Prenatal air pollution exposure is associated with inflammatory, cardiovascular, and metabolic biomarkers in mothers and newborns

BACKGROUND

Prenatal air pollution exposure has been associated with individual inflammatory, cardiovascular, and metabolic biomarkers in mothers and neonates. However, studies of air pollution and a comprehensive panel of biomarkers across maternal and cord blood samples remain limited. Few studies used data-driven methods to identify biomarker groupings that converge biomarkers from multiple biological pathways. This study aims to investigate the impacts of prenatal air pollution on groups of biomarkers in maternal and cord blood samples.

METHODS

In the Maternal And Developmental Risks from Environmental and Social Stressors (MADRES) cohort, 87 biomarkers were quantified from 45 trimester 1 maternal blood and 55 cord blood samples. Pregnancy and trimester 1-averaged concentrations of particulate matter ≤2.5 μm and ≤10 μm in diameter (PM2.5 and PM10), nitrogen dioxide (NO2), and ozone (O3) were estimated, using inverse distance squared weighted spatial interpolation from regulatory air monitoring stations. Traffic-related NOx was assessed using California Line Source Dispersion Model: freeway/highway roads, non-freeway major roads, non-freeway minor roads, and their sum as total NOx. Elastic Net (EN) regression within the rexposome R package was used to group biomarkers and assess their associations with air pollution.

RESULTS

In maternal samples, trimester 1-averaged PM10 was associated with elevated inflammation biomarkers and lowered cardiovascular biomarkers. NO2 exhibited positive associations with cardiovascular and inflammation markers. O3 was inversely associated with inflammation, metabolic, and cardiovascular biomarkers. In cord blood, pregnancy-averaged PM2.5 was associated with higher cardiovascular biomarkers and lower metabolic biomarkers. PM10 was associated with lower inflammation and higher cardiovascular biomarkers. Total and major road NOx was associated with lower cardiovascular biomarkers.

CONCLUSION

Prenatal air pollution exposure was associated with changes in biomarkers related to inflammation, cardiovascular, metabolic, cancer, and neurological function in both mothers and neonates. This study shed light on mechanisms by which air pollution can influence biological function during pregnancy.

Matrix Metalloproteinase-9 inhibitors as therapeutic drugs for traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality among young adults and the elderly. In the United States, TBI is responsible for around 30 percent of all injuries brought on by injuries in general. Vasogenic cerebral edema due to blood-brain barrier (BBB) dysfunction and the associated elevation of intracranial pressure (ICP) are some of the major causes of secondary injuries following traumatic brain injury. Matrix metalloproteinase-9 (MMP-9) is a therapeutic target for being an enzyme that degrades the proteins that make up a part of the microvascular basal lamina as well as inter-endothelial tight junctions of the blood-brain barrier. MMP-9-mediated BBB dysfunctions and the compromise of the BBB is a major pathway that leads the development of vasogenic cerebral edema, elevation of ICP, poor cerebral perfusion and brain herniation following traumatic brain injury. That makes MMP-9 an effective therapeutic target and endogenous or exogenous MMP-9 inhibitors as therapeutic drugs for preventing secondary brain damage after traumatic brain injury. Although our understanding of the mechanisms that underlie the primary and secondary stages of damage following a TBI has significantly improved in recent years, such information has not yet resulted in the successful development of novel pharmacological treatment options for traumatic brain injury. Recent pre-clinical and/or clinical studies have demonstrated that there are several compounds with specific or non-specific MMP-9 inhibitory properties either directly binding and inhibiting MMP-9 or by indirectly inhibiting MMP-9, with potential as therapeutic agents for traumatic brain injury. This article reviews the efficacy of several such medications and potential agents that include endogenous and exogeneous compounds that are at various levels of research and development. MMP-9-based therapeutic drug development has enormous potential in the pharmacological treatment of cerebral edema and/or neuronal injury resulting from traumatic brain injury.

Matrix metalloproteinase- 9 may contribute to collagen structure modification during postmortem aging of beef

Matrix metalloproteinases (MMPs) are responsible for the turnover of intramuscular connective tissue in live animals. We hypothesize that MMPs may play a role in postmortem aging of beef muscles for the degradation of connective tissues. Four different experiments were performed to: 1) characterize MMP activity during postmortem aging of beef; 2) determine if the native beef MMP can contribute to connective tissue degradation in a simulated standard industry postmortem aging condition; 3) explore approaches to improve the native beef MMP activity and 4) characterize MMP activity in beef from cattle supplemented with supranutritional level of Zn. In experiment 1, MMP was active throughout the entire aging periods (3, 21, 42 and 63 d) for beef muscles Longissimus lumborum, Gluteus medius and Gastrocnemius, and the unknown MMP responsible for the collagen degradation was identified as MMP-9 by Western Blot. In experiment 2 and 3, MMP-9 activity was noticeable in the gels after 42 d of storage in the cooler. Moreover, the addition of ZnCl2 in the model system significantly increased MMP-9 activity when compared to the control (P < 0.01). In experiment 4, Longissimus thoracis from animals supplemented with a supranutritional Zn level had increased Zn availability and MMP-9 activity than those from animals fed with a control diet (P < 0.05). Further research is needed better understand MMP-9 mechanism during postmortem aging of meat. With a better understanding of MMP-9 in the aging process, the beef industry can provide better connective tissue management strategies for lower-quality beef cuts.

Muscarinic Cholinergic Receptor Antagonism Impairs Spatial Memory Retrieval and Minimizes Retrieval-Induced Alterations in Matrix Metalloproteinase-9

Cholinergic dysfunction in the hippocampus causes memory impairment, and degradation of the forebrain cholinergic system has been implicated in several neurological disorders. One such disorder, Alzheimer's Disease (AD) is associated with the abnormal expression of various proteins including matrix metalloproteinase-9 (MMP-9), an enzyme known to regulate hippocampus-dependent memory. Memory involves several stages including acquisition, consolidation, and retrieval, but the neurobiological correlates of retrieval have been studied much less than other stages of memory. We sought to investigate the potential relationship between cholinergic signaling and hippocampal MMP-9 expression and the involvement of each in spatial memory retrieval. We trained rats in the water maze until the task was well-learned, then, seven days later, we allowed some to retrieve the memory after an intracerebroventricular injection of scopolamine or vehicle. Western blot analysis of hippocampal tissue shows elevated levels of a truncated form of MMP-9 associated with spatial memory retrieval. Additionally, our results indicate that centrally administered scopolamine both impairs spatial memory retrieval and prevents retrieval-induced elevations in MMP-9. These findings provide evidence for a potential link between cholinergic dysregulation and abnormal MMP-9 levels seen in the brains of AD patients. An important, yet unresolved question is whether MMP-9 serves to support memory retrieval itself or if it is involved in maintaining the ongoing stability of a retrieved memory.

Effects of selenium intake on the expression of prostaglandin-endoperoxide synthase 2 (cyclooxygenase-2) and matrix metallopeptidase-9 genes in the coronary artery disease: Selenegene study, a double-blind randomized controlled trial

BACKGROUND

The oxidative stress is regarded as one of the main contributors to the health problem. Cyclooxygenase-2 (COX-2) and matrix metallopeptidase-9 (MMP-9) are two of the important genes that are reported to be involved in the cardiovascular disease (CVD) development in the molecular and genetic association studies. The aim of this study was to evaluate the level of expression of COX-2 and MMP-9 after selenium supplementation in patients with coronary artery disease (CAD).

METHODS

In this sub-study of Selenegene study, subjects were randomly divided into groups, 19 subjects who received selenium and 22 patients with CAD who received placebo. Patients received either 200-mg selenium yeast tablets or placebo tablets after a meal, once daily for 60 days. The messenger ribonucleic acid (mRNA) levels of the selenium and prostaglandin-endoperoxide synthase 2 (PTGS2) (COX-2) and MMP-9 genes products were determined before and after the study.

RESULTS

In this sub-study, 41 Iranian patients with CVD were enrolled (placebo group: n = 22, selenium intervention: n = 19). Fasting blood sugar (FBS) was higher among placebo group than selenium group (93.4 ± 12.7 vs. 124.4 ± 40.6 mg/dl, P = 0.03). Triglyceride (TG) level was higher among selenium group versus placebo group (123.3 ± 34.0 vs. 184.8 ± 69.4 mg/dl, P = 0.006). The data analysis demonstrated that the expression of MMP-9 and COX-2 genes did not change significantly in both selenium and placebo groups.

CONCLUSION

This study showed a positive association between the expression of MMP-9 and COX-2 in the patients with CAD who received selenium but not the placebo groups. Yet, these findings need to be confirmed in further details and expanded sample size.

Nuclear factor-κB plays an important role in Tamarixetin-mediated inhibition of matrix metalloproteinase-9 expression

Flavonoids possess a broad spectrum of pharmacological properties, including anti-cancer, anti-oxidant and immunomodulatory activities. The current study explored the potential of some less-studied flavonoids in inhibiting Matrix Metalloproteinase-9 (MMP-9), a prominent biomarker, upregulated in a variety of cancers and known to promote migration and invasion of cancer cells. Amongst these, Tamarixetin, a naturally occurring flavonoid derivative of Quercetin, demonstrated significant dose-dependent inhibition of MMP-9 expression. Furthermore, a substantial inhibition of migration, invasion and clonogenic potential of HT1080 cells was also observed in the presence of Tamarixetin, which further suggests its role as a potential anti-cancer agent. It is noteworthy that Tamarixetin inhibits nuclear translocation as well the activity of nuclear factor kappa B (NFκB), both of which are functions essential for the activation of MMP-9 in promoting tumorigenesis. Additionally, the endogenous regulators of MMP-9 that tightly control its activity were also modulated by Tamarixetin, as evident from the 1.9 fold increase in the expression of Tissue Inhibitor of Metalloproteinase-1 (TIMP-1), with a concomitant 2.2 fold decrease in Matrix Metalloproteinase-14 (MMP-14) expression. The results obtained were further corroborated in three dimensional (3D) tumor models, which showed significant inhibition of MMP-9 activity as well as reduced invasive potential in the presence of Tamarixetin. Taken together, our observations demonstrate for the first time, the anti-invasive potential of Tamarixetin in cancer cells, indicating its possible use as a template for novel therapeutic applications.

Matrix metalloproteinase 9 positivity predicts long term decreased tear production

PURPOSE

To investigate long-term correlations between Matrix Metalloproteinase-9 (MMP-9) testing and dry eye (DE) parameters. Additionally, to evaluate variability in MMP-9 results over time and with anti-inflammatory treatment.

METHODS

Retrospective cohort study of DE patients with equal MMP-9 testing results (positive or negative) in both eyes and a minimum of 6 months of follow up. Our main outcome measure was to examine whether initial MMP-9 status affected change in DE parameters over time. Secondarily, we evaluated the frequency of MMP-9 status change over time and examined whether MMP-9 status change was impacted by treatment.

RESULTS

67 patients (76% female) fit the inclusion criteria. Mean age was 63 years with a mean follow up of 10.6 months. The majority (37/67, 55%) had concomitant systemic immune disease. MMP-9 testing was positive in both eyes in 39 individuals (58%) and negative in both eyes in 27 (42%) individuals. Of all DE parameters, initial MMP status predicted change in tear production. Individuals in the MMP-9 positive group had a greater decrease in production from baseline to final visit compared to the negative group (-2.6 vs 2.1, P = 0.013). In those initially MMP-9 positive, the frequency of becoming MMP-9 negative was higher in eyes treated with anti-inflammatory therapy compared to artificial tears (22.9% vs 3.3%, P = 0.106). However, only Lifitegrast 5% showed statistical significance compared to artificial tears (31.3% vs 3.3%, P = 0.044).

CONCLUSIONS

Eyes with detectable MMP-9 had significantly decreased tear production over time compared to those without detectable MMP-9. Anti-inflammatory treatment more frequently normalized MMP-9 compared to PFATs.

Association between focal adhesion kinase and matrix metalloproteinase-9 expression in prostate adenocarcinoma and their influence on the progression of prostatic adenocarcinoma

Focal adhesion kinase (FAK), a member of the non-receptor cytoplasmic tyrosine kinase family, is associated with the development and progression of cancer. Matrix metalloproteinase-9 (MMP-9) is directly involved in the degradation of the extracellular matrix, and basement membrane components promote cancer cell migration and invasion. There is a functional interaction among FAK, MMP-9 and vascular endothelial growth factor (VEGF), which leads to enhanced cancer angiogenesis, cancer cell invasion and progression of malignancy. FAK, MMP-9, VEGF and CD34-positive microvessel density (MVD) were examined in 100 patients with prostate adenocarcinoma using immunohistochemistry. The relationship among these proteins and their impact on angiogenesis and clinicopathological parameters were also evaluated. The FAK expression was found to be positively correlated with the Gleason score, WHO grade group, tumour stage, extracapsular extension and perineural invasion. The MMP-9 expression was positively correlated with the WHO grade group, tumour stage, extracapsular extension, positive surgical margin and lymphovascular and perineural invasion. The FAK expression was also positively correlated with MMP-9 expression and MVD. However, no correlation between FAK and VEGF expression was identified. The MMP-9 expression was positively correlated with FAK expression and MVD. Strong MMP-9 expression was associated with shorter disease-free survival. These results suggest that strong MMP-9 and FAK expressions play an essential role in the progression of prostate adenocarcinoma. Further investigations should be conducted to determine the importance of these proteins as therapeutic targets for patients with prostate adenocarcinomas.

Circulating matrix modulators (MMP-9 and TIMP-1) and their association with severity of diabetic retinopathy

AIMS

Diabetic Retinopathy (DR) is the leading cause of vision loss in the working age population. Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1), are molecules involved in extracellular tissue matrix remodelling. They are implicated in the loss of retinal tissue integrity, a major cause of DR, that leads to retinal tissue degradation and apoptosis. This study is therefore, conducted to compare the serum levels of MMP-9 and TIMP-1 in T2DM patients without and with retinopathy, and to evaluate their association with the severity of DR.

MATERIALS AND METHODS

Our study comprised of 2 groups of 41 each. Group A (cases) included T2DM patients with retinopathy and Group B (controls) included T2DM patients without retinopathy. Routine parameters, mainly, fasting blood glucose, and lipid profile were measured using autoanalyzer. Serum MMP-9, TIMP-1, and insulin levels were assessed using ELISA method.

RESULTS AND CONCLUSION

Statistically significant increase in the levels of MMP-9, insulin, fasting blood glucose and lipid profile were observed in the serum of T2DM patients with retinopathy, as compared with those without retinopathy. These results help to conclude that rise in MMP-9, and associated serum markers promote disease progress in DR. These findings suggest that the elevations of our study markers in the serum of the type 2 diabetic patients with retinopathy, as compared to those without retinopathy, play important roles in aggravating tissue matrix degradation, supporting DR disease progression.

The Alteration of Plasma Matrix Metalloproteinase-9 Level after the Addition of Bromelin 500 mg to Standard Therapy of Acute Ischemic Stroke and Its Correlation with Outcome

BACKGROUND

Matrix metalloproteinase-9 (MMP9) expression due to ischemic cause spreading of brain damage. Previous studies have reported that Bromelin was beneficial as anti-inflammation and prevent brain tissue damage.

AIM

This study aimed to determine the alteration of plasma MMP9 level after addition of Bromelin 500 mg to Standard therapy and its correlation with outcome in acute ischemic stroke.

METHODS

This was a preliminary report of a prospective randomised, double-blind study with pre and post-test design, forty-six acute ischemic stroke patients were randomly allocated with Bromelin and Standard groups. Measurement of MMP9 and outcome were performed before and after 14-days treatment.

RESULT

The Bromelin group showed a significant decrement of MMP9 level, from 6.02 ± 0.32 ng/ml before treatment to 5.50 ± 0.94 ng/ml after treatment (p = 0.028). There was a negative correlation between MMP9 level and mRS (r= -0.03; p = 0.905) and a positive correlation toward BI (r = 0.039; p = 0.859), while the Standard group showed increased MMP9 level from 5.82 ± 0.71 ng/ml to 5.91 ± 0.83 ng/ml (p = 0.616) which was correlated insignificantly to outcome.

CONCLUSION

We concluded that the addition of 500 mg Bromelin to standard ischemic stroke therapy reduced MMP9 level significantly and correlated to outcome improvement. However, there is a tight statistical correlation.

Potential of Serum and Urinary Matrix Metalloproteinase-9 Levels for the Early Detection of Renal Involvement in Children With Henoch-Schönlein Purpura

Background

Matrix metalloproteinase-9 (MMP-9) is an enzyme implicated in the pathogenesis of renal diseases. Renal involvement is the principal cause of morbidity and mortality in children with Henoch-Schönlein purpura (HSP).

Objectives

The aim of this study was to evaluate whether serum and urinary MMP-9 levels are associated with renal involvement in HSP

Patients and Methods

We evaluated 40 children with HSP (patient group) and 27 healthy volunteer children (control group). The patient group was divided into two subgroups based on the presence or absence of nephritis. Nephritis was defined as the existence of hematuria and/or proteinuria. All anthropometric data, physical examination findings, blood pressure, and laboratory parameters were recorded. The serum and urine samples were analyzed to determine the MMP-9 levels three days after the initial phase of the disease.

Results

The mean age was 7.65 ± 3.41 (range 2 - 16) years in the patient group and 9.52 ± 3.91 (range 2 - 16) years in the control group. Henoch-Schonlein purpura nephritis (HSPN) was identified in eight patients. There was no significant difference in the serum MMP-9 levels between the HSPN subgroup and the controls (P > 0.05). However, there were significant differences in the urinary MMP-9 levels between the HSP subgroup and the control group (P < 0.05), with the urinary MMP-9 levels being significantly higher in patients in the HSP subgroup (P = 0.001). Further, the urinary MMP-9 levels were significantly higher in the patients with nephritis than in the patients without nephritis (P = 0.001) and the controls (P = 0.001). The optimal cut-off point (sensitivity; specificity) of the urinary MMP-9 level for the diagnosis of HSPN was 94.7 pg/mL.

Conclusions

The levels of MMP-9 in the urine were remarkably high in patients with HSPN. This non-invasive marker may therefore be an important indicator for the early diagnosis of nephritis in children with HSP.

An uncommon case of arterial aneurysms association with high plasma levels of Matrix Metalloproteinase-9 and Neutrophil Gelatinase-Associated Lipocalin

The association of an axillary artery aneurysm and an abdominal aortic aneurysm is extremely rare. In this study, we describe this association in a 69 year-old-man. We measured this patient’s metalloproteinases (MMPs) and Neutrophil Gelatinase – Associated Lipocalin (NGAL) levels over a three years period before the abdominal aortic aneurysm rupture. We speculate that high serium levels of MMPs and NGAL may have a prognostic role and may predict aneurysm rupture in patients with an uncommon association of arterial aneurysms.