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.

BACKGROUND:Long non-coding RNA(LncRNA)plays an important role in nervous system development and neurological diseases.Previous studies by the research team have demonstrated that human umbilical cord mesenchymal stem cells overexpressing erythropoietin(EPO-MSCs)under ischemic and hypoxic conditions have better neuroprotective functions and significantly activate the expression of LncRNA XIST.Research suggests that XIST is related to the pathogenesis of hypoxic-ischemic encephalopathy,but the role and mechanism of its regulation by EPO-MSCs in protecting ischemic-hypoxic neurons remain unclear.OBJECTIVE:To explore the new mechanism by which LncRNA XIST,in response to EPO-MSC signaling,affects the apoptosis of ischemic-hypoxic SH-SY5Y cells.METHODS:(1)SH-SY5Y cell lines with knockdown of LncRNA XIST(sh-XIST)and negative control(NC-XIST)were constructed through lentiviral transfection.Oxygen-glucose deprivation was used to induce ischemic-hypoxic injury in the cells.Transwell chambers were used to create a non-contact co-culture system with EPO-MSCs,sh-XIST,and NC-XIST ischemic-hypoxic SH-SY5Y cells.Cell proliferation ability was detected using the CCK-8 assay.Cell migration ability was assessed using the scratch assay,and cell apoptosis was measured by flow cytometry.(2)RNA-seq bioinformatics analysis was performed to screen for differentially expressed genes and pathways between sh-XIST and NC-XIST cell lines.Dual-luciferase experiments were used to verify the relationship between miR-124-3p and the target genes XIST and GRIN1.qRT-PCR was conducted to validate the expression levels of downstream miR-124-3p and GRIN1 genes.(3)miR-124-3p inhibitors and mimics were added to verify phenotypic changes in SH-SY5Y cells after ischemic-hypoxic injury and co-culture with EPO-MSCs.RESULTS AND CONCLUSION:(1)Compared with the NC-XIST group,SH-SY5Y cells in the sh-XIST group showed reduced proliferation and migration abilities and increased apoptosis after ischemic-hypoxic injury and co-culture with EPO-MSCs.(2)Dual-luciferase experiments showed that miR-124-3p interacted with the target gene XIST.SH-SY5Y cells transfected with miR-124-3p mimics and co-cultured with EPO-MSCs showed decreased apoptosis after ischemic-hypoxic injury,while SH-SY5Y cells transfected with miR-124-3p inhibitors showed increased apoptosis after co-culture with EPO-MSCs.(3)Transcriptomic sequencing and bioinformatics analysis of sh-XIST revealed significant downregulation of the neuroactive ligand-receptor pathway and the key receptor gene GRIN1 for central nervous system development.(4)Dual-luciferase experiments showed that miR-124-3p interacted with GRIN1.GRIN1 expression was significantly downregulated in the sh-XIST group after ischemic-hypoxic injury compared with the NC-XIST group.These findings indicate that LncRNA XIST promotes GRIN1 expression by upregulating miR-124-3p,thereby reducing cell apoptosis after ischemic-hypoxic injury and co-culture with EPO-MSCs and enhancing proliferation and migration.sh-XIST can block this protective function.

Objective:To identify and evaluate the important risk factor set of anxiety and depression in occupational population, establish a risk prediction model, and provide scientific basis for making targeted mental health protection plan and promoting the mental health of workers.Methods:In August 2016, a cluster random sampling method was used to investigate 807 employees who underwent physical examination in a hospital as research objects. The simplified Chinese version of the core job content questionnaire, Athens Insomnia Scale, AIS-5 and Symptom Check List-90 (SCL-90) were used for the Occupational stress, insomnai and negative emotional symptom investigation. Chi-square and Fisher exact probability method were used for data analysis, and Bayesian network was used for model construcion and analysis.Results:The score of occupational stress was 0.88±0.15, and the incidence of occupational stress was 18.09% (146/807). AIS-5 scores were (3.03±2.82), and the incidence of insomnia was 15.99% (129/807). Depression (16.89±5.73) scores, anxiety (12.36±4.11) scores. Depression (16.89±5.73) score, anxiety (12.36±4.11) score, the detection rate was 8.55% (69/755), 7.31% (59/762). Gender, illness, education, insomnia and occupational stress were correlated with depression ( P<0.01), while education, illness, insomnia and anxiety were correlated ( P<0.05). When both occupational stress and insomnia existed, the detection rate of depression was the highest (0.4006) . Conclusion:Insomnia was a valid predictor of anxiety and depression, suggesting that occupational groups should pay attention to sleep quality and managers should rationalize work tasks in order to reduce the risk of anxiety and depression.

A recombinant adenovirus(rAd)for expression of Mycobacterium tuberculosis(M.tb)c-di-AMP phosphodiesterase CnpB was constructed,and its induced humoral immune response was detected.The codon-optimized gene of M.tb CnpB was cloned into the adenoviral plasmid pcADV.The recombinant plasmid pcADV-CnpB was transfected into HEK293T cells,and expression was detected with Western blot.The recombinant plasmid pcADV-CnpB and the backbone plasmid were co-transfected into HEK293T cells to obtain the recombinant adenovirus rAd-CnpB.rAd-CnpB was amplified in HEK293T cells,and the target protein expression of rAd-CnpB was detected with Western blot and immunofluorescence.Mice were immunized with rAd-CnpB intranasally,and their sera and bronchoalveolar lavage fluid(BALF)were collected.ELISA was used to detect levels of antigen-specific antibodies.Restriction enzyme digestion and sequencing indicated that the recombinant plasmid pcADV-CnpB was successfully constructed and led to protein expression in eukaryotic cells.rAd-CnpB was packaged and produced in HEK293T cells.After amplification and purification,rAd-CnpB with a titer of 5.53×1010 PFU/mL was obtained.rAd-CnpB led to CnpB expression in HEK293T cells.Intranasal immunization with rAd-CnpB increased levels of IgG and secretory IgA in BALF and led to high levels of IgG in sera.rAd-CnpB,the recombinant adenovirus for expression of c-di-AMP phosphodiesterase CnpB was successfully constructed,and was found to induce antigen-specific humoral and mucosal immune responses through mucosal immunization.Thus,rAd-CnpB may be used in further research on new TB vaccine strategies.

This study assessed the role and mechanism of the recombinant Bacillus Calmette-Gue?rin vaccine(rBCG)with c-di-AMP adjuvant in regulating metabolism and immunity in epididymal white adipose(eWAT)in mice.Male C57BL/6 mice were intravenously immunized with BCG and rBCG,and their body weights were monitored.eWAT was isolated from the mice,and the stromal vascular fractions(SVFs)cell number was counted with a hemocytometer.Sections of mouse adipose tissue were prepared,and the size,number,and morphology of eWAT adipocytes and crown-like structure(CLS)formation were compared under a microscope after HE staining.The transcription levels of lipid metabolism-associated factors,cytokines and aging-associated genes in each group were determined with qRT-PCR.The body weights of mice gradually increased after immunization with BCG and rBCG.The proportions of eWAT increased,and the SVFs cell number decreased,in rBCG immunized mice.HE staining indicated that BCG immunization promoted hyperplasia,whereas rBCG immunization promoted hypertrophy of eWAT adipocytes;moreover,both BCG and rBCG immunization induced CLS formation in eWAT.The qRT-PCR results indicated that rBCG immunization inhibited the expression of genes associated with lipolysis and energy expenditure in eWAT.BCG immunization had little effect on cytokine transcription,whereas rBCG significantly induced the transcription of IFN-γ and IL-1Ra,and inhibited that of IL-15 and IL-2,but did not induce the expression of aging-associated genes.Thus,rBCG immunization induced eWAT adipocyte hypertrophy,which was associated with the inhibition of eWAT lipolysis and the regulation of cytokine expression.

Objective:To observe the therapeutic effect of Edaravone Dexborneol combined with aspirin and clopidogrel in the treatment of acute ischemic stroke(AIS).Methods:82 AIS patients were randomly divided into control group(treated with aspirin and clopidogrel,n=41)and observation group(treated with Edaravone Dexborneol on the basis of control group,n=41)by random number table method.National Institutes of Health Stroke Scale(NIHSS),Montreal Cognitive Assessment Scale(MoCA),Barthel Index(BI),serum biochemical indicators[neuron specific enolase(NSE),superoxide dismutase(SOD),brain-derived neurotrophic factor(BDNF),malondialdehyde(MDA)],intracranial hemodynamic indicators[bilateral anterior cerebral artery(ACA),bilateral middle cerebral artery(MCA),bilateral posterior cerebral artery(PCA)],and incidence of adverse reactions during treatment were compared between the two groups.Results:The total clinical effective rate,MoCA,BI score,BDNF,SOD,and the average flow rates of ACA,MCA,and PCA in the observation group 14 d after treatment were higher than those in control group,NIHSS score,NSE,and MDA were lower than those in control group(P＜0.05).There was no significant difference in the incidence of adverse reactions between the two groups(P＞0.05).Conclusion:Edaravone Dexborneol combined with aspirin and clopidogrel in AIS treatment can significantly improve intracranial hemodynamics,regulate nerve factors,reduce nerve function damage,and has good safety.

Objective:To investigate the clinical features and multi-slice spiral computed tomography(CT)imaging features of acute appendicitis in soldiers who have been living in plateau for a long time.Methods:The clinical features and imaging data of 56 cases of acute appendicitis in soldiers who have been living in plateau for a long time confirmed by surgery from February 2022 to August 2024 were retrospectively analyzed.Results:In 56 cases with acute appendicitis in soldiers who have been living in plateau for a long time,the appendectomy position results showed:anterior ileum 4 cases(7.14％),lower ileum 10 cases(17.86％),posterior cecum 16 cases(28.57％),lower cecum 9 cases(16.07％),lateral cecum 2 cases(3.58％),posterior ileum 6 cases(10.71％),high(subhepatic)9 cases(16.07％),and left lower abdominal 0 cases,retroperitoneal appendicitis 0 cases,which was suggested that the anatomical position variation of appendicitis in soldiers with acute appendicitis who have been living at high altitude for a long time was relatively large.The direct manifestations of multi-slice spiral CT showed:appendectomy enlarged diameter＞6 mm in 49 cases(87.50％),appendicular wall thickening＞2 mm in 42 cases(75.00％),ppendiceal dilation lumen and effusion in 29 cases(51.79％),appendix indistinctness in 3 cases(5.36％),lppendix fecalith:27 cases(48.21％),gas in the appendix in 16 cases(28.57％).Indirect findings of multi-slice spiral CT showed that,periappendiceal exudation with shadow in 32 cases(57.14％),appendiceal cellulitis with peripheral abscess in 9 cases(16.07％),peritonitis and ascites in 13 cases(23.21％),ileocecal intestinal wall thickening in 22 cases(39.29％),mesenteric lymph node enlargement in 16 cases(28.57％),reflexive intestinal stasis in ileocecal region was observed in 19 cases(33.93％).Conclusion:In the officers and soldiers with acute appendicitis who lived at high altitude for a long time,multi-slice spiral CT showed the direct manifestations of appendiceal thickening,tube wall thickening,lumen dilatation,fluid accumulation,etc.,and the indirect manifestations were periappendiceal exudation with shadow,appendiceal cellulitis with peripheral abscess,ileocecal intestinal wall thickening,reflexes of small intestine and mesenteric lymph node enlargement.Multi-slice spiral CT has the advantages of clear and intuitive,high safety,high resolution and simple operation in the diagnosis of acute appendicitis.

Objective Based on a clinical cohort study of repeated ketamine infusions for treatment-resistant depression(TRD),this study aimed to examine differences in brain-derived neurotrophic factor(BDNF)methylation among patients with varying therapeutic responses and explore its potential role in predicting treatment efficacy.Methods A retrospective analysis was conducted on peripheral plasma BDNF levels in 83 patients with TRD before and after a 2-week course of ketamine treatment(6 injections total).The Montgomery-Asberg depression rating scale(MADRS)was used to assess treatment efficacy.BDNF methylation levels were compared between responder group and non-responder group.The effect of methylation of the target CpG site on transcriptional activity was verified by using the dual luciferase reporter gene system.Results In patients with TRD who completed six repeated ketamine infusions,the responder group showed significant improvements compared to baseline levels in both MADRS scores(25.20±7.54 vs.8.10±5.32,P<0.01)and plasma BDNF concentrations[8.74(5.26,13.46)ng/mL vs.16.59(7.41,24.46)ng/mL,P<0.01].At baseline,35 CpG sites within the BDNF gene displayed significant methylation differences between response groups(P<0.05).Two CpG sites(rs1240718851 and cg06260077)located in the BDNF promoter region demonstrated a hypermethylation-low expression correlation,and dual-luciferase reporter assays confirmed that one of these sites functionally modulates BDNF expression.Conclusions The plasma BDNF concentration in TRD patients increases with the remission of depressive symptoms.The regulation of BDNF gene expression by methylation can predict the antidepressant efficacy of repeated intravenous ketamine.

Aim To investigate the role of miR-130b-3p in regulating the USP47/NLRP3 inflammasome in airway remodeling associated with asthma and to explore its potential therapeutic value in asthma treat-ment.Methods An OVA-induced asthma mouse mod-el was established,and intervention with miR-130b-3p agomir was performed.Histological staining,quantita-tive real-time PCR,Western blot,immunofluorescence and flow cytometry were used to analyze the effects of miR-130b-3p on the expression of USP47,NLRP3,and related inflammatory factors,as well as the inflamma-some activity.Results miR-130b-3p was significantly downregulated in asthmatic mice,and its intervention significantly inhibited airway epithelial damage,inflam-matory cell infiltration,and collagen deposition.Addi-tionally,miR-130b-3p targeted USP47 and indirectly suppressed NLRP3 expression,leading to reduced in-flammasome activity and alleviated asthma-related in-flammatory responses.Conclusion miR-130b-3p re-duces asthma-related inflammatory responses by down-regulating USP47 expression and indirectly inhibiting NLRP3 inflammasome activity.

Paraplegia caused by spinal cord injury is a serious neurological complication, for which surgery is currently the main treatment method. Due to different surgical approaches, patients are usually expected to maintain a passive prone position for a long time or switch between the supine and prone positions. Affected by multiple factors such as neurogenic sensory disorders, pathological changes in muscle tone and operative duration, the risk of intraoperative acquired pressure injury (IAPI) is significantly increased. Current clinical prevention strategies for IAPI in these patients predominantly focus on localized pressure relief during positioning, lacking systematic, standardized comprehensive prevention protocols or evidence-based guidelines. To address it, Department of Nursing, Orthopedics Branch, China International Exchange and Promotive Association for Medical and Health Care, Spinal Trauma Professional Committee, Orthopedics Branch, Chinese Medical Doctor Association, Nursing Group of Spine and Spinal Cord Professional Committee of Chinese Association of Rehabilitation Medicine organized experts in relevant fields to formulate Guideline for the prevention of intraoperative acquired pressure injury in paraplegic patients with spinal cord injury ( version 2025), based on evidence-based medical evidence and latest research results and clinical practice at home and abroad. Eleven recommendations were put forward from the aspects of preoperative risk assessment, intraoperative prevention strategies, postoperative handover and monitoring, and supportive mechanisms for IAPI prevention, aiming to standardize the prevention measures and management strategies of IAPI in paraplegic patients with spinal cord injury and accelerate the recovery of patients and improve the therapeutic effect.