementia: clinicopathologic and genetic considerations.
        Neuropathol Appl Neurobiol. 2018; 44: 247-266
        • Arvanitakis Z
        • Capuano AW
        • Leurgans SE
        • et al.
        The relationship of cerebral vessel pathology to brain microinfarcts.
        Brain Pathol. 2017; 27: 77-85
        • Dejonckheere E
        • Vandenbroucke RE
        • Libert C.
        Matrix metalloproteinases as drug targets in ischemia/reperfusion injury.
        Drug Discov Today. 2011; 16: 762-778
        • Vandooren J
        • Van den Steen PE
        • Opdenakker G.
        Biochemistry and molecular biology of gelatinase B or matrix metalloproteinase-9 (MMP-9): the next decade.
        Crit Rev Biochem Mol Biol. 2013; 48: 222-272
        • Candelario-Jalil E
        • Thompson J
        • Taheri S
        • et al.
        Matrix metalloproteinases are associated with increased blood-brain barrier opening in vascular cognitive impairment.
        Stroke. 2011; 42: 1345-1350
        • Lee JY
        • Choi HY
        • Ahn HJ
        • et al.
        Matrix metalloproteinase-3 promotes early blood-spinal cord barrier disruption and hemorrhage and impairs long-term neurological recovery after spinal cord injury.
        Am J Pathol. 2014; 184: 2985-3000
        • Choi JI
        • Ha SK
        • Lim DJ
        • et al.
        S100ß, Matrix metalloproteinase-9, D-dimer, and heat shock protein 70 are serologic biomarkers of acute cerebral infarction in a mouse model of transient MCA occlusion.
        J Korean Neurosurg Soc. 2018; 61: 548-558
        • Swetha R
        • Gayen C
        • Kumar D
        • et al.
        Biomolecular basis of matrix metallo proteinase-9 activity.
        Future Med Chem. 2018; 10: 1093-1112
        • Vafadari B
        • Salamian A
        • Kaczmarek L.
        MMP-9 in translation: from molecule to brain physiology, pathology, and therapy.
        J Neurochem. 2016; 139: 91-114
        • Tsilibary E
        • Tzinia A
        • Radenovic L
        • et al.
        Neural ECM proteases in learning and synaptic plasticity.
        Prog Brain Res. 2014; 214: 135-157
        • Jianhua Zhao
        • Xue Peng
        • Lifang Meng
        • et al.
        Correlation between serum MMP-9 protein level and vascular cognitive impairment with no dementia in patients with cerebral small vessel diseases.
        Chin J Behav Med Brain Sci. 2020; 29: 808-812
        • limin Lu
        • kongliang Zhi
        Effect of matrix metalloproteinase 9 on cognitive dysfunction in patients with ischemic stroke.
        Chin J Clin. 2021; 49: 179-182
        • Ruiz-Vega G
        • García-Robaina A
        • Ben Ismail M
        • et al.
        Detection of plasma MMP-9 within minutes. Unveiling some of the clues to develop fast and simple electrochemical magneto-immunosensors.
        Biosens Bioelectron. 2018; 115: 45-52
        • Nguyen PD
        • Cong VT
        • Baek C
        • et al.
        Fabrication of peptide stabilized fluorescent gold nanocluster/graphene oxide nanocomplex and its application in turn-on detection of metalloproteinase-9.
        Biosens Bioelectron. 2017; 89: 666-672
        • Georgakis MK
        • Duering M
        • Wardlaw JM
        • et al.
        WMH and long-term outcomes in ischemic stroke: a systematic review and meta-analysis.
        Neurology. 2019; 92: e1298-e1308
        • Klarenbeek P
        • van Oostenbrugge RJ
        • Rouhl RP
        • et al.
        Ambulatory blood pressure in patients with lacunar stroke: association with total MRI burden of cerebral small vessel disease.
        Stroke. 2013; 44: 2995-2999
        • Jiang Y
        • Wang Y
        • Yuan Z
        • et al.
        Total cerebral small vessel disease burden is related to worse performance on the mini-mental state examination and incident dementia: a prospective 5-year follow-up.
        J Alzheimers Dis. 2019; 69: 253-262