Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs)-Exosome Carrying MiRNA-312 Inhibits Sevoflurane-Induced Cardiomyocyte Apoptosis Through Activation of Phosphatidylinositol 3-Kinase/Protein Kinase B (PI3K/AKT) Pathway

This study was to explore the mechanism by how exosomes (exo) derived from BMSCs affects cardiomyocyte apoptosis. BMSCs were isolated and incubated with cardiomyocytes while the cardiomyocytes were exposed to sevoflurane or DMSO treatment. Apoptotic cells were calculated and level of apoptosis related proteins was detected by Western blot. Through transfection with microRNA-(miRNA)-312 inhibitor, we evaluated the effect of BMSC-exo on the sevoflurane-induced apoptosis. Sevoflurane significantly inhibited the viability of cardiomyocytes and induced cardiomyocyte apoptosis. Besides, sevoflurane decreased the expression of miR-312 and enhanced Bax expression in cardiomyocytes through restraining the phosphorylation of MAPK/ERK. Treatment with BMSC-exo, however, activated MAPK/ERK signaling by up-regulating miR-312, thereby inhibiting cardiomyocyte apoptosis, promoting cardiomyocyte proliferation, and elevating the level of Bcl-2. In conclusion, BMSC-exo-derived miR-312 inhibits sevoflurane-induced cardiomyocyte apoptosis by activating PI3K/AKT signaling pathway.

Robo2 and Gen1 Coregulate Ureteric Budding by Activating the MAPK/ERK Signaling Pathway in Mice

Congenital anomalies of the kidney and urinary tract (CAKUT) are some of the most common developmental defects and have a complicated etiology, indicating an interaction of (epi-) genetic and environmental factors. Single gene mutations and copy number variations (CNVs) do not explain most cases of CAKUT, and simultaneous contributions of more than one gene (di-, oligo-, or polygenic effects; i.e., complex genetics) may lead to the pathogenesis of CAKUT. Robo2 plays a key role in regulating ureteric bud (UB) formation in the embryo, with mutations leading to supernumerary kidneys. Gen1 is a candidate gene associated with CAKUT because of its important role in early metanephric development in mice. We established a mouse model with double disruption of Robo2 and Gen1 using a piggyBac transposon and found that double gene mutation led to significantly increased CAKUT phenotypes in Robo2PB/+Gen1PB/+ mouse offspring, especially a duplicated collecting system. Increased ectopic UB formation was observed in the Robo2PB/+Gen1PB/+ mice during the embryonic period. Robo2 and Gen1 exert synergistic effects on mouse kidney development, promoting cell proliferation by activating the GDNF/RET pathway and downstream MAPK/ERK signaling. Our findings provide a disease model for CAKUT as an oligogenic disorder.

Loss of HAS2 Confers Acquired Antiestrogen Resistance By Upregulating Ezrin Expression In ER-Positive Breast Cancer

Background: Resistance to endocrine therapy is a major challenge for estrogen receptor-positive (ER+) breast cancer patients, but the underlying mechanisms remain unclear. Methods: Loss of hyaluronan synthase 2 (Has2) in adaptive resistant cells to tamoxifen and fulvestrant was observed by immunblotting assay. CRISPR/Cas9 technology was used to knock out Has2 in MCF7 cells to verify the effect of Has2 on the expression of ER and Ezrin and Akt and MAPK/ERK signaling routes. We utilized an Ezrin small-interfering RNA and Ezrin inhibitor to inhibit Ezrin expression for evaluating Has2 and ERα expression and the Akt/MAPK signaling cascade upon tamoxifen or fulvestrant treatment.Results: In this work, we showed that a Has2-loss state was acquired from adaptive resistance to tamoxifen and fulvestrant in luminal BrCas. Notably, the adapted loss of Has2 induced acquired resistance to antiestrogens in estrogen receptor (ER)-positive breast cancer cells through up-regulating the expression of Ezrin. Furthermore, we found that the loss of Has2 promoted while the consequent increase of Ezrin inhibited ERα expression/activity through the Akt and MAPK/ERK signaling routes, indicating an opposite effect on ERα expression during the development of antiestrogens-resistance. Inhibition of Ezrin reversed Has2 and ERα expression and the Akt/MAPK signaling cascade upon tamoxifen or fulvestrant, suggesting a Has2-Ezrin-ER negative-feedback loop in governing cellular sensitivity to tamoxifen or fulvestrant in luminal-like breast cancer cells. Finally, Knockdown or inhibition of Ezrin restored sensitivity to antiestrogens, implying that Ezrin could be a potential therapeutic target to tackle endocrine resistance. Conclusions: Taken together, our findings provide a direct relationship between ERα and Has2 implicated in resistance to endocrine therapy and a new insight into how ERα-signaling is regulated upon antiestrogens treatment, suggesting a novel therapeutic target for ER-positive breast cancer.

Isothiocyanate From Moringa oleifera Seeds Inhibits the Growth and Migration of Renal Cancer Cells by Regulating the PTP1B-dependent Src/Ras/Raf/ERK Signaling Pathway

Moringa oleifera Lam. is a tropical and subtropical plant that has been used for centuries as both food and traditional medicine. 4-[(α-L-Rhamnosyloxy) benzyl] isothiocyanate (MIC-1) is an active substance in M. oleifera, with anti-cancer activity. However, whether MIC-1 exerts anti-renal cancer effects is unknown. Therefore, the aim of the present study was to evaluate the effects of MIC-1 on the growth and migration of renal cell carcinoma (RCC) cells and to identify the putative underlying mechanism. We found that, among 30 types of cancer cells, MIC-1 exerted the strongest growth inhibitory effects against 786-O RCC cells. In addition, MIC-1 (10 μM) significantly inhibited the growth of five RCC cell lines, including 786-O, OSRC-2, 769-P, SK-NEP-1, and ACHN cells, but was not toxic to normal renal (HK2) cells. Also, MIC-1 suppressed 786-O and 769-P cell migration and invasion abilities, and reduced the expression of matrix metalloproteinase (MMP)-2 and MMP-9. Furthermore, MIC-1 induced apoptosis and cell cycle arrest, increased Bax/Bcl-2 ratio, and decreased cell cycle-related protein expression in 786-O cells and 769-P cells. Molecular docking and small-molecule interaction analyses with PTP1B both showed that MIC-1 inhibited PTP1B activity by binding to its active site through hydrogen bonding and hydrophobic interactions. Additionally, MIC-1 could suppress the growth and migration of 786-O cells by inhibiting PTP1B-mediated activation of the Src/Ras/Raf/ERK signaling pathway. In vivo experiments further showed that MIC-1 markedly inhibited the growth of xenograft tumors in mice, and greatly increased Bax/Bcl-2 ratio in tumor tissues. In addition, MIC-1 had no effect on the PTP1B-dependent Src/Ras/Raf/ERK signaling pathway in HCT-116 cells, Hep-G2 cells, and A431 cells. Overall, our data showed that MIC-1 could be a promising, non-toxic, natural dietary supplement for the prevention and treatment of renal cancer.