Role of TGF-β1 and TNF-α in IL-1β mediated activation of proMMP-9 in pulmonary artery smooth muscle cells: Involvement of an aprotinin sensitive protease

MMP2 and MMP9 are associated with the pathogenesis of recurrent pregnancy loss through protein expression rather than genetic polymorphism

Matrix metalloproteinases (MMPs) degrade extracellular matrix proteins and are important for placenta formation during early pregnancy. Recurrent pregnancy loss (RPL) is associated with abnormalities in endometrial extracellular matrix remodeling. This study aimed to elucidate the roles of MMP2 and MMP9 in RPL pathogenesis. In total, 295 women with a history of RPL and 101 controls were included in this genetic study. Genotype analysis was performed using polymerase chain reaction (PCR) restriction fragment length polymorphisms. For proteolytic analysis, decidua and villi were collected from 10 RPL-miscarried women with normal fetal chromosomes (NC) and 19 women with fetal chromosome aberrations (AC). The expression of MMP2 and MMP9 in the decidua and villi was measured by IHC and ELISA. All samples were collected after obtaining informed consent. There were no statistically significant differences in MMP2-735 C/T and MMP9-1562 C/T frequencies between women with RPL and the controls. There was no significant difference in MMP2 expression levels in the villi; however, MMP9 expression was significantly higher in normal fetal chromosomes. In the decidua, the expression of MMP2 in the NC group was significantly lower, and MMP9 in the NC group was significantly higher than in the AC group. Although no differences in MMP2-735 C/T and MMP9-1562 C/T gene polymorphisms were observed in the present study, it is suggested that differences at the protein level are involved in the pathogenesis of RPL since MMP expression is not only regulated by genes but also by local inflammation and various inductive signals.

Melatonin improves periodontitis-induced kidney damage by decreasing inflammatory stress and apoptosis in rats

BACKGROUND

Two main aims of this animal study were to inspect the possible effects of periodontitis on the structure and functions of the kidneys and the therapeutic effectiveness of melatonin.

METHODS

Twenty-four male Sprague-Dawley rats were randomly divided into three groups: control, experimental periodontitis (Ep), and Ep-melatonin (Ep-Mel). Periodontitis was induced by placing 3.0-silk sutures sub-paramarginally around the cervix of right-left mandibular first molars and maintaining the sutures for 5 weeks. Then melatonin (10 mg/kg body weight/day, 14 days), and the vehicle was administered intraperitonally. Mandibular and kidney tissue samples were obtained following the euthanasia. Periodontal bone loss was measured via histological and microcomputed tomographic slices. On right kidney histopathological and immunohistochemical, and on the left kidney biochemical (malonyl-aldehyde [MDA], glutathione, oxidative stress [OSI], tumor necrosis factor [TNF]-α, interleukin [IL]-1β, matrix metalloproteinase [MMP]-8, MMP-9, and cathepsin D levels) evaluations were performed. Renal functional status was analyzed by levels of serum creatinine, urea, cystatin-C, and urea creatinine.

RESULTS

Melatonin significantly restricted ligature-induced periodontal bone loss (P <0 .01) and suppressed the levels of proinflammatory cytokines (TNF-α and IL-1β), oxidative stress (MDA and OSI), and proteases (MMP-8, MMP-9, and CtD) that was significantly higher in the kidneys of the rats with periodontitis (P <0.05). In addition, periodontitis-related histological damages and apoptotic activity were also significantly lower in the Ep-Mel group (P <0.05). However, the markers of renal function of the Ep group were detected slightly impaired in comparison with the control group (P >0.05); and the therapeutic activity of melatonin was limited (P >0.05).

CONCLUSION

Melatonin restricts the periodontitis-induced inflammatory stress, apoptosis, and structural but not functional impairments.

Local upregulation of interleukin-1 beta in aortic dissecting aneurysm: correlation with matrix metalloproteinase-2, 9 expression and biomechanical decrease

OBJECTIVES

Our goal was to examine whether interleukin-1 beta (IL-1β) originates locally and its possible relationship with matrix metalloproteinases (MMPs), apoptosis, elastin fibres and biomechanics in aortic dissecting aneurysms (DAs).

METHODS

Aortic DAs were induced in 24 rats with β-aminopropionitrile (BAPN); another 12 rats without BAPN were designated as controls. Then IL-1β levels were measured both in the circulation and in local aortic specimens. The expression of MMP-2 and MMP-9 and Victoria blue and TUNEL staining were also detected. Biomechanical parameters such as the elasticity modulus were used to detect the biomechanical changes in the aortic wall. The correlation of IL-1β, MMP-2, MMP-9, apoptosis and biomechanical properties was analysed.

RESULTS

Seventeen rats (17/24, 71%) in the BAPN-treated group died of DA rupture. IL-1β levels were dramatically increased in the DA specimens but not in the circulation. Victoria blue staining confirmed the formation of the DA and the reduction of elastin content after induction by BAPN. The extent of apoptosis in the aortic media was dramatically higher in rats with BAPN-induced DA than that in the control group and that in rats treated with BAPN but without DA. MMP-2 and MMP-9 levels were significantly increased in BAPN-treated rats compared to the controls, but no statistical significance was found between rats with and without DA. There were significant differences in biomechanical parameters, such as the elasticity modulus. Among the 3 groups, IL-1β was positively correlated with MMP-2 and MMP-9 levels and with the elasticity modulus but not with apoptosis.

CONCLUSIONS

Local IL-1β might participate in the formation of aortic DA through the upregulation of MMP-2 and MMP-9 and the breakage of elastin fibres, which finally weakens the biomechanical properties of the aortic wall.

MMP-2 and 9 in Chronic Kidney Disease

Gelatinases are members of the matrix metalloproteinase (MMPs) family; they play an important role in the degradation of the extracellular matrix (ECM). This effect is also crucial in the development and progression of chronic kidney disease (CKD). Its expression, as well as its activity regulation are closely related to the cell signaling pathways, hypoxia and cell membrane structural change. Gelatinases also can affect the development and progression of CKD through the various interactions with tumor necrosis factors (TNFs), monocyte chemoattractant proteins (MCPs), growth factors (GFs), oxidative stress (OS), and so on. Currently, their non-proteolytic function is a hot topic of research, which may also be associated with the progression of CKD. Therefore, with the in-depth understanding about the function of gelatinases, we can have a more specific and accurate understanding of their role in the human body.

Role of Proteases in Lung Disease: A Brief Overview

Proteases play an important role in health and disease of the lung. In the normal lungs, proteases maintain their homeostatic functions that regulate processes like its regeneration and repair. Dysregulation of proteases–antiproteases balance is crucial in the manifestation of different types of lung diseases. Chronic inflammatory lung pathologies are associated with a marked increase in protease activities. Thus, in addition to protease activities, inhibition of anti-proteolytic control mechanisms are also important for effective microbial infection and inflammation in the lung. Herein, we briefly summarize the role of different proteases and to some extent antiproteases in regulating a variety of lung diseases.

Role of PKC-α in NF-κB-MT1-MMP-mediated activation of proMMP-2 by TNF-α in pulmonary artery smooth muscle cells

We sought to evaluate the mechanism(s) associated with pro matrix metalloprotease 2 (proMMP-2) activation in bovine pulmonary artery smooth muscle cells. Preincubation of cells with anti-TNFR1 antibody prevented tumour necrosis factor-α (TNF-α)-induced proMMP-2 activation and increase in membrane type 1 matrix metalloprotease (MT1-MMP) expression as well as inhibition of tissue inhibitor of metalloproteinase 2 (TIMP-2) expression, indicating the role of TNFR1 receptor during TNF-α stimulation. Anti-MT1-MMP antibody abrogated proMMP-2 activation by TNF-α-stimulated cell membrane, suggesting the involvement of MT1-MMP in proMMP-2 activation. Induction of MT1-MMP expression in response to TNF-α occurs via activation of nuclear factor (NF)-κB on inhibitory κB kinase (IKK) activation and subsequently phosphorylation/degradation of IκB-α. Inhibition of protein kinase C (PKC)-α activity by Go6976 and PKC-α siRNA prevented TNF-α-induced IKK activity, IκB-α phosphorylation/degradation and NF-κB activation. Inhibition of PKC-α activity also prevented TNF-α-induced MT1-MMP expression and proMMP-2 activation as well as down regulation of TIMP-2 expression. Inhibition of IκB-α phosphorylation by PS-1145, an IKK selective inhibitor, prevented TNF-α-induced increase in MT1-MMP expression and proMMP-2 activation, which although did not alter inhibition of TIMP-2 expression. Overall, we unravelled a hitherto unknown mechanism of the involvement of PKC-α in proMMP-2 activation and inhibition of TIMP-2 expression by NF-κB-MT1-MMP-dependent and -independent pathway, respectively, during TNF-α stimulation in pulmonary artery smooth muscle cells.