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.

Alcohol exposure, as a widespread environmental factor, is highly toxic and teratogenic. Embryonic stem cells (ESCs) are pluripotent and key to development, and their gene expression is tightly regulated, allowing the cells to differentiate without self-renewal. Numerous studies showed that alcohol is an important factor affecting the differentiation of ESCs. In this paper, we systematically summarized four major molecular mechanisms underlying alcohol associated differentiation of ESCs: (1) inhibition of the Wnt signaling pathway; (2) restriction of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway; (3) alteration of the expression of pluripotent transcription factors; and (4) activation of the nuclear transcriptional program. Through the above mechanisms, alcohol induces aberrant expression of differentiation-related genes and alters the direction of cellular differentiation towards specific lineages, thereby affecting normal embryonic development. Based on the studies on ESCs modeling and other in vitro and in vivo differentiation experiments, the molecular basis of how alcohol affects differentiation by interfering with signaling networks and transcriptional regulation was elucidated, and the results of current research in this field were also summarized, which is crucial for understanding alcohol-mediated toxic effects.

Objective: To investigate the regional differences in the incidence of urothelial carcinoma among kidney transplant recipients between northern and southern China，so as to provide reference for early diagnosis of this disease. Methods: A comprehensive search was conducted across multiple databases，including CNKI，Wanfang，CBM，and PubMed，using the keywords “kidney transplantation” and “tumor” to collect clinical data from qualified kidney transplant centers.The latest and most complete literature data published by 17 transplant centers in northern China and 14 in southern China were included.Statistical analyses were performed to compare the incidence of post-transplant urothelial carcinoma and non-urothelial malignancies. Results: A total of 37 475 kidney transplant recipients were included，among whom 837 (2.23%) developed post-transplant malignancies，including urothelial carcinoma (366/837，43.73%)，non-urothelial carcinoma (444/837，53.05%)，and malignancies with unspecified pathology (27/837，3.23%).The incidence of malignancies was significantly higher in northern China than in southern China [(2.82±1.39)% vs. (1.67±0.83)%，P=0.011]，with a particularly pronounced difference in the incidence of urothelial carcinoma [(1.68±1.12)% vs. (0.32±0.32)%，P<0.001].No significant difference was observed in the incidence of non-urothelial carcinoma between the two regions [(1.11±0.56)% vs. (1.35±0.65)%，P=0.279].Additionally，female transplant recipients exhibited a higher incidence of malignancies than males in both regions (southern China：2.38% vs. 1.80%; northern China：8.93% vs. 2.52%). Conclusion: The incidence of urothelial carcinoma following kidney transplantation is significantly higher in northern China than in southern China，underscoring the importance of implementing regular tumor screening for kidney transplant recipients，particularly for female patients in northern China，to facilitate early diagnosis and timely intervention.

Infertility is a common reproductive disorder affecting millions of couples worldwide. It is estimated that male factors account for about 30%-50% of infertility cases, and some studies have found that the concentration of male sperm gradually decreases over time, a trend that suggests the importance of male fertility. Many factors contribute to the decline of male fertility, among which environmental factors have received widespread attention. After reaching adulthood, spermatogonial stem cells will continue to produce sperm, but these cells exist outside the blood testicular barrier, which makes them highly sensitive to environmental conditions such as air pollution, tobacco smoke, radiation, and heavy metals. It is reported that exposure to these adverse environmental factors not only causes oxidative stress and DNA damage to germ cells, but also leads to abnormal epigenetic modification of sperm DNA, thereby causing a series of diseases. This article reviewed the abnormal methylation changes in DNA associated with exposure to environmental pollutants during spermatogenesis and how these changes affect the quantity, quality, and function of spermatozoa.

ObjectiveJunctophilin-2 (JPH2) is an essential structural protein that maintains junctional membrane complexes (JMCs) in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum, thereby facilitating excitation-contraction (E-C) coupling. Mutations in JPH2 have been associated with hypertrophic cardiomyopathy (HCM), but the molecular mechanisms governing its membrane-binding properties and the functional relevance of its membrane occupation and recognition nexus (MORN) repeat motifs remain incompletely understood. This study aimed to elucidate the structural basis of JPH2 membrane association and its implications for HCM pathogenesis. MethodsA recombinant N-terminal fragment of mouse JPH2 (residues1-440), encompassing the MORN repeats and an adjacent helical region, was purified under near-physiological buffer conditions.X-ray crystallography was employed to determine the structure of the JPH2 MORN-Helix domain. Sequence conservation analysis across species and junctophilin isoforms was performed to assess the evolutionary conservation of key structural features. Functional membrane-binding assays were conducted using liposome co-sedimentation and cell-based localization studies in COS7 and HeLa cells. In addition, site-directed mutagenesis targeting positively charged residues and known HCM-associated mutations, including R347C, was used to evaluate their effects on membrane interaction and subcellular localization. ResultsThe crystal structure of the mouse JPH2 MORN-Helix domain was resolved at 2.6 Å, revealing a compact, elongated architecture consisting of multiple tandem MORN motifs arranged in a curved configuration, forming a continuous hydrophobic core stabilized by alternating aromatic residues. A C-terminal α-helix further reinforced structural integrity. Conservation analysis identified the inner groove of the MORN array as a highly conserved surface, suggesting its role as a protein-binding interface. A flexible linker segment enriched in positively charged residues, located adjacent to the MORN motifs, was found to mediate direct electrostatic interactions with negatively charged phospholipid membranes. Functional assays demonstrated that mutation of these basic residues impaired membrane association, while the HCM-linked R347C mutation completely abolished membrane localization in cellular assays, despite preserving the overall MORN-Helix fold in structural modeling. ConclusionThis study provides structural insight into the membrane-binding mechanism of the cardiomyocyte-specific protein JPH2, highlighting the dual roles of its MORN-Helix domain in membrane anchoring and protein interactions. The findings clarify the structural basis for membrane targeting via a positively charged linker and demonstrate that disruption of this interaction—such as that caused by the R347C mutation—likely contributes to HCM pathogenesis. These results not only enhance current understanding of JPH2 function in cardiac E-C coupling but also offer a structural framework for future investigations into the assembly and regulation of JMCs in both physiological and disease contexts.

The heat shock protein 90 (Hsp90) protein family is a cluster of highly conserved molecules that play an important role in maintaining cellular homeostasis. Hsp90 and its co-chaperones regulate a variety of pathways and cellular functions, such as cell growth, cell cycle control and apoptosis. Hsp90 is closely associated with the occurrence and development of tumors and other diseases, making it an attractive target for cancer therapeutics. Inhibition of Hsp90 expression can affect multiple oncogenic pathways simultaneously. Most Hsp90 small molecule inhibitors are in clinical trials due to their low efficacy, toxicity or drug resistance, but they have obvious synergistic anti-tumor effect when used with histone deacetylase (HDAC) inhibitors, tubulin inhibitors or topoisomerase II (Topo II) inhibitors. To address this issue, the design of Hsp90 dual-target inhibitors can improve efficacy and reduce drug resistance, making it an effective tumor treatment strategy. In this paper, the domain and biological function of Hsp90 are briefly introduced, and the design, discovery and structure-activity relationship of Hsp90 dual inhibitors are discussed, in order to provide reference for the discovery of novel Hsp90 dual inhibitors and clinical drug research from the perspective of medicinal chemistry.

Objective To study the pharmacokinetic and pharmacodynamic characteristics of compound levodopa/carbidopa(250 mg/25 mg)and levodopa/benserazide(200 mg/50 mg)in patients with Parkinson's disease(PD).Methods This experiment used a levodopa challenge test with a randomized crossover design.In the first week,20 PD patients orally received either 275 mg of compound levodopa/carbidopa or 250 mg of levodopa/benserazide on an empty stomach,and in the second week,they received the other treatment.The levodopa blood concentration was measured using high-performance liquid chromatography-tandem mass spectrometry,and motor symptoms were evaluated using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale Ⅲ.Results Data from 17 patients in the compound levodopa/carbidopa group and 18 patients in the levodopa/benserazide group was included in the analysis.After administration,the Cmax values of compound levodopa/carbidopa and levodopa/benserazide groups were(3 563.76±1 003.06)and(3 642.44±1 192.70)ng·mL-1;the tmax values were(1.10±0.44)and(1.03±0.55)h;the t1/2 values were(1.52±0.15)and(1.68±0.27)h;the AUC0-t values were(7 625.19±1 706.85)and(5 846.07±1 191.16)ng·mL-1·h;the mean residence time(MRT)values were(2.39±0.361)and(2.14±0.37)h,respectively.There were no statistically significant differences in the Cmax,tmax,and t1/2 values between the two groups(all P＞0.05).Compared with the levodopa/benserazide group,the compound levodopa/carbidopa group increased levodopa AUC and prolonged MRT(all P＜0.05).The improvement in motor symptoms and levodopa blood concentration showed consistent trends at various time points in both groups.The compound levodopa/carbidopa group showed significantly better improvement in motor function at 6 and 8 hours after medication compared to the levodopa/benserazide group[(-10.82±8.91)points vs(-5.17±6.78)points,(-7.88±10.05)points vs(-2.11±4.84)points;both P＜0.05].Conclusion The pharmacokinetic and pharmacodynamic characteristics of compound levodopa/carbidopa are similar to those of levodopa/benserazide.

Objective To investigate the effects of Licorice chalcone A(LCA)on proliferation,migration,invasion and antioxidant capacity of human glioma U87 cells and its mechanism.Methods Glioma U87 cells cultured in vitro were divided into 4 groups,blank control group(conventional culture)and experimental-L,-M,-H groups(5,10,20 μmol·L-1 LC A).Cell proliferation capacity was detected by cell counting kit-8,cell clonogenesis ability was detected by clonogenesis assay,cell migration ability was detected by scratch assay,and cell invasion ability was detected by Transwell assay.Colorimetric assay was used to detect total glutathione(T-GSH),malondialdehyde(MDA)and superoxide dismutase(SOD),and Western blotting was used to detect the protein expression levels of phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt).Results The cell proliferation activities of blank control group and experimental-L,-M,-H groups were(90.20±2.17)％,(79.06±1.57)％,(66.13±2.11)％and(49.52±1.82)％;cell clone formation rates were(76.83±2.30)％,(42.33±2.09)％,(17.71±1.84)％and(12.12±1.97)％;12 h cell mobility rates were(34.92±2.24)％,(27.90±1.89)％,(18.76±1.14)％and(14.87±0.82)％;24 h cell mobility rates were(50.37±2.61)％,(39.43±2.56)％,(21.11±2.33)％and(18.32±2.39)％;the number of perforated cells were 120.39±4.16,79.95±3.83,45.67±3.55 and 18.14±2.85;T-GSH levels were(71.43±2.39),(58.51±2.91),(49.43±2.78)and(35.44±2.76)μmol·L-1;MDA levels were(4.14±0.91),(7.23±1.75),(9.20±1.56)and(11.37±1.90)nmol·mL-1;SOD levels were(41.44±2.10),(35.43±2.91),(28.56±2.32)and(20.62±2.05)U·mg-1;the relative expression levels of p-Akt were 1.27±0.03,1.06±0.02,0.89±0.01 and 0.60±0.02,respectively.The above indexes were statistically significant between experimental-L,-M,-H groups and blank control group(all P＜0.01).Conclusion LCA can inhibit the proliferation,migration,invasion and induce oxidative damage of glioma U87 cells,and its mechanism may be related to the down-regulation of p-Akt protein expression in PI3K/Akt signaling pathway.

Objective To observe the efficacy and safety of Morinda officinalis oligosaccharides in the continuation treatment of mild and moderate depression.Methods An open,single-arm,multi-center design was adopted in our study.Adult patients with mild and moderate depression who had received acute treatment of Morinda officinalis oligosaccharides were enrolled and continue to receive Morinda officinalis oligosaccharides capsules for 24 weeks,the dose remained unchanged during continuation treatment.The remission rate,recurrence rate,recurrence time,and the change from baseline to endpoint of Hamilton Depression Scale(HAMD),Hamilton Anxiety Scale(HAMA),Clinical Global Impression-Severity(CGI-S)and Arizona Sexual Experience Scale(ASEX)were evaluated.The incidence of treatment-related adverse events was reported.Results The scores of HAMD-17 at baseline and after treatment were 6.60±1.87 and 5.85±4.18,scores of HAMA were 6.36±3.02 and 4.93±3.09,scores of CGI-S were 1.49±0.56 and 1.29±0.81,scores of ASEX were 15.92±4.72 and 15.57±5.26,with significant difference(P＜0.05).After continuation treatment,the remission rate was 54.59％(202 cases/370 cases),and the recurrence rate was 6.49％(24 cases/370 cases),the recurrence time was(64.67±42.47)days.The incidence of treatment-related adverse events was 15.35％(64 cases/417 cases).Conclusion Morinda officinalis oligosaccharides capsules can be effectively used for the continuation treatment of mild and moderate depression,and are well tolerated and safe.

Objective To study the pharmacokinetic characteristics of lamotrigine tablets in Chinese healthy subjects under fasting and fed conditions,and to evaluate the bioequivalence and safety profiles between the domestic test preparation and the original reference preparation.Methods Twenty-four Chinese healthy male and female subjects were enrolled under fasting and fed conditions,18 male and 6 female subjects under fasting conditions,17 male and 7 female subjects under fed conditions.A random,open,single-dose,two preparations,two sequences and double-crossover design was used.Plasma samples were collected over a 72-hour period after give the test or reference preparations 50 mg under fasting and fed conditions.The concentration of lamotrigine in plasma was detected by liquid chromatography-tandem mass spectrometry,and the main pharmacokinetic parameters were calculated to evaluate the bioequivalence by WinNonLin 8.1 program.Results The main pharmacokinetic parameters of single-dose the tested and reference preparations were as follows:The fasting condition Cmax were(910.93±248.02)and(855.87±214.36)ng·mL-1;tmax were 0.50(0.25,4.00)and 1.00(0.25,3.50)h;t1/2 were(36.1±9.2)and(36.0±8.2)h;AUC0_72h were(27 402.40±4 752.00)and(26 933.90±4 085.80)h·ng·mL-1.The fed condition Cmax were(701.62±120.67)and(718.95±94.81)ng·mL-1;tmax were 4.00(1.00,5.00)and 4.00(0.50,5.00)h;t1/2 were(44.2±12.4)and(44.0±12.0)h;AUC0-72h were(30 253.20±7 018.00)and(30 324.60±6 147.70)h·ng·mL-1.The 90％confidence intervals of the geometric mean ratios of Cmax and AUC0-72 hfor the test preparation and reference preparation were all between 80.00％and 125.00％under fasting and fed conditions.Conclusion Two kinds of lamotrigine tablets are bioequivalent,and have similar safety in Chinese healthy male and female subjects under fasting and fed conditions.