Integrative analysis of the 3D genome structure reveals that CTCF maintains the properties of mouse female germline stem cells.

The three-dimensional configuration of the genome ensures cell type-specific gene expression profiles by placing genes and regulatory elements in close spatial proximity. Here, we used in situ high-throughput chromosome conformation (in situ Hi-C), RNA sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) to characterize the high-order chromatin structure signature of female germline stem cells (FGSCs) and identify its regulating key factor based on the data-driven of multiple omics data. By comparison with pluripotent stem cells (PSCs), adult stem cells (ASCs), and somatic cells at three major levels of chromatin architecture, A/B compartments, topologically associating domains, and chromatin loops, the chromatin architecture of FGSCs was most similar to that of other ASCs and largely different from that of PSCs and somatic cells. After integrative analysis of the three-dimensional chromatin structure, active compartment-associating loops (aCALs) were identified as a signature of high-order chromatin organization in FGSCs, which revealed that CCCTC-binding factor was a major factor to maintain the properties of FGSCs through regulation of aCALs. We found FGSCs belong to ASCs at chromatin structure level and characterized aCALs as the high-order chromatin structure signature of FGSCs. Furthermore, CTCF was identified to play a key role in regulating aCALS to maintain the biological functions of FGSCs. These data provide a valuable resource for future studies of the features of chromatin organization in mammalian stem cells and further understanding of the fundamental characteristics of FGSCs.

Mechanistic insights into HuR inhibitor MS-444 arresting embryonic development revealed by low-input RNA-seq and STORM.

With improvements in the survival rate of patients with cancer, fertility maintenance has become a major concern in terms of cancer treatment for women of reproductive age. Thus, it is important to examine the impact on fertility of anticancer drugs that are used clinically or are undergoing trials. The HuR small-molecule inhibitor MS-444 has been used in many cancer treatment studies, but its reproductive toxicity in females is unknown. Here, we reported that MS-444 blocked the nucleocytoplasmic transport of Agbl2 mRNA by inhibiting HuR dimerization, resulting in the developmental arrest of 2-cell stage embryos in mouse. Combining analysis of low-input RNA-seq for MS-444-treated 2-cell embryos and mapping binding sites of RNA-binding protein, Agbl2 was predicted to be the target gene of MS-444. For further confirmation, RNAi experiment in wild-type zygotes showed that Agbl2 knockdown reduced the proportion of embryos successfully developed to the blastocyst stage: from 71% in controls to 23%. Furthermore, RNA-FISH and luciferase reporter analyses showed that MS-444 blocked the nucleocytoplasmic transport of Agbl2 mRNA and reduced its stability by inhibiting HuR dimerization. In addition, optimized stochastic optical reconstruction microscopy (STORM) imaging showed that MS-444 significantly reduced the HuR dimerization, and HuR mainly existed in cluster form in 2-cell stage embryos. In conclusion, this study provides clinical guidance for maintaining fertility during the treatment of cancer with MS-444 in women of reproductive age. And also, our research provides guidance for the application of STORM in nanometer scale studies of embryonic cells. HuR inhibitor MS-444 arrested embryonic development at 2-cell stage. Low-input RNA-seq revealed that Agbl2 was the target gene of MS-444. MS-444 blocked the nucleocytoplasmic transport of Agbl2 mRNA by inhibiting HuR dimerization and reduced the stability of Agbl2 mRNA. STORM with our optimized protocol showed that HuR tended to form elliptical and dense clusters in 2-cell stage embryos.

[A preliminary investigation on a deep learning convolutional neural networks based pulmonary tuberculosis CT diagnostic model].

Objective: To evaluate the clinical value of a pulmonary tuberculosis CT diagnostic model based on deep learning convolutional neural networks (CNN). Methods: From March 2017 to March 2018,a total of 1 764 patients with positive sputum for tuberculous bacterium and had received high-resolution chest CT scan in radiology department of Hebei province chest hospital were enrolled. Among them, 937 were male, and 827 were female, aging from 17-73 years (average 38.4). A total of 20 139 CT images (17 kinds of image features) classified by 4 radiologists were used as training dataset to create a tuberculosis CT CNN diagnostic model. The top 5 image features in training set were: infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion. A total of 302 images were randomly selected from the marked images as testing dataset. The diagnosis of 2 senior radiologists was taken as "golden standard". The differences of sensitivity and accuracy in CT diagnosis between the CNN diagnostic model and the radiologists were compared. The classification error types and numbers of the CNN diagnostic model were recorded. FROC(free response operating characteristic curve)curve was drawn and the highest diagnostic efficiency of the model was measured. Results: The diagnostic accuracy of infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion by the CNN diagnostic model were 95.33%(10 982/11 520), 73.68%(2 151/2 920), 73.07%(1 128/1544), 83.33%(1 020/1225)and 94.11%(814/865), respectively. The overall diagnostic sensitivity and accuracy of the CNN model were 95.49%(339/355)and 90.40%(339/375), respectively, and the corresponding values ​​of radiologists were 93.80%(348/371)and 92.80%(348/375), respectively, and there was no statistical difference between the CNN model and the radiologists(sensitivity χ2=1.022,P=0.312;accuracy χ2=1.404,P=0.236). FROC curve showed that when sensitivity of the CNN model was 78% and FPI value was 2.48, it reached the highest diagnostic efficiency. The classification error of CNN diagnostic models was mainly confusion of fiber stripe components, cavitary pulmonary tuberculosis, caseous pneumonia and infiltrative pulmonary tuberculosis. Conclusions: The CNN-based pulmonary tuberculosis CT diagnostic model exhibited high sensitivity and accuracy (95.49% and 90.40% respectively). It could assist radiologists in CT diagnosis of pulmonary tuberculosis and deserve further clinical application.

Comprehensive Transcriptomic Analysis of Mouse Gonadal Development Involving Sexual Differentiation, Meiosis and Gametogenesis.

BACKGROUND: Mammalian gonadal development is crucial for fertility. Sexual differentiation, meiosis and gametogenesis are critical events in the process of gonadal development. Abnormalities in any of these events may cause infertility. However, owing to the complexity of these developmental events, the underlying molecular mechanisms are not fully understood and require further research. RESULTS: In this study, we employed RNA sequencing to examine transcriptome profiles of murine female and male gonads at crucial stages of these developmental events. By bioinformatics analysis, we identified a group of candidate genes that may participate in sexual differentiation, including Erbb3, Erbb4, and Prkg2. One hundred and two and 134 candidate genes that may be important for female and male gonadal development, respectively, were screened by analyzing the global gene expression patterns of developing female and male gonads. Weighted gene co-expression network analysis was performed on developing female gonads, and we identified a gene co-expression module related to meiosis. By alternative splicing analysis, we found that cassette-type exon and alternative start sites were the main forms of alternative splicing in developing gonads. A considerable portion of differentially expressed and alternatively spliced genes were involved in meiosis. CONCLUSION: Taken together, our findings have enriched the gonadal transcriptome database and provided novel candidate genes and avenues to research the molecular mechanisms of sexual differentiation, meiosis, and gametogenesis. SUPPLEMENTARY INFORMATION: Supplementary information accompanies this paper at 10.1186/s12575-019-0108-y.

Ablation of the MiR-17-92 MicroRNA Cluster in Germ Cells Causes Subfertility in Female Mice.

BACKGROUND/AIMS: Oogenesis is a highly complex process that is intricately regulated by interactions of multiple genes and signaling molecules. However, the underlying molecular mechanisms are poorly understood. There is emerging evidence that microRNAs contribute to oogenesis. Here, we aimed to investigate the role of miR-17-92 cluster in regulating oogenesis. METHODS: The miR-17-92 cluster was genetically ablated in germ cells of female mice by applying the Cre-loxp system for conditional gene knockout. Mating experiment, superovulation and histological analysis were used to assess the fertility of the model female mice. TUNEL assay was used to identify apoptotic cells in ovaries. The expression level of apoptosis- and follicular atresia- related genes was evaluated by qRT-PCR. Western blotting was performed to detect protein expression. Bioinformatics software and dual luciferase reporter assay were applied to predict and verify the target of miR-17-92 cluster. RESULTS: Deletion of miR-17-92 cluster in germ cells of female mice caused increased oocyte degradation and follicular atresia, perturbed oogenesis, and ultimately led to subfertility. Genes involved in follicular atresia and the mitochondrial apoptotic pathway were obviously up-regulated. Furthermore, we verified that miR-19a regulated oogenesis at the post-transcriptional level by targeting Bmf in the ovaries of miR-17-92 cluster conditional knockout female mice. CONCLUSION: The miR-17-92 cluster is an important regulator of oogenesis. These findings will assist in better understanding the etiology of disorders in oogenesis and in developing new therapeutic targets for female infertility.

Effects of bisphenol A on ovarian follicular development and female germline stem cells.

Bisphenol A (BPA), one of the most frequently detected emerging pollutants in the environment, has been implicated in adverse effects in male and female reproduction at extremely low concentrations. This study aimed to investigate the effects and potential mechanism of BPA on mouse ovarian follicular development and female germline stem cells (FGSCs). Female CD-1 adult mice were administered gradient concentrations of BPA (12.5, 25, and 50 mg/kg/day) by intraperitoneal injection. We found that the number of atretic ovarian follicles was significantly increased at high BPA concentrations. Additionally, the numbers of primordial follicles, primary follicles, and corpus luteum (CL) were significantly reduced at high BPA concentrations. Interestingly, the number of FGSCs was remarkably reduced in BPA-treated ovaries. Furthermore, the increased apoptotic rate of FGSCs in vitro was triggered by BPA accompanied by increased BPA concentrations. To investigate the mechanism of BPA in ovarian follicular development, 193 differentially expressed proteins were identified in BPA-treated ovaries by the isobaric tags for relative and absolute quantification-coupled 2D liquid chromatography-mass spectrometry technique. A total of 106 proteins were downregulated and 85 proteins were upregulated. Among these proteins, the apoptosis-related protein SAFB-like transcriptional modulator (SLTM) was remarkably upregulated, and this result was consistent with western blotting. Taken together, our results suggest that an ovarian follicular development, especially, the development of primordial follicles, primary follicles, and the CL, is inhibited by high BPA concentrations, and the ovarian follicle atresia is initiated by BPA through upregulated expression of SLTM. Furthermore, BPA induces apoptosis of cultured FGSCs. The effect of BPA on ovarian follicular development and FGSCs, especially the effect on FGSCs, suggests a novel mechanism of how BPA causes female infertility.

MicroRNA-10b regulates the renewal of spermatogonial stem cells through Kruppel-like factor 4.

MicroRNAs (miRs) are functionally important in spermatogenesis, which is the self-renewal or differentiation of spermatogonial stem cells (SSCs). Here, we report a novel role for miR-10b in regulating the self-renewal of mouse SSCs. We showed that miR-10b was highly expressed in mouse SSCs in vitro and enhanced SSC proliferation. Knockdown of miR-10b significantly increased the apoptosis of SSCs compared with controls. Kruppel-like factor 4 was found to be a target gene of miR-10b in the enhancement of SSC proliferation. These findings further our understanding of the self-renewal and differentiation of SSCs and provide a basis for the diagnosis, treatment, and prevention of male infertility.

SNP genotypes of olfactory receptor genes associated with olfactory ability in German Shepherd dogs.

To find out the relationship between SNP genotypes of canine olfactory receptor genes and olfactory ability, 28 males and 20 females from German Shepherd dogs in police service were scored by odor detection tests and analyzed using the Beckman GenomeLab SNPstream. The representative 22 SNP loci from the exonic regions of 12 olfactory receptor genes were investigated, and three kinds of odor (human, ice drug and trinitrotoluene) were detected. The results showed that the SNP genotypes at the OR10H1-like:c.632C>T, OR10H1-like:c.770A>T, OR2K2-like:c.518G>A, OR4C11-like:c.511T>G and OR4C11-like:c.692G>A loci had a statistically significant effect on the scenting abilities (P < 0.001). The kind of odor influenced the performances of the dogs (P < 0.001). In addition, there were interactions between genotype and the kind of odor at the following loci: OR10H1-like:c.632C>T, OR10H1-like:c.770A>T, OR4C11-like:c.511T>G and OR4C11-like:c.692G>A (P < 0.001). The dogs with genotype CC at the OR10H1-like:c.632C>T, genotype AA at the OR10H1-like:c.770A>T, genotype TT at the OR4C11-like:c.511T>G and genotype GG at the OR4C11-like:c.692G>A loci did better at detecting the ice drug. We concluded that there was linkage between certain SNP genotypes and the olfactory ability of dogs and that SNP genotypes might be useful in determining dogs' scenting potential.

Dynamic QTL analysis of seed reserve utilization in sh2 sweet corn germination stages.

In this study, dynamic quantitative trait loci (QTL) were mapped in a recombinant inbred line (F2:4) population derived from a BF3109 x Q267 cross. This was done during the unconditional (4, 7, and 10 days) and conditional (0 to 4, 4 to 7, and 7 to 10 days) germination stages in sh2 sweet corn. The values of seedling dry weight, weight of mobilized seed reserve (WMSR), seed reserve depletion percentage (SRDP), seed reserve utilization efficiency (SRUE), and their heritability differed across the investigated stages. The heritabilities of these traits were lower at 7D/4D and 10D/7D compared with those at the 4- (4D/0D), 7- and 10-day (D) developmental stages. WMSR and SRDP were significantly negatively correlated with SRUE at the early stage. The unconditional QTL mapping can explain the accumulation of genetic effects of seed reserve utilization from the starting time, whereas the conditional QTL mapping can reveal genetic expression in the time intervals. Fifteen and fourteen additive QTLs were identified by the unconditional and conditional mapping, respectively. The number of additive QTLs and their effect values varied among the different stages. More additive QTLs were found at the later stage (7 to 10 days), based on the conditional mapping results. The identification of QTL mapping based on a combination of time-dependent measurements is important for a better understanding of the genetic bases of seed reserve utilization. It is also important for the improvement of relevant variety traits for subsequent sweet corn-breeding studies using marker-assisted selection.

Statistical analysis of the relationship between IL-10 gene promoter polymorphisms and the development of coronary artery disease.

Here, we conducted a case-control study to investigate the association between IL-10 gene polymorphisms and development of CAD in a Chinese population. A total of 220 patients with CAD and 236 control subjects who visited the Zhengzhou People's Hospital between May 2012 and June 2014 were selected for this study. The IL-10-1082A/G and -592A/C polymorphisms were genotyped by polymerase chain reaction coupled with restriction fragment length polymorphism. The chi-squared test revealed a significant difference in the distributions of the IL-10-1082A/G genotypes (χ2 = 6.32, P = 0.04). This data was then statistically analyzed by logistic regression analysis; we observed revealed that the CC genotype of IL-10-1082A/G had a higher risk of CAD in comparison to the AA genotype (OR = 2.09, 95%CI = 1.11-3.97). Moreover, the C allele of IL-10-1082A/G had a 1.39 fold risk of CAD when compared with (OR = 1.39, 95%CI = 1.06-1.82). We did not observe any significant correlations between the IL-10-592A/C genetic variation and susceptibility to CAD. In conclusion, our study suggests that the IL-10-1082A/G genetic variation could influence the development of CAD in a Chinese population.

Interleukin-6 (IL-6) -174G/C genomic polymorphism contribution to the risk of coronary artery disease in a Chinese population.

To investigate the role of IL-6 polymorphism (-174G/C and -572C/G) in the development of coronary artery disease (CAD), CAD patients (224) and control subjects (260) were recruited between January 2012 and December 2014. Genotyping at IL-6 -174G/C and -572C/G was conducted via polymerase chain reaction coupled to restriction fragment length polymorphism. Results indicated that several disease risk factors were significantly higher in CAD patients as compared to the control subjects. These factors include hypertension (χ2 = 20.03, P < 0.001), diabetes mellitus (χ(2) = 33.53, P < 0.001), tobacco smoking (χ(2) = 28.17, P < 0.001), body mass indexes (t = 11.39, P < 0.001), total cholesterol (t = 8.25, P < 0.001), low-density lipoprotein cholesterol (t = 7.24, P < 0.001), high-density lipoprotein cholesterol (t = 3.52, P < 0.001), and triglyceride (t = 6.09, P < 0.001). By unconditional logistic regression analysis, we observed that the CC genotype at IL-6 -174G/C was had a 2.32 (95%CI = 1.33-4.06) fold risk of developing CAD compared to the GG genotype. Moreover, IL-6 -174G/C polymorphism was positively associated with the risk of developing CAD in both dominant (OR = 1.63, 95%CI = 1.12-2.38; P = 0.01) and recessive models (OR = 2.18, 95%CI = 1.26-3.77; P = 0.001). However, no statistically significant association was observed between IL-6 -572C/G polymorphism and risk of CAD. In conclusion, IL-6 -174G/C polymorphisms are associated with the pathogenesis of CAD.

MicroRNA-338-3p inhibits glucocorticoid-induced osteoclast formation through RANKL targeting.

The differentiation deficiencies of osteoclast precursors (pre-OCs) may contribute to osteoporosis. Research on osteoporosis has recently focused on microRNAs (miRNAs) that play crucial roles in pre-OC differentiation. In the current study, we aimed to analyze the expression and function of the glucocorticoid (GC)-associated miRNA-338-3p (miR-338-3p) in osteoclast formation. We found that dexamethasone induced osteoclast differentiation and inhibited miR-338-3p expression. Overexpression of an miR-338-3p mimic in osteoclast precursor cells attenuated GC-induced osteoclast formation and bone resorption, whereas inhibition of miR-338-3p reversed these effects. The expression of the nuclear factor κB ligand RANKL, a potential target gene of miR-338-3p, was inversely correlated with miR-338-3p expression in pre-OCs. Furthermore, we demonstrated that RANKL was directly regulated by miR-338-3p and re-introduction of RANKL reversed the inhibitory effects of miR-338-3p on osteoclast formation and bone resorption. Taken together, these findings demonstrate that miR-338-3p may play a significant role in GC-induced osteoclast differentiation and function by targeting RANKL in osteoclasts.

Resistance of Castanea mollissima Shuhe-WYL strain to Dryocosmus kuriphilus and its molecular mechanism.

The resistance of Castanea mollissima Shuhe-WYL strain to Dryocosmus kuriphilus and its molecular mechanism were examined. The larvae of D. kuriphilus were inoculated on the Shuhe-WYL and Qingzha strains, and mortality was observed and compared; the relative mRNA content of the OsCDPK2, receptor-like protein, OsNAC6 protein, KH domain protein, RNA-binding protein, and the bHLH genes was detected using real-time polymerase chain reaction, and then compared between the Shuhe-WYL and Qingzha strains. Phenylalanine ammonia-lyase content was detected by western blotting and compared between the inoculated Shuhe-WYL, non-inoculated Shuhe-WYL, and inoculated Qingzha strains. The mortalities of larvae inoculated on the bud, bracteal leaf, and cardiac lobe were lower in Shuhe-WYL than Qingzha at 48 and 96 h after inoculation; the contents of OsCDPK2, receptor-like protein, OsNAC6 protein, and bHLH in the cardiac lobe were higher in Shuhe-WYL than in Qingzha at 96 h after inoculation, but KH domain protein and RNA-binding protein were not significantly different. The content of phenylalanine ammonia-lyase in the cardiac lobe was higher in inoculated and non-inoculated Shuhe-WYL compared to inoculated Qingzha at 15, 30, 45, and 60 days, and higher in inoculated Shuhe-WYL than in non-inoculated Shuhe-WYL at 15, 30, 45, and 60 days. The content of phenylalanine ammonia-lyase in the cardiac lobe of inoculated Shuhe-WYL had no significant difference between at 60 and at 45 days; and was higher at 60 and 45 days than at 30 and 15 days; and was higher at 30 days than at 15 days (60≈45˃30˃15 days). The C. mollissima Shuhe-WYL strain was resistant to D. kuriphilus; high expression of OsCDPK2, receptor-like protein, OsNAC6 protein, and bHLH and phenylalanine ammonia-lyase may explain the mechanism.

Correlation between polymorphisms in the IL-17A and IL-17F genes and development of coronary artery disease.

A case-control study was conducted to investigate the association between genetic variants of IL-17A rs2275913 and IL-17F rs763780 and the development of coronary artery disease (CAD) in a Chinese population. A total of 306 individuals with CAD and 306 unaffected individuals were enrolled from the Zhengzhou People's Hospital between May 2012 and May 2014. The IL-17A rs2275913 and IL-17F rs763780 genes were genotyped by polymerase chain reaction combined with a restriction fragment length polymorphism (PCR-RFLP). Logistic regression analysis revealed that individuals with the AA genotype of rs2275913 were associated with increased risk of CAD, compared to those with the GG genotype in a codominant model [adjusted odds ratio (OR) = 1.96; 95% confidence interval (CI) = 1.10-3.53]. On the other hand, the AA genotype of rs2275913 was correlated with moderately increased risk of CAD compared to the GG + GA genotype (adjusted OR = 1.76; 95%CI = 1.02-3.07) in a recessive model. However, no significant differences were observed between polymorphisms at the IL-17F rs763780 locus and CAD risk, in codominant, dominant, and recessive models. In conclusion, the results of our study suggested that the IL-17A rs2275913 polymorphism may affect the development of CAD; however, no significant association was observed between the IL-17F rs763780 polymorphism and risk of CAD.

Comparison of the duration of neuromuscular blockade following a single bolus dose of rocuronium during laparoscopic gynaecological surgery vs conventional open surgery.

We investigated whether laparoscopic vs open surgical approaches affected the duration of neuromuscular blockade following a single bolus dose of rocuronium. Fifty-three female patients underwent either laparoscopic or open gynaecological surgery. Rocuronium 0.6 mg.kg(-1) was administered to achieve neuromuscular blockade in all subjects, and adductor pollicis train-of-four responses following ulnar nerve stimulation were monitored with mechanomyography. The mean (SD) time from injection of rocuronium until spontaneous recovery of the first twitch, and to 5% and 25% of baseline, was significantly prolonged in the laparoscopic group (27.2 (8.3) min, 31.3 (9.1) min and 38.1 (10.6) min, respectively) compared with the open surgery group (21.1 (5.8) min, 25.6 (6.3) min and 31.2 (6.7) min, respectively). Changes in liver function both before surgery and at 24 h postoperatively were similar between the two groups (p > 0.05). Our findings suggest that neuromuscular blockade may be prolonged following a single bolus dose of rocuronium given during laparoscopic procedures.

Reproductive chemical database: a curated database of chemicals that modulate protein targets regulating important reproductive biological processes.

Recent studies have shifted the spotlight from adult disease to gametogenesis and embryo developmental events, and these are greatly affected by various environmental chemicals, such as drugs, metabolites, pollutants, and others. Growing research has highlighted the critical importance of identifying and understanding the roles of chemicals in reproductive biology. However, the functions and mechanisms of chemicals in reproductive processes remain incomplete. We developed a comprehensive database called the Reproductive Chemical Database (RCDB) ( https://yu.life.sjtu.edu.cn/ChenLab/RCDB ) to facilitate research on chemicals in reproductive biology. This resource is founded on rigorous manual literature extraction and precise protein target prediction methodologies. This database focuses on the delineation of chemicals associated with phenotypes, diseases, or endpoints intricately associated with four important reproductive processes: female and male gamete generation, fertilization, and embryo development in human and mouse. The RCDB encompasses 93 sub-GO processes, and it revealed 1447 intricate chemical-biological process interactions. To date, the RCDB has meticulously cataloged and annotated 830 distinct chemicals, while also predicting 614 target proteins from a selection of 3800 potential candidates. Additionally, the RCDB offers an online predictive tool that empowers researchers to ascertain whether specific chemicals play discernible functional roles in these reproductive processes. The RCDB is an exhaustive, cross-platform, manually curated database, which provides a user-friendly interface to search, browse, and use reproductive processes modulators and their comprehensive related information. The RCDB will help researchers to understand the whole reproductive process and related diseases and it has the potential to promote reproduction research in the pharmacological and pathophysiological areas.

Measuring anisotropic muscle stiffness properties using elastography.

Physiological and pathological changes to the anisotropic mechanical properties of skeletal muscle are still largely unknown, with only a few studies quantifying changes in vivo. This study used the noninvasive MR elastography (MRE) technique, in combination with diffusion tensor imaging (DTI), to measure shear modulus anisotropy in the human skeletal muscle in the lower leg. Shear modulus measurements parallel and perpendicular to the fibre direction were made in 10 healthy subjects in the medial gastrocnemius, soleus and tibialis anterior muscles. The results showed significant differences in the medial gastrocnemius (µâ€– = 0.86 ± 0.15 kPa; µâŠ¥ = 0.66 ± 0.19 kPa, P < 0.001), soleus (µâ€– = 0.83 ± 0.22 kPa; µâŠ¥ = 0.65 ± 0.13 kPa, P < 0.001) and the tibialis anterior (µâ€– = 0.78 ± 0.24 kPa; µâŠ¥ = 0.66 ± 0.16 kPa, P = 0.03) muscles, where the shear modulus measured in the direction parallel is greater than that measured in the direction perpendicular to the muscle fibres. No significant differences were measured across muscle groups. This study provides the first direct estimates of the anisotropic shear modulus in the triceps surae muscle group, and shows that the technique may be useful for the probing of mechanical anisotropy changes caused by disease, aging and injury.

Metformin promotes female germline stem cell proliferation by upregulating Gata-binding protein 2 with histone ß-hydroxybutyrylation.

BACKGROUND: Metformin as a first-line clinical anti-diabetic agent prolongs the lifespan of model animals and promotes cell proliferation. However, the molecular mechanisms underlying the proliferative phenotype, especially in epigenetics, have rarely been reported. The aim of this study was to investigate the physiological effects of metformin on female germline stem cells (FGSCs) in vivo and in vitro, uncover ß-hydroxybutyrylation epigenetic modification roles of metformin and identify the mechanism of histone H2B Lys5 ß-hydroxybutyrylation (H2BK5bhb) in Gata-binding protein 2 (Gata2)-mediated proliferation promotion of FGSCs. METHODS: The physiological effects of metformin were evaluated by intraperitoneal injection and histomorphology. The phenotype and mechanism studies were explored by cell counting, cell viability, cell proliferation assay and protein modification omics, transcriptomics, chromatin immunoprecipitation sequencing in FGSCs in vitro. RESULTS: We found that metformin treatment increased the number of FGSCs, promoted follicular development in mouse ovaries and enhanced the proliferative activity of FGSCs in vitro. Quantitative omics analysis of protein modifications revealed that H2BK5bhb was increased after metformin treatment of FGSCs. In combination with H2BK5bhb chromatin immunoprecipitation and transcriptome sequencing, we found that Gata2 might be a target gene for metformin to regulate FGSC development. Subsequent experiments showed that Gata2 promoted FGSC proliferation. CONCLUSION: Our results provide novel mechanistic understanding of metformin in FGSCs by combining histone epigenetics and phenotypic analyses, which highlight the role of the metformin-H2BK5bhb-Gata2 pathway in cell fate determination and regulation.

YTHDF1 phase separation triggers the fate transition of spermatogonial stem cells by activating the IκB-NF-κB-CCND1 axis.

N6-methyladenosine (m6A) modification controls cell fate determination. Here, we show that liquid-liquid phase separation (LLPS) of YTH N6-methyladenosine RNA binding protein 1 (YTHDF1), a pivotal m6A "reader" protein, promotes the transdifferentiation of spermatogonial stem cells (SSCs) into neural stem cell-like cells by activating the IκB-nuclear factor κB (NF-κB)-CCND1 axis. The inhibition of IκBα/ß mRNA translation mediated by YTHDF1 LLPS is the key to the activation of the IκB-NF-κB-CCND1 axis. Disrupting either YTHDF1 LLPS or NF-κB activation inhibits transdifferentiation efficiency. Moreover, overexpression of the YTH domain of YTHDF1 inhibits the activation of the IκB-NF-κB-CCND1 axis by promoting IκBα/ß mRNA translation. Overexpression of the tau-YTH fusion protein reactivates IκB-NF-κB-CCND1 axis by inhibiting the translation of IκBα/ß mRNAs, and tau LLPS is observed, which can restore transdifferentiation efficiency. Our findings demonstrate that the protein-RNA LLPS plays essential roles in cell fate transition and provide insights into translational medicine and the therapy of neurological diseases.

Metformin Promotes Proliferation of Mouse Female Germline Stem Cells by Histone Acetylation Modification of Traf2.

Female germline stem cells (FGSCs) are adult stem cells that can both self-renew and differentiate into mature oocytes. Although small-molecule compounds are capable of regulating the development of FGSCs, the effects and mechanisms of action of metformin, a commonly used drug for diabetes, on FGSCs are largely unknown. Here, we found that metformin promoted the viability and proliferation of FGSCs through H3K27ac modification. To elucidate the mechanism by which metformin promoted FGSCs proliferation, Chromatin Immunoprecipitation Sequencing of histone 3 lysine 27 acetylation (H3K27ac) in FGSCs was performed with or without metformin-treatment. The results indicate that metformin modulates FGSCs via the mitogen-activated protein kinase (MAPK) signaling pathway, and tumor necrosis factor receptor associated factor 2 (Traf2) was identified as an important target gene for H3K27ac modification during FGSCs proliferation. Subsequent experiments showed metformin promoted FGSCs proliferation by H3K27ac modification of Traf2 to regulate MAPK signaling. Our findings deepen understanding of how H3K27ac modifications regulate FGSCs development and provide a theoretical basis for the prevention and treatment of premature ovarian failure, polycystic ovary syndrome, infertility, and related diseases.