Zinc-Chelating Compounds as Inhibitors of Human and Bacterial Zinc Metalloproteases

Inhibition of bacterial virulence is believed to be a new treatment option for bacterial infections. In the present study, we tested dipicolylamine (DPA), tripicolylamine (TPA), tris pyridine ethylene diamine (TPED), pyridine and thiophene derivatives as putative inhibitors of the bacterial virulence factors thermolysin (TLN), pseudolysin (PLN) and aureolysin (ALN) and the human zinc metalloproteases, matrix metalloprotease-9 (MMP-9) and matrix metalloprotease-14 (MMP-14). These compounds have nitrogen or sulfur as putative donor atoms for zinc chelation. In general, the compounds showed stronger inhibition of MMP-14 and PLN than of the other enzymes, with Ki values in the lower μM range. Except for DPA, none of the compounds showed significantly stronger inhibition of the virulence factors than of the human zinc metalloproteases. TPA and Zn230 were the only compounds that inhibited all five zinc metalloproteinases with a Ki value in the lower μM range. The thiophene compounds gave weak or no inhibition. Docking indicated that some of the compounds coordinated zinc by one oxygen atom from a hydroxyl or carbonyl group, or by oxygen atoms both from a hydroxyl group and a carbonyl group, and not by pyridine nitrogen as in DPA and TPA.

Articular Cartilage Fragmentation Improves Chondrocyte Migration by Upregulating Membrane Type 1 Matrix Metalloprotease

Objective This study was undertaken to elucidate the mechanism of improved chondrocyte migration after juvenile articular cartilage fragmentation. Design In vitro organ culture with rabbit cartilage fragments and cell culture with rabbit chondrocytes were performed. In part A, minced juvenile cartilage fragments (~0.5 × 0.5 × 0.5 mm) from rabbits, planted in gelatin sponge and fibrin glue, were cultured for 2, 4, or 6 weeks in vitro and compared with the cartilage chunks (~4 × 4 × 1 mm) and membrane type 1 matrix metalloprotease (MT1-MMP) inhibitor groups. Chondrocyte outgrowth was evaluated on histology and confocal laser scanning microscopy. MT1-MMP expression was compared between the cartilage fragment group and the cartilage chunks group. In part B, articular chondrocytes were harvested from juvenile rabbits, MT1-MMP was transfected into the cells, and cell migration was evaluated using the Transwell and wound healing tests. Results The histology and confocal microscopy results revealed that cell accumulation occurred at the edge of cartilage fragments, and outgrowth was better in the cartilage fragment group than those in the cartilage chunks group. Similar results were observed for MT1-MMP expression. After MT1-MMP inhibition, cells did not accumulate at the edge of the cartilage fragments, and chondrocyte outgrowth did not occur. Furthermore, overexpression of MT1-MMP enhanced the migration of articular chondrocytes. Conclusions Juvenile articular cartilage fragmentation improved chondrocyte migration by upregulating MT1-MMP.

The mechanobiological theory: a unifying hypothesis on the pathogenesis of moyamoya disease based on a systematic review

OBJECTIVE Moyamoya angiopathy (MMA) affects the distal internal carotid artery and is designated as moyamoya disease (MMD) when predisposing conditions are absent, or moyamoya syndrome (MMS) when it occurs secondary to other causes. The authors aimed to investigate the reason for this anatomical site predilection of MMA. There is compelling evidence to suggest that MMA is a phenomenon that occurs due to stereotyped mechanobiological processes. Literature regarding MMD and MMS was systematically reviewed to decipher a common pattern relating to the development of MMA. METHODS A systematic review was conducted to understand the pathogenesis of MMA in accordance with PRISMA guidelines. PubMed MEDLINE and Scopus were searched using “moyamoya” and “pathogenesis” as common keywords and specific keywords related to six identified key factors. Additionally, a literature search was performed for MMS using “moyamoya” and “pathogenesis” combined with reported associations. A progressive search of the literature was also performed using the keywords “matrix metalloprotease,” “tissue inhibitor of matrix metalloprotease,” “endothelial cell,” “smooth muscle cell,” “cytokines,” “endothelin,” and “transforming growth factor” to infer the missing links in molecular pathogenesis of MMA. Studies conforming to the inclusion criteria were reviewed. RESULTS The literature search yielded 44 published articles on MMD by using keywords classified under the six key factors, namely arterial tortuosity, vascular angles, wall shear stress, molecular factors, blood rheology/viscosity, and blood vessel wall strength, and 477 published articles on MMS associations. Information obtained from 51 articles that matched the inclusion criteria and additional information derived from the progressive search mentioned above were used to connect the key factors to derive a network pattern of pathogenesis. CONCLUSIONS Based on the available literature, the authors have proposed a unifying theory for the pathogenesis of MMA. The moyamoya phenomenon appears to be the culmination of an interplay of vascular anatomy, hemodynamics, rheology, blood vessel wall strength, and a plethora of intricately linked mechanobiological molecular mediators that ultimately results in the mechanical process of occlusion of the blood vessel, stimulating angiogenesis and collateral blood supply in an attempt to perfuse the compromised brain.

PTCSC1 Promotes Bladder Cancer Progression by AKT Pathway

In bladder cancer the expression of PTCSC1is elevated, but how PTCSC1influencetumor progression are still unclear. We found that in human bladder cancer PTCSC1 is upregulated. The study showedthat the expression level of PTCSC1 is higher in bladder cancer tissuesthan that of PTCSC1 in para-carcinoma tissue. Furthermore, PTCSC1promoted bladder cancer cell migration and invasion, and decreased expression of PTCSC1 inhibited the expression of matrix metalloprotease MMP2and MMP9, and increased the expression level of E-cadherin. PTCSC1 promoted tumor growth in a mouse model of human bladder cancer. Additionally,PTCSC1 shRNA caused a significant decrease in p-AKTexpression in T24 cells and BIU-87 cells, but the overexpression ofPTCSC1got an opposite result.Allthe results showed that PTCSC1 can influencebladder cancer cellmigration and invasion ability by the AKT pathways. PTCSC1 may be an effective therapeutic target in bladder cancer.

Wound-healing effect of Platycodon grandiflorus (Jacq.) extract in rats

Purpose: To evaluate the healing effect of Platycodon grandiflorus (Jacq.). extract (PGE) on experimental burn wounds in rats. Methods: Rats were randomly divided into four groups of eight rats each: control group, silver sulfadiazine (SSD)-treated group, moist exposed burn ointment (MEBO)-treated group and PGE-treated group. PGE, SSD and MEBO were applied topically twice daily for 7 days. SSD and MEBO were used as reference control. External observation of wound area contraction and histological analysis of wound tissues was performed respectively. The effect of PGE on matrix metalloproteases (MMPs), vascular endothelial growth factor (VEGF) and Type-III Collagen proteins of wound tissue in rats were analysed by Western blot. Results: After 10 days of topical treatment with PGE, PGE-treated group showed faster reduction in wound area when compared with control groups (p < 0.01). Matrix metalloprotease-2 (MMP-2), matrix metalloprotease-9 (MMP-9), VEGF and type-III collagen expressions in the wound tissue increased significantly (p < 0.05) when compared with the control burn wounds. Histological results showed an overall early recovery and regeneration in PGE-treated group when compared with control group. Conclusion: PGE possesses a significant wound-healing activity in full-thickness burn wounds in rats. Therefore, it can potentially be developed for the management of burns.

Constituents of Aquilaria sinensis Leaves Upregulate the Expression of Matrix Metalloproteases 2 and 9

In this novel study, we isolated 28 compounds from the leaves of Aquilaria sinensis (Lour.) Gilg based on a bioassay-guided procedure and also discovered the possible matrix metalloprotease 2 (MMP-2) and 9 (MMP-9) modulatory effect of pheophorbide A (PA). To evaluate the regulatory activity on MMP-2 and MMP-9, the HT-1080 human fibrosarcoma cells were treated with various concentrations of extracted materials and isolated compounds. PA was extracted by methanol from the leaves of A. sinensis and separated from the fraction of the partitioned ethyl acetate layer. PA is believed to be an active component for MMP expression since it exhibited significant stimulation on MMP-2 and proMMP-9 activity. When treating with 50 μM of PA, the expression of MMP-2 and MMP-9 were increased 1.9-fold and 2.3-fold, respectively. PA also exhibited no cytotoxicity against HT-1080 cells when the cell viability was monitored. Furthermore, no significant MMP activity was observed when five PA analogues were evaluated. This study is the first to demonstrate that C-17 of PA is the deciding factor in determining the bioactivity of the compound. The MMP-2 and proMMP-9 modulatory activity of PA indicate its potential applications for reducing scar formation and comparative medical purposes.

Targeted apoptosis of macrophages and osteoclasts in arthritic joints is effective against advanced inflammatory arthritis

Insufficient apoptosis of inflammatory macrophages and osteoclasts (OCs) in rheumatoid arthritis (RA) joints contributes toward the persistent progression of joint inflammation and destruction. Here, we deliver celastrol (CEL) to selectively induce apoptosis of OCs and macrophages in arthritic joints, with enzyme-responsive nanoparticles (termed PRNPs) composed of RGD modified nanoparticles (termed RNPs) covered with cleavable PEG chains. CEL-loaded PRNPs (CEL-PRNPs) dually target OCs and inflammatory macrophages derived from patients with RA via an RGD-αvβ3 integrin interaction after PEG cleavage by matrix metalloprotease 9, leading to increased apoptosis of these cells. In an adjuvant-induced arthritis rat model, PRNPs have an arthritic joint-specific distribution and CEL-PRNPs efficiently reduce the number of OCs and inflammatory macrophages within these joints. Additionally, rats with advanced arthritis go into inflammatory remission with bone erosion repair and negligible side effects after CEL-PRNPs treatment. These findings indicate potential for targeting chemotherapy-induced apoptosis in the treatment of advanced inflammatory arthritis.

Deficiency of MMP1a (Matrix Metalloprotease 1a) Collagenase Suppresses Development of Atherosclerosis in Mice

Objective: Destruction of arterial collagen allows monocyte and macrophage infiltration leading to atherosclerotic plaque formation, but it is not clear what role the MMP1 (matrix metalloprotease 1) collagenase plays in this process in vivo. To define the specific contribution of MMP1 to atherosclerotic plaque burden and pathogenesis, we generated ApoE −/− mice deficient in the human MMP1 ortholog, MMP1a. Approach and Results: After 12 to 16 weeks of Western diet, genetic loss of MMP1a resulted in a significant 50% reduction in total aortic plaque burden compared with control ApoE −/− mice. MMP1a deficiency led to significant reductions in plaque monocytes/macrophages, SMCs, and necrosis, with increases in collagen content. Collagen invasion of oxidized-LDL (low-density lipoprotein) activated peripheral blood mononuclear cells from MMP1a-deficient mice was markedly attenuated and was similar to suppressive effects with pharmacological inhibitors of MMP1 and its receptor, PAR1 (protease-activated receptor 1). Patients with coronary artery disease and acute coronary syndrome undergoing cardiac catheterization in the TRIP-PCI trial were evaluated for circulating levels of all 3 major secreted collagenases, MMP1, MMP8, and MMP13 and total number of coronary lesions with ≥50% stenosis (coronary artery disease burden). MMP1 was significantly ( P <0.001) higher by 19-fold and 5.7-fold relative to MMP13 and MMP8, respectively. MMP1 correlated with stenotic coronary artery disease burden, TNFα (tumor necrosis factor alpha) levels, and was co-expressed with PAR1 on monocytes. Treatment of patients with the PAR1 inhibitor, PZ-128, prevented a drop in monocytes following coronary catheterization, an acute protective effect that was reproduced in mice undergoing cardiac ischemia reperfusion. Conclusions: These data provide evidence for an important role for the MMP1a collagenase in atherosclerotic lesion development and leukocyte behavior and validate MMP1 as a compelling target in patients with coronary artery disease/acute coronary syndrome. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02561000.