Objective: To investigate the distribution frequency and molecular mechanism of the rare blood type Lu(a-b-) in Shenzhen, and to compare the polymorphisms of the Lutheran blood group system encoding gene LU and the In (Lu) phenotype-related gene KLF1 among Han Chinese, Indian, and Uyghur populations in Xinjiang. Methods: Serological methods were used to screen the Lu(a-b-) phenotype of blood donors in Shenzhen. Third-generation sequencing was employed to sequence the full-length of the LU and KLF1 genes in Lu (a-b-) phenotype samples as well as the samples from the Han Chinese, Indians, and Uyghur population, followed by analysis of gene haplotypes frequencies. Results: Ten individuals with the Lu(a-b-) phenotype were screened out of 14 367 blood donors in Shenzhen, yielding a frequency of approximately 0.07%. Only 2 cases showed mutations in the coding region of the LU gene, while all individuals showed heterozygous mutations in the coding region of the KLF1 gene. The highest mutation frequencies of the LU and KLF1 genes were observed in the Uyghur population in Xinjiang and the Han Chinese in Shenzhen, respectively. Conclusion: All Lu(a-b-) phenotypes are of the In (Lu) type, and their formation mechanism is mainly related to KLF1 gene mutations. Both the LU and KLF1 genes exhibit significant polymorphism in the Han Chinese, Indians, and Uyghur populations.

Inteins are unique protein insertion sequences capable of self-excision, enabling the covalent ligation of flanking extein peptides via amide bond formation. This process proceeds spontaneously without requiring external enzymes, cofactors, or chemical reagents, granting inteins exceptional biocompatibility and traceless performance in protein engineering applications. Split inteins represent a specialized and versatile subclass whose splicing domains are encoded by two separate gene fragments rather than a single continuous open reading frame. These fragments, known as the N-terminal (IntN) and C-terminal (IntC) split inteins, associate through non-covalent interactions including hydrophobic forces, hydrogen bonds, and van der Waals forces to assemble into an active three-dimensional structure, which then drives efficient extein ligation and enables protein trans-splicing. Protein trans-splicing mediated by split inteins has become a cornerstone for traceless protein ligation owing to its high specificity and irreversibility, fundamentally reshaping strategies for protein modification, assembly, and functional regulation. Compared with traditional chemical ligation methods, split intein systems require no complex chemical derivatization of peptide fragments and can operate efficiently at micromolar concentrations under physiological conditions, thus avoiding structural and functional damage caused by organic reagents. In contrast to enzymatic ligation tools such as sortase, split inteins eliminate the need for additional enzymes or cofactors, simplifying reaction systems, reducing costs, and minimizing non-specific side products. These distinctive advantages render split inteins highly promising for applications in chemical biology, synthetic biology, and biopharmaceutical development. In recent years, deepened mechanistic understanding has established structure-guided rational design as the primary approach to overcoming key limitations of split inteins, including intrinsic aggregation propensity, strict extein sequence dependence, and limited splicing efficiency. Bioinformatic tools have been used to identify aggregation-prone regions in the IntN fragment, and site-directed mutagenesis of hydrophobic residues, relocation of split sites, or removal of misfolding-prone sequences has substantially reduced in vitro aggregation and improved soluble expression and assembly activity. Rational engineering of catalytic residues and adjacent flexible loops has relaxed strict amino acid preferences at extein junctions, enhancing sequence tolerance and reducing the risk of functional impairment in target proteins. Consensus design based on multiple sequence alignments has yielded ultra-fast splicing variants such as Cfa DnaE and Cat-TerL, which exhibit significantly accelerated kinetics and improved tolerance to denaturing conditions. Meanwhile, advances in structural biology have further clarified the conformational dynamics and catalytic mechanisms of splicing, supporting the precise design of high-performance intein modules. On this basis, electrostatic interaction tuning and metagenomic screening have yielded multiple mutually orthogonal split intein pairs, enabling selective multi-fragment protein ligation and providing new routes for the efficient synthesis of large multi-domain functional proteins. With these engineered split inteins offering continuously improved performance and expanded applicability, protein trans-splicing has been widely applied in numerous cutting-edge areas of protein research and biomedicine. In gene delivery, split intein-based systems overcome the packaging limit of adeno-associated viral vectors, enabling the accurate reconstitution of large therapeutic proteins and base editors in target cells, thereby enhancing the efficacy and scope of gene therapy for genetic diseases. In internal protein sequence editing, split inteins mediate precise sequence replacement and modification in flexible regions or loops of target proteins, without the need for complex multi-step ligation and protein refolding involved in traditional protein semisynthesis. In protein-protein interaction studies, intein-mediated splicing covalently captures transient and weak intracellular complexes, enabling sensitive, high-throughput interaction detection and drug screening. In synthetic biology, conditionally controllable splicing systems support the construction of diverse intracellular and cell-surface biological logic gates for the precise regulation of cellular behavior. In mechanistic biochemical research, split inteins enable photocatalytic proximity labeling and site-specific tagging, allowing the preparation of homogeneous protein samples carrying precise post-translational modifications such as ubiquitination and polyglutamylation for chromatin interactome analysis and epigenetic studies. Moreover, covalent trapping strategies using split inteins stabilize transient enzymatic intermediates, providing unprecedented insights into molecular mechanisms such as nucleosome ubiquitination that are difficult to elucidate using conventional methods. This review systematically summarizes key technological advances in split inteins over the past decade, highlighting engineering strategies, mechanistic insights, and the development of orthogonal components. It comprehensively surveys emerging applications at the frontiers of protein research, analyzes current core challenges, and proposes future directions, particularly emphasizing artificial intelligence-driven de novo design and novel splicing pathways to break existing technical bottlenecks. By enabling traceless, efficient, and versatile protein manipulation, split inteins continue to serve as indispensable tools that drive innovation in protein engineering and fundamental life science research.

ObjectiveTo investigate the current awareness and optimization recommendations on pneumonia with unknown etiology (PUE) surveillance among Shanghai healthcare professionals, and to provide evidence for the improvement of the surveillance system. MethodsIn December 2024, healthcare professional participants from diverse medical and health institutions were randomly selected within each stratum using a stratified cluster sampling method in all 16 districts of Shanghai for questionnaire surveys on their knowledge and suggestions for optimization of the PUE surveillance system. Descriptive statistics analyses, multivariate logistic regressions, and content analyses were used for data analyses. ResultsA total of 385 survey subjects were involved in the study, including 119 professional staffs from disease prevention and control centers and 266 from medical institutions. Those who understood the case definition for PUE correctly accounted for 67.01% (258/385). Multivariate regression model analyses showed that female gender (aOR=2.22, 95%CI: 1.36‒3.66), professionals from disease control institutions (aOR=2.02, 95%CI: 1.12‒3.72), and those who self-assessed as being familiar with the monitoring system (aOR=2.18, 95%CI:1.23‒3.89) had better understanding of the definition. Overall, 89.61% (345/385) of the survey subjects acknowledged the necessity of the surveillance system. Small number of cases meeting the case definition (54.46%, 214/379), insufficient diagnostic awareness (39.84%, 151/379), and lack of incentives for case reporting (29.29%, 111/379) were major problems for the current surveillance system, with variations observed across different types of institutions. Suggested segments for optimizing the surveillance system included monitoring purpose, case definition, form of monitoring and reporting procedure, organization mechanism, and epidemiological investigation and response. ConclusionThe necessity of PUE surveillance is commonly recognized among healthcare workers. However, the existing system falls short in terms of mastery of case definition and overall surveillance adaptability. There is an urgent need for optimization and improvement to enhance the capacity for preventing and controlling emerging and sudden respiratory infectious diseases.

Diabetic nephropathy （DN） is one of the most common and serious microvascular complications of diabetes mellitus and represents a major cause of chronic kidney disease progression and end-stage kidney disease， thereby constituting a major public health problem that adversely affects the prognosis and quality of life of patients with diabetes mellitus. The pathogenesis and progression of DN are complex and involve multiple pathological processes， including insulin resistance， inflammation， oxidative stress， lipid deposition， podocyte injury， and renal fibrosis. Although current clinical therapies can delay the progression of DN to some extent， their effectiveness remains limited by marked interindividual variability in therapeutic response and the difficulty of fully reversing renal injury. Therefore， further elucidation of the key molecular mechanisms underlying DN and the exploration of effective therapeutic strategies are of considerable importance. In recent years， with advances in the understanding of DN pathogenesis， peroxisome proliferator-activated receptor γ （PPARγ）， an important nuclear receptor transcription factor involved in the regulation of insulin resistance， inflammation， oxidative stress， and fibrotic processes， has attracted increasing attention for its role in the development and progression of DN. Traditional Chinese medicine （TCM）， characterized by multi-component， multi-target， and multi-pathway synergistic regulation， may ameliorate pathological processes including metabolic abnormalities， inflammation， oxidative stress， lipid deposition， and renal fibrosis in DN by targeting PPARγ and its associated signaling networks. This review systematically summarizes the mechanisms by which PPARγ and its related signaling pathways regulate DN and reviews recent advances in TCM interventions targeting the PPARγ signaling pathway in DN. Such TCM interventions encompass single herbs such as Coptidis Rhizoma， active constituents such as quercetin， astragaloside Ⅳ， and trigonelline， extracts of herbs such as Plantaginis Herba and Dendrobii Nobilis Caulis， and formulas such as Huangkui capsules， Shenshuaining granules， and Mudan granules. This review aims to provide a theoretical basis for the prevention and treatment of DN with TCM.

Objective To study the photodynamic performance and the killing effect of photodynamic therapy on lung cancer of novel chlorin compounds 2-（4-（5,15,20-triphenyl-7H,8H-porphyrin-10-yl） phenoxy） acetic acid（D1）and 4-（4-（5,15,20-triphenyl-7H,8H-porphyrin-10-yl） phenoxy） butanoic acid （D2）. Methods The ultraviolet visible absorption spectrum and fluorescence spectrum of D1 and D2 were determined. The singlet oxygen generation capacity of D1 and D2 was measured by using DPBF as singlet oxygen capture agent. Fluorescence assay was used to detect the cellular phagocytosis rate of the compounds in A549 cells, and MTT assay was used to detect their dark toxicity and phototoxicity. A nude mouse model of lung cancer was established to investigate the antitumor activity of the compounds mediated photodynamic action in vivo, and the blood concentration of D2 in nude mice, its distribution in tumor tissue and skin tissue were further detected. Results D1 and D2 had strong absorption at 652 nm with the best excitation wavelength at 429 nm and 427 nm, and the optimal emission wavelength was at about 659 nm. They also had a higher singlet oxygen generation rate than the control drug m-THPC. D1 and D2 had no dark toxicity at concentrations below 10 μmol/L, and could be ingested by A549 cells, basically reaching saturation in 18~24 hours. After laser irradiation at 650 nm wavelength, D1 and D2 showed significant antitumor activity in vivo and in vitro （P<0.01）. However, D2 could selectively accumulate in tumor tissues after administration, and the optimal treatment time was less than 30 min after administration. Conclusion D2 had excellent photodynamic antitumor activity and could selectively aggregate in tumor tissues, which had the potential to be a candidate drug for photosensitizer and treatment of lung cancer with independent intellectual property rights, and was worth further research.

ObjectiveTo investigate the value of predictive models established based on machine learning methods in predicting the risk of metabolic associated fatty liver disease （MAFLD）， and to analyze its key risk factors. MethodsA retrospective analysis was performed for the 50 variables of 2 168 healthy individuals who underwent physical examination in Department of Health Assessment， Xiyuan Hospital， China Academy of Chinese Medical Sciences， from January 2021 to December 2024， including body composition， past history， and laboratory tests， and according to whether they were diagnosed with MAFLD or not， they were divided into MAFLD group with 265 individuals and non-MAFLD group with 1 903 individuals. The Mann-Whitney U test was used for comparison of continuous data between two groups， and the chi-square test was used for comparison of categorical data between two groups. Randomly split the research data into a training set and a validation set in a 70% to 30% ratio. Predictive factors were screened from the training set data using univariate analysis， LASSO regression， and multivariate Logistic regression analysis. Predictive models were then constructed using seven machine learning methods： Logistic regression， decision tree， random forest （RF）， eXtreme gradient boosting， light gradient boosting machine， support vector machine， and artificial neural network. Model performance was evaluated by plotting receiver operating characteristic curve for the validation set and calculating the area under the curve （AUC）， sensitivity， specificity， and Youden index for each model. Furthermore， the SHapley Additive exPlanation （SHAP） method was used to analyze the contribution of variables in the optimal model. ResultsThe prevalence rate of MAFLD among the 2 168 subjects was 12.22% （265/2 168）. Smoking， diastolic blood pressure， phase angle， visceral fat area， muscle fat ratio， waist-to-hip ratio， aspartate aminotransferase， non-HDL-C/HDL-C ratio， triglyceride-glucose index， and gallstones were independent risk factors for MAFLD （all P<0.05）. The seven predictive models of support vector machine， eXtreme gradient boosting， decision tree， light gradient boosting machine， artificial neural network， RF， and Logistic regression had an AUC of 0.738， 0.754， 0.757， 0.786， 0.795， 0.796， and 0.815， respectively， in the validation set， among which the RF model had the best discriminatory ability （AUC=0.796， 95% confidence interval： 0.754 — 0.839）， with a sensitivity of 81.01%， a specificity of 63.16%， and a Youden index of 44.17%. The SHAP analysis showed that visceral fat area， waist-to-hip ratio， and diastolic blood pressure were the top three predictive factors in terms of importance. ConclusionThe RF model， constructed based on body composition and clinical indicators， has a good performance in predicting the risk of MAFLD， and its interpretability can help to identify high-risk individuals in the early stage in clinical practice.

Objective: To investigate the distribution characteristics of CD36 antigen in healthy individuals in Xinjiang, China and analyze the molecular mechanisms underlying CD36 deficiency. Methods: Flow cytometry was used to assess CD36 antigen expression on platelets from 881 healthy individuals who underwent physical examinations between June and August 2023. Differences in CD36 antigen distribution among ethnic groups were compared, and genotyping and third-generation sequencing were conducted on samples with CD36 deficiency. Results: Among the 881 samples, 4 cases (0.5%) of CD36 type Ⅱ deficiency were identified. The deficiency frequency was 0.7% (3/430) in Han individuals and 0.3% (1/363) in Uygur individuals, with no statistically significant difference between the two groups (P>0.05). No mutations were detected in the coding regions of the deficient samples. Two samples exhibited a (TG)11 in intron 3. Among the 12 linked mutation sites, g. 55589 G>A was mutated to g. 55589G Del, while g. 55593 A del did not occur; however, g. 55591A>T was observed nearby. Additionally, 52742insGAAAA was present in 100% of the (TG)11 haplotypes, potentially representing a novel linked mutation. Conclusion: This study indicates that the positive frequency of CD36 antigen in Xinjiang is relatively high, suggesting a low risk of alloimmune diseases in clinical practice. The (TG)11 in intron 3 is not universally present in all CD36 type Ⅱ deficiency cases, and the number of linked mutation sites extends beyond the previously reported 12.

Obesity is a chronic low-grade inflammation and a risk factor for diseases such as diabetes， hypertension， dyslipidemia， and malignant tumors， demonstrating an increasingly grim development situation. The nuclear factor-kappa B （NF-κB） signaling pathway is a key signaling pathway involved in the immune response and inflammatory response. In obese individuals， the expression of NF-κB is overactivated， which leads to abnormal inflammatory responses in the body. Therefore， it is expected to alleviate inflammation and treat obesity by regulating the NF-κB signaling pathway， which has been proven effective by a large number of studies. The available studies on the NF-κB signaling pathway mostly focus on tumors， and there is no systematic review of the mechanism of this pathway in mediating obesity and the traditional Chinese medicine （TCM） treatment. We reviewed the research progress in the pathological and physiological processes of obesity mediated by NF-κB signaling pathway and TCM treatment， aiming to give insights into the clinical treatment of obesity with TCM and provide reference targets and research directions for exploring the biological foundations and the development of new TCM preparations.

Objective:An in vivo mammalian hepatocyte Unscheduled DNA Synthesis(UDS)test was used to evaluate the genotoxicity of Cross-linked Sodium Hyaluronate Gel and Bone Repair Materials,providing experimental evidence for establishing a UDS testing method for medical devices and materials.Methods:0.9％sodium chloride injection and cottonseed oil were used as the solvent for test materials and negative control,respectively.N-dimethylnitrosamine(NDMA)was used as the positive control for the early sampling times,and 2-acetylaminofluorene(2-AAF)was used as the positive control for the late sampling times.SD rats were administered a single dose for toxic exposure,and liver tissues were collected at 4 h and 16 h,respectively.Hepatocytes were isolated using collagenase perfusion.After labeling with 5-ethynyl-2'-deoxyuridine(EdU),and the net average fluorescence intensity(NAFI)of cell nuclei and nucleoplasm was measured by fluorescence microscope.Data from 50 cells were used to analyze the DNA repair level.Results:Compared with the negative control groups,the positive control groups(NDMA and 2-AAF)showed highly statistically significant differences in NAFI(P＜0.01),indicating successful induction of DNA damage.There was no statistically significant differences between the cross-linked sodium hyaluronate gel groups,bone repair material groups and the negative control group(P＞0.05),suggesting that these materials did not significantly induce DNA damage under the experimental conditions.Conclusion:This study first applied EdU labeling technology to the in vivo hepatic UDS assay,achieving non-radioactive labeling through click chemistry reactions.Under the conditions of this study,cross-linked sodium hyaluronate gel and bone repair materials did not exhibit genotoxicity.In the follow-up,the sample range can be expanded and the observation period can be prolonged to further improve the genotoxicity evaluation system of medical devices.

Objective To evaluate the subchronic systemic toxicity of disposable plasma virus-inactivated blood transfusion sets using hydroxyethyl starch(HES)130/0.4 sodium chloride injection as an extraction medium.Methods Firstly,40 Sprague Dawley(SD)rats including 20 male and 20 female ones were seleted and randomly enrolled into a sample group and a control group by sex,with 20 ones in each group.Secondly,instead of plasma HES 130/0.4 sodium chloride injection was used to leach disposable plasma virus-inactivated blood transfusion sets to prepare the test solution by simulating clinical application such as lighting,adsorption and filtration and storage.Finally,the test solution and HES 130/0.4 sodium chloride injection were injected into the tail vein of the SD rats at a dose of 20 mL/kg for 28 d in the sample group and in the control group respectively,and the subchronic systemic toxicity of disposable plasma virus-inactivated blood transfusion sets and the feasibility of using HES 130/0.4 sodium chloride injection as the extraction medium to assess their subchronic systemic toxicity were evaluated with clinical observation,body mass monitoring,clinical pathology examination,gross necropsy and histopathology examination.Results The sample group and control group had no significant differences in mortality rates,clinical observation results,body mass,gross necropsy results,hematological and coagulation examination results and organ weight(all P>0.05);blood biochemical examinations showed the male rats in the sample group had the cholesterol(CHO)values higher while the creatinine(CR)values lower than those in the control group,with the differences being statistically significant(both P<0.05)and the two indexes within the range of the laboratory's historical reference data,and other blood biochemical indexes were not significantly different(all P>0.05);the sample group had the spleen weight-to-body mass ratios of the female rates lower significantly than those in the control group(P<0.05),and the ratios of other organ weight to body mass had significant differences(all P>0.05);histopathology examination showed slight pathological changes in liver,spleen and kidney of female rats and in spleen and kidney of male rats in the sample group,and the female and male rats in the control group had similar pathological changes found in the sample group,which might be caused by HES metabolites.Conclusion Disposable plasma virus-inactivated blood transfusion sets prove to have no significant subchronic systemic toxicity,and its feasible to use HES 130/0.4 sodium chloride injection as the extraction medium to evaluate the subchronic systemic toxicity of disposable plasma virus-inactivated blood transfusion sets.[Chinese Medical Equipment Journal,2025,46(10):29-35]