Heme oxygenase 1 regulates apoptosis induced by heat stress in bovine ovarian granulosa cells via the ERK1/2 pathway

Heat stress can inhibit follicular development in dairy cows, and thus can affect their reproductive performance. Follicular granulosa cells can synthesize estrogen, that affects the development and differentiation of follicles by apoptosis. Heme oxygenase 1 (HO-1/heat shock protein 32) plays an antiapoptotic and cytoprotective role in various cells during stress-induced apoptosis, but little is known about its definitive function in bovine (ovarian) granulosa cells (bGCs). In our study, the roles and mechanism of HO-1 on the heat stress-induced apoptosis of bGCs were studied. Our results show that the expression of HO-1 was significantly increased under heat stress. Moreover, HO-1 silencing increased apoptosis, whereas its overexpression dampened apoptosis by regulating the expression of Bax/Bcl-2 and the levels of cleaved caspase-3. In addition, HO-1 can also play a cytoprotective role by affecting estrogen levels and decomposing heme to produce biologically active metabolite carbon monoxide (CO). Meanwhile, CO significantly increased the level of HO-1, decreased Bax/Bcl-2 levels, and inhibited the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. The apoptosis of ovarian GCs can affect the secretion of estrogen and lead to disorder of the ovarian microenvironment, thus affecting the normal function of the ovary. Our results indicate that HO-1 acts as a cytoprotective enzyme and plays a protective role in heat-induced apoptosis of bGCs. In conclusion, HO-1 and its metabolite CO inhibit the apoptosis of bGCs induced by heat stress through the ERK1/2 pathway. The results of this study provide a valuable clue for improving the fertility of heat stressed cows in summer.     

Uric acid induced epithelial−mesenchymal transition of renal tubular cells through PI3K/p-Akt signaling pathway

The phenotypic changes of tubular epithelial cell are hallmark features of renal diseases caused by abnormal uric acid levels. We hereby intend to investigate whether PI3K/p-Akt signaling plays a role in uric-acid induced epithelial−mesenchymal transition process. The normal rat kidney cell line (NRK-52E) was used as a proximal tubular cell model in this study. NRK-52E cells were exposed to different concentrations of uric acid, or PI3K inhibitor LY294002, or both, respectively. The effects of uric acid on cell morphology were examined by phase contrast microscopy, while molecular alternations were assessed by western blot analysis and immunofluorescence staining. We found that uric acid induced visible morphological alterations in NRK-52E cells accompanied by increased expression of α-smooth muscle actin and reduced expression of E-cadherin. Moreover, phosphorylation of Akt protein was obviously increased, whereas Akt level remained stable. Furthermore, the above effects were abolished when PI3K/p-Akt pathway was blocked by the PI3K inhibitor. These findings demonstrated that high uric acid could induce phenotypic transition of cultured renal tubular cells, which was probably via activating PI3K/p-Akt signaling pathway.     

Allosteric Inhibition as a New Mode of Action for BAY 1213790, a Neutralizing Antibody Targeting the Activated Form of Coagulation Factor XI

Factor XI (FXI), the zymogen of activated FXI (FXIa), is an attractive target for novel anticoagulants because FXI inhibition offers the potential to reduce thrombosis risk while minimizing the risk of bleeding. BAY 1213790, a novel anti-FXIa antibody, was generated using phage display technology. Crystal structure analysis of the FXIa–BAY 1213790 complex demonstrated that the tyrosine-rich complementarity-determining region 3 loop of the heavy chain of BAY 1213790 penetrated deepest into the FXIa binding epitope, forming a network of favorable interactions including a direct hydrogen bond from Tyr102 to the Gln451 sidechain (2.9 Å). The newly discovered binding epitope caused a structural rearrangement of the FXIa active site, revealing a novel allosteric mechanism of FXIa inhibition by BAY 1213790. BAY 1213790 specifically inhibited FXIa with a binding affinity of 2.4 nM, and in human plasma, prolonged activated partial thromboplastin time and inhibited thrombin generation in a concentration-dependent manner.     

Discovery of certain benzyl/phenethyl thiazolidinone-indole hybrids as potential anti-proliferative agents: Synthesis,molecular modeling and tubulin polymerization inhibition study

A series of certain benzyl/phenethyl thiazolidinone-indole hybrids were synthesized for the study of anti-proliferative activity against A549, NCI-H460 (lung cancer), MDA-MB-231 (breast cancer), HCT-29 and HCT-15 (colon cancer) cell lines by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). We found that compound G37 displayed highest cytotoxicity with IC₅₀ value of 0.92 ± 0.12 µM towards HCT-15 cancer cell line among all the synthesized compounds. Moreover, compound G37 was also tested on normal human lung epithelial cells (L132) and was found to be safe in contrast to HCT-15 cells. The lead compound G37 showed significant G2/M phase arrest in HCT-15 cells. Additionally, compound G37 significantly inhibited tubulin polymerization with IC₅₀ value of 2.92 ± 0.23 µM. Mechanistic studies such as acridine orange/ethidium bromide (AO/EB) dual staining, DAPI nuclear staining, annexinV/propidium iodide dual staining, clonogenic growth inhibition assays inferred that compound G37 induced apoptotic cell death in HCT-15 cells. Moreover, loss of mitochondrial membrane potential with elevated intracellular ROS levels was observed by compound G37. These compounds bind at the active pocket of the α/β-tubulin with higher number of stable hydrogen bonds, hydrophobic and arene-cation interactions confirmed by molecular modeling studies.     

Rational design of some substituted phenyl azanediyl (bis) methylene phosphonic acid derivatives as potential anticancer agents and imaging probes: Computational inputs,chemical synthesis,radiolabeling, biodistribution and gamma scintigraphy

Bisphosphonates are widely used for treatment of osteoporosis. Recently, they have been reported to be effective anticancer agents. In this work, we designed some substituted phenyl (azanediyl) bis (methylene phosphonic acid) to be tested for their anticancer effect. Both molecular docking and dynamics studies were used to select the top ranked highly scored compounds. The selected hits showed potential in vitro anticancer effect against some cell lines. Biodistribution pattern and gamma scintigraphy were conducted to the most effective derivative (BMBP) after radiolabeling with ^99mTc. Results of biodistribution and scintigraphic imaging of ^99mTc-BMBP in tumor bearing mice showed a notable tumor affinity, and confirmed the targeting affinity of BMBP to the tumor tissues. As a conclusion, BMBP could act as potential anticancer agent and imaging probe.