Renal fibrosis is the common pathological endpoint of many forms of chronic kidney disease (CKD), yet the mechanisms determining effective repair versus persistent fibrotic remodeling remain incompletely understood. Peritubular capillaries (PTCs) are not merely passive targets of fibrotic injury, but form a dynamic vascular microenvironment linking regional perfusion, oxygen delivery, tubular metabolism, endothelial barrier integrity, pericyte support, immune-cell trafficking, and extracellular matrix (ECM) remodeling. We propose that PTC abnormalities should not be interpreted simply as reduced capillary density, but as a multidimensional disturbance of microvascular structure and function. Structural vascular preservation does not necessarily indicate effective microcirculation: anatomically detectable capillaries may still exhibit impaired perfusion, barrier dysfunction, abnormal endothelial-pericyte interactions, disturbed oxygen metabolism, or reduced network connectivity. Conversely, increased angiogenesis does not necessarily signify successful vascular repair if vessels remain immature, poorly perfused, or inadequately integrated into the existing network. To organize these abnormalities, we conceptualize PTC remodeling into four predominant but nonexclusive states: endothelial barrier disruption with inflammatory adhesion; endothelial-pericyte uncoupling with no-reflow; dysregulated angiogenesis with network simplification; and capillary rarefaction with fibrotic matrix locking. These states are not sequential stages of CKD. They may coexist within the same kidney, overlap within the same anatomical region, and vary with disease etiology, injury phase, vascular compartment, and treatment exposure. We further propose six dimensions for evaluating PTC status—structural presence, functional perfusion, barrier integrity, pericyte coupling, oxygen metabolism, and network connectivity—so that vascular quantity, function, and reparative capacity are assessed separately rather than inferred from a single endothelial marker or capillary-density measurement. Mechanistically, these states converge on a bidirectional microvascular-fibrotic feedback loop. Barrier disruption facilitates leukocyte recruitment and alters vascular paracrine signaling. Endothelial-pericyte uncoupling compromises capillary stability, whereas abnormal pericyte contraction may increase local vascular resistance and contribute to no-reflow before overt capillary loss. Dysregulated angiogenesis may generate vessels that fail to mature or connect to an effective perfusion network. Progressive capillary rarefaction compromises oxygen delivery, while sustained tubular transport demand and mitochondrial dysfunction may aggravate regional oxygen supply-demand mismatch. Injured tubules, immune cells, endothelial cells, pericytes, and fibroblasts communicate through soluble mediators, extracellular vesicles, direct cell contact, and cell-matrix signaling. Importantly, fibrosis is not merely a downstream consequence of microvascular injury. Altered ECM may increase diffusion distance, modify mechanotransduction, impair endothelial survival and migration, and restrict capillary reopening and regeneration. We use the term matrix locking to describe this sustained constraint on vascular repair, while emphasizing that current evidence does not establish irreversible disease in humans. This framework also has therapeutic implications. PTC-directed treatment should not be reduced to increasing vessel number or uniformly promoting angiogenesis. Instead, intervention should be matched to the dominant and potentially reversible abnormality: preserving endothelial barrier function; restoring endothelial-pericyte stability and reducing pathological microvascular resistance; normalizing angiogenesis so that vascular growth is accompanied by maturation, barrier competence, network integration, and effective perfusion; and, in advanced rarefaction, relieving matrix-related constraints while supporting vascular regeneration. The context- and time-dependent effects of signaling through VEGF, Tie2, PDGF-B/PDGFRβ, eNOS/NO, and related pathways indicate that the same molecular signal may exert different effects depending on disease context and timing. Therapeutic efficacy should therefore be evaluated by restoration of effective microcirculation and tissue function rather than by isolated molecular changes or capillary counts alone. Despite increasing mechanistic evidence, the translational basis for this framework remains limited. Most causal and interventional data derive from animal or cell models, whereas human evidence is largely limited to pathological observations, patient-sample associations, and prognostic studies. Currently available circulating and urinary candidate biomarkers generally lack sufficient specificity for PTC injury or state assignment, and no standardized quantitative thresholds have been externally validated. The four-state model should therefore be regarded as a hypothesis-generating analytical framework rather than a clinicopathological classification system. Future studies should integrate spatially resolved tissue phenotyping, blood and urine biomarkers, and dynamic microcirculatory assessment in longitudinal cohorts. They should test reproducibility, assess prognostic value beyond conventional pathology, estimated glomerular filtration rate, and proteinuria, and determine whether changes in PTC status precede or mediate therapeutic benefit. Linking reproducible microvascular phenotypes to defined mechanisms, treatment response, and long-term renal outcomes will be essential to determine whether state-directed assessment and restoration of the PTC microenvironment can ultimately inform patient stratification and therapeutic decision-making.

ObjectiveTreadmill exercise intervention was evaluated for its effects on addictive behavior, learning and memory, and hippocampal neuroinflammation in methamphetamine (MA)-addicted mice, and transcriptomic screening was performed to identify candidate molecules involved in exercise-mediated attenuation of MA-related neuronal injury. MethodsTwo-month-old male C57BL/6 mice were randomly assigned to four groups: control (C), exercise control (CE), methamphetamine (M), and methamphetamine plus exercise (ME). Mice in the M and ME groups received intraperitoneal injections of MA (1 mg/kg) once daily for 7 consecutive days to establish the addiction model, whereas mice in the C and CE groups received equal volumes of saline. Subsequently, mice in the CE and ME groups underwent treadmill exercise at 12 m/min for 60 min/d for 2 weeks. Conditioned place preference (CPP), the Y-maze, and the Morris water maze (MWM) were used to assess addictive behavior, spatial recognition memory, and spatial learning and memory, respectively. Hippocampal neuronal ultrastructure was examined by transmission electron microscopy (TEM), and microglia-related responses were evaluated by immunofluorescence staining for ionized calcium-binding adapter molecule 1 (Iba-1) in the hippocampal CA1 region. Previously generated and publicly available RNA-seq data from brain tissue of the C, M, and ME groups were reanalyzed, with three biological samples per group. Differentially expressed genes (DEGs) were re-screened using the criteria of P<0.05 and fold change>1.5 or <0.67, followed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. NLR family CARD domain containing 5 (Nlrc5) was further validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and Western blot was used to determine the protein expression of NLRC5, nuclear factor kappa B (NF‑κB), interleukin-1β (IL-1β), postsynaptic density-95 (PSD-95), and synaptophysin. ResultsTreadmill exercise significantly attenuated MA-induced conditioned place preference and improved learning and memory performance in both the Y-maze and MWM tests. Exercise increased exploration time and distance in the novel arm of the Y-maze, shortened escape latency, and increased the number of platform crossings in the MWM. Average swimming speed during the probe trial did not differ significantly among groups, suggesting that the MWM differences were not attributable to obvious differences in swimming performance. TEM revealed that MA exposure induced mitochondrial swelling, disrupted cristae, reduced organelle abundance, and nuclear envelope abnormalities in hippocampal neurons, whereas these ultrastructural changes were alleviated after exercise. Immunofluorescence staining showed that MA increased Iba-1 fluorescence intensity in the hippocampal CA1 region, while treadmill exercise significantly reduced this change. Transcriptomic analysis identified 160 DEGs associated with MA exposure and 58 DEGs associated with exercise intervention, with 9 overlapping DEGs. KEGG enrichment analysis showed that MA-related DEGs were enriched in the NOD-like receptor signaling pathway. Among the overlapping DEGs, Nlrc5, which was downregulated after MA exposure and restored following exercise intervention, was selected as a candidate gene for further validation. RT-qPCR confirmed that treadmill exercise reversed the MA-induced decrease in Nlrc5 mRNA expression. Western blot analysis further showed that treadmill exercise increased NLRC5, PSD-95, and synaptophysin protein expression while reducing NF-κB and IL-1β expression. ConclusionTwo weeks of treadmill exercise attenuated MA-induced conditioned place preference and ameliorated learning and memory impairment, alleviated hippocampal neuroinflammation and neuronal ultrastructural damage, and restored the expression of synapse-related proteins. Transcriptomic screening combined with molecular validation demonstrated that exercise intervention was accompanied by restoration of NLRC5 expression, reduced NF‑κB and IL-1β expression, and increased PSD-95 and synaptophysin expression. These findings suggest that NLRC5 may represent a candidate molecule involved in exercise-mediated amelioration of MA-related neuronal injury. However, the present results mainly demonstrate coordinated changes in NLRC5 expression, inflammatory indicators, and cognitive outcomes rather than a direct causal relationship, and the specific role of NLRC5 requires further functional validation.

Long-term spaceflight,characterized by drastic changes in spatial position,disrupts the Earth's inherent environmental periodic signals,such as the day-night light-dark cycle.This leads to a misalignment between the external environmental cycles and the body's endogenous biological rhythms.The cumulative effect of this persistent"time difference"severely disrupts the core biological pathways that regulate the circadian rhythm.It triggers a series of neuroendocrine and behavioral stress responses,exemplified by sleep-wake disorders,which have become a core medical problem constraining the success of long-term space missions and astronaut health.Traditional Chinese Medicine(TCM)posits that aligning with the rhythmic changes of heaven,earth,day,night,and the four seasons,and maintaining the dynamic balance and harmonious functioning of the body's Yin and Yang vital energies,are fundamental principles for safeguarding vitality and resisting external pathogens and internal injuries.However,in the prolonged weightlessness,confinement,and abnormal lighting environment of deep space flight,the bond between the human body and natural rhythms is forcibly severed.Yin and Yang Qi become difficult to sustain,the mechanisms of ascent,descent,exit,and entry are obstructed,the visceral Qi transformation functions are impaired,and the circulation of Qi and Blood becomes disordered,ultimately leading to the onset of various disorders.This paper,grounded in the TCM temporal medicine perspective of"correspondence between heaven and human"(tian ren xiang ying)and the theories of Yin-Yang and Qi-Blood,meticulously reviews the historical classics and modern research on acupoint intervention strategies for addressing rhythm disorders and harmonizing Yin and Yang.Building upon this foundation,it innovatively proposes and argues for an integrated acupoint prescription strategy:the"Bei Xin Wu Xue"combined with the classic paired points Zhaohai(KI6)-Shenmai(BL62)on the lower limbs to regulate the dynamic balance of the Yin and Yang Heel Vessels(Yin/Yang Qiao Mai),and the classic paired points Taichong(LR3)-Yongquan(KI1)to guide Qi downward.This combination aims to work at multiple levels-"Heart-Brain,Yin-Yang,Liver-Kidney"-to calm the Heart Spirit,clear the Brain Mansion,and tonify the Liver and Kidney.The goal is to restore Yin and Yang Qi to an orderly and coordinated state,thereby assisting the disordered biological rhythm system in regaining homeostasis.This provides a novel TCM-inspired approach of"rhythm regulation and equilibrium restoration"(tiao shi fu heng)to safeguard the long-term in-orbit health of astronauts.

Objective : To investigate the mechanism of prostaglandin E synthase 3(PTGES3)/heat shock protein 90(HSP90) in the medial prefrontal cortex regulating obesity-related cognitive dysfunction. Methods: This study consisted of clinical trials and animal experiments. In part one, obese patients scheduled for bariatric surgery, and healthy adults matching gender and age were recruited at the same time to reach 10 cases in each group. The cognitive level was assessed with trail making test part A(TMT-A) and victoria stroop tests(VST). Four-dimensional data-independent acquisition(4D-DIA) was used to screen the proteome changes in peripheral blood. In part two, forty SPF healthy male C57BL/6J mice were randomly divided into four groups: normal diet group(ND group), high fat diet induced obesity group(DIO group), DIO supplemented with the control virus group(DIO+Scramble group) and DIO supplemented with the interfering virus group(DIO+shPTGES3 group). The Morris water maze test was conducted to evaluate the cognitive behavior changes of the four groups of mice. The immunofluorescence staining was performed to detect the expression of PTGES3 and HSP90 in the medial prefrontal cortex and the activation of ionized calcium binding adapter molecule 1(IBA1)-labeled microglia. Results: In the case-control study, the cognitive function of obese patients significantly decreased, and the expression of PTGES3 in peripheral blood significantly increased, while the level of PTGES3 was negatively correlated with cognitive function. In animal experiments, compared with ND group, DIO group had significantly prolonged time reaching the target platform, otherwise, the residence time in the target quadrant was shortened in the Morris water maze test. Simultaneously, there were significant increase in the expression of PTGES3 and HSP90, and the activation of IBA1 in the medial prefrontal cortex. Compared with DIO+Scramble group, mice in the DIO+shPTGES3 group spent less time reaching the target platform, and stayed longer in the target quadrant. The expression and co-localization levels of PTGES3 and HSP90 in medial prefrontal cortex significantly decreased. The activation level of microglia cells was also attenuated by PTGES3 interference. Conclusion Obesity-related cognitive dysfunction may be attributed to PTGES3/HSP90 in the medial prefrontal cortex by mediating neural inflammation.

Arsenic is a semi-metal,and lipid-soluble arsenic compounds are one of the widespread forms in the environment and food chain,but there is a lack of standards for lipid-soluble arsenic compounds,which is one of the bottlenecks in the current analytical detection and toxicological studies of organic arsenic.In this study,four saturated arsenic-containing hydrocarbons,AsHC 318,AsHC 332,AsHC 346,and AsHC 374(The number is relative molecular mass),were successfully synthesized in three steps by using dimethylarsinic acid,potassium iodide,sodium hydroxide,and four brominated alkanes(1-Bromotetradecane,1-bromopentadecane,1-bromohexadecane,and 1-bromooctadecane)as raw materials.The structures of these four saturated arsenic-containing hydrocarbons were characterized by proton nuclear magnetic resonance(1H NMR)spectroscopy,13C nuclear magnetic resonance(13C NMR)spectroscopy,and high-resolution mass spectrometry(HR-MS).The yields of the method were 8%-10%,and the synthesized compounds could be used in subsequent toxicity evaluation experiments to assess the toxic effects and mechanisms of action of arsenic-containing hydrocarbons.This study provided an effective method for synthesis of arsenic-containing hydrocarbons,enriching the synthesis methods of arsenic-containing hydrocarbons,and provided raw materials for the subsequent toxicological studies of arsenic-containing hydrocarbons.

In the process of maintaining the steady state of bone tissue, the transcription network and signal pathway of the body play a vital role. These complex regulatory mechanisms need precise coordination to ensure the balance between bone formation and bone absorption. Once this balance is broken, it may lead to pathological changes of bone and cartilage, and then lead to various bone diseases. Therefore, it is of great significance to understand these regulatory mechanisms for the prevention and treatment of bone diseases. In recent years, with the deepening of research, more and more lncRNA has been found to be closely related to bone health. Among them, nuclear paraspeckle assembly transcript 1 (NEAT1), as an extremely abundant RNA molecule in mammalian nuclei, has attracted extensive attention. NEAT1 is mainly transcribed from a specific site in human chromosome 11 by RNA polymerase II (RNaseP), which can form two different subtypes NEAT1_1 and NEAT1_2. These two subtypes are different in intracellular distribution and function, but they participate in many biological processes together. Studies have shown that NEAT1 plays a specific role in the process of cell growth and stress response. For example, it can regulate the development of osteoblasts (OB), osteoclasts (OC) and chondrocytes by balancing the differentiation of bone marrow mesenchymal stem cells (BMSCs), thus maintaining the steady state of bone metabolism. This discovery reveals the important role of NEAT1 in bone development and remodeling. In addition, NEAT1 is closely related to a variety of bone diseases. In patients with bone diseases such as osteoporosis (OP), osteoarthritis (OA) and osteosarcoma (OS), the expression level of NEAT1 is different. These differential expressions may be closely related to the pathogenesis and progression of bone diseases. By regulating the level of NEAT1, it can affect a variety of signal transduction pathways, and then affect the development of bone diseases. For example, some studies show that by regulating the expression level of NEAT1, the activity of osteoclasts can be inhibited, and the proliferation and differentiation of osteoblasts can be promoted, thus improving the symptoms of osteoporosis. It is worth noting that NEAT1 can also be used as a key sensor for the prevention and treatment of bone diseases. When exercising or receiving some natural products, the expression level of NEAT1 will change, thus reflecting the response of bones to external stimuli. This feature makes NEAT1 an important target for studying the prevention and treatment strategies of bone diseases. However, although the role of NEAT1 in bone biology and bone diseases has been initially recognized, its specific mechanism and regulatory relationship are still controversial. For example, the expression level, mode of action and interaction with other molecules of NEAT1 in different bone diseases still need further in-depth study. This paper reviews the role of NEAT1 in maintaining bone and cartilage metabolism, and discusses its expression and function in various bone diseases. By combing the existing research results and controversial points, this paper aims to provide new perspectives and ideas for the prevention and treatment of bone diseases, and provide useful reference and enlightenment for future research.

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.

The development of bone in human body and the maintenance of bone mass in adulthood are regulated by a variety of biological factors. Myocyte enhancer factor 2C (MEF2C), as one of the many factors regulating bone tissue development and balance, has been shown to play a key role in bone development and metabolism. However, there is limited systematic analysis on the effects of MEF2C on bone tissue. This article reviews the role of MEF2C in bone development and metabolism. During bone development, MEF2C promotes the development of neural crest cells (NC) into craniofacial cartilage and directly promotes cartilage hypertrophy. In terms of bone metabolism, MEF2C exhibits a differentiated regulatory model across different types of osteocytes, demonstrating both promoting and other potential regulatory effects on bone formation, with its stimulating effect on osteoclasts being determined. In view of the complex roles of MEF2C in bone tissue, this paper also discusses its effects on some bone diseases, providing valuable insights for the physiological study of bone tissue and strategies for the prevention of bone diseases.
Humans ; MEF2 Transcription Factors/physiology* ; Bone and Bones/metabolism* ; Animals ; Bone Development/physiology* ; Osteogenesis/physiology* ; Myogenic Regulatory Factors/physiology*

Tripartite motif-containing (TRIM) family proteins are crucial E3 ubiquitin ligases that have garnered significant attention for their regulatory roles in bone metabolism in recent years. This article reviews the function and regulatory mechanisms of TRIM family proteins in bone metabolism, focusing on their dual roles in bone formation and resorption. It also provides a detailed analysis of signaling pathways and molecular mechanisms by which TRIM family members regulate the activities of osteoblasts and osteoclasts. Research findings suggest that modulating the expression or activity of TRIM family proteins could be beneficial for treating bone diseases such as osteoporosis. This review highlights the molecular mechanisms of TRIM family members in bone physiology and pathology, aiming to provide theoretical basis and scientific guidance for developing novel therapeutic strategies for bone diseases.
Humans ; Ubiquitin-Protein Ligases/physiology* ; Bone and Bones/metabolism* ; Animals ; Tripartite Motif Proteins/physiology* ; Osteoclasts/metabolism* ; Osteoblasts/metabolism* ; Signal Transduction/physiology* ; Osteogenesis/physiology*

The therapeutic effects of Yueju Pills on depression and cardiovascular diseases have been widely recognized. Previous studies have shown that the drug can significantly improve depressive-like behaviors induced by chronic unpredictable mild stress(CUMS) combined with atherosclerosis(AS). Given the complex pathogenesis of psychocardiac diseases, this study integrated metabolomics and network pharmacology to systematically elucidate the mechanism of Yueju Pills in alleviating depressive symptoms in psychocardiac diseases. The results demonstrate that, after Yueju Pill intervention, the levels of 9 abnormal metabolites in the hippocampus restore to normal ranges, primarily involving key pathways or signaling pathways, including the cyclic adenosine monophosphate(cAMP), mammalian target of rapamycin(mTOR), glycine/serine/threonine metabolism, and aminoacyl-tRNA biosynthesis. In a high-fat diet-induced CUMS ApoE~(-/-) mouse model, Yueju Pills significantly increases adenosine monophosphate(AMP) levels and decreases L-alanine and D-glyceric acid levels in the hippocampus. In conclusion, Yueju Pills exert antidepressant effects by regulating multiple metabolic axes, including glycine/serine/threonine metabolism and the cAMP, mTOR signaling pathways. Network pharmacology predictions reveal that the treatment of CUMS combined with AS by its core active components may be realized through modulating pathways concerning neuroinflammation and synaptic plasticity, including serine/threonine-protein kinase 1(AKT1), mitogen-activated protein kinase 1(MAPK1), and prostaglandin-endoperoxide synthase 2(PTGS2). This study provides a theoretical reference for the clinical application of Yueju Pills in alleviating the depressive symptoms of psychocardiac diseases.
Animals ; Network Pharmacology ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Metabolomics ; Male ; Depression/genetics* ; Humans ; Hippocampus/drug effects* ; Mice, Inbred C57BL ; Signal Transduction/drug effects*