Urinary matrix metalloproteinase-8 and -9 activities in type 2 diabetic subjects: A marker of incipient diabetic nephropathy?

Syndecans and diabetic complications: A narrative review

Syndecan (SDC) is a member of the heparan sulfate proteoglycan (HSPG) family. It appears to play a role in the aetiology of diabetic complications, with decreased levels of SDCs being reported in the kidney, retina, and cardiac muscle in models of diabetes mellitus (DM). The reduced levels of SDCs may play an important role in the development of albuminuria in DM. Some studies have provided the evidence supporting the mechanisms underlying the role of SDCs in DM. However, SDCs and the molecular mechanisms involved are complex and need to be further elucidated. This review focuses on the underlying molecular mechanisms of SDCs that are involved in the development and progression of the complications of DM, which may help in developing new strategies to prevent and treat these complications.

Mineralocorticoid receptor antagonism in diabetes reduces albuminuria by preserving the glomerular endothelial glycocalyx

The glomerular endothelial glycocalyx (GEnGlx) forms the first part of the glomerular filtration barrier. Previously, we showed that mineralocorticoid receptor (MR) activation caused GEnGlx damage and albuminuria. In this study, we investigated whether MR antagonism could limit albuminuria in diabetes and studied the site of action. Streptozotocin-induced diabetic Wistar rats developed albuminuria, increased glomerular albumin permeability (Ps'alb), and increased glomerular matrix metalloproteinase (MMP) activity with corresponding GEnGlx loss. MR antagonism prevented albuminuria progression, restored Ps'alb, preserved GEnGlx, and reduced MMP activity. Enzymatic degradation of the GEnGlx negated the benefits of MR antagonism, confirming their dependence on GEnGlx integrity. Exposing human glomerular endothelial cells (GEnC) to diabetic conditions in vitro increased MMPs and caused glycocalyx damage. Amelioration of these effects confirmed a direct effect of MR antagonism on GEnC. To confirm relevance to human disease, we used a potentially novel confocal imaging method to show loss of GEnGlx in renal biopsy specimens from patients with diabetic nephropathy (DN). In addition, patients with DN randomized to receive an MR antagonist had reduced urinary MMP2 activity and albuminuria compared with placebo and baseline levels. Taken together, our work suggests that MR antagonists reduce MMP activity and thereby preserve GEnGlx, resulting in reduced glomerular permeability and albuminuria in diabetes.

Marker for kidney fibrosis is associated with inflammation and deterioration of kidney function in people with type 2 diabetes and microalbuminuria

BACKGROUND

Diabetic kidney disease is a major cause of morbidity and mortality. Dysregulated turnover of collagen type III is associated with development of kidney fibrosis. We investigated whether a degradation product of collagen type III (C3M) was a risk marker for progression of chronic kidney disease (CKD), occurrence of cardiovascular disease (CVD), and mortality during follow up in people with type 2 diabetes (T2D) and microalbuminuria. Moreover, we investigated whether C3M was correlated with markers of inflammation and endothelial dysfunction at baseline.

METHODS

C3M was measured in serum (sC3M) and urine (uC3M) in 200 participants with T2D and microalbuminuria included in an observational, prospective study at Steno Diabetes Center Copenhagen in Denmark from 2007-2008. Baseline measurements included 12 markers of inflammation and endothelial dysfunction. The endpoints were CVD, mortality, and CKD progression (>30% decline in eGFR).

RESULTS

Mean (SD) age was 59 (9) years, eGFR 90 (17) ml/min/1.73m2 and median (IQR) urine albumin excretion rate 102 (39-229) mg/24-h. At baseline all markers for inflammation were positively correlated with sC3M (p≤0.034). Some, but not all, markers for endothelial dysfunction were correlated with C3M. Median follow-up ranged from 4.9 to 6.3 years. Higher sC3M was associated with CKD progression (with mortality as competing risk) with a hazard ratio (per doubling) of 2.98 (95% CI: 1.41-6.26; p = 0.004) adjusted for traditional risk factors. uC3M was not associated with CKD progression. Neither sC3M or uC3M were associated with risk of CVD or mortality.

CONCLUSIONS

Higher sC3M was a risk factor for chronic kidney disease progression and was correlated with markers of inflammation.

Inhibition of Matrix Metalloproteinase-8 Protects Against Sepsis Serum Mediated Leukocyte Adhesion

Purpose

Leukocyte adhesion to vascular and matrix Metalloproteinase-8 (MMP8) expression is increased in sepsis and associated with poor prognosis in sepsis patients. This study aimed to investigate the role of MMP8 in sepsis serum mediated leukocyte adhesion.

Methods

Bioinformatics analysis of GSE64457 and GSE65682 was performed to evaluate the role of MMP8 in the progression of sepsis. Expression of MMP8 in blood samples from patients with sepsis was detected by qRT-PCR and ELISA. Human umbilical vein endothelial cells (HUVECs) were treated with sepsis serum, control serum, and MMP8 inhibitor. Expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) were detected by qRT-PCR and ELISA, respectively. The protein expression of total p38, phosphorylated-p38, ERK1/2, and p-ERK1/2 was detected by Western blotting. Peripheral blood mononuclear cells (PBMCs) and polymorphonuclear neutrophils (PMNs) were incubated with the treated HUVECs to calculate leukocyte adhesion.

Results

Four hundred and twenty-nine differentially expressed genes (DEGs) and seven hub genes between sepsis patients and healthy controls were identified. GO function analysis of DEGs and hub genes indicated that the DEGs and hub genes were mainly enriched in neutrophil activation. MMP8 was selected as a key gene with an unfavorable prognosis in sepsis patients. The mRNA and protein expression of MMP8 in blood from sepsis patients were significantly higher than controls. Leukocyte adhesion and mRNA and protein expression of VCAM-1 and ICAM-1 were significantly increased in the sepsis serum group compared to that in the control group, as was the protein expression of p-p38 and p-ERK1/2. However, the MMP8 inhibitor suppressed the leukocyte adhesion promoted by sepsis serum by decreasing the expression of VCAM-1, ICAM-1, p-p38, and p-ERK1/2.

Conclusion

Our study indicated that MMP8 acts as a key gene in the development of sepsis, and sepsis serum promotes leukocyte adhesion to HUVECs via MMP8, which suggest that MMP8 might be a potential therapeutic target for sepsis.

TNF-α, IL-1β, MMP-8 Crevicular Profile in Patients with Chronic Kidney Disease and Periodontitis

Increasing evidence sustains the potential of periodontitis as a risk factor for chronic kidney disease (CKD). Our study aimed to analyze several periodontal specific inflammatory biomarkers within the gingival crevicular fluid (GCF) of patients with CKD, compared to patients with normal kidney function, providing an inflammatory profile of the dialysis patient. The study comprised 79 patients divided into: group 1 (59 subjects with periodontitis and CKD) and group 2 (20 patients with periodontitis, without other systemic conditions). Clinical diagnosis was performed via dental and periodontal examination. GCF samples were collected from each patient, and the levels of TNF-α, IL-1β and MMP-8 were determined by using ELISA assay. In group 1, the average values were: 22.85 ± 5.87 pg/mL for TNF-α, 33.00 ± 39.68 pg/mL for IL-1β and 18.80 ± 27.75 ng/mL for MMP-8. In group 2, the mean values were: 2.10 ± 1.34 pg/mL for TNF-α, 0.71 ± 2.42 pg/mL for IL-1β and 5.35 ± 0.37 ng/mL for MMP-8. Statistical analysis revealed significant differences between groups as referring to all three biomarkers and, TNF-α and MMP-8, in certain stages of periodontitis. The level of TNF-α, IL-1β and MMP-8 points out the increased inflammatory status of the dialysis patient with PD, supporting the mutual connection of the two pathologies.

Novel Cardiovascular Risk Factors in Patients with Diabetic Kidney Disease

Patients with diabetic kidney disease (DKD) are at very high risk for cardiovascular events. Only part of this increased risk can be attributed to the presence of diabetes mellitus (DM) and to other DM-related comorbidities, including hypertension and obesity. The identification of novel risk factors that underpin the association between DKD and cardiovascular disease (CVD) is essential for risk stratification, for individualization of treatment and for identification of novel treatment targets.In the present review, we summarize the current knowledge regarding the role of emerging cardiovascular risk markers in patients with DKD. Among these biomarkers, fibroblast growth factor-23 and copeptin were studied more extensively and consistently predicted cardiovascular events in this population. Therefore, it might be useful to incorporate them in risk stratification strategies in patients with DKD to identify those who would possibly benefit from more aggressive management of cardiovascular risk factors.

Matrix Metalloproteinase-8 Inhibitor Ameliorates Inflammatory Responses and Behavioral Deficits in LRRK2 G2019S Parkinson's Disease Model Mice

Parkinson’s disease (PD) is a neurodegenerative disorder that involves the loss of dopaminergic neurons in the substantia nigra (SN). Matrix metalloproteinases-8 (MMP-8), neutrophil collagenase, is a functional player in the progressive pathology of various inflammatory disorders. In this study, we administered an MMP-8 inhibitor (MMP-8i) in Leucine-rich repeat kinase 2 (LRRK2) G2019S transgenic mice, to determine the effects of MMP-8i on PD pathology. We observed a significant increase of ionized calcium-binding adapter molecule 1 (Iba1)-positive activated microglia in the striatum of LRRK2 G2019S mice compared to normal control mice, indicating enhanced neuro-inflammatory responses. The increased number of Iba1-positive activated microglia in LRRK2 G2019S PD mice was down-regulated by systemic administration of MMP-8i. Interestingly, this LRRK2 G2019S PD mice showed significantly reduced size of cell body area of tyrosine hydroxylase (TH) positive neurons in SN region and MMP-8i significantly recovered cellular atrophy shown in PD model indicating distinct neuro-protective effects of MMP-8i. Furthermore, MMP-8i administration markedly improved behavioral abnormalities of motor balancing coordination in rota-rod test in LRRK2 G2019S mice. These data suggest that MMP-8i attenuates the pathological symptoms of PD through anti-inflammatory processes.

The complex interplay between kidney injury and inflammation

Acute kidney injury (AKI) has gained significant attention following patient safety alerts about the increased risk of harm to patients, including increased mortality and hospitalization. Common causes of AKI include hypovolaemia, nephrotoxic medications, ischaemia and acute glomerulonephritis, although in reality it may be undetermined or multifactorial. A period of inflammation either as a contributor to the kidney injury or resulting from the injury is almost universally seen. This article was compiled following a workshop exploring the interplay between injury and inflammation. AKI is characterized by some degree of renal cell death through either apoptosis or necrosis, together with a strong inflammatory response. Studies interrogating the resolution of renal inflammation identify a whole range of molecules that are upregulated and confirm that the kidneys are able to intrinsically regenerate after an episode of AKI, provided the threshold of damage is not too high. Kidneys are unable to generate new nephrons, and dysfunctional or repeated episodes will lead to further nephron loss that is ultimately associated with the development of renal fibrosis and chronic kidney disease (CKD). The AKI to CKD transition is a complex process mainly facilitated by maladaptive repair mechanisms. Early biomarkers mapping out this process would allow a personalized approach to identifying patients with AKI who are at high risk of developing fibrosis and subsequent CKD. This review article highlights this process and explains how laboratory models of renal inflammation and injury assist with understanding the underlying disease process and allow interrogation of medications aimed at targeting the mechanistic interplay.

Matrix metalloproteinase-9 gene polymorphism (-1562 C/T) and its correlation with diabetic nephropathy

Background

Matrix metalloproteinase 9 (MMP-9) is an important inflammatory marker in diabetic nephropathy. Many studies assessed the association between MMP-9 gene polymorphism and different microvascular complications of type 2 diabetes mellitus, though the results were inconclusive and need further exploration. Our study aimed to assess the association between MMP-9 -1562C/T gene polymorphism and diabetic nephropathy in patients with type 2 diabetes mellitus.

Results

Taking CC genotype of rs3918242 (MMP-9-1562C/T SNP) as the reference genotype and C as the reference allele, TT genotype, T allele showed significantly lower frequency in diabetic nephropathy group than without nephropathy (2.9% versus 20%, 20% versus 35.7% respectively), with the possible significant protective effect against diabetic nephropathy development (OR = 0.269, 0.450 respectively); it was considered as an independent predictor for diabetic nephropathy occurrence.

Conclusions

This study suggested that T allele of MMP-9 -1562C/T single nucleotide polymorphism had a protective role against diabetic nephropathy development and also had a role for early prediction of patients susceptible to this complication, so it helps in prevention and management of those patients.

Urinary MMP-9/UCr association with albumin concentration and albumin-creatinine-ratio in Mexican patients with type 2 diabetes mellitus

BACKGROUND

Chronic kidney disease is one of the most common complications of type 2 diabetes mellitus (T2DM), causing an increased risk of cardiovascular morbidity and mortality. Matrix metalloproteinase (MMP) activity has been proposed as useful biomarker for diabetic renal and vascular complications.

METHODS

A cross-sectional study was conducted among T2DM patients who attended a public secondary hospital in Mexico. We performed clinical, biochemical, and microbiological assessments, as well chronic kidney disease diagnosis according to the KDIGO guideline. Urinary MMP-9 was quantified by ELISA and adjusted using urinary creatinine (UCr).

RESULTS

A total of 111 patients were included. Most participants were women (66%). Mean age was 61 ± 10 years and median T2DM duration was estimated at 11 years. Through multivariate analysis, MMP-9/UCr was found to be associated with albumin concentration and albumin to creatinine ratio.

DISCUSSION

Validation of non-invasive biomarkers of chronic kidney disease among T2DM patients is necessary. Here, we demonstrate MMP-9/UCr as a potential biomarker of albumin concentration and albumin to creatinine ratio in Mexican patients with T2DM.

Biomarkers in Progressive Chronic Kidney Disease. Still a Long Way to Go

The traditional chronic kidney disease (CKD) biomarkers (eGFR based on serum creatinine, sex and age and albuminuria) cannot predict a patient's individual risk for developing progressive CKD. For this reason, it is necessary to identify novel CKD biomarkers that will be able to predict which patients are prone to develop progressive disease and discriminate between disease processes in different parts of the nephron (glomeruli or tubules). A good biomarker should change before or simultaneously with lesion development and its changes should correlate strongly with lesion development. Also, there should be a close relationship between severity of injury and amount of detectable biomarker and its levels should decrease with diminishing injury. Among the large number of molecules under investigation, we have reviewed the most promising ones: NGAL and KIM-1, MCP-1, MMP-9, clusterin, MMP-9, TIMP-1, Procollagen I alpha 1 and suPAR. All these, have been studied as biomarkers for prediction of CKD progression in cohorts of patients with chronic kidney disease of different stages and various aetiologies (proteinuric and non-proteinuric, glomerulonephritides, diabetic, hypertensive and polycystic kidney disease). There is evidence that these molecules could be useful as biomarkers for progressive chronic kidney disease, however, the available data are not enough to draw final conclusions. Further studies with large cohorts and long follow-up are required to identify appropriate biomarkers, that will be able to accurately and reliably define the risk for progressive chronic kidney disease.

Association of MMP-9 polymorphisms with diabetic nephropathy risk: A protocol for systematic review and meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is a multifactorial disease with gene-environment interaction resulting in progressive renal function damage. Multiple studies have assessed the association between matrix metalloproteinase-9 (MMP-9) gene promoter polymorphism and DN susceptibility. However, the results are inconclusive. In the present study, we will conduct a meta-analysis to further examine this relationship more precisely.

METHODS

Electronic databases (Pubmed, Web of Science, Embase, Google Scholar, Wanfang, China Biological Medicine and China National Knowledge Infrastructure) will be used to search clinical case-control studies about MMP-9 polymorphism and DN published until 18 August 2020. The language will be restricted to Chinese and English. Two reviewers will take charge of completing the selection of study, the extraction of data as well as the assessment of study quality independently. The Newcastle-Ottawa Scale will be used to evaluate the study quality. We will evaluate the association under 5 genetic models. Fixed-effects or random-effects models will be used to calculate the effect sizes of odds ratio and 95% confidence intervals. Afterwards, subgroup analysis will be conducted in terms of the ethnicity and genotyping method. Additionally, sensitivity analysis will be performed via sequentially omitting each of the included studies one at a time. The funnel plots, Egger regression test, and Begg rank correlation test will be used to test the potential publication bias. All the statistical analyses will be performed using Review Manager 5.3 and Stata 12.0.

RESULTS

This protocol reported according to the Preferred Reporting ltems for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement. This study will provide a better understanding of the association between MMP-9 polymorphisms and DN risk.

CONCLUSION

Publishing this protocol will minimize the potential bias related to data mining, thus contributing to generation of reliable evidence.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/H5FS4.

Blocking matrix metalloproteinase-mediated syndecan-4 shedding restores the endothelial glycocalyx and glomerular filtration barrier function in early diabetic kidney disease

The endothelial glycocalyx is a key component of the glomerular filtration barrier. We have shown that matrix metalloproteinase (MMP)-mediated syndecan 4 shedding is a mechanism of glomerular endothelial glycocalyx damage in vitro, resulting in increased albumin permeability. Here we sought to determine whether this mechanism is important in early diabetic kidney disease, by studying streptozotocin-induced type 1 diabetes in DBA2/J mice. Diabetic mice were albuminuric, had increased glomerular albumin permeability and endothelial glycocalyx damage. Syndecan 4 mRNA expression was found to be upregulated in isolated glomeruli and in flow cytometry-sorted glomerular endothelial cells. In contrast, glomerular endothelial luminal surface syndecan 4 and Marasmium oreades agglutinin lectin labelling measurements were reduced in the diabetic mice. Similarly, syndecan 4 protein expression was significantly decreased in isolated glomeruli but increased in plasma and urine, suggesting syndecan 4 shedding. Mmp-2, 9 and 14 mRNA expression were upregulated in isolated glomeruli, suggesting a possible mechanism of glycocalyx damage and albuminuria. We therefore characterised in detail the activity of MMP-2 and 9 and found significant increases in kidney cortex, plasma and urine. Treatment with MMP-2/9 inhibitor I for 21 days, started six weeks after diabetes induction, restored endothelial glycocalyx depth and coverage and attenuated diabetes-induced albuminuria and reduced glomerular albumin permeability. MMP inhibitor treatment significantly attenuated glomerular endothelial and plasma syndecan 4 shedding and inhibited plasma MMP activity. Thus, our studies confirm the importance of MMPs in endothelial glycocalyx damage and albuminuria in early diabetes and demonstrate that this pathway is amenable to therapeutic intervention. Hence, treatments targeted at glycocalyx protection by MMP inhibition may be of benefit in diabetic kidney disease.

Long noncoding RNA growth arrest-specific transcript 5 alleviates renal fibrosis in diabetic nephropathy by downregulating matrix metalloproteinase 9 through recruitment of enhancer of zeste homolog 2

Diabetic nephropathy (DN) is a frequently occurred microvascular complication associated with type I and type II diabetes mellitus. The participation of long noncoding RNAs (lncRNAs) in diabetes-related microvascular complications has been reported extensively. We attempted to unveil the possible regulatory mechanism of lncRNA growth arrest-specific transcript 5 (GAS5) and matrix metalloproteinase 9 (MMP9), an important inflammatory protein, in the progression of DN. A rat DN model was induced by streptozocin (STZ). The low expression of GAS5 and high expression of MMP9 in DN rats with DN was then determined by RT-qPCR and western blot analysis, and lentivirus-mediated GAS5 overexpression was shown to ameliorate STZ-induced renal interstitial fibrosis (RIF) and inflammatory reaction in the kidney of DN rats. Moreover, MMP9 was found to be upregulated in STZ-induced DN, while MMP9 silencing induced by lentivirus expressing shRNA against MMP9 reduced RIF and suppressed inflammation in the kidney of DN rats. RIP, RNA pull-down, and ChIP assays demonstrated that GAS5 downregulated MMP9 via recruiting enhancer of zeste homolog 2 (EZH2) in the promoter region of MMP9. Overall, our study reveals that GAS5 downregulates MMP9 expression through recruiting EZH2 to MMP9 promoter region and alleviates the progression of renal fibrosis in DN rats, which sheds new light on the therapeutic potential of GAS5-targeted therapies in combating that disease.

MMP-10 is Increased in Early Stage Diabetic Kidney Disease and can be Reduced by Renin-Angiotensin System Blockade

Matrix metalloproteinases have been implicated in diabetic microvascular complications. However, little is known about the pathophysiological links between MMP-10 and the renin-angiotensin system (RAS) in diabetic kidney disease (DKD). We tested the hypothesis that MMP-10 may be up-regulated in early stage DKD, and could be down-regulated by angiotensin II receptor blockade (telmisartan). Serum MMP-10 and TIMP-1 levels were measured in 268 type 2 diabetic subjects and 111 controls. Furthermore, histological and molecular analyses were performed to evaluate the renal expression of Mmp10 and Timp1 in a murine model of early type 2 DKD (db/db) after telmisartan treatment. MMP-10 (473 ± 274 pg/ml vs. 332 ± 151; p = 0.02) and TIMP-1 (573 ± 296 ng/ml vs. 375 ± 317; p < 0.001) levels were significantly increased in diabetic patients as compared to controls. An early increase in MMP-10 and TIMP-1 was observed and a further progressive elevation was found as DKD progressed to end-stage renal disease. Diabetic mice had 4-fold greater glomerular Mmp10 expression and significant albuminuria compared to wild-type, which was prevented by telmisartan. MMP-10 and TIMP-1 are increased from the early stages of type 2 diabetes. Prevention of MMP-10 upregulation observed in diabetic mice could be another protective mechanism of RAS blockade in DKD.

A New Perspective in Utilizing MMP-9 as a Therapeutic Target for Alzheimer's Disease and Type 2 Diabetes Mellitus

Matrix metalloprotease 9 (MMP-9) is a 92 kDa type IV collagenase and a member of the family of endopeptidases. MMP-9 is involved in the degradation of extracellular matrix components, tissue remodeling, cellular receptor stripping, and processing of various signaling molecules. In the CNS, the effects of MMP-9 are quite complex, since it exerts beneficial effects including neurogenesis, angiogenesis, myelogenesis, axonal growth, and inhibition of apoptosis, or destructive effects including apoptosis, blood-brain barrier disorder, and demyelination. Likewise, in the periphery, physiological events, as the involvement of MMP-9 in angiogenesis, for instance in wound healing, can be turned into pathological, such as in tumor metastasis, depending on the state of the organism. Alzheimer's disease is a neurodegenerative disorder, characterized by amyloid accumulation and deposition in the brain. Amyloidogenesis, however, also occurs in diseases of the periphery, such as type II diabetes mellitus, where an analogous type of amyloid, is deposited in the pancreas. Interestingly, both diseases exhibit similar pathology and disease progression, with insulin resistance being a major common denominator. Hence, combinatorial strategies searching new or existing molecules to apply for therapeutic use for both diseases are gaining momentum. MMP-9 is extensively studied due to its association with a variety of physiological and pathological processes. Consequently, meticulous design could render MMP-9 into a potential therapeutic target for Alzheimer's disease and type 2 diabetes mellitus; two seemingly unrelated diseases.

Urine Levels of Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases in Children with Type 1 Diabetes Mellitus

OBJECTIVE

Histopathological changes in the kidney in type 1 diabetes mellitus (T1DM) begin before detection of microalbuminuria. Therefore, there is interest in finding a better biomarker for the early detection of diabetic kidney injury. The aim of this present study was to determine whether urinary indicators of fibrosis are detectable early in the development of T1DM in children and if they may predict progressive renal injury.

METHODS

Urinary matrix metalloproteinase 2 and 9 (MMP2 and MMP9), tissue inhibitor of metalloproteinase 1 and 2 (TIMP1 and TIMP2) and transforming growth factor-β1 (TGF-β1) were assessed in 33 patients with T1DM with normal renal functions and in 24 healthy controls. Microalbuminuria was not present in the patient group with the exception of three patients. The results were adjusted to urine creatinine (Cr) and the differences between patients and controls were evaluated. These measurements were repeated after one year and the results were compared with the first year results.

RESULTS

Urine MMP2/Cr, MMP9/Cr, TIMP1/Cr, TIMP2/Cr, TGF-β1/Cr were not different between the patient and control groups (p>0.05). There were also no significant differences between the first and second year results for these biomarkers (p>0.05). None of these parameters were correlated with hemoglobin A1c, body mass index and duration of T1DM. Interestingly, all parameters were negatively correlated to age of onset of T1DM (p<0.05).

CONCLUSION

Our findings suggest that urinary biomarkers of fibrosis do not show an increase in diabetic children without microalbuminuria. The results also indicate that the risk of early fibrosis may increase as age of onset of T1DM decreases.

Association of urinary activity of MMP-9 with renal impairment in Mexican patients with type 2 diabetes mellitus

BACKGROUND

Diabetic kidney disease is the most common cause of chronic kidney disease (CKD). An early event in diabetic kidney disease is alteration of the glomerular basement membrane and the mesangial expansion. Matrix metalloproteinases (MMP) are a family of endopeptidases responsible for controlling the pathophysiological remodeling of tissues, including renal tissues. MMP-9 in human urine has been proposed as a marker of diabetic nephropathy and urinary tract infections (UTI).

METHODS

A cross-sectional study was conducted in type 2 diabetes mellitus (T2DM) patients who receive first level medical attention in Mexico. We used ELISA to measure MMP-9 levels in the urine of subjects with T2DM ≥ 18 years of age, who fulfilled the clinical requirements for calculation of glomerular filtration rate (GFR), according to the K/DOQI guide, in an attempt to identify whether MMP-9 levels in T2DM differ in patients with and without renal impairment. Univariate and multivariable analyses were performed in order to identify the association between MMP-9 and renal impairment.

RESULTS

Included in the study were 34 (45%) subjects with renal impairment and 42 (55%) without. In the group with renal impairment, 10 subjects corresponded to stages 1-2 and 24 subjects corresponded to stage 3, according to their values of GFR and urinary albumin, following that proposed by the K/DOQI. No differences were found relating to sex, age, having or not having a partner, education, being able to read and write a message and duration of T2DM. Moreover, no differences were found between the groups in terms of weight, height, body mass index, waist size in general and frequency of UTI. In contrast, serum creatinine and urinary albumin were higher in the group with renal impairment, while GFR was greater in the group without renal impairment. Levels of MMP-9 were greater in women compared to men. Through univariate analysis in the general population, the presence of MMP-9 and that of its percentile 90 (P90) P90 were associated with the renal impairment group; however, in patients without UTI, only the presence of MMP-9 was associated with the renal impairment group, and no association was found with its P90. Multivariate analysis revealed an association between MMP-9 and its P90 with renal impairment.

DISCUSSION

It is necessary to validate sensitive and non-invasive biological markers of CKD. We demonstrate that the presence and P90 of urinary MMP-9 are associated with renal impairment in Mexican patients with T2DM. While high levels of MMP-9 were associated to females and UTI, the presence of UTI was not associated with the incidence of renal impairment.

Urinary metalloproteinases and tissue inhibitors of metalloproteinases as potential early biomarkers for renal fibrosis in children with nephrotic syndrome

In chronic glomerulopathies, renal fibrosis (RF) results from extracellular matrix remodeling processes regulated by matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP). We assessed urinary (u-) and serum (s-) MMP-1, -2, -9, TIMP-1, -2 concentrations and MMP-1, -2, -9/TIMP-1, -2 ratios in children with nephrotic syndrome. Steroid-dependent and steroid-resistant nephrotic patients (SDNS-Ps and SRNS-Ps, respectively) were compared with respect to measured parameters. The correlations of measured parameters with magnitude of proteinuria and histopathological diagnosis were determined.The study comprised of 39 children with nephrotic syndrome and 20 healthy controls. Twenty-three patients had SDNS and 16 ones-SRNS. The concentrations MMPs and TIMPs were measured using enzyme-linked immunosorbent assay.In nephrotic patients, higher u-MMP-1, -2, -9/creatinine ratios and u-TIMP-1, -2/creatinine ratios were observed as compared with controls. Nephrotic children were also characterized by lower MMP-1, -2, -9/TIMP-1 ratios. In SRNS-Ps, u-MMP-2/creatinine ratio and u-TIMP-1/creatinine ratio were higher as compared with SDNS-Ps. Magnitude of proteinuria correlated positively with u-MMP-2/creatinine ratio and negatively with u-MMP-2/TIMP-1. In minimal change disease (MCD) patients as compared with those with other glomerulopathies, there was higher u-MMP-2/TIMP-1 ratio. No significant differences in s-MMPs, s-TIMPs, and s-MMPs/TIMPs ratios between nephrotic patients and controls were observed.Children with nephrotic syndrome are characterized by increased u-fibrotic biomarkers excretions. U-MMP-1, -2, -9 excretions and u-MMP-2/TIMP-1 ratio may become potential early biomarkers for RF. SRNS-Ps, those with heavier proteinuria and other than MCD glomerulopathies, seem to be more susceptible to early RF.

Matrix metalloproteinase 14 modulates diabetes and Alzheimer's disease cross-talk: a meta-analysis

Diabetes mellitus is associated with dementia, but whether diabetes is associated with Alzheimer's disease remains controversial. Alzheimer's disease is characterized by amyloid beta aggregation. We hypothesized that genes, involved in amyloid beta degradation, may be altered due to diabetes and thus participate in progression of Alzheimer's disease. Expression profiling of amyloid beta-degrading enzymes in streptozotocin-induced diabetic mice and their correlation with expression of amyloid precursor protein in hippocampus of Alzheimer's disease patients were accessed. We found that matrix metalloproteinase 14 decreased in brain but not in other tissues of streptozotocin-induced diabetic mice, and was negatively correlated with expression of amyloid precursor protein in hippocampus of Alzheimer's disease patients. These findings suggested matrix metalloproteinase 14 may link insulin-deficient diabetes to Alzheimer's disease.

Endocytosis of Albumin Induces Matrix Metalloproteinase-9 by Activating the ERK Signaling Pathway in Renal Tubule Epithelial Cells

Matrix metalloproteinase-9 (MMP-9) is dysregulated in chronic kidney diseases including diabetic nephropathy. This study was performed to examine the expression of MMP-9 in renal tubule epithelial cells (TECs) under diabetic conditions and its regulatory mechanisms. We characterized MMP-9 protein in diabetic animals and primary cultured rat TECs exposed to exogenous albumin and high glucose. We also used specific inhibitors to determine if internalization of albumin and/or extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation were required for MMP-9 secretion. Immunostaining of kidney sections revealed enhanced MMP-9 signal in the damaged proximal tubules in Zucker diabetic fatty (ZDF) rats. ZDF rats also exhibited an albuminuria-related and age-dependent increase in MMP-9 excretion, which was prevented by rosiglitazone. In primary cultured rat TECs, high glucose exposure did not increase MMP-9 secretion. In contrast, administration of rat serum albumin (RSA, 0.1–0.5 mg/mL) resulted in a dose-dependent increase in MMP-9 expression and secretion by TECs, which was abolished in the presence of an ERK1/2-specific inhibitor, U0126. Simvastatin, an inhibitor of albumin endocytosis, also prevented MMP-9 secretion. Taken together, these results demonstrate that endocytosis of albumin stimulates MMP-9 secretion by TECs through the ERK signaling pathway.

Matrix Metalloproteinases in Kidney Disease: Role in Pathogenesis and Potential as a Therapeutic Target

Matrix metalloproteinases (MMPs) are large family of proteinases. In addition to a fundamental role in the remodeling of the extracellular matrix, they also cleave a number of cell surface proteins and are involved in multiple cellular processes. MMP activity is regulated via numerous mechanisms, including inhibition by endogenous tissue inhibitors of metalloproteinases (TIMPs). Similar to MMPs, a role for TIMPs has been established in multiple cell signaling pathways. Aberrant expression of MMPs and TIMPS in renal pathophysiology has long been recognized, and with the generation of specific knockout mice, the mechanistic role of several MMPs and TIMPs is becoming more understood and has revealed both pathogenic and protective roles. This chapter will focus on the expression and localization of MMPs and TIMPs in the kidney, as well as summarizing the current information linking these proteins to acute kidney injury and chronic kidney disease. In addition, we will summarize studies suggesting that MMPs and TIMPs may be biomarkers of renal dysfunction and represent novel therapeutic targets to attenuate kidney disease.

Matrix Metalloproteinase-9 -1562C/T Gene Polymorphism Is Associated with Diabetic Nephropathy

To investigate the association between the metalloproteinase-9 (MMP9) −1562C/T polymorphism and diabetic nephropathy (DN) in Han Chinese, the patients with type 2 diabetes were collected and divided into the non-DN (NDN) and DN groups; controls were recruited. Genotype and allele frequencies were assessed using polymerase chain reaction and restriction fragment length polymorphism. Results showed that SBP, DBP, HbA1c, UAER, Cr, BUN, TG, and TC were higher in the DN group compared with the control and NDN groups. SBP, HbA1c, and TC in DN patients with the TT and CT genotypes were lower than in those with CC. Compared with controls, the frequency of the T allele in the DN group was significantly lower. The MMP9 −1562C allele, SBP, Cr, BUN, TG, and TC were independent risk factors for DN. All of the above suggested that the MMP9 −1562C/T polymorphism was associated with DN in Han Chinese.

GJB2, SLC26A4, and mitochondrial DNA12S rRNA hot-spots in 156 subjects with non-syndromic hearing loss in Tengzhou, China

CONCLUSION

In this cohort of 156 non-syndromic hearing-impaired subjects of Tengzhou area, the most common deafness-associated genes GJB2, SLC26A4 and mtDNA 12S rRNA were investigated by SNPscan efficiently. GJB2 c.235delC and SLC26A4 c.IVS7-2A > G were the most common mutation sites.

OBJECTIVES

Until now, there is no systematic gentic analysis in patients with non-syndromic hearing loss for Tengzhou area, so we evaluated the molecular etiology to investigate the hot-sports.

METHODS

Peripheral blood samples were obtained from 156 patients with severe-to-profound non-syndromic deafness in Tengzhou. The SNP scan assay technique was performed for a rapid multiplex genetic screening to detect the 115 mutations of the most common three genes. All results were statistically analyzed with SPSS software.

RESULTS

Among the 156 analyzed patients, 60 patients were demonstrated with deafness genes, accounting for 38.46% (60/156), including GJB2 (22.44%, 35/156), SLC26A4 (13.66%, 22/156), and mtDNA 12S rRNA (2.56%, 4/156). In this study, we confirmed 23 deafness-causing mutations and 27 different allelic combinations including GJB2 (eight variants, 11 allelic combinations), SLC26A4 (13 variants, 16 allelic combinations) and mtDNA 12S rRNA (two variants). The occurrence rates of these deafness-causing mutations GJB2 c.235delC and SLC26A4 c.IVS7-2A > G were significantly higher than other mutation sites (p < 0.01).

A glimpse of matrix metalloproteinases in diabetic nephropathy

Matrix metalloproteinases (MMPs) are proteolytic enzymes belonging to the family of zinc-dependent endopeptidases that are capable of degrading almost all the proteinaceous components of the extracellular matrix (ECM). It is known that MMPs play a role in a number of renal diseases, such as, various forms of glomerulonephritis and tubular diseases, including some of the inherited kidney diseases. In this regard, ECM accumulation is considered to be a hallmark morphologic finding of diabetic nephropathy, which not only is related to the excessive synthesis of matrix proteins, but also to their decreased degradation by the MMPs. In recent years, increasing evidence suggest that there is a good correlation between the activity or expression of MMPs and progression of renal disease in patients with diabetic nephropathy and in various experimental animal models. In such a diabetic milieu, the expression of MMPs is modulated by high glucose, advanced glycation end products (AGEs), TGF-β, reactive oxygen species (ROS), transcription factors and some of the microRNAs. In this review, we focused on the structure and functions of MMPs, and their role in the pathogenesis of diabetic nephropathy.

Schizophrenia gene expression profile reverted to normal levels by antipsychotics

BACKGROUND

Despite the widespread use of antipsychotics, little is known of the molecular bases behind the action of antipsychotic drugs. A genome-wide study is needed to characterize the genes that affect the clinical response and their adverse effects.

METHODS

Here we show the analysis of the blood transcriptome of 22 schizophrenia patients before and after medication with atypical antipsychotics by next-generation sequencing.

RESULTS

We found that 17 genes, among the 21 495 genes analyzed, have significantly-altered expression after medication (p-value adjusted [Padj] <0.05). Six genes (ADAMTS2, CD177, CNTNAP3, ENTPD2, RFX2, and UNC45B) out of the 17 are among the 200 genes that we characterized with differential expression in a previous study between antipsychotic-naïve schizophrenia patients and controls (Sainz et al., 2013). This number of schizophrenia-altered expression genes is significantly higher than expected by chance (Chi-test, Padj 1.19E-50), suggesting that at least part of the antipsychotic beneficial effects is exerted by modulating the expression of these genes. Interestingly, all six of these genes were overexpressed in patients and reverted to control levels of expression after treatment. We also found a significant enrichment of genes related to obesity and diabetes, known adverse affects of antipsychotics.

CONCLUSIONS

These results may facilitate understanding of unknown molecular mechanisms behind schizophrenia symptoms and the molecular mechanisms of antipsychotic drugs.

Effects of reduced β2-glycoprotein I on the expression of aortic matrix metalloproteinases and tissue inhibitor matrix metalloproteinases in diabetic mice

Background

Reduced β₂-glycoprotein I (reduced β₂GP I), which has free sulfhydryl groups, is present in plasma and serum; it can protect vascular endothelial cells from damage due to oxidative stress in vitro. We investigated the effects of reduced β₂GP I on the expression of various matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the aortas of diabetic mice.

Methods

We provided 120 female 8-week-old Balb/c mice with a high sugar, high fat diet. After 8 weeks they were injected with streptozotocin to induce diabetes. We treated mice in the mono dose groups with β₂GP I, reduced β₂GP I, or phosphate-buffered saline (PBS) on day 1 and fed them for 3 weeks. The mice in the complex dose groups were treated with β₂GP I, reduced β₂GP I, or PBS on days 1 and 22 and fed for 6 weeks. Control mice were given a standard chow diet. Blood lipids were measured at the end of 3 or 6 weeks, and aortas removed to observe morphological and molecular biological changes.

Results

The low-density lipoprotein cholesterol levels in mice of the reduced β₂GP I group were lower than those in the diabetic group. Aortic lipid deposition in the reduced β₂GP I group was significantly less than in the diabetic control group. In the aortas, reduced β₂GP I decreased MMP2/TIMP2 mRNA and protein expression levels, and MMP9/TIMP1 expression levels compared with those in diabetic controls. Reduced β₂GP I down-regulated p38 mitogen-activated protein kinase (p38MAPK) mRNA expression and phosphorylated p38MAPK protein expression compared with those in diabetic controls of the complex dose group.

Conclusions

Reduced β₂GP I plays a role in diabetic mice related to vascular protection, inhibiting vascular lipid deposition, and plaque formation by reducing MMPs/TIMPs expression through down-regulation of the p38MAPK signaling pathway.

Effects of doxycycline on clinical, microbiological and immunological parameters in well-controlled diabetes type-2 patients with periodontal disease: a randomized, controlled clinical trial

AIM

To evaluate the clinical, microbiological and immunological effects of systemic doxycycline as an adjunct to scaling and root planing (SRP) in chronic periodontitis patients with well-controlled type 2 diabetes.

MATERIALS AND METHODS

Sixty-six patients compliant to oral hygiene (Hygiene Index <20%) allocated to either a test (systemic doxycycline for 21 days) or a control (placebo) group participated in the present randomized controlled trial (RCT). Clinical assessments were recorded at baseline, 3 and 6 months after therapy and included clinical attachment level (CAL), set as the primary outcome of the study, probing pocket depth (PPD), recession (RE) and bleeding on probing (BOP). At the same time points, counts of 15 subgingival species were evaluated by "checkerboard" DNA-DNA hybridization, gingival crevicular fluid samples were analysed for matrix metalloproteinase-8 (MMP-8) by ELISA and HbA1c levels were determined. Comparisons between and within groups were performed by non-parametric tests (Mann-Whitney, Wilcoxon signed-ranks and z-test for proportions with Bonferroni corrections) at the 0.05 level.

RESULTS

No major differences were noticed in clinical and microbiological parameters of periodontal disease or levels of MMP-8 between the two groups.

CONCLUSIONS

Adjunctive systemic doxycycline does not seem to significantly enhance the effects of SRP in well-controlled diabetes type 2 patients.

Mast cell chymase and tryptase as targets for cardiovascular and metabolic diseases

Mast cells are critical effectors in inflammatory diseases, including cardiovascular and metabolic diseases and their associated complications. These cells exert their physiological and pathological activities by releasing granules containing histamine, cytokines, chemokines, and proteases, including mast cell-specific chymases and tryptases. Several recent human and animal studies have shown direct or indirect participation of mast cell-specific proteases in atherosclerosis, abdominal aortic aneurysms, obesity, diabetes, and their complications. Animal studies have demonstrated the beneficial effects of highly selective and potent chymase and tryptase inhibitors in several experimental cardiovascular and metabolic diseases. In this review, we summarize recent discoveries from in vitro cell-based studies to experimental animal disease models, from protease knockout mice to treatments with recently developed selective and potent protease inhibitors, and from patients with preclinical disorders to those affected by complications. We hypothesize that inhibition of chymases and tryptases would benefit patients suffering from cardiovascular and metabolic diseases.

Lumbrokinase attenuates diabetic nephropathy through regulating extracellular matrix degradation in Streptozotocin-induced diabetic rats

OBJECTIVE

The present study was undertaken to investigate the therapeutic effect and underlying mechanisms of lumbrokinase on diabetic nephropathy.

METHODS

Type I diabetes was induced in male Sprague-Dawley rats via intraperitoneal injection of Streptozotocin (STZ). Lumbrokinase was administered to the diabetic rats at a dose of 600,000 U/kg body weight by gavage. As a positive control, perindopril, an angiotensin-converting enzyme inhibitor (ACEI), was given to diabetic rats at a dose of 4 mg/kg body weight. Following 12 weeks treatment, we measured the creatinine clearance rate (Ccr), urinary albumin excretion (UAE) and kidney injury scores. In addition, the expression of collagen IV, MMP-2 and MMP-9 in renal tissue was evaluated.

RESULTS

The diabetic rats developed proteinuria, glomerulosclerosis, tubulointerstitial fibrosis and a marked increase of renal cortical collagen IV. In contrast, MMP-2 and MMP-9 were significantly reduced in the renal cortex of diabetic rats. Interestingly, lumbrokinase treatment markedly reduced the proteinuria and improved the glomerulosclerosis and tubulointerstitial fibrosis in diabetic rats. The induction of collagen IV and the down-regulation of MMP-2 and MMP-9 was significantly attenuated by lumbrokinase. All these beneficial effects of lumbrokinase were comparable to the ACEI group.

CONCLUSION

Lumbrokinase treatment attenuated diabetic nephropathy in rats, possibly through increasing the activity of MMPs and the subsequent degradation of extracellular matrix.

Urinary matrix metalloproteinase activity in diabetic kidney disease: a potential marker of disease progression

BACKGROUND

Progressive kidney fibrosis, associated with chronic kidney disease (CKD), results from an imbalance in extracellular matrix (ECM) homeostasis. Reduced matrix metalloproteinases (MMP) activity causing lower clearance of ECM proteins has been implicated mainly through an overproduction of tissue inhibitors of metalloproteinases (TIMP), but also by reduced MMP synthesis. We tested the hypothesis that MMP activity can be measured in human urine and can be used as a potential biomarker of the progression of diabetic kidney disease (DKD).

METHODS

An observational prospective study was performed on 102 DKD patients using 21 diabetic patients without kidney disease and 21 healthy volunteers as controls. The Molecular Probes EnzChek Gelatinase/Collagenase Assay Kit were used to determine urinary MMP activity using DQ™ Gelatin (total MMPs), DQ™ Collagen I (interstitial collagenases) and DQ™ Collagen IV (gelatinises) substrates. A broad-spectrum synthetic inhibitor of all MMP, 1,10-phenanthroline, was used to confirm that the proteolytic activity is due to MMP activity. All MMP values were expressed per unit of urine creatinine.

RESULTS

Overall urinary MMP activity (DQ Gelatin substrate) was significantly elevated in DKD patients (14.76 ± 3.65 Δ fl/h/mmol creatinine) compared to diabetes mellitus controls (7.09 ± 2.12 Δ fl/h/mmol creatinine) and healthy volunteers (1.87 ± 0.74 Δ fl/h/mmol creatinine) (ANOVA p = 0.01). Within the DKD cohort, there was an approximate threefold higher urinary MMP activity in nonprogressive DKD patients compared to those with progressive disease (p = 0.002). The urinary MMP activity:creatinine ratio was significantly higher in normoalbuminuric and microalbuminuric DKD compared to macroalbuminuric DKD. Positive correlations were observed between the rate of total MMP activity and interstitial collagenases (r = 0.75, p < 0.0001) and gelatinases (r = 0.59, p = 0.0001). The accuracy of MMP activity to predict the rate of annual eGFR decline (ROC analysis) was 77% compared to 64% for albuminuria.

CONCLUSIONS

Total MMP activity can be easily measured in human urine. Surprisingly and in contrast to MMP activity in the kidney, urine MMP activity is elevated in DKD. However, there is a significantly lower MMP activity in patients with progressive DKD. ROC analysis demonstrates that single urine MMP activity estimation is superior to albuminuria in predicting DKD patients with progressive disease.

Matrix metalloproteinases in kidney homeostasis and diseases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have been increasingly linked to both normal physiology and abnormal pathology in the kidney. Collectively able to degrade all components of the extracellular matrix, MMPs were originally thought to antagonize the development of fibrotic diseases solely through digestion of excessive matrix. However, increasing evidence has shown that MMPs play a wide variety of roles in regulating inflammation, epithelial-mesenchymal transition, cell proliferation, angiogenesis, and apoptosis. We now have robust evidence for MMP dysregulation in a multitude of renal diseases including acute kidney injury, diabetic nephropathy, glomerulonephritis, inherited kidney disease, and chronic allograft nephropathy. The goal of this review is to summarize current findings regarding the role of MMPs in kidney diseases as well as the mechanisms of action of this family of proteases.

Matrix metalloproteinases in metabolic syndrome

Metabolic syndrome is commonly accompanied by an elevated cardiovascular risk with high morbidity and mortality. The alterations of the arterial vasculature begin with endothelial dysfunction and lead to micro- and macrovascular complications. The remodeling of the endothelial basal membrane, that promotes erosion and thrombosis, has a multifactorial pathogenesis that includes leukocyte activation, increased oxidative stress and also an altered matrix metalloproteinases (MMPs) expression. MMPs are endopeptidases which degrade extracellular matrix proteins, such as collagen, gelatins, fibronectin and laminin. They can be secreted by several cells within the vascular wall, but macrophages are determinant in the atherosclerotic plaques. Their activity is regulated by tissue inhibitors of MMP (TIMPs) and also by other molecules, such as plasmin. MMPs could be implicated in plaque instability predisposing to vascular complications. It has been demonstrated that an impaired MMP or TIMP expression is associated with higher risk of all-cause mortality. A large number of studies evaluated MMPs pattern in obesity, diabetes mellitus, arterial hypertension and dyslipidemia, all of which define metabolic syndrome according to several Consensus Statement (i.e. IDF, ATP III, AHA). However, few research have been carried out on subjects with metabolic syndrome. The evidences of an improvement in MMP/TIMP ratio with diet, exercise and medical therapy should encourage further investigations with the intent to contrast the atherosclerotic process and to reduce morbidity and mortality of this kind of patients.

The role of matrix metalloproteinases and their inhibitors in the development of renal fibrosis in the patients with diabetes mellitus

The accumulation of components of extracellular matrix in the glomerular and interstitial compartments of the kidneys is a characteristic feature of diabetic nephropathy. The leading role in the extracellular matrix catabolism is played by matrix metalloproteinases (MMP). The activity of these enzymes is regulated by a group of inhibitors including tissue metalloproteinase inhibitors, plasminogen activator inhibitor-1, etc. Both in vivo and in vitro studies have demonstrated that a reduction of MMP activities and/or an increase of expression of MMP tissue inhibitors in the glomerular and tubular cells result in the suppression of catabolism of the components of extracellular matrix under the hyperglycemic conditions. Both circulating and urinary MMP as well as their inhibitors are considered to be new potential markers of renal fibrosis associated with diabetes mellitus. It is concluded that the directed activation of MMP and neutralization of their inhibitors provide a promising tool for the treatment of diabetic nephropathy.

Urinary matrix metalloproteinase activities: biomarkers for plaque angiogenesis and nephropathy in diabetes

Diabetic complications of nephropathy and accelerated atherosclerosis are associated with vascular remodeling and dysregulated angiogenesis. Matrix metalloproteinases (MMP) modify extracellular matrix during vascular remodeling and are excreted in urine of patients with vascular malformation or tumor angiogenesis. We hypothesized that urinary MMP activities would be sensitive biomarkers for vascular remodeling in diabetic complications. Activities of MMP-2, MMP-9, and its complex with neutrophil gelatinase-associated lipocalin (NGAL/MMP-9) were measured by substrate gel zymography in urine from nondiabetic (ND) and type 1 diabetic (T1D) rodents that were susceptible to both T1D-induced plaque angiogenesis and nephropathy, or nephropathy alone. Additionally, these urine activities were measured in ND and T1D adolescents. Urinary MMP-9, MMP-2, and NGAL/MMP-9 activities were increased and more prevalent in T1D compared with ND controls. Urinary MMP-2 activity was detected in mice with T1D-induced plaque neovascularization. In nephropathy models, urinary NGAL/MMP-9 and MMP-9 activities appeared before onset of albuminuria, whereas MMP-2 was absent or delayed. Finally, urinary MMP activities were increased in adolescents with early stages of T1D. Urinary MMP activities may be sensitive, noninvasive, and clinically useful biomarkers for predicting vascular remodeling in diabetic renal and vascular complications.

Biomarkers for Diabetes Complications: The Results of Several Clinical Studies

Diabetes is a common metabolic disorder. Its microvascular and macrovascular complications contribute to death, disabilities, and reduction in life expectancy in diabetes. It is a costly disease, and affects not only the patient and family, but also the public health, communities and society. It takes an increasing proportion of the national health care expenditure. The prevention of the development of diabetes and its complications is a major concern. Biomarkers have been investigated for understanding the mechanisms of the development and progression of diabetic complications. In this paper, the biomarkers which are recommended in the clinical practice and laboratory medicine guidelines, and which have been investigated for prediction or diagnosis of diabetes complications, have been reviewed. The results of several clinical studies will be summarized.

Matrix metalloproteinase8 has a central role in inflammatory disorders and cancer progression

The predominant role of matrix metalloproteinase 8 in extracellular matrix turnover, modulation of inflammatory responses and other physiological processes is well documented. Several recent studies highlight the involvement of MMP8 in a wide range of pathologies. This review will shed light on the putative role of MMP8 as a drug target or disease marker in some inflammatory disorders and in cancer progression.