Arginine methylation is a critical post-translational modification that plays multifaceted biological functions. However, the manipulation of protein arginine methylation largely depends on genetic or pharmaceutic inhibition of the regulatory enzymes, protein arginine methyltransferases (PRMTs), or non-methylation substitution of corresponding arginine residue to lysine or alanine of protein of interest (POI), which inevitably affects other substrates, or disrupts the structure of POI. Thus, it urges an approach to specifically modulate the arginine methylation of a POI under physiological conditions. To this end, we report the discovery of a methylation tagging system (MeTAG), that enables targeted modification of protein arginine methylation. Through bridging the methyltransferase PRMT5 proximity to a POI, MeTAG facilitates the arginine methylation of POIs, including known arginine methylated proteins, androgen receptor (AR) and protein kinase B (AKT), as well as a neo-substrate E1A binding protein (p300), in a reversible and PRMT5-dependent manner. Moreover, MeTAG can regulate downstream signaling in a methylation dependent manner, leading to downregulation of PSMA mRNA level and activation of AKT. Therefore, MeTAG represents a feasible approach to modulate protein methylation and thereby perturbs protein function in biological and therapeutic contexts.

Objective:To observe the effects of electroacupuncture at "Shenting", "Benshen" and "Baihui" acupoints on the mechanical pain threshold and JAK/PI3K/TRPV1 pathway in the trigeminal ganglion of rats with trigeminal neuralgia model; To explore the related mechanism.Methods:Totally 36 male SD rats were divided into sham-operation group, model group and electroacupuncture group using random number table method, with 12 rats in each group. Except for the sham-operation group, rats in the model group and electroacupuncture group were modeled by infraorbital nerve chronic constriction injury. In the electroacupuncture group, electroacupuncture was performed at "Shenting", "Benshen" and "Baihui" 14 days after surgery, 20 min every day, once every other day, and every 3 times for 1 course of treatment with an interval of 2 d between each course of treatment. A total of 2 courses of treatment were performed. VonFrey fiber wire was used to measure the mechanical pain threshold of rat whisker pads. HE staining was used to observe the morphology and structure of trigeminal ganglion of rats in each group. Immunohistochemistry and Western blot method were used to observe the protein expressions of JAK, PI3K and TRPV1 in trigeminal ganglion of rats, and the serum level of IL-6 was detected in the serum of rats by ELISA.Results:Compared with the model group, the pain threshold of the electroacupuncture group increased significantly ( P<0.05), and the infiltration of inflammatory cells and demyelination in the trigeminal nerve ganglion decreased, and the positive expressions of JAK, PI3K, and TRPV1 in the trigeminal ganglion decreased ( P<0.05 or P<0.01), the protein expressions of JAK2, PI3K, and TRPV1 decreased ( P<0.05 or P<0.01), and the serum IL-6 level decreased ( P<0.01). Conclusions:Electroacupuncture at "Shenting", "Benshen" and "Baihui" may play an analgesic role by regulating IL-6 levels and inhibiting the activation of JAK/PI3K/TRPV1 signaling pathway.

In recent years, the third medical education reform characterized by competency-based medical education (CBME) is being carried out around the world; however, there are still challenges in bridging competency framework with clinical practice during implementation. With reference to the three-step method for constructing a CBME curriculum system based on entrustable professional activities (EPAs) and related policies and studies in China in recent years, this article constructs a framework of EPAs with the features of orthopedics by detailing the EPAs of specified clinical operation. On this basis, this article proposes a competency-oriented standardized training system for orthopedic residents, with the help of teaching evaluation methods to ensure the successful implementation of courses, so as to provide a reference for establishing a training system for surgery based on EPAs.

In recent years, the third medical education reform characterized by competency-based medical education (CBME) is being carried out around the world; however, there are still challenges in bridging competency framework with clinical practice during implementation. With reference to the three-step method for constructing a CBME curriculum system based on entrustable professional activities (EPAs) and related policies and studies in China in recent years, this article constructs a framework of EPAs with the features of orthopedics by detailing the EPAs of specified clinical operation. On this basis, this article proposes a competency-oriented standardized training system for orthopedic residents, with the help of teaching evaluation methods to ensure the successful implementation of courses, so as to provide a reference for establishing a training system for surgery based on EPAs.

Objective:To investigate the effect and mechanism of SIRT7 in epithelial mesenchymal transformation (EMT) of pancreatic cancer cells.Methods:The pancreatic cancer cells were divided into siControl, siSIRT7, over-expression SIRT7, siSIRT7+siCOL4A1, and siSIRT7+siSLUG groups using siRNA or plasmid transfection. The proliferation, migration and invasion of pancreatic cancer cells were detected by EdU, wound healing assay and Transwell experiments, respectively. The expression of EMT and cancer stem cell (CSC) markers were detected by quantitative real-time reverse transcription polymerase chain reaction assay (qRT-PCR) and western blot. RNA sequencing (RNA-seq) in SIRT7 knockdown PANC-1 cells was performed to explore the signaling pathways and target genes regulated by SIRT7. Then the target genes directly regulated by SIRT7 were identified with quantitative chromatin immunoprecipitation experiment (q-ChIP) and chromatin immunoprecipitation polymerase chain reaction (ChIP-PCR). The expressions of SIRT7 and target genes were detected by immunohistochemical (IHC) in pancreatic cancer tissues, and the correlation between SIRT7 and target gene expression was analyzed using TCGA dataset. The correlation between expression of SIRT7 or target genes and survival was analyzed on KM-plotter website. Finally, GeneMANIA, STRING and ENCORI were used to predict SIRT7-related proteins and miRNAs.Results:EdU assay showed that the cell proliferation rates in SIRT7-overexpressed PANC-1 [(19.33±0.35)%] and BxPC-3 cells [(17.00±1.89)%] were lower than those in the control group [(31.60±1.37)% and (24.33±0.78)%, respectively, P＜0.05]. The proliferation rates of SIRT7-knockdown PANC-1 [(23.94±1.00)% and (27.08±0.97)%] and BxPC-3 cells [(22.00±1.86)% and (25.96±1.61)%] were higher than those of the siControl group [(11.80±1.86)% and (13.42±1.39)%, respectively, P＜0.05]. In PANC-1 cells, the wound healing assay showed that the relative migration rate of SIRT7-overexpression cells [(76.67±2.74)%] was lower than that of control cells [(100.00±2.13)%, P＜0.05]; the relative migration rate of cells with SIRT7 knockdown [(134.22±4.08)% and (199.82±9.20)%, respectively] was higher than that of siControl group [(102.24±3.13)%, P＜0.05]. Compared with the control group, SIRT7 overexpression decreased the number of migrated BxPC-3 cells (45.66±1.69 vs 28.33±2.62, P＜0.05); while SIRT7 knockdown increased these numbers (65.66±2.86 and 82.00±2.94 versus 33.00±0.81, P＜0.01). Transwell experiment revealed that the number of invaded cells in SIRT7 overexpression groups (16.33±2.05 and 34.66±1.69) was lower than that control groups (54.33±4.64 and 58.66±5.90, P＜0.05); with SIRT7 knockdown, the numbers of invaded PANC-1 (63.66±2.49 and 69.33±3.29) and BxPC-3 cells (134.33±3.09 and 181.66±4.02) were higher than those in control groups (35.33±2.49 and 42.00±0.81, P?0.05). Also, SIRT7 knockdown decreased the expressions of epithelial markers and increased the expressions of mesenchymal and CSC markers. RNA-seq analysis showed that SIRT7 was involved in regulating a variety of cancer-related signaling pathways, including the pancreatic cancer pathway and the EMT pathway. Furthermore, SIRT7 could directly bind to the promoter regions of target genes, such as COL4A1 and SLUG. SIRT7 was negatively correlated with the expression and function of COL4A1 and SLUG in pancreatic cancer cells. The expressions of SIRT7, COL4A1, SLUG and SOX2 were verified in pancreatic cancer tissues by IHC. Finally, SIRT7 was predicted to be associated with many proteins and miRNAs based on GeneMANIA, STRING, and ENCORI online tools. Conclusions:SIRT7 can inhibit the EMT of pancreatic cancer cells through transcriptionally inhibiting the expression of target genes, such as COL4A1 and SLUG. Thus, SIRT7 may serve as a potential tumor suppressor gene in pancreatic cancer.

Objective:To investigate the effect and mechanism of SIRT7 in epithelial mesenchymal transformation (EMT) of pancreatic cancer cells.Methods:The pancreatic cancer cells were divided into siControl, siSIRT7, over-expression SIRT7, siSIRT7+siCOL4A1, and siSIRT7+siSLUG groups using siRNA or plasmid transfection. The proliferation, migration and invasion of pancreatic cancer cells were detected by EdU, wound healing assay and Transwell experiments, respectively. The expression of EMT and cancer stem cell (CSC) markers were detected by quantitative real-time reverse transcription polymerase chain reaction assay (qRT-PCR) and western blot. RNA sequencing (RNA-seq) in SIRT7 knockdown PANC-1 cells was performed to explore the signaling pathways and target genes regulated by SIRT7. Then the target genes directly regulated by SIRT7 were identified with quantitative chromatin immunoprecipitation experiment (q-ChIP) and chromatin immunoprecipitation polymerase chain reaction (ChIP-PCR). The expressions of SIRT7 and target genes were detected by immunohistochemical (IHC) in pancreatic cancer tissues, and the correlation between SIRT7 and target gene expression was analyzed using TCGA dataset. The correlation between expression of SIRT7 or target genes and survival was analyzed on KM-plotter website. Finally, GeneMANIA, STRING and ENCORI were used to predict SIRT7-related proteins and miRNAs.Results:EdU assay showed that the cell proliferation rates in SIRT7-overexpressed PANC-1 [(19.33±0.35)%] and BxPC-3 cells [(17.00±1.89)%] were lower than those in the control group [(31.60±1.37)% and (24.33±0.78)%, respectively, P＜0.05]. The proliferation rates of SIRT7-knockdown PANC-1 [(23.94±1.00)% and (27.08±0.97)%] and BxPC-3 cells [(22.00±1.86)% and (25.96±1.61)%] were higher than those of the siControl group [(11.80±1.86)% and (13.42±1.39)%, respectively, P＜0.05]. In PANC-1 cells, the wound healing assay showed that the relative migration rate of SIRT7-overexpression cells [(76.67±2.74)%] was lower than that of control cells [(100.00±2.13)%, P＜0.05]; the relative migration rate of cells with SIRT7 knockdown [(134.22±4.08)% and (199.82±9.20)%, respectively] was higher than that of siControl group [(102.24±3.13)%, P＜0.05]. Compared with the control group, SIRT7 overexpression decreased the number of migrated BxPC-3 cells (45.66±1.69 vs 28.33±2.62, P＜0.05); while SIRT7 knockdown increased these numbers (65.66±2.86 and 82.00±2.94 versus 33.00±0.81, P＜0.01). Transwell experiment revealed that the number of invaded cells in SIRT7 overexpression groups (16.33±2.05 and 34.66±1.69) was lower than that control groups (54.33±4.64 and 58.66±5.90, P＜0.05); with SIRT7 knockdown, the numbers of invaded PANC-1 (63.66±2.49 and 69.33±3.29) and BxPC-3 cells (134.33±3.09 and 181.66±4.02) were higher than those in control groups (35.33±2.49 and 42.00±0.81, P?0.05). Also, SIRT7 knockdown decreased the expressions of epithelial markers and increased the expressions of mesenchymal and CSC markers. RNA-seq analysis showed that SIRT7 was involved in regulating a variety of cancer-related signaling pathways, including the pancreatic cancer pathway and the EMT pathway. Furthermore, SIRT7 could directly bind to the promoter regions of target genes, such as COL4A1 and SLUG. SIRT7 was negatively correlated with the expression and function of COL4A1 and SLUG in pancreatic cancer cells. The expressions of SIRT7, COL4A1, SLUG and SOX2 were verified in pancreatic cancer tissues by IHC. Finally, SIRT7 was predicted to be associated with many proteins and miRNAs based on GeneMANIA, STRING, and ENCORI online tools. Conclusions:SIRT7 can inhibit the EMT of pancreatic cancer cells through transcriptionally inhibiting the expression of target genes, such as COL4A1 and SLUG. Thus, SIRT7 may serve as a potential tumor suppressor gene in pancreatic cancer.

Previous studies have found that As2 O3 can interfere with serum thyroid hormone TH levels in rats and cause chronic liver damage,but the mechanism remains unclear.In order to ex-plore the role of TH signaling pathway in As2 O3-induced chronic liver injury,qRT-PCR and West-ern blot techniques were used to detect the expression changes of genes and protein of TRβ1(a key regulator of TH signaling pathway in rat liver)and cyclin D1(the downstream factor of TRβ1 in nuclear pathway).Meanwhile,the changes in the protein of key factors(Bax,Bcl-2)of the TH sig-nal nuclear outside pathway were detected.The results indicated that:after As2 O3 treatment for 110 days,compared with the control group,the expression of TRβ1 protein in the liver of female mice significantly decreased(P＜0.01),the expression of cyclin D1 significantly increased in the 0.1 and 0.2 mg/L groups(P＜0.01).Meanwhile,the expression of TRβ1 protein in male mice sig-nificantly decreased in 0.4 mg/L group(P＜0.01),and the expression of cyclin D1 in each group significantly increased(P＜0.01).The mRNA expression results were basically the same as those of protein expression.After As2 O3 treatment for 194 days,compared with the control group,the expression of TRβ1 protein in each group significantly decreased(P＜0.01),and the expression of cyclin D1 significantly increased(P＜0.01).The mRNA expression results were basically consist-ent with the protein.As2 O3 interfered with the expression of Bcl-2 and Bax proteins in rats and in-duced the increase in the ratio of Bcl-2/Bax protein as the action time increased.Among them,the Bcl-2/Bax ratio of female rats in each group and male rats in the 0.4 mg/L group significantly in-creased(P＜0.01),and male rats in the 0.1 mg/L group significantly increased(P＜0.05).It shows that As2O3 can cause abnormal levels of TRβ1,cyclin D1 and the Bcl-2/Bax ratio in rat liv-er.

Polycystic ovary syndrome (PCOS) is one of the most common gynaecological endocrine diseases in women and the main cause of anovulatory infertility. Compared with women with normal ovulation, PCOS patients are more likely to face ovarian hyperstimulation syndrome, poor-quality of oocyte and fertilization failure in assisted reproduction treatment, so ovulation induction in PCOS patients has attracted much attention in the reproductive field. Progestin-primed ovarian stimulation (PPOS) protocol uses exogenous progesterone effectively to block luteinizing hormone surge to achieve ideal number of retrieved oocytes, embryo quality and pregnancy outcomes. This article reviews the mechanism, clinical application and development of PPOS protocol in PCOS patients.

Polycystic ovary syndrome (PCOS) is one of the most common gynaecological endocrine diseases in women and the main cause of anovulatory infertility. Compared with women with normal ovulation, PCOS patients are more likely to face ovarian hyperstimulation syndrome, poor-quality of oocyte and fertilization failure in assisted reproduction treatment, so ovulation induction in PCOS patients has attracted much attention in the reproductive field. Progestin-primed ovarian stimulation (PPOS) protocol uses exogenous progesterone effectively to block luteinizing hormone surge to achieve ideal number of retrieved oocytes, embryo quality and pregnancy outcomes. This article reviews the mechanism, clinical application and development of PPOS protocol in PCOS patients.

A global expert consensus (the Delphi consensus) on follicular development, pituitary inhibition, triggering ovulation, and luteal phase support was organized and published in 2021 by Merck Darmstadt, Germany, to further complement the 2019 European Society of Human Reproduction and Embryology (ESHRE) Guidelines on Ovarian Stimulation by in vitro Fertilization (IVF)/Intracytoplasmic Sperm Injection(ICSI). Compared with the ESHRE guidelines, the Delphi consensus incorporates more types of research evidence and expert experience, and finally the expert group has reached a good consensus on follicular development, pituitary suppression and triggering of ovulation, but luteal support is still controversial. This article intends to provide a reference for the optimization of assisted reproductive technology through the interpretation of this consensus.