The trypsin inhibitor pro-peptide induces toxic effects in Indianmeal moth, Plodia interpunctella.

The inhibitory potential of an inhibitor peptide based on the pro-region of trypsin zymogen was investigated in Indianmeal moth, P. interpunctella, which is a world-wide insect pest of stored food. Five peptides were designed based on molecular docking simulations. The designed peptide with the best score was selected and synthesized for further screening in vitro and in vivo. The peptide was characterized and its inhibitory effects towards the insect trypsin were evaluated and the kinetic analysis revealed a competitive type of inhibition against the target enzyme. The results showed that the peptide could successfully suppress the pest midgut trypsin, and more interestingly, it did not show considerable inhibitory effects on a mammalian trypsin. We also aimed to assess the effect of dietary insect meal treated with different concentrations of the peptide and observed a significant growth and development retardation in pupa and adult insects fed with the inhibitor peptide. The outcomes of the present study suggest an efficient inhibitor peptide that could specifically bind the P. interpunctella trypsin and inhibit its activity, which would be safe against human being health and environment. Notably, this is the first report on in vivo assessment of the direct effect of a pro-region as the specific inhibitor in development as well as survival of the pest insect. Furthermore, our findings could be a promising for future designed pesticides used in pest management.

Reversible permeabilization of the mitochondrial membrane promotes human cardiomyocyte differentiation from embryonic stem cells.

Cell death and differentiation appear to share similar cellular features. In this study, we aimed to investigate whether differentiation and mitochondrial cell death use a common pathway. We assessed the hallmarks of apoptosis during cardiomyocyte differentiation of human embryonic stem cells and found remarkable changes in P53, reactive oxygen species, apoptotic protease-activating factor 1, poly[ADP-ribose]polymerase 1, cellular adenosine triphosphate, and mitochondrial complex I activity. Furthermore, we observed reversible mitochondrial membrane permeabilization during cardiomyocyte differentiation accompanied by reversible loss of mitochondrial membrane potential, and these changes coincided with the fluctuating patterns of cytosolic cytochrome c accumulation and subsequent caspase-9 and -3/7 activation. Moreover, the use of apoptosis inhibitors (BCL2-associated X protein [BAX] inhibitor and caspase-3/7 inhibitor) during differentiation impaired cardiomyocyte development, resulting in substantial downregulation of T, MESP1, NKX2.5, and α-MHC. Additionally, although the expression of specific differentiation markers (T, MESP1, NKX2.5, MEF2C, GATA4, and SOX17) was enhanced in doxorubicin-induced human embryonic stem cells, the stemness-specific markers (OCT4 and NANOG) showed significant downregulation. With increasing doxorubicin concentration (0.03-0.6 µM; IC50 = 0.5 µM), we observed a marked increase in the expression of mesoderm and endoderm markers. In summary, we suggest that reversible mitochondrial outer membrane permeabilization promotes cardiomyocyte differentiation through an attenuated mitochondria-mediated apoptosis-like pathway.

Evaluation of the cytotoxic, apoptosis inducing activity and molecular docking of spiroquinazolinone benzamide derivatives in MCF-7 breast cancer cells.

Previous studies have suggested that quinazolinone derivatives are potent apoptosis-inducing agents in various cancer cell lines. In the present study, we have investigated cytotoxic, apoptosis induction, and molecular docking activities of the spiroquinazolinone benzamide derivatives family on MCF-7 human breast cancer cells. The MTT cytotoxicity assays and docking studies showed that 4t-CHQB was the most active compound among the prepared spiroquinazolinone benzamide compounds with IC50 of 50 ± 1.2 µM and was selected for further assessments. Apoptosis, as the mechanism of cell death, was assessed morphologically by acridine orange/ethidium bromide (AO/EtBr) double staining, evaluation of the cell surface phosphatidylserine (PS) expression through annexin V/PI technique and, the formation of DNA ladder. Down regulation of survivin was evaluated in protein level after cell treatment with 4t-CHQB using western blotting method. Molecular modeling experiments involving 4t-CHQB binding site of survivin showed several strong hydrogen bonds and hydrophobic interactions between many important amino acid residues. Overall, the obtained data suggest that the assessed spiroquinazolinone benzamide compounds may provide a novel therapeutic approach for further evaluation, as an effective chemotherapeutic family acting through down regulation of survivin and apoptosis induction in breast cancer.

Inhibition of cell proliferation and induction of apoptosis in K562 human leukemia cells by the derivative (3-NpC) from dihydro-pyranochromenes family.

Leukemia is a particular type of cancer characterized by the failure of cell death or disability in differentiation of hematopoietic cells. Chronic myelogenus leukemia (CML) is the most studied kind of this cancer. In this study, anti-cancer effect of dihydro-pyranochromenes derivatives were investigated in the human leukemia K562 cells. These compounds were found to be active cell proliferation inhibitors using MTT assay. Among these compounds, 3-NpC was determined as stronger compound with IC50 value of 100 ± 3.1 µM and was chosen for further studies. Induction of apoptosis was analyzed by AO/EtBr staining, DNA fragmentation assay, Annexin V/PI double staining and cell cycle analysis. Furthermore, Western Blot analysis showed that treatment of the cells with 3-NpC led to up-regulation and activation of caspase-3. The results of this investigation clearly indicated that dihydro-pyranochromenes derivatives induce apoptosis in the K562 cell line. This information signalizes also that these compounds may prepare a new therapeutic approach for the treatment of leukemia.