Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Tumor drug resistance is an important problem in the failure of chemotherapy and targeted drug therapy, which is a complex process involving chromatin remodeling. SWI/SNF is one of the most studied ATP-dependent chromatin remodeling complexes in tumorigenesis, which plays an important role in the coordination of chromatin structural stability, gene expression, and post-translation modification. However, its mechanism in tumor drug resistance has not been systematically combed. SWI/SNF can be divided into 3 types according to its subunit composition: BAF, PBAF, and ncBAF. These 3 subtypes all contain two mutually exclusive ATPase catalytic subunits (SMARCA2 or SMARCA4), core subunits (SMARCC1 and SMARCD1), and regulatory subunits (ARID1A, PBRM1, and ACTB, etc.), which can control gene expression by regulating chromatin structure. The change of SWI/SNF complex subunits is one of the important factors of tumor drug resistance and progress. SMARCA4 and ARID1A are the most widely studied subunits in tumor drug resistance. Low expression of SMARCA4 can lead to the deletion of the transcription inhibitor of the BCL2L1 gene in mantle cell lymphoma, which will result in transcription up-regulation and significant resistance to the combination therapy of ibrutinib and venetoclax. Low expression of SMARCA4 and high expression of SMARCA2 can activate the FGFR1-pERK1/2 signaling pathway in ovarian high-grade serous carcinoma cells, which induces the overexpression of anti-apoptosis gene BCL2 and results in carboplatin resistance. SMARCA4 deletion can up-regulate epithelial-mesenchymal transition (EMT) by activating YAP1 gene expression in triple-negative breast cancer. It can also reduce the expression of Ca²⁺ channel IP3R3 in ovarian and lung cancer, resulting in the transfer of Ca²⁺ needed to induce apoptosis from endoplasmic reticulum to mitochondria damage. Thus, these two tumors are resistant to cisplatin. It has been found that verteporfin can overcome the drug resistance induced by SMARCA4 deletion. However, this inhibitor has not been applied in clinical practice. Therefore, it is a promising research direction to develop SWI/SNF ATPase targeted drugs with high oral bioavailability to treat patients with tumor resistance induced by low expression or deletion of SMARCA4. ARID1A deletion can activate the expression of ANXA1 protein in HER2+ breast cancer cells or down-regulate the expression of progesterone receptor B protein in endometrial cancer cells. The drug resistance of these two tumor cells to trastuzumab or progesterone is induced by activating AKT pathway. ARID1A deletion in ovarian cancer can increase the expression of MRP2 protein and make it resistant to carboplatin and paclitaxel. ARID1A deletion also can up-regulate the phosphorylation levels of EGFR, ErbB2, and RAF1 oncogene proteins.The ErbB and VEGF pathway are activated and EMT is increased. As a result, lung adenocarcinoma is resistant to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Although great progress has been made in the research on the mechanism of SWI/SNF complex inducing tumor drug resistance, most of the research is still at the protein level. It is necessary to comprehensively and deeply explore the detailed mechanism of drug resistance from gene, transcription, protein, and metabolite levels by using multi-omics techniques, which can provide sufficient theoretical basis for the diagnosis and treatment of poor tumor prognosis caused by mutation or abnormal expression of SWI/SNF subunits in clinical practice.

Platelets have long been recognized as key players in hemostasis and thrombosis; however, there is growing evidence that they are also involved in cancer. Preclinical and clinical studies have shown that platelets can promote tumorigenesis and metastasis through various crosstalks between platelets and cancer cells. Platelets play an active role in all stages of tumorigenesis, including tumor growth, tumor cell extravasation, and metastasis. In addition, thrombocytosis in cancer patients is associated with poor patient survival. Platelets are also well-placed to coordinate local and distant tumor-host interactions due to the a- bundance of microparticles and exosomes. Therefore, antitumor drugs targeting platelets have great development and application prospects. The following will review the research progress of anti-tumor drugs targeting platelets.

Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.

Objective To retrospectively investigate the efficacy of pelvic floor muscle training(PFMT)using APP-based home device in the real-world scenario.Methods A retrospective survey was conducted among 171 000 Chinese female users over 18 years old who freely registered APP and performed PFMT using a domestic manufactured home device from Oct 1,2019 to Mar 31,2021.The Patient Global Impression of Improvement(PGI-I)questionnaires concerning pelvic floor general condition,sexual satisfaction and other three major symptoms related to pelvic floor muscle laxity such as stress urinary incontinence(SUI),pelvic organ prolapse(POP),and vaginal laxity(VL)were broadcast public online for users to self-assess the improvement.The vaginal muscle strength values prior and post training recorded by APP were also reported.All data were collected anonymously for further stratified analysis.Results A total of 984 valid questionnaires were collected by systematic sampling.The PGI-I scores of pelvic floor general condition(P=0.000 1),sexual satisfaction(P=0.009),SUI(P=0.000 1),POP(P=0.044)and VL(P=0.034)were statistically significant in users who reported to use the device for 3 months or more compared with those less than 3 months.In addition,the increase of vaginal muscle strength was related to the improvement of PGI-I scores in SUI and POP with statistical significance.There were no significant difference in subgroups such as age,education,parity,and delivery mode.Conclusion The subjective benefit of pelvic floor function-related symptoms and the improvement of vaginal muscle strength could be observed after PFMT for three months or more using APP-based home device in Chinese women in the real-world scenario.

BACKGROUND:Croton cream can activate ERK pathways and have anti-apoptotic effects on neuronal cells.It is not clear whether it synergistically exerts anti-apoptotic effects by inhibiting the activation of JNK and p38 pathways. OBJECTIVE:To explore the effects and mechanisms of croton cream on neuronal damage and apoptosis in the ischemic cortex of rats with cerebral ischemia-reperfusion injury. METHODS:(1)Ninety Sprague-Dawley rats were randomly divided into sham operation group,model group,croton cream low-dose group,croton cream medium-dose group,croton cream high-dose group and nimodipine group,with 15 rats in each group.Except for the sham operation group,animal models of middle cerebral artery occlusion were prepared in rats by the thread method.Rats in the three croton cream groups were given 20,40,and 60 mg/kg croton cream,respectively.Rats in the sham operation and model groups were given the same amount of normal saline,once a day,for 7 consecutive days.The optimal concentration of croton cream,namely the high dose of croton cream,was selected based on neurological deficit score,TTC staining,brain tissue water content,hematoxylin-eosin staining and Nissl staining.(2)Another 120 Sprague-Dawley rats were randomly divided into sham operation group,model group,croton cream group,JNK inhibitor group,croton cream+JNK inhibitor group,p38 MAPK inhibitor group,croton cream+p38 MAPK inhibitor group,and nimodipine group,with 15 rats in each group.Animal models of middle cerebral artery occlusion were prepared using the thread method in all the groups except in the sham operation group.Thirty minutes before modeling,10 μL of SP600125(JNK inhibitor)and 10 μL of SB203580(p38 MAPK inhibitor)were injected into the lateral ventricle of the rats,respectively.Rats in croton cream groups were intragastrically given 60 mg/kg croton cream.Seven days later,the JNK/p38 MAPK signaling pathway,apoptosis-related proteins and cell apoptosis were detected by western blot,TUNEL staining and flow cytometry,respectively. RESULTS AND CONCLUSION:(1)Compared with the sham operation group,neurological deficit score,cerebral water content,cerebral infarction volume and apoptosis rate were significantly increased in the model group(P<0.05),where nerve cells showed scattered distribution.Compared with the model group,neurological deficit score,water content of brain tissue and cerebral infarction volume were significantly decreased in the croton cream medium-dose group,high-dose group and nimodipine group(P<0.05),and the pathological morphology of nerve cells was significantly improved.(2)Compared with the JNK inhibitor group,p-JNK/JNK,p-p38/p38 and Bax expressions in rat brain tissue and the apoptotic rate were significantly decreased in the croton cream+inhibitor groups(P<0.05),while the expression of and Bcl-2 was significantly increased(P<0.05).To conclude,croton cream may inhibit the activation of JNK/p38 MAPK signaling pathway and reduce neuronal apoptosis to achieve neuroprotective effects in rats with cerebral ischemia-reperfusion injury.

Acupuncture, a therapeutic treatment defined as the insertion of needles into the body at specific points (ie, acupoints), has growing in popularity world-wide to treat various diseases effectively, especially acute and chronic pain. In parallel, interest in the physiological mechanisms underlying acupuncture analgesia, particularly the neural mechanisms have been increasing. Over the past decades, our understanding of how the central nervous system and peripheral nervous system process signals induced by acupuncture has developed rapidly by using electrophysiological methods. However, with the development of neuroscience, electrophysiology is being challenged by calcium imaging in view field, neuron population and visualization in vivo. Owing to the outstanding spatial resolution, the novel imaging approaches provide opportunities to enrich our knowledge about the neurophysiological mechanisms of acupuncture analgesia at subcellular, cellular, and circuit levels in combination with new labeling, genetic and circuit tracing techniques. Therefore, this review will introduce the principle and the method of calcium imaging applied to acupuncture research. We will also review the current findings in pain research using calcium imaging from in vitro to in vivo experiments and discuss the potential methodological considerations in studying acupuncture analgesia.
Calcium ; Acupuncture Therapy ; Acupuncture ; Acupuncture Analgesia/methods* ; Acupuncture Points ; Technology

Objective To investigate the involvement of phosphofurin acidic cluster sorting protein-2(PACS-2)in mitochondrial function and apoptosis in N2a/APP695swe cells and further explore the role and significance of PACS-2 in the development of Alzheimer's disease(AD).Methods The CCK8 method was used to analyze the cell survival rate of N2a/APP695swe cells treated with different concentrations of tetrahydroxy stilbene glycoside(TSG)for 48h and to select the appropriate concentration of TSG for subsequent experiments.N2a/WT cells and N2a/APP695swe cells were routinely cultured in vitro,and the experimental cells were divided into 3 groups:blank control group(WT group):N2a/WT cells;model group(APP group):N2a/APP695swe cells;treatment group(TSG group):N2a/APP695swe cells with appropriate concentrations of TSG intervention.TUNEL method to observe apoptosis by fluorescence microscopy;JC-1 method for flow detection of cellular mitochondrial membrane potential;WB to detect protein expression of PACS-2;RT-qPCR to detect PACS-2 mRNA expression.Results CCK8 method was used to analyze the cell survival rate of different concentrations of TSG acting on cells after 48h:the protective effect of 100 μmol/L TSG was the most significant and the difference was statistically significant(P<0.01).The TUNEL method of fluorescence microscopy observed the apoptosis:compared with the WT group,the apoptosis rate of APP group was increased,compared with the APP group,the apoptosis rate of TSG group was decreased,and the differences were statistically significant(P<0.05).The JC-1 method was used to detect the mitochondrial membrane potential of cells:compared with the WT group,the membrane potential of APP group was decreased,compared with the APP group,the membrane potential of TSG group was increased,and the differences were statistically significant(P<0.05);Western blot(WB)detection of PACS-2 protein expression:compared with the WT group,PACS-2 expression was significantly higher in the APP group,and compared with the APP group,PACS-2 expression was significantly lower in the TSG group,with statistically significant differences(P<0.05);The RT-qPCR detected the mRNA expression of PACS-2:the expression of PACS-2 was elevated in the APP group compared with the WT group and decreased in the TSG group compared with the APP group,with statistically significant differences(P<0.05).Conclusion PACS-2 has an important role in the development of AD,and its upregulation may promote the development of AD.The cerebroprotective drug TSG may exert cytoprotective effects by downregulating PACS-2 to inhibit apoptosis and improve mitochondrial function in AD model cells.

ObjectiveProtein arginine methyltransferases (PRMTs) play pivotal roles in numerous cellular biological processes. However, the precise regulatory effects of PRMTs on the fate determination of mesenchymal stromal/stem cells (MSCs) remain elusive. Our previous studies have shed light on the regulatory role and molecular mechanism of PRMT5 in MSC osteogenic differentiation. This study aims to clarify the role and corresponding regulatory mechanism of PRMT7 during the adipogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Methods(1) Human bone marrow-derived mesenchymal stem cells (hBMSCs) were cultured in a medium that induces adipogenesis. We used qRT-PCR and Western blot to monitor changes in PRMT7 expression during adipogenic differentiation. (2) We created a cell line with PRMT7 knocked down and assessed changes in PRMT7 expression and adipogenic capacity using Oil Red O staining, qRT-PCR and Western blot. (3) We implanted hBMSCs cell lines mixed with a collagen membrane subcutaneously into nude mice and performed Oil Red O staining to observe ectopic lipogenesis in vivo. (4) A cell line overexpressing PRMT7 was generated, and we examined changes in PRMT7 expression using qRT-PCR and Western blot. We also performed Oil Red O staining and quantitative analysis after inducing the cells in lipogenic medium. Additionally, we assessed changes in PPARγ expression. (5) We investigated changes in insulin-like growth factor 1 (IGF-1) expression in both PRMT7 knockdown and overexpressing cell lines using qRT-PCR and Western blot, to understand PRMT7’s regulatory effect on IGF-1 expression. siIGF-1 was transfected into the PRMT7 knockdown cell line to inhibit IGF-1 expression, and knockdown efficiency was confirmed. Then, we induced cells from the control and knockdown groups transfected with siIGF-1 in lipogenic medium and performed Oil Red O staining and quantitative analysis. Finally, we assessed PPARγ expression to explore IGF-1’s involvement in PRMT7’s regulation of adipogenic differentiation in hBMSCs. Results(1) During the adipogenesis process of hBMSCs, the expression level of PRMT7 was significantly reduced (P<0.01). (2) The adipogenic differentiation ability of PRMT7 knockdown group was significantly stronger than that of control group (P<0.001). (3) The ectopic adipogenic differentiation ability of PRMT7 knockdown group was significantly stronger than that of control group. (4) The adipogenic differentiation ability of the PRMT7 overexpression group was significantly weaker than that of the control group (P<0.01). (5) The expression level of IGF-1 increased after PRMT7 knockdown (P<0.000 1). The expression level of IGF-1 decreased after PRMT7 overexpression (P<0.000 1), indicating that PRMT7 regulates the expression of IGF-1. After siIGF-1 transfection, the expression level of IGF-1 in all cell lines decreased significantly (P<0.001). The ability of adipogenic differentiation of knockdown group transfected with siIGF-1 was significantly reduced (P<0.01), indicating that IGF-1 affects the regulation of PRMT7 on adipogenic differentiation of hBMSCs. ConclusionIn this investigation, our findings elucidate the inhibitory role of PRMT7 in the adipogenic differentiation of hBMSCs, as demonstrated through both in vitro cell-level experiments and in vivo subcutaneous transplantation experiments conducted in nude mice. Mechanistic exploration revealed that PRMT7’s regulatory effect on the adipogenic differentiation of hBMSCs operates via modulation of IGF-1 signaling pathway. These collective findings underscore PRMT7 as a potential therapeutic target for fatty metabolic disorders, thereby offering a novel avenue for leveraging PRMT7 and hBMSCs in the therapeutic landscape of relevant diseases.

Objective The aim of the study was to investigate how morphine(Mor)effects mitochondrial dynamics change of H9c2 induced by hypoxia/reoxygenation(H/R).Methods Myocardial H9c2 cells were divided into blank group(without treatment),model group(H/R treatment),control group(5 μmol·L-1 Mor treatment)and experimental group(H/R+5 μmol·L-1 Mor treatment).The content of reactive oxygen species(ROS),mitochondrial membrane potential(MMP),and complex of Ⅰ and Ⅲ activity were detected using ROS,tetramethylrhodamine ethyl ester(TMRE),and mitochondrial complex of Ⅰ and Ⅲ activity detection kits,respectively.The morphology of mitochondria and lysosomes was observed by transmission electron microscope electron microscopy(TEM);Western blot was used to detect the expression of GTPase kinetic protein 1(Drp1),cytochrome c oxidase Ⅳ(COX Ⅳ)and transporters of the outer mitochondrial membrane(TOM20).Results The nuclear membrane was smooth and complete;the mitochondrial size was consistent;the crest arrangement was neat;vacuolization was reduced or even disappeared;the mitochondrial matrix electron density was increased;the number of autophagosomes was decreased in the experimental group.The contents of ROS in blank group,model group,control group and experimental group were 1.03±0.04,1.53±0.10,1.06±0.06 and 1.10±0.11;MMP were 1.00±0.15,0.80±0.16,1.06±0.19 and 1.00±0.19;the activities of complex of Ⅰ were 1.00±0.08,2.28±0.82,1.05±0.26 and 1.13±0.37;the activities of complex of Ⅲ were 1.00±0.09,2.13±0.38,0.83±0.22 and 0.96±0.11;the expression of Drp1 protein were 1.00±0.14,1.27±0.07,0.97±0.21 and 0.93±0.17;the expression of fission protein 1(Fis1)protein were 1.00±0.16,1.33±0.18,1.17±0.25 and 0.99±0.05;the expression of COX Ⅳ protein were 1.00±0.25,0.62±0.08,0.79±0.26 and 0.97±0.16;the expression of TOM20 protein were 1.00±0.13,0.67±0.15,0.75±0.13 and 0.89±0.05.The above indexes of model group were significantly different from those of blank group(P＜0.05,P＜0.01,P＜0.001,P＜0.000 1).The above indexes of experimental group were significantly different from those of model group(P＜0.05,P＜0.01,P＜0.001,P＜0.000 1).Conclusion Morphine may inhibit mitophagy and fission,and alleviated mitochondrial oxidative stress damage by decreasing the activity of respiratory chain complex of Ⅰ and Ⅲ,thus maintaining mitochondrial dynamic homeostasis and alleviating H/R-induced myocardial cell damage.