Circadian rhythm is an endogenous biological clock mechanism that enables organisms to adapt to the earth’s alternation of day and night. It plays a fundamental role in regulating physiological functions and behavioral patterns, such as sleep, feeding, hormone levels and body temperature. By aligning these processes with environmental changes, circadian rhythm plays a pivotal role in maintaining homeostasis and promoting optimal health. However, modern lifestyles, characterized by irregular work schedules and pervasive exposure to artificial light, have disrupted these rhythms for many individuals. Such disruptions have been linked to a variety of health problems, including sleep disorders, metabolic syndromes, cardiovascular diseases, and immune dysfunction, underscoring the critical role of circadian rhythm in human health. Among the numerous systems influenced by circadian rhythm, the skin—a multifunctional organ and the largest by surface area—is particularly noteworthy. As the body’s first line of defense against environmental insults such as UV radiation, pollutants, and pathogens, the skin is highly affected by changes in circadian rhythm. Circadian rhythm regulates multiple skin-related processes, including cyclic changes in cell proliferation, differentiation, and apoptosis, as well as DNA repair mechanisms and antioxidant defenses. For instance, studies have shown that keratinocyte proliferation peaks during the night, coinciding with reduced environmental stress, while DNA repair mechanisms are most active during the day to counteract UV-induced damage. This temporal coordination highlights the critical role of circadian rhythms in preserving skin integrity and function. Beyond maintaining homeostasis, circadian rhythm is also pivotal in the skin’s repair and regeneration processes following injury. Skin regeneration is a complex, multi-stage process involving hemostasis, inflammation, proliferation, and remodeling, all of which are influenced by circadian regulation. Key cellular activities, such as fibroblast migration, keratinocyte activation, and extracellular matrix remodeling, are modulated by the circadian clock, ensuring that repair processes occur with optimal efficiency. Additionally, circadian rhythm regulates the secretion of cytokines and growth factors, which are critical for coordinating cellular communication and orchestrating tissue regeneration. Disruptions to these rhythms can impair the repair process, leading to delayed wound healing, increased scarring, or chronic inflammatory conditions. The aim of this review is to synthesize recent information on the interactions between circadian rhythms and skin physiology, with a particular focus on skin tissue repair and regeneration. Molecular mechanisms of circadian regulation in skin cells, including the role of core clock genes such as Clock, Bmal1, Per and Cry. These genes control the expression of downstream effectors involved in cell cycle regulation, DNA repair, oxidative stress response and inflammatory pathways. By understanding how these mechanisms operate in healthy and diseased states, we can discover new insights into the temporal dynamics of skin regeneration. In addition, by exploring the therapeutic potential of circadian biology in enhancing skin repair and regeneration, strategies such as topical medications that can be applied in a time-limited manner, phototherapy that is synchronized with circadian rhythms, and pharmacological modulation of clock genes are expected to optimize clinical outcomes. Interventions based on the skin’s natural rhythms can provide a personalized and efficient approach to promote skin regeneration and recovery. This review not only introduces the important role of circadian rhythms in skin biology, but also provides a new idea for future innovative therapies and regenerative medicine based on circadian rhythms.

To investigate whether Tasquinimod can influence cisplatin resistance in drug-resistant ovarian cancer (OC) cell lines by regulating histone deacetylase 4 (HDAC4) or p21, we explored its effects on the cell cycle, and associated mechanisms.RT-PCR and Western blot analyses, flow cytometry, CCK8 assay, and immunofluorescence were utilized to investigate the effects of Tasquinimod on gene expression, cell cycle, apoptosis, viability, and protein levels in OC cells. The results showed that Tasquinimod inhibited cell viability and promoted apoptosis in SKOV3/DDP (cisplatin) and A2780/DDP cells more effectively than DDP alone. In combination with cisplatin, Tasquinimod further enhanced cell apoptosis and reduced cell viability in these cell lines, an effect that could be reversed following HDAC4 overexpression. Tasquinimod treatment down-regulated HDAC4, Bcl-2, and cyclin D1, and CDK4 expression and up-regulated the cleaved-Caspase-3, and p21 expression in SKOV3/DDP and A2780/ DDP cells. Additionally, Tasquinimod inhibited DDP resistance in OC/DDP cells. These effects were similarly observed in OC mouse models treated with Tasquinimod. In conclusion, Tasquinimod can improve OC cells' sensitivity to DDP by down-regulating the HDAC4/p21 axis, offering insights into potential strategies for overcoming cisplatin resistance in OC.

To investigate whether Tasquinimod can influence cisplatin resistance in drug-resistant ovarian cancer (OC) cell lines by regulating histone deacetylase 4 (HDAC4) or p21, we explored its effects on the cell cycle, and associated mechanisms.RT-PCR and Western blot analyses, flow cytometry, CCK8 assay, and immunofluorescence were utilized to investigate the effects of Tasquinimod on gene expression, cell cycle, apoptosis, viability, and protein levels in OC cells. The results showed that Tasquinimod inhibited cell viability and promoted apoptosis in SKOV3/DDP (cisplatin) and A2780/DDP cells more effectively than DDP alone. In combination with cisplatin, Tasquinimod further enhanced cell apoptosis and reduced cell viability in these cell lines, an effect that could be reversed following HDAC4 overexpression. Tasquinimod treatment down-regulated HDAC4, Bcl-2, and cyclin D1, and CDK4 expression and up-regulated the cleaved-Caspase-3, and p21 expression in SKOV3/DDP and A2780/ DDP cells. Additionally, Tasquinimod inhibited DDP resistance in OC/DDP cells. These effects were similarly observed in OC mouse models treated with Tasquinimod. In conclusion, Tasquinimod can improve OC cells' sensitivity to DDP by down-regulating the HDAC4/p21 axis, offering insights into potential strategies for overcoming cisplatin resistance in OC.

Objective:To investigate the anti-heart failure mechanism of N-acetylcysteine(NAC)in diabetic cardiomyop-athy independent from coronary artery factors.Methods:A total of 40 diabetic mice after heart failure model construction were randomly divided into two groups,NAC group(n=20,NAC 100mg·kg-1·d-1)and control group(n=20,Saline 100 mg·kg-1·d-1).Echocardiography was performed to detect left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular ejection fraction(LVEF),mitral left ventricular early-dias-tolic peak flow velocity/left ventricular late-diastolic peak flow velocity(E/A),isovolumic relaxation time(IVRT)and cardiac output(CO)after 4 weeks.Terminal uridine nick-end labeling(TUNEL)was performed to detect apoptosis in-dex,and Western Blot was performed to detect the expression of extracellular regulated protein kinases(ERK)1/2 after 6 weeks in two groups.Results:Compared to those in control group,mice in NAC group had significant higher LVEF[(40.5±3.4)％vs.(36.9±3.2)％],E/A[(1.5±0.1)vs.(1.4±0.1)]and CO[(10.3±0.6)ml/min vs.(9.9±0.5)ml/min](P＜0.05 or＜0.01);and significant lower LVESV[(23.1±1.3)μl vs.(24.7±1.5)μl],apoptosis index[(31.2±0.5)％vs.(45.1±0.9)％]and the expression of ERK1/2[(2.2±0.2)vs.(3.9±0.1)](P＜0.001 all).Conclusion:NAC exerts anti-heart failure effect by attenuating apoptosis of cardiomyocytes via regulating ERK1/2 pathway.

Aim To explore the mechanisms of PM2.5 exposure exacerbating bleomycin(BLM)-induced idio-pathic pulmonary fibrosis(IFP)by regulating ferropto-sis via nuclear factor 2 related factor 2(Nrf2)/solute carrier family 7 member 11(SLC7A11)/glutathione peroxidase(GPX)4 axis.Methods Forty C57BL/6J mice were randomized into the control,BLM,PM2.5,BLM+PM2.5 and sulforaphane(SFN,Nrf2 agonist)groups,with eight mice in each group.PM2.5 expo-sures were conducted to the BLM-induced IPF mice for two weeks.The lung function was measured,and the content of hydroxyproline(HYP)in lung tissue and the pathomorphology of lungs were observed.Reactive oxygen species(ROS),malondialdehyde(MDA),ferrous ion(Fe2+)and glutathione(GSH)of the lung tissue were measured by ELISA.The mRNA and pro-teins levels of Nrf2,SLC7A11,GPX4,collagen typeⅠ(COL-1),α-smooth muscle actin(α-SMA)were measured by quantitative polymerase chain reaction(qPCR)and Western blot.Results Compared with the control group,the lung function of mice was signif-icantly reduced(P＜0.01)in the BLM and PM2.5 groups,while lung tissue showed the characteristic pathological changes of pulmonary fibrosis such as a large number of inflammatory cell infiltration,alveolar wall fracture,thickening,collagen deposition,and sig-nificantly increased HYP,Fe2+,ROS,MDA(P＜0.05,P＜0.01),genes and proteins of COL-1,α-SMA(P＜0.01);and decreased GSH,Nrf2,SLC7A11,GPX4 genes and proteins(P＜0.05,P＜0.01).The above-mentioned lesions were markedly aggravated in the BLM+PM2.5 group compared with the BLM(P＜0.05)and PM2.5 groups(P＜0.01),and were also improved in the SFN group(P＜0.05,P＜0.01).Conclusions PM2.5 exposures can exac-erbate IPF-induced IPF in mice,and the regulating of Nrf2/SLC7 A1 1/GPX4 axis and ferroptosis might be in-volved in the related mechanisms.

Objective:To investigate the current status of attitudes toward seeking professional psychological help in patients after gastrointestinal tumor surgery and to analyze their influencing factors.Methods:Convenience sampling was used to select 153 patients who underwent surgery at the Gastrointestinal Tumor Center of Peking University Cancer Hospital as study subjects. General Information Questionnaire, Chinese version of Attitude Seeking Professional Psychological Help Scale-Short Form (ATSPPH-SF) , Simplified Coping Style Questionnaire, and General Self-Efficacy Scale were used to conduct the survey. Spearman correlation was used to analyze the correlation between attitudes toward seeking professional psychological help and coping styles and self-efficacy in patients after gastrointestinal tumor surgery. Multiple linear regression was used to explore the factors influencing attitudes toward seeking professional psychological help in patients after gastrointestinal tumor surgery. A total of 153 questionnaires were distributed and 149 valid questionnaires were recovered, with a valid recovery rate of 97.39% (149/153) .Results:The total ATSPPH-SF score of 149 patients with gastrointestinal tumor surgery was [16.00 (13.00, 19.00) ]. Multiple linear regression analysis showed that work status, seeking professional psychological help, and coping styles were the influencing factors on the attitude toward seeking professional psychological help in patients after gastrointestinal tumor surgery ( P<0.05) . Conclusions:The level of attitudes toward seeking professional psychological help in patients after gastrointestinal tumor surgery is low and is influenced by a number of factors. Healthcare professionals can carry out individualized interventions for different patients, enhance absentee patients' disease knowledge, sense of self-worth, and encourage them to carry out professional psychological counseling and establish a positive coping style, so as to increase the initiative of patients to seek professional psychological help.

AIM To investigate the protective effect of Sanfeng Tongqiao Dropping Pills against house dust mite(HDM)-induced allergic asthma in mice.METHODS Compared to the intact BALB/c mice in the blank control group,the BALB/c mice randomly assigned into the model group,the dexamethasone group(0.67 mg/kg),and the low-dose,medium-dose,and high-dose Sanfeng Tongqiao Dropping Pills groups(15,30 and 60 mg/kg),were induced into acute allergic asthma models via weekly intraperitoneal sensitization with 0.1 mL HDM solution(0.5 mg/mL)for three weeks followed by three consecutive daily intranasal challenges with 10 μL HDM solution(2.5 mg/mL)starting in the third week.The drug administered continuously 7 days after the last excitation.The mice had their airway reactive Penh value detected,their pulmonary pathological changes observed by HE staining,their blood eosinophils(EOS)counted,their Th2 cytokines in lung tissue and serum IgE levels detected by ELISA,and their number of peripheral blood mononuclear cells(PBMC)and pulmonary Th2 cells detected by flow cytometry.Chronic allergic asthma was induced in grouped BALB/c mice through repeated intranasal challenges with 10 μL HDM solution(2.5 mg/mL)administered five times weekly for five consecutive weeks.Drug treatment continued for 14 days following the final challenge.After the final treatment,the mice had their pulmonary pathological changes observed by HE staining,and their levels of Th2 cytokines in B ALF and lung tissue and serum IgE detected by ELISA.RESULTS Compared to the blank control group,the acute allergic asthma model group exhibited increases in Penh value,EOS count and IgE level in serum,IL-4 and IL-5 levels in lung tissue(P＜0.01);obvious pulmonary inflammatory cells infiltration,and thickened airway wall;and increase in pulmonary number of Th2 cells(P＜0.01).Compared to the model group,the groups intervened with Sanfeng Tongqiao Dropping Pills demonstrated decreased Penh value,serum EOS count,IgE level and IL-5 level in lung tissue(P＜0.05,P＜0.01);reduced pulmonary inflammatory infiltration and alleviated airway wall thickening;and decreased number of pulmonary Th2 cells.Compared to the blank group,the chronic allergic asthma model group showed obvious pulmonary inflammatory infiltration and airway wall thickening;and increased EOS count and IgE level in serum,IL-4 and IL-13 in lung tissue and IL-14 in BALF(P＜0.05,P＜0.01).Compared to the model group,the groups intervened with either medium-dose or high-dose Sanfeng Tongqiao Dropping Pills demonstrated reduced pulmonary inflammatory infiltration;and decreased serum EOS count,IgE level,IL-13 in lung tissue and IL-14 in BALF(P＜0.05,P＜0.01).CONCLUSION Sanfeng Tongqiao Dropping Pills reduce Th2 cells in peripheral blood and lung tissue,suppress type 2 inflammation,and thereby alleviate allergic asthma.

Aim To investigate the effect of high-fat diet on the tight junction function injury of Sertoli cells through the NF-κB/NLRP3 signaling pathway in mice and to explore the underlying mechanism.Methods Male C57BL/6J mice were fed with high-fat or normal diet for five months.The body and gonadal organ weight of mice were measured,and their indices were calculated.The sperm concentration,the sperm viabili-ty,the testicular histomorphology and the expression levels of tight junction proteins ZO-1,Occludin and Claudin-11 were measured.TM4 cells were treated with palmitic acid(PA)for 24 h.Cell viability was detected by CCK-8 method.Then,TM4 cells were di-vided into different groups treated with PA(0,50,100,200 and 300 μmnol·L-1),and the expression lev-els of tight junction proteins ZO-1,Occludin and Clau-din-11 were detected by Western blot.The tight junc-tion permeability of TM4 cells were detected by transepithelial electrical resistance(TEER)and FITC-dextran.The expression levels of mRNA and proteins for the NF-κB/NLRP3 pathway-related factors were de-tected by RT-qPCR and Western blot.Results The results from animal experiments showed that high-fat diet increased body weight and seminal vesicle weight of mice,and decreased testicular index,epididymal in-dex,sperm concentration and sperm motility of mice.High-fat diet also caused testicular tissue structure damage and down-regulated the expression levels of tight junction proteins ZO-1 and Occludin,without af-fecting the expression of Claudin-11.In vitro,PA sig-nificantly down-regulated the expression levels of ZO-1,Occludin and Claudin-11 in TM4 cells,increased the cell permeability,as well as up-regulated the mRNA and protein expression levels of NLRP3/NF-κB signa-ling pathway-related factors in TM4 cells.Conclusions High-fat diet can impair the function of tight junction of testicualr Sertoli cells,and the machanism may be related to the activation of the NF-κB/NLRP3 signaling pathway,resulting in Sertoli cell inflammation in mice.

Aim To investigate the effect of high-fat diet on the tight junction function injury of Sertoli cells through the NF-κB/NLRP3 signaling pathway in mice and to explore the underlying mechanism.Methods Male C57BL/6J mice were fed with high-fat or normal diet for five months.The body and gonadal organ weight of mice were measured,and their indices were calculated.The sperm concentration,the sperm viabili-ty,the testicular histomorphology and the expression levels of tight junction proteins ZO-1,Occludin and Claudin-11 were measured.TM4 cells were treated with palmitic acid(PA)for 24 h.Cell viability was detected by CCK-8 method.Then,TM4 cells were di-vided into different groups treated with PA(0,50,100,200 and 300 μmnol·L-1),and the expression lev-els of tight junction proteins ZO-1,Occludin and Clau-din-11 were detected by Western blot.The tight junc-tion permeability of TM4 cells were detected by transepithelial electrical resistance(TEER)and FITC-dextran.The expression levels of mRNA and proteins for the NF-κB/NLRP3 pathway-related factors were de-tected by RT-qPCR and Western blot.Results The results from animal experiments showed that high-fat diet increased body weight and seminal vesicle weight of mice,and decreased testicular index,epididymal in-dex,sperm concentration and sperm motility of mice.High-fat diet also caused testicular tissue structure damage and down-regulated the expression levels of tight junction proteins ZO-1 and Occludin,without af-fecting the expression of Claudin-11.In vitro,PA sig-nificantly down-regulated the expression levels of ZO-1,Occludin and Claudin-11 in TM4 cells,increased the cell permeability,as well as up-regulated the mRNA and protein expression levels of NLRP3/NF-κB signa-ling pathway-related factors in TM4 cells.Conclusions High-fat diet can impair the function of tight junction of testicualr Sertoli cells,and the machanism may be related to the activation of the NF-κB/NLRP3 signaling pathway,resulting in Sertoli cell inflammation in mice.

Organ transplantation is an effective treatment for end-stage organ failure, but postoperative infections and rejection reactions are key factors affecting the survival of the patients. Recently, the incidence of human parvovirus B19 (B19V) infection following transplantation has increased. B19V is a non-enveloped virus that primarily infects the upper respiratory tract and exhibits significant tropism for erythroid progenitor cells in the bone marrow, leading to the lysis of erythrocytes and hematological abnormalities. After B19V viremia, it may further infect other cells, triggering inflammatory responses and tissue damage. B19V infection may lead to chronic anemia in organ transplant patients, thereby affecting the success of the transplant and the survival of the patients. Therefore, it is essential to diagnose and monitor B19V infection post-transplantation. Due to the immunosuppressive therapy following transplantation, traditional serological detection methods, such as IgM and IgG antibody tests, are often unreliable. In contrast, molecular biological detection, especially real-time fluorescent quantitative PCR technology, provides more accurate results. However, the diversity of B19V genotypes may lead to the missed detection of some genotypes. Thus, it is necessary to use different detection techniques to improve the diagnostic accuracy of B19 virus infections. Additionally, there is a need to explore more precise diagnostic methods to enhance the early identification and management of B19V infection, further improving the survival and life quality of the patients.