A functional single nucleotide polymorphism -1562C>T in the matrix metalloproteinase-9 promoter is associated with type 2 diabetes and diabetic foot ulcers

Assessment of potential genetic markers for diabetic foot ulcer among Moscow residents

PURPOSE

Diabetic foot ulcer (DFU) is one of the most severe complications of type 2 diabetes, which is manifested in chronic skin ulcers of lower extremities. DFU treatment remains complex and expensive despite the availability of well-established protocols. Early prediction of potential DFU development at the onset of type 2 diabetes can greatly improve the aftermath of this complication.

METHODS

To assess potential genetic markers for DFU, a group of diabetic patients from Moscow region with and without DFU was genotyped for a number of SNPs previously reported to be associated with the DFU.

RESULTS

Obtained results did not confirm previously claimed association of rs1024611, rs3918242, rs2073618, rs1800629, rs4986790, rs179998, rs1963645 and rs11549465 (respectively, in MCP1, MMP9, TNFRSF11B, TNFα, TLR4, eNOS, NOS1AP and HIF1α genes) with the DFU. Surprisingly, the t allele of rs7903146 in the TCF7l2 gene known as one of the most prominent risk factors for type 2 diabetes has shown a protective effect on DFU with OR(95%) = 0.68(0.48-0.96).

CONCLUSION

Non-replication of previously published SNP associations with DFU suggests that the role of genetic factors in the DFU onset is either highly variable in different populations or is not as significant as the role of non-genetic factors.

Targeting Matrix Metalloproteinase-9 for Therapeutic Intervention in Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are a complication of diabetes that have long been neglected. To date, a single drug (becaplermin containing platelet-derived growth factor, PDGF) has been approved by the FDA 27 years ago; however, it is seldom used because of its modest efficacy. The standard-of-care for DFUs is debridement, off-loading, and infection control with antibiotics, with hyperbaric oxygen (HBO) therapy being the treatment of last recourse. The paucity of understanding what accelerates diabetic wound healing results in more than 150,000 lower-limb amputations in the United States every year. A new paradigm for treatment of DFUs is proposed based on the higher levels of active matrix metalloproteinase (MMP)-9 with the more severe and infected human DFUs, and the demonstrated detrimental role of MMP-9 and the beneficial repair role of MMP-8 in diabetic mice. Selective inhibition of MMP-9 with the small molecule (R)-ND-336 lowered inflammation, reduced reactive oxygen species (ROS), and increased angiogenesis, without affecting MMP-8 to allow the natural repair mechanisms to take place. (R)-ND-336 showed better efficacy than becaplermin in diabetic mice. Becaplermin (PDGF) and HBO therapy work by decreasing MMP-9, but they do not completely suppress MMP-9 activity.

Impact of Epigenetics, Diet, and Nutrition-Related Pathologies on Wound Healing

Chronic wounds pose a significant challenge to healthcare. Stemming from impaired wound healing, the consequences can be severe, ranging from amputation to mortality. This comprehensive review explores the multifaceted impact of chronic wounds in medicine and the roles that diet and nutritional pathologies play in the wound-healing process. It has been well established that an adequate diet is crucial to proper wound healing. Nutrients such as vitamin D, zinc, and amino acids play significant roles in cellular regeneration, immune functioning, and collagen synthesis and processing. Additionally, this review discusses how patients with chronic conditions like diabetes, obesity, and nutritional deficiencies result in the formation of chronic wounds. By integrating current research findings, this review highlights the significant impact of the genetic make-up of an individual on the risk of developing chronic wounds and the necessity for adequate personalized dietary interventions. Addressing the nutritional needs of individuals, especially those with chronic conditions, is essential for improving wound outcomes and overall patient care. With new developments in the field of genomics, there are unprecedented opportunities to develop targeted interventions that can precisely address the unique metabolic needs of individuals suffering from chronic wounds, thereby enhancing treatment effectiveness and patient outcomes.

Association of Matrix Metalloproteinase-2 (MMP-2) and MMP-9 Promoter Variants, Their Serum Levels, and Activities with Aortic Valve Calcification (AVC) in a Population from Western Iran

Background: Matrix metalloproteinase (MMP) enzyme gene polymorphisms MMP-2-1575G/A and MMP-9-1562C/T promoter polymorphism, their serum levels, and activity are associated with aortic valve calcification (AVC). Materials and Methods: The synergistic link between the risk of AVC and the alleles T and A of MMP-9 and MMP-2 was investigated, respectively. Ninety-two cases with AVC and 92 healthy individuals from the west of Iran were included, and MMP- 2-1575G/A and MMP-9-1562C/T promoter polymorphisms were detected using PCR-RFLP. The serum levels and activity of MMP-2 and -9 were assessed using ELISA and gelatin zymography methods, respectively. In addition, serum biochemical markers, including FBS, urea and creatinine, cholesterol, triglyceride, HDL, LDL, calcium, phosphorus, and blood pressure: systolic blood pressure and diastolic blood pressure were measured. Results: Heart valve calcification disease was associated with a comparatively higher frequency of the A allele of the MMP2-1575 variation (p = 0.002). In addition, the frequency of T allele of the MMP9-1562 variant was higher than the control group (p = 0.007). Conclusion: MMP-2 and MMP-9 serum levels and activities were observed to be considerably higher in the experimental group than in the control group (p < 0.001). Patients are more susceptible to cardiovascular disease than the control group due to elevated serum levels and activity of MMP-2 and MMP-9.

MMP9 Gene Polymorphism (rs3918242) Increases the Risk of Cardiovascular Disease in Type 2 Diabetes Patients

Matrix metalloproteinase 9 (MMP-9) C(-1562)T gene polymorphism has been considered a risk factor for cardiovascular disease (CVD). Our study aimed to evaluate the association between this polymorphism and CVD in diabetes patients. The genotyping was performed in 740 patients with T2DM and 400 healthy subjects. A significant difference in the polymorphism distribution was revealed between patients and controls. The T allele and TT homozygote were associated with increased risk of diabetes (OR 1.88, p < 0.0001 and OR 3.77, p = 0.0002, respectively). The comparison between CVD+ and CVD- subgroups showed a much higher frequency of the T allele in patients with CVD (OR 2.87, 95% CI 2.14-3.85, p < 0.0001). Patients with the TT genotype had a higher prevalence of CVD (OR 3.19, 95% CI 1.55-6.56, p = 0.0015). The carrier genotypes (CT/TT) were correlated with HDL levels in both CVD+ and CVD- subgroups (p < 0.001 for both). In the logistic regression analysis, only C(-1562)T SNP was a significant predictor of CVD in diabetic patients (p < 0.001). In conclusion, our study suggests an association between MMP-9 C(-1562)T polymorphism and an increased risk of CVD in T2DM. If replicated in other studies, it could be considered a genetic marker for predicting risk of T2DM and its cardiovascular comorbidity.

Based on Clinical Research Matrix Metalloprotease (MMP) Inhibitors to Promote Diabetic Wound Healing

Chronic inflammation is a common factor in obesity, diabetes mellitus, and the complications of diabetes, including diabetic wounds. These ulcers are characterized by persistent lesions that are challenging to heal, significantly decreasing patients' quality of life and imposing a substantial financial burden on society. MMP are zinc endopeptidases that play a role in wound healing in response to various stimuli, including diabetes mellitus. MMP levels fluctuate throughout the wound healing process in diabetic patients' serum, skin tissues, and wound fluid, indicating their potential as biomarkers for diabetic foot ulcers. Targeting MMP has emerged as a promising strategy for treating diabetic wounds, as these enzymes are involved in critical biological processes related to wound healing, including extracellular matrix secretion, angiogenesis, granulation tissue formation, collagen growth, re-epithelization, inflammatory response, and oxidative stress.

Targeting matrix metalloproteases in diabetic wound healing

Chronic inflammation participates in the progression of multiple chronic diseases, including obesity, diabetes mellitus (DM), and DM related complications. Diabetic ulcer, characterized by chronic wounds that are recalcitrant to healing, is a serious complication of DM tremendously affecting the quality of life of patients and imposing a costly medical burden on society. Matrix metalloproteases (MMPs) are a family of zinc endopeptidases with the capacity of degrading all the components of the extracellular matrix, which play a pivotal part in healing process under various conditions including DM. During diabetic wound healing, the dynamic changes of MMPs in the serum, skin tissues, and wound fluid of patients are in connection with the degree of wound recovery, suggesting that MMPs can function as essential biomarkers for the diagnosis of diabetic ulcer. MMPs participate in various biological processes relevant to diabetic ulcer, such as ECM secretion, granulation tissue configuration, angiogenesis, collagen growth, re-epithelization, inflammatory response, as well as oxidative stress, thus, seeking and developing agents targeting MMPs has emerged as a potential way to treat diabetic ulcer. Natural products especially flavonoids, polysaccharides, alkaloids, polypeptides, and estrogens extracted from herbs, vegetables, as well as animals that have been extensively illustrated to treat diabetic ulcer through targeting MMPs-mediated signaling pathways, are discussed in this review and may contribute to the development of functional foods or drug candidates for diabetic ulcer therapy. This review highlights the regulation of MMPs in diabetic wound healing, and the potential therapeutic ability of natural products for diabetic wound healing by targeting MMPs.

Matrix Metalloproteinases in Cardioembolic Stroke: From Background to Complications

Matrix metalloproteinases (MMPs) are endopeptidases participating in physiological processes of the brain, maintaining the blood-brain barrier integrity and playing a critical role in cerebral ischemia. In the acute phase of stroke activity, the expression of MMPs increase and is associated with adverse effects, but in the post-stroke phase, MMPs contribute to the process of healing by remodeling tissue lesions. The imbalance between MMPs and their inhibitors results in excessive fibrosis associated with the enhanced risk of atrial fibrillation (AF), which is the main cause of cardioembolic strokes. MMPs activity disturbances were observed in the development of hypertension, diabetes, heart failure and vascular disease enclosed in CHA₂DS₂VASc score, the scale commonly used to evaluate the risk of thromboembolic complications risk in AF patients. MMPs involved in hemorrhagic complications of stroke and activated by reperfusion therapy may also worsen the stroke outcome. In the present review, we briefly summarize the role of MMPs in the ischemic stroke with particular consideration of the cardioembolic stroke and its complications. Moreover, we discuss the genetic background, regulation pathways, clinical risk factors and impact of MMPs on the clinical outcome.

Association of MMP-2 and MMP-9 Polymorphisms with Diabetes and Pathogenesis of Diabetic Complications

Type 2 diabetes mellitus (T2D) affects millions of people around the world, and its complications have serious health consequences. In addition to external factors, the causes of morbidity and increased risk were also sought in the variability of the human genome. A phenomenon that can answer these questions is the occurrence of single-nucleotide polymorphisms (SNP). They constitute a field for research into genetic determinants responsible for the increase in the risk of the discussed metabolic disease. This article presents the outline of two enzymes: metalloproteinases 2 and 9 (MMP-2, MMP-9), their biological activity and the effect caused by differences in individual alleles in the population, as well as the reports on the importance of these DNA sequence variations in the occurrence of diabetes mellitus type 2 and associated conditions. The results of the conducted research indicate a relationship between two MMP-2 polymorphisms (rs243865, rs243866) and two MMP-9 polymorphisms (rs3918242, rs17576) and the presence of T2D. This could offer a promising possibility to use them as predictive and diagnostic markers. However, due to the low number of reports, more research is needed to clearly confirm the link between these SNPs and diabetes.

Matrix Metalloproteinase-2 (MMP-2) and-9 (MMP-9) Gene Variants and Microvascular Complications in Type 2 Diabetes Patients

Vascular complications are the leading cause of increased morbidity and mortality of diabetic patients. It has been postulated that matrix metalloproteinases MMP-2 and MMP-9, zinc-dependent endopeptidases through remodeling of the extracellular matrix, can contribute to the onset and progression of diabetic vascular complications. The aim of our study was to assess whether there is a major difference in single nucleotide polymorphisms in the MMP-2 (at position -1306C˃T) and MMP-9 (at position -1562C˃T) gene in type 2 diabetic patients and healthy controls and to determine whether there is an association of these gene variants with the presence of microvascular complications in diabetic patients. Our study included 102 type 2 diabetes patients and a control group which was comprised of 56 healthy controls. All diabetic patients were screened for microvascular diabetes complications. Genotypes were detected by polymerase chain reactions followed by restriction analyses with specific endonucleases and their frequencies were determined. The MMP-2 variant -1306C>T showed a negative correlation with type 2 diabetes (p=0.028). It was also shown that the presence of the -1306C allele increases the probability of developing type 2 diabetes. This was a 2.2 fold increase and that the -1306 T allele has a protective role in regards to type 2 diabetes. The MMP-2 variant -1306T showed a negative correlation with diabetic polyneuropathy (p=0.017), meaning that allele-1306T has a protective role in regards to diabetic polyneuropathy while the presence of allele -1306C increases the probability of developing diabetic polyneuropathy by 3.4 fold. Our study showed that the MMP-2 gene variant (-1306C) doubles the risk of developing type 2 diabetes, and for the first time an association of this gene variant and the presence of diabetic polyneuropathy was shown.

Single nucleotide substitutions in the matrix metalloproteinase 9 gene in hypertensive individuals of European and South Asian ethnicity in the Far Eastern Federal District

Aim. To determine the association of single nucleotide polymorphism (SNP) -1562C>T (rs3918242) in the matrix metalloproteinase 9 (MMP-9) gene in hypertensive (HTN) in individuals of European and South Asian ethnicity of Primorsky Krai and Sakhalin Oblast.

Material and methods. The analysis of conventional and additional risk factors for cardiovascular diseases (35 parameters) in 377 people as a part of regional stage of the Epidemiology of Cardiovascular Diseases and their Risk Factors in Regions of Russian Federation (ESSE-RF) study (2014-2019), of whom 240 people of European (Slavic) and 137 people of South Asian (Korean, second- and third-generation immigrants) ethnicity. Substitutions in the MMP-9 gene -1562C>T (rs3918242) was identified by real-time polymerase chain reaction using TaqMan technology.

Results. Compared to Koreans, the Slavs have a higher blood pressure (p=0,002). There were no significant differences between ethnic groups (p=0,07) in cardiovascular risk levels using the Systematic Coronary Risk Evaluation (SCORE). Significant differences (p=0,003) were determined in cardiovascular risk levels for healthy Koreans and HTN patients. It was shown that among patients with HTN, the pulse wave velocity exceeded the recommended values in 22,2% of Europeans and in 46,6% of Koreans (p=0,003). The number of hypertensive Europeans and minor MMP-9 rs3918242 T allele exceeded 2,6 times the number of healthy persons (odds ratio, 4,7; 95% confidence interval: 1,1 -7,8 (p=0,03)). MMP-9 rs3918242 T allele in Koreans of the Sakhalin Oblast was not associated with HTN (odds ratio, 0,81; 95% confidence interval: 0,12-5,54 (p=0,83)). Moreover, in South Asian population, heterozygous carriers of T allele prevailed, which significantly (p=0,002) differed from Europeans, who, in general, had a homozygous CC genotype.

Conclusion. In Far Eastern Federal District, SNPs in the MMP-9 C-1562T gene were found mainly in hypertensive patients of European ethnicity, while in Koreans, a significant relationship between the carriage of minor T allele in this gene and the presence of HTN was not established.

Epigenetic basis of diabetic vasculopathy

Type 2 diabetes mellitus (T2DM) causes peripheral vascular disease because of which several blood-borne factors, including vital nutrients fail to reach the affected tissue. Tissue epigenome is sensitive to chronic hyperglycemia and is known to cause pathogenesis of micro- and macrovascular complications. These vascular complications of T2DM may perpetuate the onset of organ dysfunction. The burden of diabetes is primarily because of a wide range of complications of which nonhealing diabetic ulcers represent a major component. Thus, it is imperative that current research help recognize more effective methods for the diagnosis and management of early vascular injuries. This review addresses the significance of epigenetic processes such as DNA methylation and histone modifications in the evolution of macrovascular and microvascular complications of T2DM.

Association of Matrix Metalloproteinase-2 (MMP-2) and MMP-9 Promoter Polymorphisms, Their Serum Levels, and Activities with Coronary Artery Calcification (CAC) in an Iranian Population

The serum levels and activity of matrix metalloproteinases (MMPs) are associated with the risk of coronary artery calcification (CAC). We sought to investigate the association between MMP-2 -1575G>A (rs243866) and MMP-9 -1562 C>T (rs3918242) SNPs with MMP-2 and MMP-9 serum levels and activity in individuals with CAC. One hundred and fifty-five cases with CAC and 155 healthy individuals as control group from West of Iran were included and frequency of genotypes and alleles of rs243866 and rs3918242 in MMP-2 and MMP-9 genes were determined using PCR-RFLP. We also investigated the serum levels of MMP-2 and MMP-9 and their activity using ELISA and gelatin zymography, respectively. Additionally, serum biochemical parameters including FBS (fasting blood sugar), urea, creatinine, cholesterol, triglyceride, HDL (high-density lipoprotein), LDL (low-density lipoprotein), calcium, and phosphorus as well as blood pressure (systolic blood pressure (SBP) and diastolic blood pressure (DBP)) were measured. Our results showed that both serum levels of MMP-2 and MMP-9 (P < 0.001) and their activity (P < 0.001) were higher in individuals with CAC when compared to the control group. Carrying A and T alleles in MMP-2 -1575G>A (rs243866) and MMP-9 -1562 C>T (rs3918242) SNPs, respectively, may predispose the individuals to CAC by acting as the risk factors. Serum levels and activity of MMP-2 and MMP-9 were found to be higher in CAC cases when compared to the healthy controls. Carriers of A allele in rs243866 SNP and T allele in rs3918242 SNP were shown to have higher MMP-2 and MMP-9 serum levels and activity that may result in increased ECM degradation and support the initiation and development of calcification.

Analysis of the association of polymorphisms of genes markers functions of endothelium and vascular-plate hemostasis with development of diabetic foot syndrome

The aim. To study the prevalence of various combinations of polymorphic variants of genes markers of endothelial function and vascular-platelet hemostasis in the development of diabetic foot syndrome.Materials and methods. In 198 patients with uncomplicated diabetes mellitus and 199 patients with diabetic foot syndrome, the frequency of polymorphic variants of the NOS 786C>T, END1 Lys198Asn, ITGB3 1565T>C (Leu33Pro), F5 1691G>A, F2 20210G>A, MMP9 8202A>G, MTHFR 1298A>C, VEGFA-634C>G genes was studied. Using binary logistic regression analysis, the relationship of various combinations of polymorphisms of the studied genes with the development of diabetic foot was assessed.Results. In diabetic foot syndrome, the most significant contribution is made by the combination of polymorphic variants of the ITGB3 1565T>C (Leu33Pro) and MTHFR 1298A>C genes. With the development of this complication of diabetes mellitus, a combination of the 1565 TC polymorphism of gene ITGB3 and the 1298AA polymorphism of gene MTHFR is 2.1 times more common. The association of the 1565TT polymorphism of gene ITGB3 and the 1298AC polymorphism of gene MTHFR is 2 times more common in diabetes mellitus without complications.Conclusion. The combination of the 1565TС polymorphism of gene ITGB3 and the 1298АА polymorphism of gene MTHFR is associated with the risk of developing a diabetic foot and increases the risk of developing this complication by 2.4 times. The presence of a combination of the 1565TT polymorphisms of gene ITGB3 and the 1298AC polymorphism of gene MTHFR is more common in uncomplicated diabetes mellitus, which suggests its protective effect against the development of diabetic foot syndrome.

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.

Genetic Polymorphisms and the Risk of Diabetic Foot: A Systematic Review and Meta-Analyses

BACKGROUND

Diabetic foot (DF) is a dangerous complication of diabetes. The aim of the study was to synthesize all the published single nucleotide polymorphisms (SNPs) of DF to objectively evaluate the relationship of SNPs and DF risks.

METHODS

The HuGE database and CNKI were searched for eligible publications on genetic polymorphisms and the risk of DF systematically. The quality of literatures was evaluated by the Newcastle-Ottawa scale. Pooled odds ratios with a 95% confidence interval for SNPs were evaluated through 3 genetic models.

RESULTS

Citing 29 different polymorphisms from 24 articles and the study met our selection criteria. There were 24 polymorphisms summarized systematically, and 5 merged polymorphisms for a meta-analysis: 9 positively associated with DF: HIF-1α rs11549465, TNF-α rs1800629, TLR-9 rs5743836, FIB rs6056, HSP70-2437C/T, VDR rs2228570, LOX rs1800449, ITLN1 rs2274907, and OPG rs2073617, but OPG rs3134069 was not a risk factor in DF; 6 negatively associated with DF: VEGF rs833061 and rs2010963, MCP-1 rs1024611, SDF-1 rs1801157, SIRT1 rs12778366, and OPG rs2073617. In addition, 13 polymorphisms were not associated with DF: MMP-9 rs3918242, eNOS rs1799983, VEGF rs3025039, -7C/T, rs1570360, rs13207351, and rs699947, IL-6 rs1800795, HIF-1α rs11549467, TNF-α rs361525, TLR-2 rs3804100, SIRT1 rs3758391, and TIMP-1 rs2070584.

CONCLUSIONS

The study provided some evidence for SNPs to the development of diabetic foot. The meta-analysis showed that rs1024611 of MCP-1 may be regarded as a protective factor, especially in Asian populations. Other loci indicated inconsistent results.

Single nucleotide polymorphisms in cytokine/chemokine genes are associated with severe infection, ulcer grade and amputation in diabetic foot ulcer

Compared to other complications the genetics of diabetic foot ulcer is poorly studied. The Interleukin (IL)-6 (-174G > C/rs1800795), Tumor Necrosis Factor (TNF)-α (-308G > A/rs1800629) and (-238G > A/rs361525) and Stromal cell Derived Factor (SDF)-1 (+801G > A/rs1801157) are well characterized single nucleotide polymorphisms (SNPs) which were previously shown to be associated with Diabetic Foot Ulcer (DFU). In the present study, we looked at the association of these SNPs with foot microbial infection, Wagner's ulcer grade and treatment procedure, along with serum levels of these cytokines (intermediate phenotype) and other serum biomarkers (adiponectin, leptin, CRP and HOMA-IR) in subjects with DFU. Subjects with DFU (n = 270) were genotyped by PCR-RFLP and the serum levels of IL-6, TNF-α and SDF-1 were determined by ELISA. Microbial infections were determined by standard microbiological methods. Ulcer grade and treatment procedures were recorded. IL-6 (-174G > C), TNF-α (-308G > A) and SDF-1 (+801G > A) SNPs were associated with severe microbial infections. TNF-α (-308G > A) and (-238G > A) SNPs were associated with severe ulcer grades. SDF-1 (+801G > A) SNP was associated with major amputation even after adjusting for confounding variables. Identification of these SNPs in DFU subjects would help in identifying high risk individuals who need better treatment care.

Genetic variation of MMP-2(-735 C>T) and MMP-9(-1562 C>T) gene in risk of development of HAND and severity of HAND

BACKGROUND

Astrocytes are susceptible to HIV-1 infection. Neurocognitive dysfunction has also been associated with the toxicity of certain antiretroviral drugs. HIV-1 induced neurological toxicity has been associated with deficiency of matrix metalloproteinases. Therefore, we evaluated the association of MMP-2(-735C > T) and MMP-9(-1562C > T) polymorphisms with respect to the susceptibility of developing HIV-associated neurocognitive disorders (HAND) and its severity.

METHODS

We enrolled 50 HIV-infected individuals with HAND, 130 without HAND and 150 unrelated healthy controls. Polymorphism for MMP-2-735C > T and MMP-9-1562C > T genes was genotyped by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Individuals with the MMP-2 -735 CT genotype and -735 T allele were at higher risk of developing HAND [odds ratio (OR) = 5.27, 95% confidence interval (CI) = 1.30-21.35, p = 0.02 and OR = 2.27, 95% CI = 1.57-3.27, p = 0.0001 respectively]. The MMP-2 -735 CT genotype and -735 T allele of MMP-2 were associated with a reduced likelihood of severe HAND (OR =0.32, 95% CI = 0.15-0.66, p = 0.002 and OR = 0.32, 95% CI = 0.14-0.71, p = 0.005). When evaluating gene-gene interaction models, the combined genotype MMP-2-735TT + MMP-9-1562CC and MMP-2-735CT + MMP-9-1562CT was associated with the risk of developing HAND (OR = 4.84, p = 0.0001, OR = 1.81, p = 0.03). However, individuals with the combined genotype of MMP-2-735TT + MMP-9-1562CC were found to be protective for severe HAND (OR = 0.30, 95% CI = 0.13-0.67, p = 0.003).

CONCLUSIONS

Individuals with the MMP-2 -735CT genotype, -735 T allele and combined genotype MMP-2 -735TT + MMP-9 -1562CC had an enhanced risk of developing HAND. Those with the MMP-2 -735 CT genotype, -735 T allele and combined genotype of MMP-2-735TT + MMP-9-1562CC were suggested to have protection from developing severe HAND.

Association of functional SNP-1562C>T in MMP9 promoter with proliferative diabetic retinopathy in north Indian type 2 diabetes mellitus patients

OBJECTIVE

Retinal angiogenesis is a hallmark of diabetic retinopathy. Matrix Metalloproteinases (MMPs) are involved in degradation of extracellular matrix (ECM). Functional SNP-1562C>T in the promoter of the MMP-9 gene results increase in transcriptional activity. The present work was designed to evaluate the contribution of functional SNP-1562C>T of MMP-9 gene to the risk of proliferative diabetic retinopathy (PDR) in type 2 diabetes mellitus (T2DM) patients in north Indian Population.

METHODS

This Case control study comprised of a total of 645 individuals in which 320 were T2DM patients out of which 73 had PDR, 98 had non- proliferative diabetic retinopathy (NPDR), 149 T2DM cases without any eye related disease (DM) and 325 non diabetic healthy individuals as controls (non DM controls). Genotyping for SNP-1562C>T of MMP-9 was done by polymerase chain reactions followed by restriction analyses with specific endonucleases (PCR-RFLP). DNA sequencing was used to ascertain PCR-RFLP results.

RESULTS

T allele frequency in PDR patients was 32.1%, 20.4% in NPDR, 15.4% in DM and 13.7% in controls. Statistically significant difference was observed in both allele and genotype distribution between the PDR versus non-DM control group (p<0.0001 by T allele; p=0.002 by TT and p<0.0001 by CT genotype).

CONCLUSIONS

The present study suggests that the functional SNP-1562C>T in the promoter of the MMP-9 gene could be regarded as a major risk factor for PDR as increased MMP-9 production from high expressing T allele may promote retinal angiogenesis.

Mesothelin promoter variants are associated with increased soluble mesothelin-related peptide levels in asbestos-exposed individuals

BACKGROUND

Soluble mesothelin-related peptide (SMRP) is a promising diagnostic biomarker for malignant pleural mesothelioma (MPM), but various confounders hinder its usefulness in surveillance programmes. We previously showed that a single nucleotide polymorphism (SNP) within the 3'untranslated region (3'UTR) of the mesothelin (MSLN) gene could affect the levels of SMRP.

OBJECTIVES

To focus on SNPs located within MSLN promoter as possible critical genetic variables in determining SMRP levels.

METHODS

The association between SMRP and SNPs was tested in 689 non-MPM subjects and 70 patients with MPM. Reporter plasmids carrying the four most common haplotypes were compared in a dual luciferase assay, and in silico analyses were performed to investigate the putative biological role of the SNPs.

RESULTS

We found a strong association between serum SMRP and variant alleles of rs3764247, rs3764246 (in strong linkage disequilibrium with rs2235504) and rs2235503 in non-MPM subjects. Inclusion of the genotype information led to an increase in SMRP specificity from 79.9% to 85.5%. Although not statistically significant, the group with MPM showed the same trend of association. According to the in vitro luciferase study, rs3764247 itself had a functional role. In silico approaches showed that the binding sites for transcription factors such as Staf and ZNF143 could be affected by this SNP. The other SNPs were shown to interact with each other in a more complex way.

CONCLUSIONS

These data support the suggestion that SMRP performance is affected by individual (ie, genetic) variables and that MSLN expression is influenced by SNPs located within the promoter regulatory region.

Expression and Influence of Matrix Metalloproteinase–9/Tissue Inhibitor of Metalloproteinase–1 and Vascular Endothelial Growth Factor in Diabetic Foot Ulcers

A high matrix metalloproteinase–9/tissue inhibitor of metalloproteinase–1 (MMP9/TIMP1) ratio is associated with poor ulcer healing, yet how the ratio of MMP9/TIMP1 changes in diabetic foot ulcers (DFUs) with infection and how these changes may affect wound healing remain unclear. Therefore, the objective of this investigation was to explore relationships among the MMP9/TIMP1 ratio, infection, and DFUs. After being informed of the details of this study, 32 patients signed consent forms. Skin biopsies were performed for all patients. Wound tissues were obtained from all patients with wounds, and healthy skin samples were collected from patients without wounds during orthopedic surgery. Microbial cultures were obtained using the samples from diabetic patients with wounds. All patients were divided into 4 groups according to colony-forming units (CFUs) per gram of tissue (>1 × 106 or <1 × 106): group A (diabetic wounds with high quantities of bacteria), group B (diabetic wounds with low quantities of bacteria), group C (diabetic patients without wounds), and group D (nondiabetic patients with wounds). In addition, the biopsies were evaluated by both reverse transcription–quantitative polymerase chain reaction and Western blotting to assess the levels of MMP9, TIMP1, and vascular endothelial growth factor (VEGF). The results show that for both mRNA and protein, expression of MMP9 (fold change 1.14 ± 0.12 vs 0.60 ± 0.08 vs 0.39±0.09 vs 0.13 ± 0.06, P < .01) decreased, whereas that of TIMP1 (1.01 ± 0.09 vs 2.86 ± 0.85 vs 4.88 ± 0.83 vs 7.29 ± 1.55, P < .01) and VEGF (1.01 ± 0.22 vs 3.55 ± 0.97 vs 5.72 ± 0.55 vs 6.92 ± 1.55, P < .01) increased from group A to group D. These results suggest that an increase in the MMP9/TIMP1 ratio in infected DFUs may induce a decrease in VEGF expression.

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.

Evaluation of physiological risk factors, oxidant-antioxidant imbalance, proteolytic and genetic variations of matrix metalloproteinase-9 in patients with pressure ulcer

Pressure ulcer (PU) remains a common worldwide problem in all health care settings, it is synonymous with suffering. PU is a complex disease that is dependent on a number of interrelated factors. It involves multiple mechanisms such as physiological risk factors, chronic inflammation, oxidant–antioxidant imbalance and proteolytic attack on extracellular matrix by matrix metalloproteinases (MMP). Therefore, we propose that these wounds lead to molecular variations that can be detected by assessing biomarkers. In this study, we aimed to evaluate the major clinical elements and biological scars in Tunisian patients suffering from PU. Consistently, non-healing wound remains a challenging clinical problem. The complex challenges of the wound environment, involving nutrient deficiencies, bacterial infection, as well as the critical role played by inflammatory cells, should be considered because of their negative impact on wound healing. In addition, an imbalance between pro-oxidants and antioxidant systems seems to be more aggravated in patients with PU compared to healthy subjects. Of interest, this study provides further evidence to support a core role of the biological activity of MMP-9 in the pathogenesis of PU and indicates that the MMP9-1562 C/T (rs 3918242) functional polymorphism is associated with protection against this disease.

Matrix Metalloproteinase 9 Gene Promoter (rs 3918242) Mutation Reduces the Risk of Diabetic Microvascular Complications

BACKGROUND

Many studies have evaluated the association between matrix metalloproteinase 9 (MMP9) gene promoter polymorphism and diabetic microvascular complications. However, the results are conflicting and inconclusive. The aim of this meta-analysis was to evaluate the association more precisely.

MATERIALS AND METHODS

Studies were retrieved from the PubMed, Embase, Medline, China National Knowledge Infrastructure, Web of Science, and Cochrane databases. All statistical analyses were performed using Review Manager 5.2.

RESULTS

Data were abstracted from four case-control studies that included 446 patients with diabetic microvascular complications and 496 diabetic control subjects. The MMP9-1562 C/T genotype was significantly associated with the risk of diabetic nephropathy after stratification by specific type of microvascular complication (CT + TT vs. CC: OR = 0.42, 95% CI = 0.26-0.69, p = 0.0006; TT vs. CC + CT: OR = 0.37, 95% CI = 0.19-0.76, p = 0.006).

CONCLUSIONS

This study adds to the evidence that MMP9-1562 T gene mutation might reduce the risk of diabetic nephropathy.

Decreased expression of heat shock proteins may lead to compromised wound healing in type 2 diabetes mellitus patients

BACKGROUND

Heat shock proteins (HSPs) are inducible stress proteins expressed in cells exposed to stress. HSPs promote wound healing by recruitment of dermal fibroblasts to the site of injury and bring about protein homeostasis. Diabetic wounds are hard to heal and inadequate HSPs may be important contributors in the etiology of diabetic foot ulcers (DFU).

OBJECTIVE

To analyze the differential expression of HSPs and their downstream molecules in human diabetic wounds compared to control wounds.

METHODS

Expressional levels of HSP27, HSP47 and HSP70 and their downstream molecules like TLR4, p38-MAPK were seen in biopsies from 101 human diabetic wounds compared to 8 control subjects without diabetes using RT-PCR, western blot and immunohistochemistry.

RESULTS

Our study suggested a significant down regulation of HSP70, HSP47 and HSP27 (p value=<0.001 for HSP70; p value=0.007 for HSP47; p value=0.007 for HSP27) in DFU along with their downstream molecules TLR4 and p38-MAPK (p value=0.006 for p38-MAPK; p value=0.02 for TLR4). HSP70 levels were significantly lower in male subjects and their levels increased significantly with the grades of wound on Wagner's scale. Infection status of the wounds was found to be significantly associated with the increased levels of HSP70 and HSP27 in infected diabetic wounds.

CONCLUSIONS

Our study demonstrates that the down regulation of HSPs in diabetic wounds is associated with wound healing impairment in T2DM subjects.

Genetic and epigenetic alterations in Toll like receptor 2 and wound healing impairment in type 2 diabetes patients

AIM

Persistent hyperglycemic microenvironment in type 2 diabetes mellitus (T2DM) leads to the development of secondary complications like wound healing impairment. Proper co-ordination of innate immune system plays an integral role in wound healing. Toll like receptors (TLRs) are prominent contributors for the induction of the innate immune and inflammation response. TLR2 is an important extracellular member in mammalian TLR family and has been shown to be a potent player in the wound healing mechanism.

METHODS

Expressional status of TLR2 was seen in wounds of T2DM cases with respect to the severity of wounds in 110 human lower extremity wounds. The methylation status of TLR2 promoter was also examined.

RESULTS

Although TLR2 transcripts were downregulated in T2DM wounds compared to control, their levels tend to increase with the severity of T2DM wounds. The methylation status of TLR2 gene promoter was not significantly different among different grades of wounds in T2DM subjects. The CpG sites investigated were totally or partially methylated in majority of DFU cases.

CONCLUSION

TLR2 down regulation in wounds of T2DM patients compared to non diabetic patients may lead to development of non healing chronic ulcers in them.

Increased expression of endosomal members of toll-like receptor family abrogates wound healing in patients with type 2 diabetes mellitus

The inflammatory phase of wound healing cascade is an important determinant of the fate of the wound. Acute inflammation is necessary to initiate proper wound healing, while chronic inflammation abrogates wound healing. Different endosomal members of toll-like receptor (TLR) family initiate inflammatory signalling via a range of different inflammatory mediators such as interferons, internal tissue damaged-associated molecular patterns (DAMPs) and hyperactive effector T cells. Sustained signalling of TLR9 and TLR7 contributes to chronic inflammation by activating the plasmacytoid dendritic cells. Diabetic wounds are also characterised by sustained inflammatory phase. The objective of this study was to analyse the differential expression of endosomal TLRs in human diabetic wounds compared with control wounds. We analysed the differential expression of TLR7 and TLR9 both at transcriptional and translational levels in wounds of 84 patients with type 2 diabetes mellitus (T2DM) and 6 control subjects without diabetes using quantitative real-time polymerase chain reaction (RT-PCR), western blot and immunohistochemistry. TLR7 and TLR9 were significantly up-regulated in wounds of the patients with T2DM compared with the controls and were dependent on the infection status of the diabetic wounds, and wounds with microbial infection exhibited lower expression levels of endosomal TLRs. Altered endosomal TLR expression in T2DM subjects might be associated with wound healing impairment.

Matrix metalloproteinases as biomarkers of disease: updates and new insights

Matrix metalloproteinases (MMPs) play a pivotal role in remodeling the extracellular matrix (ECM) and are therefore of interest for new diagnostic tools for the clinical management of diseases involving ECM disruption. This setting ranges from the classical areas of MMP studies, such as vascular disease, cancer progression or bone disorders, to new emerging fields of application, such as neurodegenerative disease or sepsis. Increasing the knowledge about the role of MMPs in the pathogenesis of diseases where a clear diagnostic panel is still lacking could provide new insight and improve the identification and the clinical treatment of these human diseases. This review focuses on the latest descriptions of the clinical use of MMP as biomarkers in the diagnosis, prognosis and monitoring of different diseases, such as diabetes, cardiovascular diseases, cancer and metastasis, neurodegenerative disorders and sepsis.

Differential Expression of Matrix Metalloproteinase-9 Gene in Wounds of Type 2 Diabetes Mellitus Cases With Susceptible -1562C>T Genotypes and Wound Severity

Coordinated extracellular matrix deposition is a prerequisite for proper wound healing which is mainly orchestrated by matrix metalloproteinases (MMPs). Diabetic wounds generally show compromised wound healing cascade and abnormal MMP9 concentration is one of the cause. Our group have recently shown that the polymorphism -1562 C>T in the promoter region of MMP9 gene is associated with pathogenesis of wound healing impairment in T2DM patients. In present study we have done expression profiling of MMP9 gene in the wound biopsy of DFU cases. Expression level of MMP9 mRNA was then compared with susceptible -1562 C>T genotypes (TT and CT) as well as with different grades of wounds. We also screened the promoter region of MMP9 gene to see the methylation state of CpGs present there. Our study suggests that levels of MMP9 mRNA increase significantly with the wound grades. Moreover, the MMP9 levels in diabetic wounds were also dependent on -1562 C>T polymorphism in the promoter region of MMP9. Diabetic wounds also showed a significant unmethylated status of MMP9 promoter compared to control wounds. In conclusion, The risk genotypes of -1562 C>T polymorphism along with lack of methylation of CpG sites in MMP9 gene promoter may result in altered expression of MMP9 in wounds of T2DM cases resulting into nonhealing chronic ulcers in them.

Association of variant rs7903146 (C/T) single nucleotide polymorphism of TCF7L2 gene with impairment in wound healing among north Indian type 2 diabetes population: a case-control study

The variants of transcription factor 7-like 2 (TCF7L2) gene have been shown to be associated with type 2 diabetes mellitus (T2DM) and its several secondary complications. Here, we aimed to examine the possible role of one of the common variant of this gene, rs7903146 (C/T), with impairment of wound healing in cases with T2DM. A total of 750 individuals, including 322 patients with T2DM and 120 patients with diabetic foot ulcers (DFUs) and 308 controls, were analyzed for rs7903146 variant of the TCF7L2 gene. Genotyping was done by polymerase chain reaction-restriction fragment length polymorphism. For rs7903146 variant, TT genotype frequency in patients with DFU was 10.8% and in controls was 5.2%. Risk genotype (TT) frequencies showed statistically significant difference between the DFU patients versus non-DM control group (odds ratio = 2.44, P = .037, 95% confidence interval = 1.05-5.64) compared with nonrisk genotype (CC + CT). In the present study, a positive significant association between DFU and the TT genotype of rs7903146 (C/T) variant of TCF7L2 gene was found.