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.

As a common neurological disease in China, stroke has an extremely high rate of death and disability, of which 80% is ischemic stroke (IS), causing a serious burden to individuals and society. Neuronal death is an important factor in the pathogenesis of stroke. Studies have shown that mitochondrial dynamics, as a key mechanism regulating intracellular energy metabolism and cell death, plays an important role in the pathogenesis of IS. In recent years, targeting mitochondrial dynamics has become an emerging therapeutic tool to improve neurological impairment after stroke. This paper reviews the research advance in recent years in IS mitochondrial dynamics, summarizing and discussing the overview of mitochondrial dynamics, the role of mitochondrial dynamics in IS, and the studies on mitochondrial dynamics-based treatment of IS. This paper helps to explore the mechanism of the role of mitochondrial dynamics in IS and effective interventions, and provides a theoretical strategy for targeting mitochondrial dynamics to treat IS in the clinic.
Humans ; Mitochondrial Dynamics/physiology* ; Ischemic Stroke/metabolism* ; Mitochondria/physiology* ; Animals ; Brain Ischemia/physiopathology* ; Energy Metabolism

Network pharmacology and molecular docking were employed to predict the mechanism of Zhizhu Decoction in regulating macrophage polarization to reduce adipose tissue inflammation in obese children, and animal experiments were then carried out to validate the prediction results. The active ingredients and targets of Zhizhu Decoction were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP). The inflammation related targets in the adipose tissue of obese children were searched against GeneCards, OMIM, and DisGeNET, and a drug-disease-target network was established. STRING was used to construct a protein-protein interaction(PPI) network and screen for core targets. R language was used to carry out Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses. AutoDock was used for the molecular docking between core targets and active ingredients. 24 SPF grade 6-week C57B/6J male mice were adaptively fed for 1 week, and 8 mice were randomly selected as the blank group. The remaining 16 mice were fed with high-fat diet for 8 weeks to onstruct a high-fat diet induced mouse obesity model. After successful modeling, the 16 mice were randomly divided into model group and Zhizhu Decoction group, with 8 mice in each group. Zhizhu Decoction group was intervened by gavage for 14 days, once a day. Blank group and model group were given an equal amount of sterile double distilled water(ddH_2O) by gavage daily. After the last gavage, serum and inguinal adipose tissue were collected from mice for testing. The morphology of inguinal adipose tissue was observed by hematoxylin-eosin(HE) staining, the levels of inflammatory factors interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α)were detected by enzyme-linked immunosorbent assay(ELISA), and the protein expression of macrophage marker molecule nitric oxide synthase(iNOS) and epidermal growth factor like hormone receptor 1(F4/80) was detected by immunofluorescence staining. Network pharmacology predicted luteolin, naringenin, and nobiletin as the main active ingredients in Zhizhu Decoction and 15 core targets. KEGG pathway enrichment analysis revealed involvement in the key signaling pathway of nuclear factor κB(NF-κB). Molecular docking showed that the active ingredients of Zhizhu Decoction bound well to the core targets. Animal experiment showed that compared with the model group, Zhizhu Decoction reduced the distribution of inflammatory cytokines in the inguinal adipose tissue of mice, lowered the levels of TNF-α and IL-6 in the serum(P<0.05, P<0.01), and down-regulated the expression of iNOS and F4/80(P<0.05). The results showed that the active ingredients in Zhizhu Decoction, such as luteolin, naringenin, and nobiletin, inhibit the aggregation of macrophages in adipose tissue, downregulate their classic activated macrophage(M1) polarization, reduce the expression of inflammatory factors IL-6 and TNF-α, and thus improve adipose tissue inflammation in obese mice.
Animals ; Drugs, Chinese Herbal/pharmacology* ; Molecular Docking Simulation ; Adipose Tissue/immunology* ; Mice ; Male ; Humans ; Network Pharmacology ; Macrophages/immunology* ; Mice, Inbred C57BL ; Child ; Protein Interaction Maps/drug effects* ; Obesity/genetics* ; Inflammation/drug therapy*

This study aimed to investigate the effect of saltwater stir-fried Plantaginis Semen(SPS) on renal fibrosis in rats and decipher the underlying mechanism. Thirty-six Sprague-Dawley rats were randomly assigned into control, model, losartan potassium, and low-, medium-, and high-dose(15, 30, and 60 g·kg~(-1), respectively) SPS groups. Rats in other groups except the control group were subjected to unilateral ureteral obstruction(UUO) to induce renal fibrosis, and the modeling and gavage lasted for 14 days. After 14 consecutive days of treatment, the levels of serum creatinine(Scr) and blood urea nitrogen(BUN) in rats of each group were determined by an automatic biochemical analyzer. Hematoxylin-eosin(HE) and Masson staining were used to evaluate pathological changes in the renal tissue. Western blot and immunofluorescence assay were conducted to determine the protein levels of fibronectin(FN), collagen Ⅰ, vimentin, and α-smooth muscle actin(α-SMA) in the renal tissue. The mRNA levels of epithelial-mesenchymal transition(EMT)-associated transcription factors including twist family bHLH transcription factor 1(TWIST1), snail family transcriptional repressor 1(SNAI1), and zinc finger E-box binding homeobox 1(ZEB1), as well as inflammatory cytokines such as interleukin-1β(IL-1β), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α), were determined by RT-qPCR. Human renal proximal tubular epithelial(HK2) cells exposed to transforming growth factor-β(TGF-β) for the modeling of renal fibrosis were used to investigate the inhibitory effect of SPS on EMT. Network pharmacology and Western blot were employed to explore the molecular mechanism of SPS in alleviating renal fibrosis. The results showed that SPS significantly reduced Scr and BUN levels and alleviated renal injury and collagen deposition in UUO rats. Moreover, SPS notably down-regulated the protein levels of FN, collagen Ⅰ, vimentin, and α-SMA as well as the mRNA levels of SNAI1, ZEB1, TWIST1, IL-1β, IL-6, and TNF-α in the kidneys of UUO rats and TGF-β-treated HK-2 cells. In addition, compared with Plantaginis Semen without stir-frying with saltwater, SPS showed increased content of specific compounds, which were mainly enriched in the mitogen-activated protein kinase(MAPK) signaling pathway. SPS significantly inhibited the phosphorylation of extracellular signal-regulated kinase(ERK) and p38 MAPK in the kidneys of UUO rats and TGF-β-treated HK2 cells. In conclusion, SPS can alleviate renal fibrosis by attenuating EMT through inhibition of the MAPK signaling pathway.
Animals ; Epithelial-Mesenchymal Transition/drug effects* ; Rats, Sprague-Dawley ; Male ; Rats ; Fibrosis/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Kidney Diseases/pathology* ; Kidney Tubules/pathology* ; Humans

This study explored the mechanism of Xiangsha Liujunzi Decoction(XSLJZD) in the treatment of functional dyspepsia(FD) based on inositol-requiring enzyme 1(IRE1)/apoptosis signal-regulating kinase 1(ASK1)/c-Jun N-terminal kinase(JNK) pathway-mediated autophagy in interstitial cells of Cajal(ICC). Forty-eight SPF-grade male SD suckling rats were randomly divided into a blank group and a modeling group, and the integrated modeling method(iodoacetamide gavage + disturbance of hunger and satiety + swimming exhaustion) was used to replicate the FD rat model. After the model replications were successfully completed, the rats were divided into a model group, high-dose, medium-dose, and low-dose groups of XSLJZD(12, 6, and 3 g·kg~(-1)·d~(-1)), and a positive drug group(mosapride of 1.35 mg·kg~(-1)·d~(-1)), and the intervention lasted for 14 days. The gastric emptying rate and intestinal propulsion rate of rats in each group were measured. The histopathological changes in the gastric sinus tissue of rats in each group were observed by hematoxylin-eosin(HE) staining. The ultrastructure of ICC was observed by transmission electron microscopy. The immunofluorescence double staining technique was used to detect the protein expression of phospho-IRE1(p-IRE1), TNF receptor associated factors 2(TRAF2), phospho-ASK1(p-ASK1), phospho-JNK(p-JNK), p62, and Beclin1 in ICC of gastric sinus tissue of rats in each group. Western blot was used to detect the related protein expression of gastric sinus tissue of rats in each group. Compared with those in the blank group, the rats in the model group showed decreased body weight, gastric emptying rate, and intestinal propulsion rate, and transmission electron microscopy revealed damage to the endoplasmic reticulum structure and increased autophagosomes in ICC. Immunofluorescence staining revealed that the ICC of gastric sinus tissue showed a significant elevation of p-IRE1, TRAF2, p-ASK1, p-JNK, and Beclin1 proteins and a significant reduction of p62 protein. Western blot revealed that the expression levels of relevant proteins in gastric sinus tissue were consistent with those of proteins in ICC. Compared with the model group, the body weight of rats in the high-dose and medium-dose groups of XSLJZD was increased, and the gastric emptying rate and intestinal propulsion rate were increased. Transmission electron microscopy observed amelioration of structural damage to the endoplasmic reticulum of ICC and reduction of autophagosomes, and the p-IRE1, TRAF2, p-ASK1, p-JNK, and Beclin1 proteins in the ICC of gastric sinus tissue were significantly decreased. The p62 protein was significantly increased. Western blot revealed that the expression levels of relevant proteins in gastric sinus tissue were consistent with those of proteins in ICC. XSLJZD can effectively treat FD, and its specific mechanism may be related to the inhibition of the expression of molecules related to the endoplasmic reticulum stress IRE1/ASK1/JNK pathway in ICC and the improvement of autophagy to promote gastric motility in ICC.
Animals ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Autophagy/drug effects* ; Rats ; Rats, Sprague-Dawley ; Interstitial Cells of Cajal/metabolism* ; Dyspepsia/physiopathology* ; Protein Serine-Threonine Kinases/genetics* ; MAP Kinase Kinase Kinase 5/genetics* ; MAP Kinase Signaling System/drug effects* ; Humans ; Endoribonucleases/genetics* ; Multienzyme Complexes