1.Application of Recombinant Collagen in Biomedicine
Huan HU ; Hong ZHANG ; Jian WANG ; Li-Wen WANG ; Qian LIU ; Ning-Wen CHENG ; Xin-Yue ZHANG ; Yun-Lan LI
Progress in Biochemistry and Biophysics 2025;52(2):395-416
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.
2.The clinical value of artificial intelligence quantitative parameters in distinguishing pathological grades of stage Ⅰ invasive pulmonary adenocarcinoma
Yun LIANG ; Mengmeng REN ; Delong HUANG ; Jingyan DIAO ; Xuri MU ; Guowei ZHANG ; Shuliang LIU ; Xiuqu FEI ; Dongmei DI ; Ning XIE
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(05):598-607
Objective To explore the clinical value of artificial intelligence (AI) quantitative parameters in distinguishing pathological grades of stageⅠ invasive adenocarcinoma (IAC). Methods Clinical data of patients with clinical stageⅠ IAC admitted to Yantaishan Hospital Affiliated to Binzhou Medical University from October 2018 to May 2023 were retrospectively analyzed. Based on the 2021 WHO pathological grading criteria for lung adenocarcinoma, IAC was divided into gradeⅠ, grade Ⅱ, and grade Ⅲ. The differences in parameters among the groups were compared, and logistic regression analysis was used to evaluate the predictive efficacy of AI quantitative parameters for grade Ⅲ IAC patients. Parameters were screened using least absolute shrinkage and selection operator (LASSO) regression analysis. Three machine learning models were constructed based on these parameters to predict grade Ⅲ IAC and were internally validated to assess their efficacy. Nomograms were used for visualization. Results A total of 261 IAC patients were included, including 101 males and 160 females, with an average age of 27-88 (61.96±9.17) years. Six patients had dual primary lesions, and different lesions from the same patient were analyzed as independent samples. There were 48 patients of gradeⅠ IAC, 89 patients of grade Ⅱ IAC, and 130 patients of grade Ⅲ IAC. There were statitical differences in the AI quantitive parameters such as consolidation/tumor ratio (CTR), ect among the three goups. (P<0.05). Univariate analysis showed that the differences in all variables except age were statistically significant (P<0.05) between the group gradeⅠ+grade Ⅱand the group grade Ⅲ . Multivariate analysis suggested that CTR and CT standard deviation were independent risk factors for identifying grade Ⅲ IAC, and the two were negatively correlated. Grade Ⅲ IAC exhibited advanced TNM staging, more pathological high-risk factors, higher lymph node metastasis rate, and higher proportion of advanced structure. CTR was positively correlated with the proportion of advanced structures in all patients. This correlation was also observed in grade Ⅲ but not in gradeⅠand grade ⅡIAC. CTR and CT median value were selected by using LASSO regression. Logistic regression, random forest, and XGBoost models were constructed and validated, among which, the XGBoost model demonstrated the best predictive performance. Conclusion Cautious consideration should be given to grade Ⅲ IAC when CTR is higher than 39.48% and CT standard deviation is less than 122.75 HU. The XGBoost model based on combined CTR and CT median value has good predictive efficacy for grade Ⅲ IAC, aiding clinicians in making personalized clinical decisions.
3.Analysis of T7 RNA Polymerase: From Structure-function Relationship to dsRNA Challenge and Biotechnological Applications
Wei-Chen NING ; Yu HUA ; Hui-Ling YOU ; Qiu-Shi LI ; Yao WU ; Yun-Long LIU ; Zhen-Xin HU
Progress in Biochemistry and Biophysics 2025;52(9):2280-2294
T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.
4.Clinical phenotype and genotype analysis of retinitis pigmentosa sine pigmento caused by BBS gene mutations
Zijie CHEN ; Yufei TAO ; Yun WANG ; Qinyu HUANG ; Mingmin YANG ; Xuyang LIU ; Ning FAN
Chinese Journal of Ocular Fundus Diseases 2025;41(3):178-185
Objective:To observe and analyze the pathogenic genes and clinical phenotype characteristics of retinitis pigmentosa sinepigmento(RPSP).Methods:A retrospective clinical study. Two patients (proband) and five family members from two RPSP families admitted to Xiamen Eye Center of Xiamen University in December 2022 and Shenzhen Eye Hospital in July 2023 were included in the study. Two families have no blood relationship and were both Han Chinese. Detailed ocular and systemic medical history and specialized examinations were performed for all members, including color fundus photography, fundus autofluorescence (FAF), and full field electroretinogram (ff-ERG) examination. The peripheral venous blood of all members was collected, and genomic DNA was extracted. Pathogenic genes and their loci were screened using whole exome high-throughput sequencing technology. Sanger sequencing was used to verify the pathogenic genes in the two pedigrees. The pathogenicity of candidate variants was evaluated according to the American Society for American College of Medical Genetics and Genomics (ACMG) classification criteria and guidelines for genetic variants.Results:The two probands were male, aged 9 and 7 years, respectively. The main complaint was poor binocular vision for 6 and 3 years and poor treatment effect of amblyopia. The proband (Ⅱ2) in family 1 had a pale red color on the optic disc, with leopard-like changes in the posterior pole and thinner retinal arteries. FAF showed mottled fluorescence attenuation outside the macular vascular arch. There was no significant waveform in both bright and dark visual responses of ff-ERG. He also had 6-toed deformity of both feet, renal cysts, and a slightly overweight body. The clinical diagnosis was non-pigmentary retinitis pigmentosa. The proband of family 2 (Ⅱ1) had poor binocular vision in a dark environment and had atrophy lesions on the nasal side of the optic disc and leopard print like changes in the fundus. FAF showed uneven enhancement in the fovea. ff-ERG showed severe abnormalities in dark and light response, with significant decrease and delay in b-wave amplitude and latency. He had no other systemic abnormalities. The clinical diagnosis was binocular RPSP. There were no abnormal ocular and systemic manifestations in the two family members. Gene sequencing revealed a homozygous mutation (c.534+1G>T) of BBS2 gene, which was inherited from the mother and father respectively. Based on clinical manifestations and genetic testing results, the final diagnosis was Bardet Biedl syndrome. The genetic sequencing results confirmed a novel compound heterozygous mutation (c.950T>G: p. Leu317Arg missense mutation and c.849+1G>C splicing mutation) of BBS7 gene. His father (Ⅰ1) and mother (Ⅰ2) carried M1 heterozygous variants. Combined with the clinical manifestations and genetic testing results, the final diagnosis was Bardet-Biedl syndrome (BBS). Family 2 proband (Ⅱ1) carried the BBS7 gene C.950T>G (p.Leu317Arg) (M2) missense variation and C.849 +1G>C (M3) splice site variation. His father (Ⅰ1) and mother (Ⅰ2) carried M3 shear site variation and M2 missense variation, respectively. The two families all fit the autosomal recessive inheritance pattern, and the genotype and clinical phenotype were coseparated. According to ACMG guidelines, M1, M2 and M3 were all identified as possible pathogenic variants. Conclusions:BBS2 gene M1 homozygous variation and BBS7 gene M2, M3 complex heterozygous variation are the possible pathogenic genes in family 1 and family 2, respectively. Two families are affected by BBS and RPSP, respectively.
5.Pharmacokinetics study of Dayuanyin in normal and febrile rats.
Yu-Jie HOU ; Kang-Ning XIAO ; Jian-Yun BI ; Xin-Jun ZHANG ; Xin-Rui LI ; Yu-Qing WANG ; Ming SU ; Xin-Ru SUN ; Hui ZHANG ; Bo-Yang WANG ; Li-Jie WANG ; Shan-Xin LIU
China Journal of Chinese Materia Medica 2025;50(2):527-533
Based on the pharmacokinetics theory, this study investigated the pharmacokinetic characteristics of albiflorin, paeoniflorin, wogonoside, and wogonin in normal and febrile rats and summarized absorption and elimination rules of Dayuanyin in them to provide reference for further development and clinical application of Dayuanyin. Blood samples were taken from the fundus venous plexus of normal and model rats after intragastric administration of Dayuanyin at different time points. The concentration of each substance in blood was determined by ultra performance liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS) technique at different time points. DAS 2.0, a piece of pharmacokinetics software, was used to calculate the pharmacokinetic parameters of each component. The results show that the 4 components had good linear relationship in their respective ranges, and the results of methodological investigation met the requirements. The pharmacokinetic parameters of C_(max), T_(max), t_(1/2), AUC_(0-t), AUC_(0-∞), and MRT_(0-t) were calculated by the DAS 2.0 non-compartmental model. Compared with those in the normal group, C_(max) and AUC_(0-t) of the 4 components in the model group were significantly increased. There were significant differences in the pharmacokinetic characteristics between the normal and model groups, suggesting that the absorption and elimination of Dayuanyin may be affected by the changes of internal environment of the body in different physiological states.
Animals
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Rats
;
Drugs, Chinese Herbal/administration & dosage*
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Male
;
Rats, Sprague-Dawley
;
Fever/metabolism*
;
Tandem Mass Spectrometry
;
Chromatography, High Pressure Liquid
;
Glucosides/pharmacokinetics*
;
Monoterpenes
6.Identification of tissue distribution components and mechanism of antipyretic effect of famous classical formula Dayuanyin.
Yu-Jie HOU ; Kang-Ning XIAO ; Jian-Yun BI ; Xin-Rui LI ; Ming SU ; Li-Jie WANG ; Yu-Qing WANG ; Dan-Dan SUN ; Hui ZHANG ; Xin-Jun ZHANG ; Shan-Xin LIU
China Journal of Chinese Materia Medica 2025;50(10):2810-2824
Based on the ultra performance liquid chromatography-quadrupole Exactive Orbitrap mass spectrometry(UPLC-Q-Exactive Orbitrap-MS) technology, combined with related literature, databases, and reference material information, this study qualitatively analyzed the components of Dayuanyin in the tissue of rats after gavage and employed molecular docking technology to predict the rationality of the mechanism behind the antipyretic effect of the in vivo components in Dayuanyin. A total of 21, 26, 20, 21, 14, and 31 prototype components and 3, 16, 3, 7, 5, and 24 metabolites were identified from the heart, liver, spleen, lung, kidney, and hypothalamus of the rats, respectively, and the binding ability of key components and targets was further verified by molecular docking. The results showed that all components had good binding ability with targets. The established UPLC-Q-Exactive Orbitrap-MS could effectively and quickly identify the Dayuanyin components distributed in tissue and preliminarily identify their metabolites. Many components were identified in the hypothalamus, which suggested that the components delivered to the brain should be focused on in the study on Dayuanyin in the treatment of febrile diseases. The molecular docking technology was used to predict the rationality of the mechanism behind its antipyretic effect, which lays the foundation for the clarification of the material basis and action mechanism of Dayuanyin, the development of new preparations, and the prediction of quality markers.
Animals
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Drugs, Chinese Herbal/administration & dosage*
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Rats
;
Molecular Docking Simulation
;
Male
;
Antipyretics/metabolism*
;
Rats, Sprague-Dawley
;
Tissue Distribution
;
Mass Spectrometry
;
Chromatography, High Pressure Liquid
;
Hypothalamus/metabolism*
7.Association between metabolic parameters and erection in erectile dysfunction patients with hyperuricemia.
Guo-Wei DU ; Pei-Ning NIU ; Zhao-Xu YANG ; Xing-Hao ZHANG ; Jin-Chen HE ; Tao LIU ; Yan XU ; Jian-Huai CHEN ; Yun CHEN
Asian Journal of Andrology 2025;27(4):482-487
The relationship between hyperuricemia (HUA) and erectile dysfunction (ED) remains inadequately understood. Given that HUA is often associated with various metabolic disorders, this study aims to explore the multivariate linear impacts of metabolic parameters on erectile function in ED patients with HUA. A cross-sectional analysis was conducted involving 514 ED patients with HUA in the Department of Andrology, Jiangsu Province Hospital of Chinese Medicine (Nanjing, China), aged 18 to 60 years. General demographic information, medical history, and laboratory results were collected to assess metabolic disturbances. Sexual function was evaluated using the 5-item version of the International Index of Erectile Function (IIEF-5) questionnaire. Based on univariate analysis, variables associated with IIEF-5 scores were identified, and the correlations between them were evaluated. The effects of these variables on IIEF-5 scores were further explored by multiple linear regression models. Fasting plasma glucose ( β = -0.628, P < 0.001), uric acid ( β = -0.552, P < 0.001), triglycerides ( β = -0.088, P = 0.047), low-density lipoprotein cholesterol ( β = -0.164, P = 0.027), glycated hemoglobin (HbA1c; β = -0.562, P = 0.012), and smoking history ( β = -0.074, P = 0.037) exhibited significant negative impacts on erectile function. The coefficient of determination ( R ²) for the model was 0.239, and the adjusted R ² was 0.230, indicating overall statistical significance ( F -statistic = 26.52, P < 0.001). Metabolic parameters play a crucial role in the development of ED. Maintaining normal metabolic indices may aid in the prevention and improvement of erectile function in ED patients with HUA.
Humans
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Male
;
Erectile Dysfunction/metabolism*
;
Hyperuricemia/metabolism*
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Adult
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Middle Aged
;
Cross-Sectional Studies
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Glycated Hemoglobin/metabolism*
;
Blood Glucose/metabolism*
;
Uric Acid/blood*
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Young Adult
;
Triglycerides/blood*
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Adolescent
;
Cholesterol, LDL/blood*
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Penile Erection/physiology*
;
Surveys and Questionnaires
8.Efficacy and Survival Analysis of Chidamide Combined with DICE Regimen in Patients with Relapsed/Refractory Diffuse Large B-Cell Lymphoma.
Li-Li WU ; Li SHI ; Wei-Jing LI ; Wei LIU ; Yun FENG ; Shao-Ning YIN ; Cui-Ying HE ; Li-Hong LIU
Journal of Experimental Hematology 2025;33(2):373-378
OBJECTIVE:
To investigate the efficacy and safety of chidamide combined with DICE regimen (cisplatin+ ifosfamide + etoposide + dexamethasone) for relapsed/refractory diffuse large B-cell lymphome(R/R DLBCL).
METHODS:
The clinical data of 31 R/R DLBCL patients treated by chidamide combined with DICE regimen in the Hematology Department of the Fourth Hospital of Hebei Medical University from October 2016 to October 2020 were retrospectively analyzed. The clinical efficacy and adverse events were observed.
RESULTS:
Among the 31 patients, 20 were male and 11 were female. The median age of the patients was 55 (range: 27-71) years old, 21 cases were < 60 years old, 10 cases were ≥60 years old. 26 cases were refractory and 5 cases were relapsed. There were 13 cases of germinal center B-cell like (GCB), 17 cases of non-GCB, and 1 case had missing Hans type. There were 17 cases of double-expression lymphoma (DEL) and 14 cases of non-DEL. The complete response rate of patients was 38.7%(12/31), the overall response rate was 67.7%(21/31). The median progression-free survival time and the median overall survival time were 9.8(95%CI : 4.048-15.552) months, 13.9(95%CI : 9.294-18.506) months, respectively. Multipvariate analysis showed that GCB and DEL reduced the risk of disease recurrence in R/R DLBCL patients. The main grade 3/4 hematological adverse events in this study were thrombocytopenia, agranulocytosis, anemia and leukopenia.
CONCLUSION
The chidamide combined with DICE regimen is effective in the treatment of R/R DLBCL, and hematological adverse events should be closely monitored.
Humans
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Lymphoma, Large B-Cell, Diffuse/drug therapy*
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Middle Aged
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Female
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Male
;
Adult
;
Aged
;
Retrospective Studies
;
Antineoplastic Combined Chemotherapy Protocols/therapeutic use*
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Benzamides/administration & dosage*
;
Aminopyridines/administration & dosage*
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Etoposide/therapeutic use*
;
Cisplatin/administration & dosage*
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Ifosfamide/administration & dosage*
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Dexamethasone/therapeutic use*
9.Guideline for the prevention of intraoperative acquired pressure injury in paraplegic patients with spinal cord injury (version 2025)
Aijun XU ; Shuixia LI ; Bo CHEN ; Mengyuan YE ; Lejiao LANG ; Ning NING ; Lin ZHANG ; Changqing LIU ; Zhonglan CHEN ; Weihu MA ; Weishi LI ; Xiaoning WANG ; Dongmei BIAN ; Jiancheng ZENG ; Xin WANG ; Yuan GAO ; Yaping CHEN ; Jiali CHEN ; Yun HAN ; Xiuting LI ; Yang ZHOU ; Xiaojing SU ; Qiong ZHANG ; Tianwen HUANG ; Ping ZHANG ; Hua LIN ; Xingling XIAO ; Ruifeng XU ; Fanghui DONG ; Bing HAN ; Luo FAN ; Yanling PEI ; Suyun LI ; Xiaoju TAN ; Rongchen GUO ; Yefang ZOU ; Xiaoyun HAN ; Junqin DING ; Yi WANG ; Shuhua DENG ; Jinli GUO ; Yinhua LIANG ; Yuan CEN ; Xiaoqin LIU ; Junru CHEN ; Haiyang YU ; Lunlan LI ; Ying REN ; Yunxia LI ; Jianli LU ; Ying YING ; Lan WEI ; Yin WANG ; Qinhong XU ; Yanqin ZHANG ; Yang LYU ; Shijun ZHANG ; Sui WENJIE ; Sanlian HU ; Shuhong YANG ; Guoqing LI ; Jingjing AN ; Baorong HE ; Leling FENG
Chinese Journal of Trauma 2025;41(6):530-541
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.
10.6-Shogaol alleviates cerebral injury after cardiac arrest-cardiopulmonary resuscitation in rats by inhibiting death-associated protein kinase 1-mediated autophagy.
Ouyang RAO ; Shixin LI ; Ning ZHU ; Hangxiang ZHOU ; Jie HU ; Yun LI ; Junling TAO ; Yehong LI ; Ying LIU
Chinese Critical Care Medicine 2025;37(6):568-575
OBJECTIVE:
To observe the neuroprotective effect of 6-shogaol (6-SH) in global cerebral ischemia/reperfusion injury (CIRI) following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in rats.
METHODS:
Computer-aided molecular docking was used to determine whether 6-SH could spontaneously bind to death-associated protein kinase 1 (DAPK1). SPF-grade male SD rats were randomly divided into a sham group (n = 5), a CPR group (n = 7), and a CPR+6-SH group (n = 7). The CPR group and CPR+6-SH group were further divided into 12-, 24-, and 48-hour subgroups based on observation time points. A rat model of global CIRI after CA-CPR was established by asphyxiation. In the sham group, only tracheal and vascular intubation was performed without asphyxia and CPR induction. The CPR group was intraperitoneally injected with 1 mL of normal saline immediately after successful modeling. The CPR+6-SH group received an intraperitoneal injection of 20 mg/kg 6-SH (1 mL) immediately after successful modeling, followed by administration every 12 hours until the endpoint. Neurological Deficit Score (NDS) was recorded at each time point after modeling. After completion of observation at each time point, rats were anesthetized and sacrificed, and brain tissue specimens were collected. Histopathological changes of neurons were observed under light microscopy after hematoxylin-eosin (HE) staining. Ultrastructural changes of hippocampal neurons and autophagy were observed by transmission electron microscopy (TEM). Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect mRNA expression levels of DAPK1, vacuolar protein sorting 34 (VPS34), Beclin1, and microtubule-associated protein 1 light chain 3 (LC3) in brain tissues. Western blotting was used to detect protein expression levels of DAPK1, phosphorylated DAPK1 at serine 308 (p-DAPK1 ser308), VPS34, Beclin1, and LC3. Immunofluorescence was used to observe Beclin1 and LC3 expression in brain tissues under a fluorescence microscope.
RESULTS:
Molecular docking results indicated that 6-SH could spontaneously bind to DAPK1. Compared with the sham group, the NDS scores of the CPR group rats were significantly increased at all modeling time points; under light microscopy, disordered cell arrangement, widened intercellular spaces, and edema were observed in brain tissues, with pyknotic and necrotic nuclei in some areas; under TEM, mitochondria were markedly swollen with intact membranes, dissolved matrix, reduced or disappeared cristae, vacuolization, and increased autophagosomes. Compared with the CPR group, the NDS scores of the CPR+6-SH group rats were significantly decreased at all modeling time points; under light microscopy, local neuronal edema and widened perinuclear space were observed; under TEM, mitochondria were mostly mildly swollen with intact membranes, fewer autophagosomes, and alleviated injury. RT-qPCR results showed that compared with the sham group, mRNA expression levels of DAPK1, VPS34, Beclin1, and LC3 in brain tissues were significantly upregulated in all CPR subgroups, with the most pronounced changes at 24 hours. Compared with the CPR group, the CPR+6-SH group showed significantly lower mRNA expression of the above indicators at each time point [24 hours post-modeling (relative expression): DAPK1 mRNA: 3.41±0.68 vs. 4.48±0.62; VPS34 mRNA: 3.63±0.49 vs. 4.66±1.18; Beclin1 mRNA: 3.08±0.49 vs. 4.04±0.22; LC3 mRNA: 2.60±0.36 vs. 3.67±0.62; all P < 0.05]. Western blotting results showed that compared with the sham group, the protein expression levels of DAPK1, VPS34, Beclin1, and LC3 in all CPR subgroups were significantly increased, while the expression of p-DAPK1 ser308 was significantly decreased, with the most pronounced changes observed in the CPR 24-hour subgroup. Compared with the CPR group, the CPR+6-SH subgroups exhibited significantly reduced protein expression of DAPK1, VPS34, Beclin1, and LC3 [24-hour post-modeling: DAPK1/β-actin: 1.88±0.22 vs. 2.47±0.22; VPS34/β-actin: 2.55±0.06 vs. 3.46±0.05; Beclin1/β-actin: 2.12±0.03 vs. 2.87±0.03; LC3/β-actin: 2.03±0.24 vs. 3.17±0.23; all P < 0.05]. Conversely, the expression of p-DAPK1 ser308 was significantly upregulated in the CPR+6-SH group compared to the CPR group [24-hour post-modeling: p-DAPK1 ser308/β-actin: 0.40±0.02 vs. 0.20±0.07, P < 0.05]. Under the fluorescence microscope, fluorescence intensities of Beclin1 and LC3 in the CPR 24-hour group were significantly higher than those in the sham 24-hour group; compared with the CPR 24-hour group, the CPR+6-SH 24-hour group showed significantly reduced fluorescence intensities of Beclin1 and LC3.
CONCLUSION
6-SH inhibited the expression of DAPK1, alleviated excessive autophagy after global CIRI following CA-CPR in rats, and exerted neuroprotective effects. The mechanism may be related to phosphorylation at the DAPK1 ser308 site.
Animals
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Rats, Sprague-Dawley
;
Male
;
Rats
;
Cardiopulmonary Resuscitation
;
Autophagy/drug effects*
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Heart Arrest/therapy*
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Death-Associated Protein Kinases/metabolism*
;
Reperfusion Injury/metabolism*
;
Disease Models, Animal
;
Neuroprotective Agents/pharmacology*
;
Brain Ischemia/metabolism*

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