Discerning the mechanism of action of HtrA4: a serine protease implicated in the cell death pathway

High-temperature requirement protease A4 (HtrA4) is a secretary serine protease whose expression is up-regulated in pre-eclampsia (PE) and hence is a possible biomarker of PE. It has also been altered in cancers such as glioblastoma, breast carcinoma, and prostate cancer making it an emerging therapeutic target. Among the human HtrAs, HtrA4 is the least characterized protease pertaining to both structure and its functions. Although the members of human HtrA family share a significant structural and functional conservation, subtle structural changes have been associated with certain distinct functional requirements. Therefore, intricate dissection of HtrA4 structural and functional properties becomes imperative to understand its role in various biological and pathophysiological processes. Here, using inter-disciplinary approaches including in silico, biochemical and biophysical studies, we have done a domain-wise dissection of HtrA4 to delineate the roles of the domains in regulating oligomerization, stability, protease activity, and specificity. Our findings distinctly demonstrate the importance of the N-terminal region in oligomerization, stability and hence the formation of a functional enzyme. In silico structural comparison of HtrA4 with other human HtrAs, enzymology studies and cleavage assays with X-linked inhibitor of apoptosis protein (XIAP) show overall structural conservation and allosteric mode of protease activation, which suggest functional redundancy within this...
Source: Biochemical Journal - Category: Biochemistry Authors: Tags: Research Articles Source Type: research

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Conclusions: The constantly increasing prevalence of NAFLD in the general population can contribute to a growing role of NAFLD/NASH in HCC epidemiology. Moreover, some particular challenges specific for patients with liver steatosis may impede proper HCC diagnosis, treatment and follow-up. PMID: 31631714 [PubMed - as supplied by publisher]
Source: Current Medical Research and Opinion - Category: Research Tags: Curr Med Res Opin Source Type: research
Source: St. Michael's Hospital News and Media - Category: Hospital Management Tags: Hospital News Source Type: news
Conclusions: SIF + XRT caused changes in patterns of endothelial cell death and survival, proinflammatory molecule release, and adhesion molecule expression at early time points post-XRT associated with early reduction of immune cell recruitment. These findings suggest that SIF could mediate its radioprotective effects in irradiated lungs by limiting excessive immune cell homing via vascular endothelium into damaged lung tissue and curtailing the overall inflammatory response to radiation. PMID: 31633433 [PubMed - as supplied by publisher]
Source: International Journal of Radiation Biology - Category: Radiology Tags: Int J Radiat Biol Source Type: research
This study aimed to evaluate immunohistochemical expression of cyclin D1 and PSA in breast carcinoma and their relation to prognosis. It includes 79 specimens of breast invasive duct carcinoma. Overall survival time was available for all patients. There is a statistically significant association between positive PSA expression and lower tumor stage, nodal stage and tumor grade and between negative PSA expression and presence of metastasis (P value = .05, 0.01, 0.03 and 0.011, respectively). There is a highly statistically significant association between low percentage of cyclin D1 expression (
Source: Journal of Immunoassay and Immunochemistry - Category: Biochemistry Tags: J Immunoassay Immunochem Source Type: research
Altered miRNA expression participates in the biological progress of thyroid carcinoma and functions as a diagnostic marker or therapeutic agent. However, the role of miR-7-2-3p is currently unclear. The authors' study was the first investigation of miR-7-2-3p expression level and diagnostic ability in several public databases. Potential target genes were obtained from DIANA Tools, and function enrichment analysis was then performed. Furthermore, the authors examined expression levels of potential targets in the Human Protein Atlas (HPA) and the Cancer Genome Atlas (TCGA). Finally, the potential transcription factors (TFs) ...
Source: IET Systems Biology - Category: Biology Source Type: research
This study shows the prediction power of association rule mining algorithm over the traditional classifier model without choosing a negative data set. The time complexity of the biclustering-based association rule mining is also analysed and compared to traditional association rule mining. The authors are able to discover 38 new PPIs which are not present in the cancer database. The biological relevance of these newly predicted interactions is analysed by published literature. Recognition of such interactions may accelerate a way of developing new drugs to prevent different cancer-related diseases.
Source: IET Systems Biology - Category: Biology Source Type: research
In humans, oxidative stress is involved in the development of diabetes, cancer, hypertension, Alzheimers' disease, and heart failure. One of the mechanisms in the cellular defence against oxidative stress is the activation of the Nrf2-antioxidant response element (ARE) signalling pathway. Computation of activity, efficacy, and potency score of ARE signalling pathway and to propose a multi-level prediction scheme for the same is the main aim of the study as it contributes in a big amount to the improvement of oxidative stress in humans. Applying the process of knowledge discovery from data, required knowledge is gathered an...
Source: IET Systems Biology - Category: Biology Source Type: research
This study develops an integrated model of the p53-Mdm2 interaction composed of five basic components and time delay in the DNA damage response based on the existing research work. Some critical factors, including time delay, system parameters, and their interactions in the p53-Mdm2 system are investigated to examine their effects on the oscillatory behaviour induced by Hopf bifurcation. It is shown that the positive feedback formed between p53 and the activity of Mdm2 in the cytoplasm can cause a slight decrease in the amplitude of the p53 oscillation. The length of the time delay plays an important role in determining th...
Source: IET Systems Biology - Category: Biology Source Type: research
Tumor-associated macrophages (TAMs) usually display an antiinflammatory M2-like phenotype to facilitate tumor growth. However, what drives M2 polarization of TAMs and how TAMs suppress antitumor immunity within the tumor microenvironment (TME) remain largely undefined. Using several murine tumor models, we showed that hedgehog (Hh) signaling in myeloid cells is critical for TAM M2 polarization and tumor growth. We also found that tumor cells secrete sonic hedgehog (SHH), an Hh ligand, and that tumor-derived SHH drives TAM M2 polarization. Furthermore, Hh-induced functional polarization in TAMs suppresses CD8+ T cell recrui...
Source: Journal of Clinical Investigation - Category: Biomedical Science Authors: Source Type: research
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Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
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