Peran Matriks Metalloproteinase 8 Pada Metastasis Sel Kanker Payudara

MMP-8 merupakan protease yang diproduksi oleh neutrofil dan berperan dalam degradasi kolagen yang terdapat pada jaringan ikat pada mamalia. Pada manusia, protein MMP-8 disandi oleh gen MMP-8. Pada umumnya, MMP disekresi dalam bentuk proprotein yang diaktifkan ketika dipecah oleh proteinase ekstraseluler. Peningkatan Ekspresi MMP-8 berlebih pada penderita kanker payudara di fase yang berbeda, peningkatan ekspresi MMP-8 tidak ditemukan pada sel payudara normal. MMP-8 memiliki substrat yang berbeda dengan MMP-2 dan MMP-9 yang berperan langsung dalam penyebab metastasis sel kanker payudara ke organ lain. Peran MMP-8 terhadap kanker payudara telah dilaporkan oleh penelitian sebelumnya bahwa MMP-8 mampu memicu metastasis kanker payudara melalui peningkatan sitokin proinflamasi yaitu IL-6 dan IL-8. IL-6 dan IL-8 menginduksi metastasis melalui jalur persinyalan JAK/STAT3 yang akan mengaktifkan snail/slug/twist yang akan menekan ekspresi E-cadherin, selain itu IL-6 dan IL-8 memicu sintesis VEGF sehingga mengakibatkan pembentukan pembuluh darah baru. MMP-8 is a protease produced by neutrophils and plays a role in the degradation of collagen found in connective tissue in mammals. In humans, the MMP-8 protein is encoded by the MMP-8 gene. In general, MMPs are secreted in the form of proproteins that are activated when cleaved by extracellular proteinases. MMP-8 Ekspression increased in breast cancer patients at different stages, but it is not happenin normal breast cells. MMP-8 has a different substrate with MMP-2 and MMP-9 which play a direct role in causing breast cancer cell metastasis to other organs. The role of MMP-8 in breast cancer has been reported by previous studies that MMP-8 is able to trigger breast cancer metastasis through an increase in proinflammatory cytokines,such as IL-6 and IL-8. IL-6 and IL-8 induce metastasis through the JAK/STAT3 signaling pathway which will activate snail/slug/twist which will suppress E-cadherin expression, in addition IL-6 and IL-8 trigger VEGF synthesis, resulting in the formation of new blood vessels.

Adamts18 Deficiency Causes Spontaneous SMG Fibrogenesis in Adult Mice

Chronic sclerosing sialadenitis of the submandibular gland (also known as Küttner tumor) is characterized by concomitant swelling of the submandibular glands secondary to strong lymphocytic infiltration and fibrosis. The pathogenesis of this disease has been unclear, but it is associated with immune disorders. ADAMTS18 is a member of the ADAMTS superfamily of extracellular proteinases. In this study, we showed that Adamts18 is highly expressed in submandibular salivary gland (SMG) during embryonic development and decreases but is retained in adult SMG tissue in mice. Adamts18 deficiency led to reduced cleft formation and epithelial branching in embryonic SMG before embryonic day 15.5 in mice. No significant histologic changes in the later stages of branching or the morphology of SMG were detected in Adamts18−/− mice. However, Adamts18 deficiency causes spontaneous SMG fibrogenesis and fibrosis in adult mice. At 8 wk of age, Adamts18−/− mice began to manifest the first signs of pathologic changes of mild fibrosis and CD11b+ cell infiltration in SMG tissues. At ≥8 mo, all male and female Adamts18−/− mice developed unilateral or bilateral SMG scleroma that is similar to patients with chronic sclerosing sialadenitis of the submandibular gland. Adamts18−/− mice also showed secretory dysfunction and severe dental caries. Histologically, SMG scleroma is characterized by progressive periductal fibrosis, acinar atrophy, irregular duct ectasis, and dense infiltration of IgG-positive plasma cells. A significant infiltration of CD4+ T lymphocytes and CD11b+ monocytes and macrophages was also detected in the SMG scleroma of Adamts18−/− mice. The levels of TGF-β1, IL-6, and IL-33 were significantly increased in Adamts18−/− SMGs, which induces chronic inflammation and myofibroblast activation, ultimately leading to fibrosis. This study indicates that Adamts18 regulates the early branching morphogenesis of embryonic SMG and plays a role in protecting from spontaneous SMG fibrogenesis via modulating local inflammation, autoimmune reaction, and myofibroblast activation in adult mice.

β-citronellol alters cell surface properties of Candida albicans to influence pathogenicity related traits

The pathogenicity of Candida albicans, an opportunistic human fungal pathogen, is attributed to several virulence factors. β-citronellol is a monoterpenoid present in several plant essential oils. The present study explores the antifungal potential and mode of action of β-citronellol against C. albicans ATCC 90028 (standard), C. albicans D-27 (FLC-sensitive), and C. albicans S-1 (FLC-resistant). Anti-Candida potential was studied by performing MIC, MFC, growth curves, disc diffusion, spot assay, and WST1 cytotoxic assay. Morphological transition was monitored microscopically in both solid and liquid hyphae inducing media. β-citronellol inhibits yeast to hyphal transition in both liquid and solid hyphae inducing media. It had a significant inhibitory effect on biofilm formation and secretion of extracellular proteinases and phospholipases. We showed that it has an adverse effect on membrane ergosterol levels and modulates expression of related ERG genes. Expression profiles of selected genes associated with C. albicans pathogenicity displayed reduced expression in treated cells. This work suggests that β-citronellol inhibits morphological transition in C. albicans and decreases the secretion of hydrolytic enzymes involved in the early stage of infection as well as modulates the expression of associated genes. Pleiotropic phenotype shown by β-citronellol treated Candida cells suggests various modes of action. Further studies will assess the clinical application of β-citronellol in the treatment of fungal infections.

Defense peptides: recent developments

Defense peptides are small amphipathic molecules that exhibit antimicrobial, antitumor, antiviral, and immunomodulatory properties. This review summarizes current knowledge on the mechanisms of antimicrobial activity of cationic and anionic defense peptides, indicating peptide-based as well as microbial cell-based factors affecting this activity. The peptide-based factors include charge, hydrophibicity, and amphipathicity, whereas the pathogen-based factors are membrane lipid composition, presence of sterols, membrane fluidity, cell wall components, and secreted factors such as extracellular proteinases. Since defense peptides have been considered very promising molecules that could replace conventional antibiotics in the era of drug-resistant pathogens, the issue of microbial resistance to antimicrobial peptides (AMPs) is addressed. Furthermore, selected approaches employed for optimization and de novo design of effective AMPs based on the properties recognized as important for the function of natural defense peptides are presented.