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.

In this study,the immunological characteristics of the PhoP protein were explored with a two-component system of Mycobacterium tuberculosis(Mtb).Bioinformatics was used to predict the B and T cell epitopes of the PhoP protein.A re-combinant expression plasmid was constructed by PCR analysis of the phoP sequence and cloning into the prokaryotic expres-sion vector pET-28a(+).Competent Escherichia coli BL21 cells were transformed with the recombinant plasmid and expres-sion was induced with IPTG.The recombinant PhoP protein was purified by affinity chromatography.Serum levels of PhoP-specific antibodies in Mtb-infected mice and tuberculosis(TB)patients were analyzed with an ELISA.BALB/c mice were im-munized with the PhoP recombinant protein by intramuscular injection.Sera of mice were collected and antibody titers were detected with an ELISA and specificity was assessed by West-ern blot analysis.Mouse splenocytes were isolated and the pro-portions of IFN-y-positive cells and cytokine levels were detec-ted with an ELISpot and ELISA,respectively.Bioinformatics i-dentified 24 B cell and 11 T cell epitopes of the PhoP protein.A prokaryotic recombinant vector of PhoP was successfully con-structed and the recombinant PhoP protein was obtained by purification.Specific antibody levels to PhoP in sera of Mtb in-fected mice and TB patients increased significantly,with preci-sion of 99.9％and 82.5％,and specificity of 100％,respectively.PhoP protein immunization successfully induced production of specific antibodies in mice.Stimulated by antigens in vitro,IL-2 and IFN-γ levels were significantly increased in the splenocytes of immunized mice.Immunization with the PhoP protein induce a humoral immune response and Thl-dominated cellular immu-nity,indicating that the PhoP protein was immunogenic with diagnostic efficacy for TB.These results lay a foundation to clari-fy the role of PhoP in Mtb infection and application for diagnosis and prevention of TB.

Objective:To systematically screen and identify long noncoding RNA(lncRNA)associated with bone marrow adiposity changes in aplastic anemia(AA).Methods:The PPARγ and C/EBPα ChIP-Seq data in ChIPBase was analyzed by bioinformatics and the potential lncRNA co-transcriptionally regulated by PPARγ and C/EBPα was screened.The expression of candidate lncRNA was verified by qRT-PCR in the in vitro adipogenic differentiation model of BM-MSC,BM-MSC infected with lenti-shPPARγ and lenti-shC/EBPα as well as clinical BM-MSC samples derived from AA and controls.Results:PPARγ and C/EBPα were significantly highly expressed in AA BM-MSC,and knock-down of PPARγ and C/EBPα impaired the adipogenic capacity of AA BM-MSC.PPARγ and C/EBPα cotranscriptionally activate LINC01230 promoter activity in binding sites dependant manner.The LINC01230 was also aberrantly highly expressed in AA BM-MSC compared with controls.Conclusion:PPARγ and C/EBPα are aberrantly expressed in AA BM-MSC and may promote the adipogenic differentiation of AA BM-MSC,and to a certain extent mediate the bone marrow adiposity alteration by transcriptionally activating LINC01230 expression.

Objective:To investigate the changes in serum homeobox A9(HOXA9),soluble E-cadherin(SE-CAD)and type Ⅲ procollagen(PCⅢ)levels in acute myeloid leukemia(AML)patients after chemotherapy with DCAG regimen and their relationship with prognosis.Methods:The clinical data of 80 patients with relapsed/refractory AML diagnosed and treated in our hospital from March 2018 to December 2021 were retrospectively analyzed.According to different treatment regimen,the patients were divided into DCAG group(n=40)and CAG group(n=40).The clinical efficacy and changes of HOXA9,SE-CAD and PCⅢ levels before and after treatment were compared.In addition,all patients were divided into remission group(n=58)and non-remission group(n=22)according to the clinical efficacy.Univariate and multivariate analyses were performed to analyze the risk factors affecting the prognosis of AML patients.The predictive efficacy of the three single indicators,HOXA9,SE-CAD,and PC Ⅲ,and their combination on prognosis was analyzed.Results:Compared with before treatment,the levels of HOXA9,SE-CAD and PCⅢ in both the DCAG and CAG groups were decreased after treatment,and the improvement of each indicator and the clinical efficacy in the DCAG group were significantly better than those in the CAG group(all P＜0.05).Multivariate analysis showed that increased bone marrow blast count,HOXA9 mRNA,SE-CAD and PCⅢ levels were independent risk factors affecting the efficacy of chemotherapy in AML patients(all P＜0.05).ROC curves showed that the combination of HOXA9 mRNA,SE-CAD and PCⅢ could effectively predict the prognosis of AML patients,with a sensitivity of 84.80％and a specificity of 88.20％.Conclusion:DCAG regimen can significantly improve the levels of HOXA9 mRNA,SE-CAD and PCⅢ in AML patients,these three indicators are all independent risk factors affecting the prognosis of AML patients,and the combination of the three indicators can effectively predict the prognosis of the patients.

Objective:To investigate the prevalence of uremic pruritus (UP) in patients with peritoneal dialysis and its association with life behaviors.Methods:A total of 255 patients with peritoneal dialysis were followed up in Peritoneal Dialysis Center of Hangzhou Hospital of Traditional Chinese Medicine from October to December 2023 were enrolled. The general clinical data, disease awareness, treatment, and lifestyle behaviors (smoking, drinking, diet, bathing, and exercising etc) were compared between patients with or without UP, and among patients with different severity of UP.Results:Among 255 peritoneal dialysis patients, there were 144 UP cases with a prevalence rate of 56.5%, including 55 cases with mild itching (38.2%), 61 cases with moderate itching (42.4%), and 28 cases with severe itching (19.4%). The awareness rate of UP was 22.2% (32/144), the treatment rate of UP was 12.5% (18/144). There were significant differences in bath frequency (χ 2=7.03), and using alkaline body wash (χ 2=6.47) between UP group and non-UP group ( P<0.05). The severity of UP was associated with old age (≥60 years, Z=-3.13), low educational levels (primary school or lower, Z=-3.56), less water drinking (<500 ml/d, H=18.01), more spicy food and meat ( H=9.34), bath more than 3 times per week ( H=10.96), and using alkaline body wash ( H=6.57) (all P<0.05). Conclusion:Peritoneal dialysis patients have a high incidence of UP and a low rate of knowledge and treatment, and it is necessary to strengthen the health education and to modify their life behaviors in order to reduce the incidence of UP.

Objective Based on quantile regression analysis, the influencing factors of relapse hospitalization expenses of adult leukemia patients were analyzed. Methods Analyze the composition and influencing factors of hospitalization expenses for leukemia recurrence patients in our hospital. Results From 2017 to 2022 , the per capita hospitalization cost for leukemia patients with recurrence showed an increasing trend year by year. The results of quantile regression model showed that age, payment method , length of stay, times of stay, operation and complications had an impact on the hospitalization expenses of patients at different quantiles, and the difference between different quantiles was statistically significant (P<0.05). Conclusions The quantile regression method can more clearly reflect the distribution of the variables of each factor , we can reduce the hospitalization expenses of patients by improving the coverage rate of medical insurance and controlling the length of stay.

Objective To investigate the effects of DNA demethylation drugs combined with histone deacetylase in-hibitors on fragile X mental retardation 1 neighbor protein (FMR1NB) expression and its promoter methylation in human oral cancer cells and try to find a strategy of weakening the heterogeneity of FMR1NB expression.Methods Human oral cancer cell lines Cal27 and SCC-9 were treated with decitabine (DAC) , an inhibitor of DNA meth-yltransferase, combined with trichostatin A (TSA) and valproic acid (VPA), inhibitors of histone deacetylase.Then reverse transcription-polymerase chain reaction (RT-PCR) , quantitative real-time PCR (qRT-PCR) and Western blot were used to detect the expression of FMR1 NB and pyrosequencing was used to detect the methylation of FMR1NB promoter.Results Compared with the blank control group, DAC and its combination with TSA and VPA significantly induced the expression of FMR1NB mRNA and protein in Cal27 and SCC-9 cells.Compared with DAC alone group, FMR1NB mRNA expression of each DAC-combined drug groups significantly increased, but FMR1NB protein did not significantly change in Cal27 cells; for SCC-9 cells, except for DAC+TSA group, the mRNA and protein levels of FMR1NB significantly increased in all other groups.In addition, there was no signifi-cant difference in the expression of FMR1 NB mRNA and protein between the three-combined drugs group and two-combined drugs groups.Further methylation assay showed that the methylation level of the overall FMR1NB promot-er and its each CpG site measured were reduced to varying degrees in all treatment groups except for three-combina-tion drug group of SCC-9.Conclusion DAC and its combination with TSA and VPA can enhance the expression of FMR1NB by mediating the demethylation of FMR1NB promoter, wherein the enhanced expression effect of the com-bination of the two drugs is stronger, suggesting that they have the potential to weaken the heterogeneity of FMR1NB expression and improve the immunotherapy effect of oral cancer.

Objective To investigate the role of magnesium ion(Mg2+)in cisplatin-induced acute kidney injury(Cis-AKI)in kidney organoids and HK-2 cells,as well as the potential mechanism.Methods Initially,we utilized human-derived induced pluripotent stem cells(iPSCs)to construct kidney organoids,and then built a Cis-AKI model based on kidney organoids.HE staining was used to observe the structure of kidney organoids,and immunofluorescence staining was used to observe the localization of markers and the expression of cleaved caspase-3.qRT-PCR was conducted to detect mRNA levels of tubular and glomerular markers,as well as inflammatory factors.Subsequently,the kidney organoids were randomly divided into control group,cisplatin group(Cis group),and Mg2+pretreatment group(Cis+Mg2+group).CCK-8 and ATP content assays were employed to evaluate the cell viability of renal tubular epithelial cells.TUNEL staining was performed to detect the apoptosis of renal tubular epithelial cells.Western blot was utilized to detect the expression of apoptosis-associated proteins(Bcl-2,Bax,cleaved caspase-3)and organic cation transporter 2(OCT2).Immunofluorescence was used to detect the localization and expression of OCT2.Results On the 10th day,the tubular structure in kidney organoids was visible,with abundant expression of renal markers.Treatment with 10 μmol/L cisplatin resulted in structural damage to kidney organoids,significantly increased expression of cleaved caspase-3 and mRNA levels of inflammatory factors,and significantly decreased ATP content.Compared with the Cis group,the Cis+Mg2+group showed increased ATP content in kidney organoids,reduced number of TUNEL-positive cells,significantly decreased expression of apoptosis-associated proteins,and significantly decreased expression of OCT2.However,there was no significant improvement in HK-2 cell viability,the number of TUNEL-positive cells,or apoptosis-associated proteins in the Cis+Mg2+group,and HK-2 cells did not express OCT2.Conclusion Kidney organoid is an ideal in vitro model to study the pathogenesis and treatment of Cis-AKI.Mg2+pretreatment can significantly reduce the damage of kidney organoids induced by cisplatin,and the mechanism may be related to the downregulation of OCT2.

Objective:To re-evaluate the reliability of the conclusions of the systematic reviews (SR)/meta-analysis (MA) of Traditional Chinese Medicine (TCM) in the treatment of functional dyspepsia (FD).Methods:CNKI, CBM, WanFang Data, VIP, PubMed, Cochrane Library, and Embase were searched from the establishment of the database to March 30, 2022. Two researchers independently screened literature and extracted data, and included SRs/MAs in the treatment of FD with TCM. The AMSTAR 2 and GRADE tools were used to evaluate the included the study carried out methodological quality evaluation, outcome evidence quality grading, and descriptive analysis of the main outcome.Results:A total of 28 SRs/MAs were included, with 34 outcome indicators. According to the AMSTAR 2 evaluation results, 21 SRs/MAs were of medium quality, and 7 SRs/MAs were of low quality. The GRADE quality of evidence grading results showed that of the 100 evidence bodies, 13 were of high quality, 58 were of moderate quality, 24 were of low quality, and 5 were of very low quality.Conclusion:TCM in the treatment of FD can improve the clinical efficiency, improve the cure rate, reduce the recurrence rate, and improve the clinical symptoms, but the methodological quality and evidence quality of related SRs/MAs have certain defects, so this conclusion should be treated with caution.

Objective:To analyze the clinical characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine breakthrough infections in children, and to provide reference basis for the SARS-CoV-2 vaccination in children.Methods:A total of 97 children aged 3 to 14 years and diagnosed with coronavirus disease 2019 (COVID-19) admitted to Xi′an People′s Hospital (Xi′an Fourth Hospital) from December 27, 2021 to February 7, 2022 were included. According to the COVID-19 vaccination status, the enrolled children were divided into unvaccinated group, partially vaccinated group and fully vaccinated group, and the clinical data of the children in the three groups were collected and compared. Chi-square test, two independent sample t-test and Kruskal-Wallis H test were used for statistical analysis. Results:Totally 97 children including 49 males and 48 females were enrolled, with 87(89.7%) children of mild type, 10(10.3%) children of common type, and no severe or critical case. The proportions of unvaccinated, partially vaccinated and fully vaccinated preschool-aged children (3 to 6 years old) were 56.5%(13/23), 30.8%(12/39) and 17.1%(6/35), respectively, while those of school-aged children (7 to 14 years old) were 43.5%(10/23), 69.2%(27/39) and 82.9%(29/35), respectively. The vaccination proportion in preschool-aged children was significantly lower than that in school-age children ( χ2=9.94, P=0.007). The proportion of the children with fever in fully vaccinated group was 17.1%(6/35), which was lower than that in unvaccinated group (43.5%, 10/23), and the difference was statistically significant ( χ2=4.82, P=0.028). The cycle threshold (Ct) values of the open reading frame ( ORF)1 ab gene in the unvaccinated, partially vaccinated and fully vaccinated groups were 33.77(26.87, 36.58), 35.23 (33.45, 38.57) and 37.12 (34.91, 39.39), respectively, and there was a statistically significant difference among the groups ( H=7.76, P=0.021). The Ct values of the nucleocapsid protein ( N) gene in the three groups were 32.26(25.85, 36.18), 35.12(33.18, 37.96) and 37.26(34.27, 39.24), respectively, and the difference among the groups was statistically significant ( H=7.84, P=0.020). The Ct values of ORF1 ab gene and N gene in fully vaccinated group were higher than those in unvaccinated group, and the differences were statistically significant ( Z=-2.69, P=0.007 and Z=-2.39, P=0.017, respectively). The duration of viral shedding in fully vaccinated children was (9.9±4.1) d, which was shorter than that in unvaccinated children ((12.8±3.7) d), and the difference was statistically significant ( t=2.72, P=0.009). Conclusions:The majority of children with breakthrough infections with SARS-CoV-2 are mild. Vaccination may effectively shorten the duration of viral shedding. And fully vaccination is associated with mild clinical symptoms and lower serum viral load compared to unvaccinated children.