Downregulation of gene expression and activity of GRIM-19 affects mouse oocyte viability, maturation, embryo development and implantation

GRIM19 deficiency aggravates metabolic disorder and ovarian dysfunction in PCOS

CONTEXT

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women. Retinoid-interferon-induced mortality 19 (GRIM19) is a functional component of mitochondrial complex I that plays a role in cellular energy metabolism. However, the role of GRIM19 in the pathogenesis of PCOS is still unclear.

OBJECTIVE

To investigate the role of GRIM19 in the pathogenesis of PCOS.

DESIGN

We first measured the expression of GRIM19 in human granulosa cells (hGCs) from patients with and without PCOS (n = 16 per group), and then established a PCOS mouse model with WT and Grim19+/- mice for in vivo experiments. Glucose uptake-related genes RAC1 and GLUT4 and energy metabolism levels in KGN cells were examined in vitro by knocking down GRIM19 in the cell lines. Additionally, ovulation-related genes such as p-ERK1/2, HAS2, and PTX3 were also studied to determine their expression levels.

RESULTS

GRIM19 expression was reduced in hGCs of PCOS patients, which was negatively correlated with BMI and serum testosterone level. Grim19+/- mice with PCOS exhibited a markedly anovulatory phenotype and disturbed glycolipid metabolism. In vitro experiments, GRIM19 deficiency inhibited the RAC1/GLUT4 pathway, reducing insulin-stimulated glucose uptake in KGN cells. Moreover, GRIM19 deficiency induced mitochondrial dysfunction, defective glucose metabolism, and apoptosis. In addition, GRIM19 deficiency suppressed the expression of ovulation-related genes in KGN cells, which was regulated by dihydrotestosterone mediated androgen receptor.

CONCLUSIONS

GRIM19 deficiency may mediate ovulation and glucose metabolism disorders in PCOS patients. Our results suggest that GRIM19 may be a new target for diagnosis and treatment.

Heterogeneity of GRIM-19 Expression in the Adult Mouse Brain

Gene associated with retinoid-interferon-induced mortality-19 (GRIM-19) is a subunit of the mitochondrial respiratory chain complex I that has a significant effect on ATP production. The brain is particularly susceptible to ATP deficiency due to its limited energy storage capability and its high rate of oxygen consumption. Thus, GRIM-19 might be involved in regulating ATP level in the brain or cell death caused by several neurological disorders. To understand the physiological and pathophysiological roles of GRIM-19 in the brain, a thorough investigation of the neuroanatomic distribution of GRIM-19 in the normal brain is necessary. Therefore, the present study examined the distribution patterns of GRIM-19 in the adult C57BL/6 mouse brain using immunohistochemistry and identified cell types expressing GRIM-19 using double immunofluorescence staining. We found that GRIM-19 was ubiquitously but not homogenously expressed throughout the brain. GRIM-19 immunoreactivity was predominantly observed in neurons, but not in astrocytes, microglia, or oligodendrocytes under normal physiological conditions. Following transient global cerebral ischemia, GRIM-19-positive immunoreactivity was, however, observed in neurons as well as glial cells including astrocytes in the hippocampus. Furthermore, GRIM-19 was weakly expressed in the hippocampal subgranular zone, in which neural stem and progenitor cells are abundant, but highly expressed in the immature and mature neuronal cells in the granular cell layer of the normal brain, suggesting an inverse correlation between expression of GRIM-19 and stemness activity. Collectively, our study demonstrating widespread and differential distribution of GRIM-19 in the adult mouse brain contributes to investigating the functional and pathophysiological roles of this protein.

Grim-19 expressed by recombinant adenovirus for esophageal neoplasm target therapy

Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EA) are the two most common types of esophageal cancer, which is the sixth highest cause of cancer‑associated mortality and the eighth most common cancer worldwide. Gene associated with retinoid‑interferon (IFN)‑induced mortality‑19 (Grim‑19) is reported to be a cell death activator that may be used to define mechanisms involved in IFN‑β‑ and retinoic acid‑induced cell death and apoptosis in a number of tumor cell lines. The present study constructed a recombinant adenovirus expressing Grim‑19 (rAd‑Grim‑19) and investigated its therapeutic outcomes in ESCC cells and tumor‑bearing mice. Grim‑19 expression was detected in EC‑109 (ESCC) cells by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. Tumor cell death and apoptosis induced by rAd‑Grim‑19 in EC‑109 cells were analyzed by flow cytometry. The inhibitory effects of rAd‑Grim‑19 on EC‑109 growth were determined by MTT assays. Furthermore, the therapeutic effects of rAd‑Grim‑19 were investigated in EC‑109‑bearing mice. The results demonstrated that Grim‑19 mRNA and protein expression was downregulated in EC‑109 esophageal carcinoma cells compared with Het‑1A normal esophageal epithelial cells. In addition, EC‑109 cells exhibited a significant reduction in tumor cell growth in the rAd‑Grim‑19 group compared with the control groups. Furthermore, rAd‑Grim‑19 increased EC‑109 cell apoptosis compared with the control group. These results indicated that rAd-Grim-19 may regulate tumor cell growth and apoptosis. Additionally, the results demonstrated that rAd‑Grim‑19 led to beneficial outcomes and prolonged the survival of esophageal tumor‑bearing mice. In conclusion, the present study demonstrated that rAd‑Grim‑19 may have potential as an antitumor agent for esophageal neoplasms and may therefore be beneficial for patients with esophageal neoplasms.

Expression of NDUFA13 in asthenozoospermia and possible pathogenesis

Asthenozoospermia is a common cause of male infertility, which is characterized by reduced forward motility of spermatozoa. The cause and pathogenesis of asthenozoospermia are not fully understood. The purpose of this study was to investigate the expression of nicotinamide adenine dinucleotide (NADH) dehydrogenase (ubiquinone) 1 alpha subcomplex, 13 (NDUFA13) in the spermatozoa of men with asthenozoospermia and its possible pathogenesis. Protein content of NDUFA13 in spermatozoa was measured by Western blot analysis. The results showed that NDUFA13 expression in spermatozoa was significantly lower in men with asthenozoospermic than in men with normozoospermia (P < 0.01). Immunofluorescence experiments showed that NDUFA13 was expressed predominantly in the sperm mid-piece. A lower mitochondrial membrane potential, a higher intracellular reactive oxygen species (ROS) level and more apoptotic cells were also detected in men with asthenozoospermia. NDUFA13-specific small interfering RNA was used in the mouse spermatocyte GC2-spd cell line to down-regulate the expression of NDUFA13. The knockdown of NDUFA13 in the GC2-spd cells caused a collapse of mitochondrial membrane potential, an increase in ROS level and more apoptotic cells. Our study showed that NDUFA13 deficiency may be associated with asthenozoospermia through the disturbance of spermatozoa mitochondrial membrane potential and by increasing apoptosis and intracellular ROS.

TIIA attenuates LPS-induced mouse endometritis by suppressing the NF-κB signaling pathway

Endometritis is one of the main diseases that harms the dairy cow industry. Tanshinone IIA (TIIA), a fat-soluble alkaloid isolated from Salviae miltiorrhizae, has been reported to have potent anti-inflammatory properties. However, the anti-inflammatory effects of TIIA on a mouse model of lipopolysaccharide (LPS)-induced endometritis remain to be elucidated. The purpose of the present study was to investigate the effects of TIIA on LPS-induced mouse endometritis. TIIA was intraperitoneally injected 1 h before and 12 h after perfusion of LPS into the uterus. A histological examination was then performed, and the concentrations of myeloperoxidase (MPO) and nitric oxide (NO) in the uterine tissue were determined. The levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in a homogenate of the uterus were detected by enzyme-linked immunosorbent assay. The extent of phosphorylation of IκBα and p65 was detected by Western blotting. TIIA markedly reduced the infiltration of neutrophils, suppressed MPO activity and the concentration of NO, and attenuated the expression of TNF-α and IL-1β. Furthermore, TIIA inhibited the phosphorylation of the nuclear factor-kappa B (NF-κB) p65 subunit and the degradation of its inhibitor IκBα. All the results suggest that TIIA has strong anti-inflammatory effects on LPS-induced mouse endometritis.