Objective: To investigate the process by which quercetin suppresses atherosclerosis by upregulating MST1-mediated autophagy in RAW264.7 macrophages. Methods: An in vitro foam cell model was established by culturing RAW264.7 macrophages with oxidized low-density lipoprotein (ox-LDL). The cells were treated with quercetin alone or in combination with the autophagy inhibitor, 3-methyladenine, and autophagy agonist, rapamycin. Cell viability was detected with a CCK-8 kit. Lipid accumulation was detected by oil red O staining, senescence was detected by SA-β-gal (senescence-associated β-galactosidase) staining, reactive oxygen species were detected by ROS assay kit. Autophagosomes and mitochondria were detected by transmission electron microscope (TEM), and expression of MST1, LC3-II/I, Beclin1, Bcl-2, P21, and P16 were detected by immunofluorescence and Western blot. Results: Ox-LDL induced RAW264.7 macrophage-derived foam cell formation, reduced survival, aggravated cell lipid accumulation, and induced a senescence phenotype. This was accompanied by decreased formation of autophagosome; increased expression of P53, P21, and P16; and decreased expression of LC3-II/I and Beclin1. After intervention with quercetin, the cell survival rate was increased, and lipid accumulation and senescence phenotype were reduced. Furthermore, the expression of LC3-II/I and Beclin1 were increased, which was consistent with the ability of quercetin to promote autophagy. Ox-LDL also increased the expression of MST1, and this increase was blocked by quercetin, which provided a potential mechanism by which quercetin may protect foam cells against age-related detrimental effects. Conclusion: Quercetin can inhibit the formation of foam cells induced by ox-LDL and delay senescence. The mechanism may be related to the regulation of MST1-mediated autophagy of RAW264.7 cells.

The incidence of premature ovarian failure (POF), also known as ovarian insufficiency, has been increasing in recent years. Although some treatments are currently available, improved treatment strategies are urgently required. Many researchers have reported that human endometrial stem cells (HuMenSCs), which exhibit stem/progenitor cell properties in vitro repaired damaged cells in vivo. Thus, we aimed to determine whether HuMenSCs can serve as cell therapy tools and be used for the treatment of POF. After treating with cyclophosphamide, on the first estrus period (we predicted mouse estrus cycle was generally 5 days), HuMenSCs were injected into a cyclophosphamide-induced mouse model of POF. The results revealed that the HuMenSCs could survive within POF mouse ovaries for at least 14 days in vivo; further, ovaries of the HuMenSCs-transplanted group expressed higher levels of ovarian markers [AMH, inhibin α/β, and follicle-stimulating hormone receptor (FSHR)], and the proliferative marker Ki67. In addition, the ovarian weight, plasma E ₂ level, and the number of normal follicles increased over time in the HuMenSC group compared with the control group. Further, microarray analysis of cDNA expression patterns revealed that, after HuMenSC transplantation, the gene mRNA expression patterns in the ovarian cells following stimulation of the host ovarian niche became increasingly similar to those observed in human ovarian tissue compared with the pretransplantation mRNA expression pattern in HuMenSCs. Hence, we can safely conclude that the mesenchymal stem cell properties and in vivo survival of HuMenSCs make them ideal seed cells for stem cell transplantation in the treatment of POF.

Although large numbers of long noncoding RNAs (lncRNAs) expressed in the mammalian nervous system have been detected, their functions and mechanisms of regulation remain to be fully clarified. It has been reported that the lncRNA antisense transcript for β‑secretase‑1 (BACE1‑AS) is elevated in Alzheimer's disease (AD) and drives the rapid feed‑forward regulation of β‑secretase, suggesting that it is critical in AD development. In the present study, the senile plaque (SP) AD SH‑SY5Y cell model was established using the synthetic amyloid β‑protein (Aβ) 1‑42 in vitro. Using this model, the potential of siRNA‑mediated silencing of lncRNA BACE1‑AS expression to attenuate the ability of β‑secretase‑1 (BACE1) to cleave amyloid precursor protein (APP) and to reduce the production of Aβ1‑42 oligomers was investigated. MTT assays demonstrated that exogenous Aβ1‑42 suppressed SH‑SY5Y cell proliferation and induced APP‑related factor expression and SP formation. Furthermore, quantitative polymerase chain reaction and western blot analysis revealed that the mRNA and protein expression of Aβ1‑42 and Aβ1‑40 was significantly increased in the AD model group, with a marked decrease in Ki‑67 expression at day six. RNase protection assays (RPA) and northern blotting analysis confirmed that exogenous Aβ1‑42 not only promoted the expression of the APP‑cleaving enzyme BACE1, but also induced lncRNA BACE1‑AS expression. Furthermore, lncRNA BACE1‑AS formed RNA duplexes and increased the stability of BACE1 mRNA. Downregulation of lncRNA BACE1‑AS expression in SH‑SY5Y cells by siRNA silencing resulted in the attenuation of the ability of BACE1 to cleave APP and delayed the induction of SP formation in the SP AD SH‑SY5Y cell model.

Premature ovarian failure (POF) is a common cause of female infertility, for which there are currently no ideal treatments or medications. Furthermore, apoptosis of ovarian granulosa cells (OGCs) is an important mechanism underlying the decline in ovarian reserve and function. In the present study, several cellular growth factors and hormones were used to induce the differentiation of human induced pluripotent stem cells (iPSCs) into ovarian granulosa‑like cells (OGLCs) in vitro. Immunohistochemical staining demonstrated that OGLCs derived from iPSCs strongly expressed granulosa cell markers, including anti‑Müllerian hormone, inhibin α, inhibin β and follicle‑stimulating hormone receptor, but did not express stem cell markers, including octamer‑binding transcription factor 4, SRY (sex determining region Y)-box 2, Nanog and stage-specific embryonic antigen-4 12 days post‑induction. In addition, a mouse model of POF was generated by cyclophosphamide treatment. Subsequently, iPSC‑derived OGLCs were transplanted into the POF mice (OGLCs‑iPSCs‑POF group) in vivo. Results indicated that, compared with the control group (POF mice treated with phosphate‑buffered saline), the growth state of OGLCs was markedly improved, and mature follicles could be detected in the ovarian tissue of the OGLCs‑iPSCs‑POF group. Immunohistochemical staining demonstrated that iPSC‑derived OGLCs transplanted into POF mice not only exhibited substantial growth in murine ovarian tissues, but also strongly expressed OGC markers. Furthermore, enzyme‑linked immunosorbent assays indicated that the levels of the hormone estradiol in peripheral blood samples were significantly enhanced following transplantation of iPSC‑derived OGLCs into POF mice. Furthermore, ovarian tissue weight was significantly higher in the OGLCs‑iPSCs‑POF group compared with in the control group, and the number of atretic follicles in OGLCs‑iPSCs‑POF mice was significantly reduced, as compared with in the control mice. These results suggest that OGLCs derived from human iPSCs may not only effectively enhance OGC growth and repair damaged ovarian tissue, but may also maintain the ovarian tissue niche, promoting follicular development and maturation in a mouse model of POF.