The research and development of innovative drug have progressed remarkably, but the long development circle and high failure rate have become the bottleneck. Drug repurposing, discovering new indications of approved drugs, is a strategy to overcome these obstacles. By exploring new indications for approved drugs, rapid progress has been made in basic research and clinical translation in recent years. Rich resources of drugs, proven security, efficient development workflow and reduced cost are core advantages of this strategy, making the strategy a crucial direction of optimizing the pipeline of drug research and development. This review systematically summarizes drug repurposing cases that have received clinical approval over the past five years, and proposes core strategies for drug repurposing, including approaches based on targets, pathways, drug similarity, post-treatment phenotypes, and clinical side effects, aiming to provide some strategic guidance for drug repurposing efforts.

Flap transplantation is a critical surgical strategy for the reconstruction of tissue defects caused by trauma, tumor resection, and congenital malformations, and its survival rate directly determines surgical efficacy and patient prognosis. Following transplantation, flaps inevitably undergo ischemia-reperfusion (I/R) injury, during which oxidative stress, inflammatory responses, and metabolic disturbances are intricately intertwined, ultimately leading to cellular injury and tissue necrosis. Recent studies have demonstrated that multiple forms of programmed cell death—including apoptosis, pyroptosis, ferroptosis, necroptosis, and PANoptosis—play central roles in flap I/R injury. The extensive crosstalk and molecular interactions among these pathways form a highly complex cell death network. Specifically, apoptosis is mediated by the imbalance of Bcl-2 family proteins and the activation of cysteine-dependent aspartate-specific protease (caspase) cascades; pyroptosis is driven by the NLRP3-caspase-1-GSDMD axis, resulting in membrane pore formation and the release of pro-inflammatory cytokines; ferroptosis is characterized by iron-dependent lipid peroxidation and dysfunction of glutathione peroxidase 4 (GPX4); necroptosis is triggered by the receptor-interacting serine/threonine-protein kinase 1 (RIPK1)-RIPK3-MLKL signaling complex, leading to membrane rupture; and PANoptosis represents an integrated form of inflammatory cell death that coordinates multiple death pathways. Importantly, these forms of programmed cell death are not independent but are interconnected through extensive signaling crosstalk. Key regulatory molecules, including caspase-8, reactive oxygen species (ROS), nuclear factor-κB (NF-κB), and nuclear factor erythroid 2-related factor 2 (Nrf2), collectively modulate the dynamic balance among these pathways. Therefore, the multidimensional interplay and spatiotemporal dynamics of programmed cell death constitute a fundamental pathological basis of flap I/R injury. This review systematically summarizes the latest advances in the mechanisms and interactions of various programmed cell death pathways in flap I/R injury, aiming to elucidate the underlying regulatory network. These insights may provide novel theoretical foundations for optimizing flap protection strategies, improving flap survival, and promoting tissue repair.

AIM: To investigate the association between dyslipidemia and macular hard exudates(HEs)in non-proliferative diabetic retinopathy(NPDR)secondary to type 2 diabetes mellitus(T2DM).METHODS: NPDR patients attending the outpatient ophthalmology clinic from January 2021 to December 2023 were selected and divided into three groups according to the severity of macular HEs. Group A: None or minimal HEs; Group B: Definite HEs; Group C: Prominent HEs. Total cholesterol(TC), triglycerides(TG), low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C), lipoprotein(a)[Lp(a)] levels and other lipid-related indicators were routinely measured. The correlation between these indicators and HEs was analyzed.RESULTS:Group A(24 eyes)consisted of 9 males and 15 females with the mean age of 54.71±6.15 y, group B(52 eyes)consisted of 20 males and 32 females with the mean age of 55.08±6.27 y, group C(14 eyes)consisted of 9 males and 5 females with the mean age of 53.93±6.08 y. The concentration of TC, TG, LDL-C and Lp(a)was highest in group C, followed by group B and lowest in group A with statistically significant differences(P<0.001). There were no statistically significant differences between the three groups for fasting plasma glucose(FPG), glycated hemoglobin A1c(HbA1c), creatinine(Cr), and HDL-C(P>0.05). The results of multivariate Logistic regression analysis showed that elevated levels of TC, TG, LDL-C, and Lp(a)were associated with the presence of macular HEs. Receiver operating characteristiccurve analysis showed that the area under the curve(AUC)for TC, TG, LDL-C, Lp(a), and their combination in predicting macular HEs in NPDR were 0.785, 0.718, 0.784, 0.742, and 0.911, respectively, with the combined model demonstrating the highest predictive performance.CONCLUSION: Dyslipidemia is closely associated with the development and progression of macular HEs in patients with NPDR and T2DM. The levels of TC, TG, LDL-C, and Lp(a)were correlated with the severity of macular HEs, suggesting that dyslipidemia may be involved in the pathological process of macular HEs formation.

Patients with inflammatory bowel disease (IBD) require long-term pharmacotherapy. Due to the wide variety of clinically available drugs, medication safety has become increasingly concerning. As an indispensable component of pharmaceutical formulations, drug excipients may induce various adverse reactions, including rash, allergic responses, and gastrointestinal discomfort, and may even lead to severe organic injury. However, they are often overlooked in clinical practice. Therefore, identifying and managing excipient-related adverse reactions is crucial for ensuring medication safety. To address this issue, this article systematically reviews common excipients in IBD therapeutics, the underlying mechanisms of excipient-induced adverse reactions, and corresponding management strategies, aiming to enhance clinicians' awareness of excipient-related issues, improve their ability to recognize and manage such reactions, and ultimately ensure patient safety.

ObjectiveTo investigate the ameliorating effect of Xiao Chaihutang combined with Erchen Tang （XAE） on metabolic-associated fatty liver disease （MAFLD） in mice and the influence of this therapy on the silent information regulator 1 （SIRT1）/peroxisome proliferator-activated receptor γ coactivator-1α （PGC-1α）/peroxisome proliferator-activated receptor α （PPARα） signaling pathway. MethodsForty-eight C57BL/6 mice were randomized into six groups： normal （CHOW）， atorvastatin （ATO， 0.05 g·kg^-1）， high-fat diet （HFD）， low-dose XAE （XAE-L， 10 g·kg^-1）， medium-dose XAE （XAE-M， 20 g·kg^-1）， and high-dose XAE （XAE-H， 40 g·kg^-1）. Each group contained 8 mice. Except the CHOW group， the other groups of mice were fed a HFD for the modeling of MAFLD. The experiment lasted for 20 weeks. Starting from the 13th week， mice were administered corresponding agents daily by gavage， and the mice in both the CHOW and HFD groups received equal volumes of purified water. At the end of the experiment， cardiac blood， liver， and adipose tissue samples were collected. Pathological staining was performed on the liver and adipose tissue separately. The levels of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， high-density lipoprotein cholesterol （HDL-C）， low-density lipoprotein cholesterol （LDL-C）， triglycerides （TG）， and total cholesterol （TC） in the serum， as well as TG and TC in the liver， were determined. Additionally， the mRNA levels of fatty acid synthetase （FASN）， stearoyl-CoA desaturase 1 （SCD1）， sterol regulatory element-binding protein 1c （SREBP-1c）， SIRT1， PPARα， PGC-1α， interleukin 6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α） in the liver were measured by real-time PCR. The protein levels of SIRT1， PGC-1α， PPARα， and CPT1α in the mouse liver tissue were determined by Western blot. ResultsCompared with the CHOW group， the HFD group exhibited increased body weight， liver weight， and white adipose tissue weight （P<0.01）. After XAE intervention， these parameters were reduced compared with those in the HFD group （P<0.01）. Pathological section results showed that the morphology of hepatocytes and epididymal white adipocytes in the model mice was significantly improved after XAE intervention， with decreases in both the number and volume of lipid droplets. Furthermore， the XAE groups had lower levels of AST， ALT， HDL-C， LDL-C， TG， and TC in the serum and TG and TC in the liver than the HFD group （P<0.05，P<0.01）. Moreover， XAE administration downregulated the mRNA levels of lipid synthesis-related genes （FASN and SCD1） （P<0.05） and upregulated the mRNA levels of lipid oxidation-related genes （SIRT1， PPARα， and PGC-1α） （P<0.05，P<0.01）. Additionally， the protein levels of SIRT1， PGC-1α， PPARα， and CPT1α in the liver were upregulated after XAE treatment compared with those in the HFD group （P<0.05，P<0.01）. ConclusionXAE exerts a therapeutic effect on MAFLD by activating the SIRT1/PGC-1α/PPARα signaling pathway.

Objective To investigate whether aberrant DNA methylation of ubiquinol-cytochrome C reductase core protein 1(UQCRC1)is related to cognitive impairment caused by neonatal sevoflurane exposure.Methods A total of 94 SPF C57 mice of either sex,aged 6 d,and weighing 4～6 g,were randomly divided into 7 groups:control group(Con,n=6),sevoflurane-6 and-24 h exposure groups(Sev-6 and-24 h,n=6),control+DMSO group(Con+DMSO,n=19),control+5-aza-2'-deoxycytidine(5-AZA,methylation inhibitor)group(Con+5-AZA,n=19),sevoflurane+DMSO group(Sev+DMSO group,n=19),and sevoflurane+5-AZA group(Sev+5-AZA group,n=19).From 6 to 8 d after birth,the mice of the Sev-6 and-24 h exposure groups were exposed to 3％sevoflurane daily(with 97％oxygen,2 L/min,2 h per day),while those from the Con groups were given exposure of 100％oxygen(2 L/min,2 h per day).For the mice of the 5-AZA and DMSO groups,1 mg/kg of 5-AZA or an equal volume of DMSO was injected intraperitoneally 30 min before daily exposure.In 6 and 24 h after the last exposure to sevoflurane,6 mice from the Con,Sev-6 h,and Sev-24 h groups were euthanized for biochemical analysis,and in 24 h post-exposure,6 mice from the Con+DMSO,Con+5-AZA,Sev+DMSO,and Sev+5-AZA groups were randomly selected for biochemical analysis,while another 3 mice from above each group were also randomly selected for morphological analysis.The remaining 10 mice in these groups underwent behavioral testing(open field test,novel object test,and Y-maze test)at 30～33 d after birth to assess cognitive function,and were euthanized in 24 h after the final behavioral test.RT-qPCR and Western blotting were used to detect the hippocampal expression of UQCRC1,DNA methyltransferases(Dnmts),and methyl CpG binding protein 2(Mecp2)at mRNA and protein levels,respectively.Immunofluorescence assay was employed to observe the distribution and expression of UQCRC1 in the hippocampus.Bisulfite sequencing PCR(BSP)was applied to measure the methylation in the UQCRC1 promoter region.Results Compared with the Con group,the mRNA and protein levels of UQCRC1 were down-regulated(P<0.05),and the mRNA level of Dnmts was up-regulated(P<0.05)in both the Sev-6 h and Sev-24 h exposure groups,while the methylation level in the UQCRC1 promoter region was enhanced in the Sev-24 h exposure group(P<0.05).Additionally,the Sev+5-AZA group had obviously increased mRNA and protein levels of UQCRC1(P<0.05),and notable improvement in cognitive impairment(P<0.05)when compared with the Sev+DMSO group.Conclusion Hypermethylation of UQCRC1 promoter region and thus down-regulating its mRNA and protein expression might be the main mechanism by which repeated neonatal sevoflurane exposure induces cognitive impairment later in life.

Bronchopulmonary dysplasia（BPD）is a chronic respiratory disease characterized by developmental disorders and abnormal repair of lung tissue in premature infants.Its clinical manifestations are characterized by persistent respiratory distress syndrome，which can cause progressive lung function damage and significantly affect the quality of life and long-term prognosis of the affected children.Vitamin D has been proven to have multiple lung protective effects in recent years.It not only participates in regulating normal lung development，but also effectively inhibits inflammatory reactions，promotes the biosynthesis of pulmonary surfactant，regulates cell apoptosis，and maintains lung tissue function and structural integrity.The above physiological functions are significantly correlated with the pathophysiology of BPD，providing a new theoretical perspective for further elucidating the pathogenesis of BPD.Based on existing evidence，vitamin D may provide new treatment and research directions for BPD.

Due to the high prevalence of periodontitis, the control of periodontal inflammation, as well as the regeneration and repair of periodontal tissues have attracted extensive attentions. To better understand the mechanism of periodontal diseases, in vivo and in vitro models are usually required. With the rapid development of tissue engineering, in vitro models with the advantages of easy observation, high controllability, low cost, and high efficiency has become a unique choice for current research. In vitro models of periodontitis are no longer limited to cellular models, researchers are increasingly inclined to develop simple, effective, and realistic models to simulate the periodontal microenvironment. This article reviews in vitro models of periodontitis that have been successfully established, aiming to provide researchers with new ideas to simulate the human periodontitis microenvironment in vitro, which is helpful to explore the pathogenesis of periodontitis.

Objective:To explore the protective mechanism of dexmedetomidine (Dex) in a model of broncho-pulmonary dysplasia (BPD) in mice exposed to hyperoxia.Methods:Neonatal rats were randomly assigned to four groups:air control group,hyperoxia injury group,Dex control group,and hyperoxia+Dex group,with six animals in each group.The air control and Dex control groups were exposed to ambient air,while the hyperoxia injury and hyperoxia+Dex groups were exposed to 90% O 2.The Dex control and hyperoxia+Dex groups received daily intraperitoneal injections of Dex at a dosage of 500 μg/kg.Lung tissue samples were collected after 7 days.Histomorphological changes in lung tissue were evaluated using hematoxylin and eosin (HE) staining,and mitochondrial ultrastructural changes in type I epithelial cells of neonatal rat lung tissue were observed via transmission electron microscopy.The activity of Complex Ⅰ in neonatal rat lung tissue was assessed.The expression levels of PINK1 and Parkin in neonatal rat lung tissue were measured using quantitative PCR (qPCR).Western blot analysis was conducted to determine the protein expression levels of PINK1 and Parkin in lung tissues. Results:Under transmission electron microscopy,mitochondrial structures were intact in the lung tissues of both the air control group and the Dex control group.However,significant mitochondrial damage was observed in the hyperoxia injury group,while the hyperoxia+Dex group exhibited some relief from mitochondrial damage compared to the hyperoxia injury group.The activity of the oxidized respiratory chain Complex Ⅰ in the hyperoxia injury group was significantly lower than that in the air control group (4.824±0.804 vs.15.276±0.804, P<0.05) and the hyperoxia+Dex group(4.824±0.804 vs.9.648±0.804, P<0.05).After qPCR analysis,the expression levels of PINK1 and Parkin in the hyperoxia injury group were higher than those in the air control group(1.80±0.06 vs.1.00±0.07,2.10±0.14 vs.1.00±0.09, P<0.05),but lower than those in the hyperoxia+Dex group(1.80±0.06 vs.3.61±0.19,2.10±0.10 vs.4.24±0.43, P<0.05).Western blot analysis revealed that the expression levels of PINK1 and Parkin in the hyperoxia injury group were higher than those in the air control group(2.16±0.11 vs.1.00±0.01,3.82±0.13 vs.1.00±0.01, P<0.05),but lower than those in the hyperoxia+Dex group(2.16±0.11 vs.3.35±0.14,3.82±0.13 vs.5.48±0.15, P<0.05).There were no significant differences in mitochondrial structure integrity,Complex Ⅰ enzyme activity,or the expression levels of PINK1 and Parkin,as assessed by qPCR and Western blot analysis,between the air control and Dex control groups( P>0.05). Conclusion:Dex effectively mitigates mitochondrial ultrastructural damage in BPD model mice,enhances the activity of Complex Ⅰ in the oxidative respiratory chain,reduces mitochondrial damage,and increases the activation of the PINK1-Parkin-mediated mitophagy pathway,thereby promoting lung protection.

Due to the high prevalence of periodontitis, the control of periodontal inflammation, as well as the regeneration and repair of periodontal tissues have attracted extensive attentions. To better understand the mechanism of periodontal diseases, in vivo and in vitro models are usually required. With the rapid development of tissue engineering, in vitro models with the advantages of easy observation, high controllability, low cost, and high efficiency has become a unique choice for current research. In vitro models of periodontitis are no longer limited to cellular models, researchers are increasingly inclined to develop simple, effective, and realistic models to simulate the periodontal microenvironment. This article reviews in vitro models of periodontitis that have been successfully established, aiming to provide researchers with new ideas to simulate the human periodontitis microenvironment in vitro, which is helpful to explore the pathogenesis of periodontitis.