Mating system shifts a species’ range

Understanding the ecological and evolutionary mechanisms that shape a species’ range is an important goal in evolutionary biology. Evidence indicates that mating system is an effective predictor of the global range of native species or naturalized alien plants, but the mechanisms underlying this predictability are not elaborated. Here, we develop a theoretical model to account for the ranges of plants under different mating systems based on migration‐selection processes (an idea proposed by Haldane). The model includes alternation of gametophyte and sporophyte generations in one life cycle and the dispersal of haploid pollen and diploid seeds as vectors for gene flow. We show that the interaction between selfing rates and gametophytic selection determines the role of mating system in shaping a species’ range. Selfing restricts the species’ range under gametophytic selection in nonrandom mating systems, but expands the species’ range under the absence of gametophytic selection in any mating system. Gametophytic selection slightly restricts the species’ range in random mating. Both logarithmic and logistic models of population demography yield similar conclusions in the case of fixed or evolving genetic variance. The theory also helps to explain a broader relationship between mating system and range size following biological invasion or plant naturalization.     

Melatonin alleviates the deterioration of oocytes from mice subjected to repeated superovulation

Induction of repeated superovulation with exogenous hormones is widely used in assisted reproductive technology (ART). Though it is generally safe, emerging evidence has indicated that repeated superovulation may compromise oocyte quality. However, few studies have explored how to ameliorate such impairment. Because melatonin has beneficial influences on oocytes in various detrimental environments, we aimed to explore whether melatonin could protect mouse oocytes after repeated superovulation. We found that repeated superovulation markedly reduced meiotic maturation and disrupted spindle organization and chromosome alignment. Furthermore, we observed reduced mitochondrial content and enhanced early apoptosis in oocytes from mice subjected to repeated superovulation. In addition, 5-methylcytosine (5mc) fluorescence intensity was lower in oocytes from experimental mice than in those from control mice, indicating that repeated superovulation disrupts genomic DNA methylation, and elevations in reactive oxygen species levels indicated that repeated superovulation also induces oxidative stress. Conversely, melatonin administration improved oocyte maturation and attenuated the observed defects. Interestingly, supplementation with melatonin during in vitro maturation had the same protective effects on oocytes as in vivo melatonin administration. In summary, our results show that melatonin can improve oocyte quality after repeated superovulation and thus provide a potential strategy to improve ART efficiency.     

MiR-455-5p ameliorates HG-induced apoptosis,oxidative stress and inflammatory via targeting SOCS3 in retinal pigment epithelial cells

Diabetic retinopathy (DR) remains the leading cause of blindness in adults with diabetes mellitus. Numerous microRNAs (miRNAs) have been identified to modulate the pathogenesis of DR. The main purpose of this study was to evaluate the potential roles of miR-455-5p in high glucose (HG)-treated retinal pigment epithelial (RPE) cells and underlying mechanisms. Our present investigation discovered that the expression of miR-455-5p was apparently downregulated in ARPE-19 cells stimulated with HG. In addition, forced expression of miR-455-5p markedly enhanced cell viability and restrained HG-induced apoptosis accompanied by decreased BCL2-associated X protein (Bax)/B-cell leukemia/lymphoma 2 (Bcl-2) ratio and expression of apoptotic marker cleaved caspase-3 during HG challenged. Subsequently, augmentation of miR-455-5p remarkably alleviated HG-triggered oxidative stress injury as reflected by decreased the production of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) content as well as NADPH oxidase 4 expression, concomitant with enhanced the activities of superoxide dismutase, catalase, and GPX stimulated with HG. Furthermore, enforced expression of miR-455-5p effectively ameliorated HG-stimulated inflammatory response as exemplified by repressing the secretion of inflammatory cytokines interleukin 1β (IL-1β), IL-6, and tumour necrosis factor-α in ARPE-19 cells challenged by HG. Most importantly, we successfully identified suppressor of cytokine signaling 3 (SOCS3) as a direct target gene of miR-455-5p, and miR-455-5p negatively regulated the expression of SOCS3. Mechanistically, restoration of SOCS3 abrogated the beneficial effects of miR-455-5p on apoptosis, accumulation of ROS, and inflammatory factors production in response to HG. Taken together, these findings demonstrated that miR-455-5p relieved HG-induced damage through repressing apoptosis, oxidant stress, and inflammatory response by targeting SOCS3. The study gives evidence that miR-455-5p may serve as a new potential therapeutic agent for DR treatment.     

Identification and validation of key genes associated with non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is one of the main causes of death induced by cancer globally. However, the molecular aberrations in NSCLC patients remain unclearly. In the present study, four messenger RNA microarray datasets (GSE18842, GSE40275, GSE43458, and GSE102287) were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between NSCLC tissues and adjacent lung tissues were obtained from GEO2R and the overlapping DEGs were identified. Moreover, functional and pathway enrichment were performed by Funrich, while the protein–protein interaction (PPI) network construction were obtained from STRING and hub genes were visualized and identified by Cytoscape software. Furthermore, validation, overall survival (OS) and tumor staging analysis of selected hub genes were performed by GEPIA. A total of 367 DEGs (95 upregulated and 272 downregulated) were obtained through gene integration analysis. The PPI network consisted of 94 nodes and 1036 edges in the upregulated DEGs and 272 nodes and 464 edges in the downregulated DEGs, respectively. The PPI network identified 46 upregulated and 27 downregulated hub genes among the DEGs, and six (such as CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M) of that have not been identified to be associated with NSCLC so far. Moreover, the expression differences of the mentioned hub genes were consistent with that in lung adenocarcinoma and lung squamous cell carcinoma in the TCGA database. Further analysis showed that all the six hub genes were associated with tumor staging except MYH11, while only the upregulated DEG CENPE was associated with the worse OS of patients with NSCLC. In conclusion, the current study showed that CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M might be the key genes contributed to tumorigenesis or tumor progression in NSCLC, further functional study is needed to explore the involved mechanisms.     

Scutellarein inhibits RANKL-induced osteoclast formation in vitro and prevents LPS-induced bone loss in vivo

Osteoporosis, arthritis, Peget's disease, bone tumor, periprosthetic joint infection, and periprosthetic loosening have a common characteristic of osteolysis, which is characterized by the enhanced osteoclastic bone resorptive function. At present, the treatment target of these diseases is to interfere with osteoclastic formation and function. Scutellarein (Scu), a flavonoids compound, can inhibit the progress of tumor and inflammation. However, the role of Scu in inflammatory osteolysis isn’t elucidated clearly. Our study showed that Scu inhibited bone destruction induced by LPS in vivo and OC morphology and function induced by RANKL in vitro. Mechanistic studies revealed that Scu suppressed osteoclastic marker gene expression by RANKL-induced, such as Ctsk9, Mmp9, Acp5, and Atp6v0d2. In addition, we found that the inhibition effects of osteoclastogenesis and bone resorption function of Scu were mediated via attenuating NF-κB and NFAT signaling pathways. In conclusion, the results showed that Scu may become a potential new drug for the treatment of inflammatory osteolysis.     

A single nuclear polymorphism in let-7g binding site affects the doubling time of thyroid nodule by regulating KRAS-induced cell proliferation

As an indicator for the malignancy of thyroid nodules (TN), the doubling time of TN was studied in this study to evaluate the effect of rs712 polymorphism on the progression of TN. In addition, we aimed to study the potential molecular mechanisms underlying the pathological effect of rs712 polymorphism upon TN. A Taqman method was used to genotype the patients according to their rs712 polymorphism. Real-time polymerase chain reaction, western blot, Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay was conducted to study the correlation between KRAS expression and the pathological effect of rs712 polymorphism. In-silicon analysis and luciferase assay were utilized to establish the regulatory relationship between let-7g and KRAS. KRAS messenger RNA (mRNA)/protein levels in the GG group were upregulated with a decreased apoptosis index. KRAS mRNA was validated to be a virtual target of let-7g. In addition, the mRNA/protein level of KRAS as well as cell proliferation index was decreased in primary thyroid cancer cells genotyped as TT/TG and transfected with KRAS small interfering RNA (siRNA)/let-7g precursors. The cell apoptosis index was evidently elevated in the KRAS siRNA/let-7g precursors group compared with that in the scramble controls. Moreover, KRAS mRNA/protein only showed slight reduction when GG-genotyped primary thyroid cancer cells were transfected by let-7g precursors. Additionally, let-7g precursors exhibited no significant effect on cell proliferation index or cell apoptosis in GG cells. Rs712 polymorphism T>G in the 3′-untranslated region of KRAS interrupts the interactions between let-7g and KRAS mRNA, leading to a higher cell proliferation index and reduced doubling time of TN.     

Evidence for calpains in cancer metastasis

Metastatic dissemination represents the final stage of tumor progression as well as the principal cause of cancer-associated deaths. Calpains are a conserved family of calcium-dependent cysteine proteinases with ubiquitous or tissue-specific expression. Accumulating evidence indicates a central role for calpains in tumor migration and invasion via participating in several key processes, including focal adhesion dynamics, cytoskeletal remodeling, epithelial-to-mesenchymal transition, and apoptosis. Activated after the increased intracellular calcium concentration () induced by membrane channels and extracellular or intracellular stimuli, calpains induce the limited cleavage or functional modulation of various substrates that serve as metastatic mediators. This review covers established literature to summarize the mechanisms and underlying signaling pathways of calpains in cancer metastasis, making calpains attractive targets for aggressive tumor therapies.     

Retracted: miR-150 might inhibit cell proliferation and promote cell apoptosis by targeting LMO4 in Burkitt lymphoma

This study aimed at investigating the effect of microRNA-150 (miR-150) on cell proliferation of Burkitt lymphoma and its molecular mechanism. Gene expression analysis was applied to identify target genes of miR-150 in Burkitt lymphoma cell line ST486 based on the dataset from the Gene Expression Omnibus (GEO) datasets GSE86432. miRNA mimics, inhibitor and small interfering RNA (siRNA) were fluorescently labeled by Cy3, whereas plasmid vector was labeled by EGFP. Cells were viewed by fluorescence microscope and transfection efficiency was evaluated through fluorescent cell percentage. Quantitative real-time polymerase chain reaction analysis (qRT-PCR) and western blot were applied to detect the expression level of miR-150 and LMO4. Cell proliferation, cell cycle, and apoptosis were explored by CCK-8, flow cytometry. Targeting relationship was validated by the Luciferase reporter assay. Tumor xenograft and immunohistochemical analysis were conducted in nude mice model. In Burkitt lymphoma cells, miR-150 expression was significantly lower than normal ones, whereas the expression of LMO4 was upregulated. miR-150 might inhibit cell proliferation and promoted apoptosis in Burkitt lymphoma deterioration by downregulating LMO4. The results of tumor xenograft further confirmed the role of miR-150 in Burkitt lymphoma. Targeting LMO4 is a significant mechanism by which miR-150 suppresses cell growth and promotes apoptosis in Burkitt lymphoma cells, thus may provide a novel target for Burkitt lymphoma therapy in the future.