1.Skeleton Binding Protein 1 of Plasmodium berghei Influences Deformability and Cytoskeletal Ultrastructure of Infected Erythrocyte
Xin-Yue GUO ; Huan-Qi ZHAO ; Yan-Xuan ZHONG ; Ru-Meng JIANG ; Yao-Xian LI ; Lei-Ting PAN ; Qian WANG ; Xiao-Yu SHI
Progress in Biochemistry and Biophysics 2026;53(4):1015-1027
ObjectiveThe malaria parasites remodel the host erythrocyte structure by exporting parasite proteins that interact with the membrane skeleton proteins of red blood cells (RBCs), facilitating their intracellular survival and pathogenicity. Skeleton-binding protein 1 (SBP1) is a conserved exported protein across Plasmodium species. In Plasmodium falciparum, SBP1 has been reported to interact with erythrocyte membrane skeleton proteins 4.1R and spectrin, while its contribution to erythrocyte remodeling and parasite virulence in Plasmodium berghei (Pb) remains unclear. This study aims to determine whether PbSBP1 associates with the host cytoskeletal protein 4.1R and to investigate its role in the remodeling of host RBCs and the pathogenicity of Plasmodium berghei. MethodsIn Plasmodium berghei, the relationship between PbSBP1 and the erythrocyte cytoskeletal protein 4.1R was examined using co-immunoprecipitation. A Pbsbp1 gene knockout mutant of Plasmodium berghei (Pbsbp1∆) was generated based on the principle of double crossover homologous recombination. The deformability of erythrocytes infected with Pbsbp1∆ parasites was assessed using microfluidic methods. Microchannels with an array of cylindrical pillars were used to detect modifications in infected RBC deformability. The infected RBCs were squashed between the rows and recovered between the columns and the transit velocity (μm/s) of infected RBCs travelling through the microchannel was recorded. The component of the erythrocyte membrane skeleton junctional complex, tropomodulin (TMOD), was fluorescently labeled, and the cytoskeletal network of infected erythrocytes was imaged using super-resolution stochastic optical reconstruction microscopy (STORM) to analyze ultrastructural changes in the cytoskeleton of wild-type (WT) and Pbsbp1∆-infected erythrocytes. Actin-based junctional complexes were displayed as individual clusters by the labeled TMOD in the STORM images, and the cluster densities and distances between adjacent clusters of infected RBCs were calculated. Additionally, rodent malaria models (BALB/c mice) and experimental cerebral malaria models (C57BL/6 mice) were employed to monitor the growth of Pbsbp1∆ and WT parasites during the intraerythrocytic stage and their capacity to induce cerebral malaria in mice. ResultsPbSBP1 may participate in the remodeling of infected erythrocytes through direct or indirect interaction with the erythrocyte cytoskeletal protein 4.1R. Microfluidic assays revealed that the deformability of erythrocytes infected with Pbsbp1∆ parasites was significantly enhanced compared to those infected with WT parasites. STORM imaging further demonstrated that the ultrastructure of the erythrocyte cytoskeleton in Pbsbp1∆-infected cells was altered relative to that in WT-infected erythrocytes. The distances between nearest neighbors of clusters had a tendency to increase while the cluster densities were decreased in Pbsbp1∆-infected RBCs compared to WT-infected RBCs. Subsequent phenotypic analysis indicated that the growth rate of Pbsbp1∆ parasites during the intraerythrocytic stage was significantly slower than that of WT parasites, and their ability to induce cerebral malaria in mice was also attenuated. These findings suggest that PbSBP1 is involved in the remodeling of the erythrocyte membrane skeleton, likely through its direct or indirect interaction with protein 4.1R, thereby regulating the deformability of infected erythrocytes and influencing the pathogenicity of the blood-stage parasites. ConclusionThis study establishes a role for PbSBP1 in host erythrocyte remodeling and parasite virulence, providing new research strategies for the prevention and treatment of malaria.
2.The Structure and Function of The YopJ Family Effectors in The Bacterial Type III Secretion System
Ao-Ning LI ; Wen-Bo LI ; Yu-Ying LU ; Min-Hui ZHU ; Yu-Long QIN ; Yong ZHAO ; Zhao-Huan ZHANG
Progress in Biochemistry and Biophysics 2026;53(3):516-533
The Type III Secretion System (T3SS) serves as a pivotal virulence apparatus for numerous Gram-negative bacterial pathogens, enabling them to infect both animal and plant hosts. Functioning as a molecular syringe, the T3SS directly translocates bacterial effector proteins from the bacterial cytoplasm into the interior of eukaryotic host cells. These effectors are central weapons that precisely manipulate a wide spectrum of host cellular physiological processes, ranging from cytoskeletal dynamics to immune signaling, to establish a favorable niche for bacterial survival and proliferation. Among the diverse arsenal of T3SS effectors, the YopJ family constitutes a critical group of virulence factors. Members of this family are characterized by a conserved catalytic triad structure—a hallmark of the CE clan of cysteine proteases that has been evolutionarily repurposed to confer acetyltransferase activity. A defining and intriguing feature of these enzymes is their stringent dependence on a host-derived eukaryotic cofactor, inositol hexakisphosphate (IP6), for allosteric activation. This requirement acts as a sophisticated molecular safeguard, ensuring enzymatic activity only within the appropriate host environment, thereby preventing detrimental effects on the bacterium itself. While seminal studies on individual members such as Yersinia’s YopJ and Salmonella’s AvrA have provided deep mechanistic insights, a systematic and integrative understanding of the structure-function relationships across the entire family remains fragmented. Key questions persist regarding how a conserved catalytic core has diverged to recognize distinct host substrates in different kingdoms of life. To address this gap, this article provides a systematic review of the YopJ family, focusing on three interconnected aspects: their structural features, their catalytic mechanism, and their divergent immunosuppressive strategies in animal versus plant hosts. By conducting a comparative analysis of the sequences and resolved three-dimensional structures of three representative members (e.g., HopZ1a, PopP2, AvrA), we elucidate regions of significant variation embedded within the conserved core catalytic architecture. These variable regions, often involving surface loops and substrate-binding interfaces, are crucial determinants of target specificity and functional specialization. The functional divergence of this effector family is most apparent when comparing their modes of action in different hosts. In animal hosts, YopJ-family effectors primarily sabotage innate immune signaling pathways. They achieve this by acetylating key serine and threonine residues within the activation loops of critical kinases in the MAPK and NF‑κB pathways. This post-translational modification blocks the phosphorylation and subsequent activation of these kinases, leading to potent suppression of inflammatory cytokine production. Conversely, in plant hosts, the strategy broadens to dismantle the two-tiered plant immune system. YopJ homologs target a more diverse set of substrates, including immune-associated receptor-like cytoplasmic kinases (RLCKs), microtubule networks via tubulin acetylation (which disrupts cellular trafficking and signaling), and transcription factors central to defense gene regulation. This multi-target approach effectively suppresses both Pattern-Triggered Immunity (PTI) and Effector-Triggered Immunity (ETI). In conclusion, this synthesis aims to deepen the mechanistic understanding of YopJ family-mediated pathogenesis by integrating structural biology with cellular function across host kingdoms. Elucidating the precise molecular basis for substrate selection—how conserved platforms achieve target diversity—is a major frontier. Furthermore, this knowledge provides a vital theoretical foundation for developing novel anti-virulence strategies. Targeting the conserved IP6-binding pocket or the catalytic acetyltransferase activity itself represents a promising avenue for designing broad-spectrum inhibitors that could disarm this critical family of bacterial effectors, potentially offering new therapeutic approaches against a range of pathogenic bacteria.
3.Analysis of Toxicity Characteristics and Rational Drug Use of Polygoni Multiflori Radix
Qiongyi FU ; Yupu QI ; Yu HUAN ; Yagang SONG ; Xiangxiang WU ; Mingsan MIAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):222-231
ObjectivePolygoni Multiflori Radix is a commonly used tonic traditional Chinese medicine (TCM) in clinical practice, but liver injury has often been reported in recent years. Some related preparations containing Polygoni Multiflori Radix have been reported by the National Medical Products Administration many times for the risk of liver injury. This has caused extensive discussion on the potential toxicity of TCM in China and abroad, which has limited the clinical use of Polygoni Multiflori Radix to some extent. To understand the adverse reactions of Polygoni Multiflori Radix, the safe and rational use of Polygoni Multiflori Radix in clinical practice was discussed. MethodsThe pharmacovigilance thought of modern Chinese medicine and the TCM pharmacovigilance system framework of ''identification of poison, use of poison, anti-poison, and detoxification'' were employed to mine the relevant toxicity records, usage and dosage, processing compatibility, and contraindication of taking Polygoni Multiflori Radix in ancient books. The drug safety information of Polygoni Multiflori Radix was summarized by comparing with modern reports. ResultsA total of 74 ancient books related to Polygoni Multiflori Radix were included, suggesting that the toxicity of Polygoni Multiflori Radix was recognized in ancient times. The main chemical components of Polygoni Multiflori Radix had both efficacy and toxicity, and the adverse reactions may be related to long-term use, excessive use, and individual differences. The results showed that the toxic components of Polygoni Multiflori Radix could be reduced by peeling, steaming with black beans, and processing without iron tools. The toxic effects of Polygoni Multiflori Radix could be reduced by the compatibility of Polygoni Multiflori Radix with Poria, Psoraleae Fructus, and Cistanches Herba. ConclusionReasonable dosage, standard processing, correct compatibility, and syndrome differentiation are the key points to standardize the use of Polygoni Multiflori Radix and reduce the incidence of adverse reactions. Clinically, the toxicity classification of TCM should be strengthened, and the susceptible population should be prioritized. The detection indicators and early warning mechanisms should be improved, and precise drug dosage and course of treatment should be guaranteed. These measures can ensure the safe use of Polygoni Multiflori Radix.
4.Analysis of Toxicity Characteristics and Rational Drug Use of Polygoni Multiflori Radix
Qiongyi FU ; Yupu QI ; Yu HUAN ; Yagang SONG ; Xiangxiang WU ; Mingsan MIAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):222-231
ObjectivePolygoni Multiflori Radix is a commonly used tonic traditional Chinese medicine (TCM) in clinical practice, but liver injury has often been reported in recent years. Some related preparations containing Polygoni Multiflori Radix have been reported by the National Medical Products Administration many times for the risk of liver injury. This has caused extensive discussion on the potential toxicity of TCM in China and abroad, which has limited the clinical use of Polygoni Multiflori Radix to some extent. To understand the adverse reactions of Polygoni Multiflori Radix, the safe and rational use of Polygoni Multiflori Radix in clinical practice was discussed. MethodsThe pharmacovigilance thought of modern Chinese medicine and the TCM pharmacovigilance system framework of ''identification of poison, use of poison, anti-poison, and detoxification'' were employed to mine the relevant toxicity records, usage and dosage, processing compatibility, and contraindication of taking Polygoni Multiflori Radix in ancient books. The drug safety information of Polygoni Multiflori Radix was summarized by comparing with modern reports. ResultsA total of 74 ancient books related to Polygoni Multiflori Radix were included, suggesting that the toxicity of Polygoni Multiflori Radix was recognized in ancient times. The main chemical components of Polygoni Multiflori Radix had both efficacy and toxicity, and the adverse reactions may be related to long-term use, excessive use, and individual differences. The results showed that the toxic components of Polygoni Multiflori Radix could be reduced by peeling, steaming with black beans, and processing without iron tools. The toxic effects of Polygoni Multiflori Radix could be reduced by the compatibility of Polygoni Multiflori Radix with Poria, Psoraleae Fructus, and Cistanches Herba. ConclusionReasonable dosage, standard processing, correct compatibility, and syndrome differentiation are the key points to standardize the use of Polygoni Multiflori Radix and reduce the incidence of adverse reactions. Clinically, the toxicity classification of TCM should be strengthened, and the susceptible population should be prioritized. The detection indicators and early warning mechanisms should be improved, and precise drug dosage and course of treatment should be guaranteed. These measures can ensure the safe use of Polygoni Multiflori Radix.
5.Traditional Chinese Medicine Intervention in Parkinson's Disease Based on Keap1/Nrf2/ARE Signaling Pathway: A Review
Liuping YUE ; Yongkang SUN ; Fangbiao XU ; Yanbo SONG ; Yijun WU ; Huan YU ; Xinzhi WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(9):307-317
Parkinson's disease (PD) is a chronic progressive neurodegenerative disorder primarily characterized by motor dysfunction. The main pathological features include the loss of dopaminergic neurons in the substantia nigra, abnormal aggregation of alpha-Synuclein (α-Syn), and the formation of Lewy bodies. However, the exact mechanisms remain unclear. In recent years, the PD incidence has gradually increased, while current treatment methods are limited to symptom alleviation, incapable of halting disease progression, and prone to adverse effects, thus making it urgent to search for medicines effective for PD. Modern research indicates that the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor E2 related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway is closely related to oxidative stress, neuroinflammation, apoptosis, ferroptosis, and mitochondrial dysfunction, playing a crucial role in the pathophysiological development of PD. A large number of studies have further confirmed that traditional Chinese medicine (TCM) can regulate diseases through a holistic view of Syndrome differentiation and microscopic molecular pathways. With unique advantages, such as multiple targets, multiple pathways, and fewer adverse reactions, TCM provides a new strategy for PD treatment. This article elucidates the mechanism of the Keap1/Nrf2/ARE signaling pathway in the occurrence and development of PD, while summarizing the latest research on PD intervention by TCM monomers, active ingredients, and compounds, as well as acupuncture via the precise targeted regulation of the Keap1/Nrf2/ARE pathway, aiming to provide a reference for clinical medicine development to prevent and treat PD.
6.Neuroprotective effect and mechanism of eleutheroside B on Parkinson’s disease model mice by regulating the IKKβ/NF-κB signaling pathway
Xiaoli WANG ; Hua RONG ; Siwen PAN ; Chunlei YU ; Tianjiao XU ; Yu SUN ; Huan CONG ; Yu PANG ; Gang CHEN ; Xiaoming LI
China Pharmacy 2026;37(8):998-1002
OBJECTIVE To investigate the neuroprotective effect and mechanism of eleutheroside B (ELB) on Parkinson’s disease (PD) model mice by regulating the IκB kinase β (IKKβ)/nuclear factor-κB (NF-κB) signaling pathway. METHODS Fifty mice were randomly divided into normal control group, model group, positive control group (selegiline hydrochloride, 10 mg/kg), and ELB low-dose and high-dose groups (80, 160 mg/kg), with 10 mice in each group. Each group was given relevant medicine or normal saline intragastrically for 14 consecutive days. Starting from the 10th day of administration, the model group and all administration groups were intraperitoneally injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) 30 mg/kg, for five consecutive days to establish the chronic PD model. After the last administration for 24 h, six mice were randomly selected from each group to test their behavioral abilities; detect the levels of interleukin-1β (IL-1β), IL-10, tumor necrosis factor-α (TNF-α) in brain tissue and their mRNA expressions were measured, and positive expression of tyrosine hydroxylase (TH), protein expressions of TH, α -synuclein ( α -syn), ionized calcium-binding adaptor molecule 1 (Iba-1), as well as phosphorylation levels of IKKβ and NF-κB p65 proteins in the brain tissue were detected. The ultrastructure of neurons in substantia nigra was observed. RESULTS Compared with the model group, rotarod endurance time and climbing score of each administration group (except for the ELB low-dose group) were increased significantly ( P <0.05), while the levels and mRNA expressions of IL-1β, TNF-α, α -syn, and Iba-1, as well as phosphorylation levels of IKKβ and NF-κB p65 proteins in brain tissue were decreased significantly (except for TNF-α in the ELB low-dose group). Conversely, the level and mRNA expression of IL-10 (except for the ELB low-dose group), TH positive expression and protein expressions were significantly increased ( P <0.05). Typical neurodegenerative pathological changes, such as neuronal karyopyknosis, mitochondrial swelling and vacuolization, and endoplasmic reticulum dilation, all showed varying degrees of improvement. CONCLUSIONS ELB may exert neuroprotective effects by inhibiting the activation of the IKKβ/NF-κB signaling pathway, alleviating inflammatory responses, reducing abnormal α -syn aggregation and neuronal loss, and further improving motor dysfunction in PD mice.
7.The Role and Mechanism of Aerobic Exercise in Enhancing Insulin Sensitivity by Reducing Circulating Glutamate
Xiao-Rui XING ; Qin SUN ; Huan-Yu WANG ; Ruo-Bing FAN ; Ru WANG
Progress in Biochemistry and Biophysics 2025;52(6):1373-1385
ObjectiveTo explore the role and potential mechanism of circulating glutamate in enhancing insulin sensitivity by aerobic exercise. This research may provide a novel strategy for preventing metabolic diseases through precise exercise interventions. MethodsTo investigate the effects of elevated circulating glutamate on insulin sensitivity and its potential mechanisms, 18 male C57BL/6 mice aged 6 to 8 weeks were randomly divided into 3 groups: a control group (C), a group receiving 500 mg/kg glutamate supplementation (M), and a group receiving 1 000 mg/kg glutamate supplementation (H). The intervention lasted for 12 weeks, with treatments administered 6 d per week. Following the intervention, an insulin tolerance test (ITT) and a glucose tolerance test (GTT) were conducted. Circulating glutamate levels were measured using a commercial kit, and the activity of the skeletal muscle InsR/IRS1/PI3K/AKT signaling pathway was analyzed via Western blot. To further investigate the role of circulating glutamate in enhancing insulin sensitivity through aerobic exercise, 30 male C57BL/6 mice were randomly assigned to 3 groups: a control group (CS), an exercise intervention group (ES), and an exercise combined with glutamate supplementation group (EG). The ES group underwent treadmill-based aerobic exercise, while the EG group received glutamate supplementation at a dosage of 1 000 mg/kg in addition to aerobic exercise. The intervention lasted for 10 weeks, with sessions occurring 6 d per week, and the same procedures were followed afterward. To further elucidate the mechanism by which glutamate modulates the InsR/IRS1/PI3K/AKT signaling pathway, C2C12 myotubes were initially subjected to graded glutamate treatment (0, 0.5, 1, 3, 5, 10 mmol/L) to determine the optimal concentration for cellular intervention. Subsequently, the cells were divided into 3 groups: a control group (C), a glutamate intervention group (G), and a glutamate combined with MK801 (an NMDA receptor antagonist) intervention group (GK). The G group was treated with 5 mmol/L glutamate, while the GK group received 50 μmol/L MK801 in addition to 5 mmol/L glutamate. After 24 h of intervention, the activity of the InsR/IRS1/PI3K/AKT signaling pathway was analyzed using Western blot. ResultsCompared to the mice in group C, the circulating glutamate levels, the area under curve (AUC) of ITT, and the AUC of GTT in the mice of group H were significantly increased. Additionally, the expression levels of p-InsRβ, IRS1, p-AKT, and p-mTOR proteins in skeletal muscle were significantly downregulated. Compared to the mice in group CS, the circulating glutamate levels, the AUC of ITT, and the AUC of GTT in the mice of group ES were significantly reduced. Additionally, the expression levels of p-InsRβ, IRS1, p-AKT, and p-mTOR proteins in skeletal muscle of group ES mice were significantly upregulated. There were no significant changes observed in the mice of group EG. Compared to the cells in group 0 mmol/L, the expression levels of p-InsRβ, p-IRS1, p-PI3K, and p-AKT proteins in cells of group 5 mmol/L were significantly downregulated. Compared to the cells in group C, the expression levels of p-InsRβ, p-IRS1, p-PI3K, and p-AKT proteins in the cells of group G were significantly downregulated. No significant changes were observed in the cells of group GK. ConclusionLong-term aerobic exercise can improve insulin sensitivity by lowering circulating levels of glutamate. This effect may be associated with the upregulation of the InsR/IRS1/AKT signaling pathway activity in skeletal muscle. Furthermore, glutamate can weaken the activity of the InsR/IRS1/PI3K/AKT signaling pathway in skeletal muscle, potentially by binding to NMDAR expressed in skeletal muscle.
8.4 Weeks of HIIT Modulates Metabolic Homeostasis of Hippocampal Pyruvate-lactate Axis in CUMS Rats Improving Their Depression-like Behavior
Yu-Mei HAN ; Chun-Hui BAO ; Zi-Wei ZHANG ; Jia-Ren LIANG ; Huan XIANG ; Jun-Sheng TIAN ; Shi ZHOU ; Shuang-Shuang WU
Progress in Biochemistry and Biophysics 2025;52(6):1468-1483
ObjectiveTo investigate the role of 4-week high-intensity interval training (HIIT) in modulating the metabolic homeostasis of the pyruvate-lactate axis in the hippocampus of rats with chronic unpredictable mild stress (CUMS) to improve their depressive-like behavior. MethodsForty-eight SPF-grade 8-week-old male SD rats were randomly divided into 4 groups: the normal quiet group (C), the CUMS quiet group (M), the normal exercise group (HC), and the CUMS exercise group (HM). The M and HM groups received 8 weeks of CUMS modeling, while the HC and HM groups were exposed to 4 weeks of HIIT starting from the 5th week (3 min (85%-90%) Smax+1 min (50%-55%) Smax, 3-5 cycles, Smax is the maximum movement speed). A lactate analyzer was used to detect the blood lactate concentration in the quiet state of rats in the HC and HM groups at week 4 and in the 0, 2, 4, 8, 12, and 24 h after exercise, as well as in the quiet state of rats in each group at week 8. Behavioral indexes such as sucrose preference rate, number of times of uprightness and number of traversing frames in the absenteeism experiment, and other behavioral indexes were used to assess the depressive-like behavior of the rats at week 4 and week 8. The rats were anesthetized on the next day after the behavioral test in week 8, and hippocampal tissues were taken for assay. LC-MS non-targeted metabolomics, target quantification, ELISA and Western blot were used to detect the changes in metabolite content, lactate and pyruvate concentration, the content of key metabolic enzymes in the pyruvate-lactate axis, and the protein expression levels of monocarboxylate transporters (MCTs). Results4-week HIIT intervention significantly increased the sucrose preference rate, the number of uprights and the number of traversed frames in the absent field experiment in CUMS rats; non-targeted metabolomics assay found that 21 metabolites were significantly changed in group M compared to group C, and 14 and 11 differential metabolites were significantly dialed back in the HC and HM groups, respectively, after the 4-week HIIT intervention; the quantitative results of the targeting showed that, compared to group C, lactate concentration in the hippocampal tissues of M group, compared with group C, lactate concentration in hippocampal tissue was significantly reduced and pyruvate concentration was significantly increased, and 4-week HIIT intervention significantly increased the concentration of lactate and pyruvate in hippocampal tissue of HM group; the trend of changes in blood lactate concentration was consistent with the change in lactate concentration in hippocampal tissue; compared with group C, the LDHB content of group M was significantly increased, the content of PKM2 and PDH, as well as the protein expression level of MCT2 and MCT4 were significantly reduced. The 4-week HIIT intervention upregulated the PKM2 and PDH content as well as the protein expression levels of MCT2 and MCT4 in the HM group. ConclusionThe 4-week HIIT intervention upregulated blood lactate concentration and PKM2 and PDH metabolizing enzymes in hippocampal tissues of CUMS rats, and upregulated the expression of MCT2 and MCT4 transport carrier proteins to promote central lactate uptake and utilization, which regulated metabolic homeostasis of the pyruvate-lactate axis and improved depressive-like behaviors.
9.Four Weeks of HIIT Modulates Lactate-mediated Synaptic Plasticity to Improve Depressive-like Behavior in CUMS Rats
Yu-Mei HAN ; Zi-Wei ZHANG ; Jia-Ren LIANG ; Chun-Hui BAO ; Jun-Sheng TIAN ; Shi ZHOU ; Huan XIANG ; Yong-Hong YANG
Progress in Biochemistry and Biophysics 2025;52(6):1499-1510
ObjectiveThis study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms. MethodsA total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%-90% maximal training speed, Smax) alternated with one minute at low speed (50%-55% Smax), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1). ResultsCompared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery. ConclusionFour weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the PFC, thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.
10.Effect of Carbohydrate Intake Order on Metabolic Profiles of Endurance Exercise Mice in a High-temperature Environment
Huan-Yu WANG ; Guo-Dong ZHOU ; Ru-Wen WANG ; Jun QIU ; Ru WANG
Progress in Biochemistry and Biophysics 2025;52(6):1529-1543
ObjectiveThe primary objective of this study was to investigate the effects of carbohydrate intake order on post-exercise recovery and metabolic regulation under heat stress, particularly in models of exercise induced fatigue. Given the increasing significance of optimizing nutritional strategies to support performance in extreme environmental conditions, this study aimed to provide experimental evidence that contributes to a better understanding of how the sequence in which carbohydrates are consumed impacts exercise recovery, metabolic homeostasis, and fatigue alleviation in a high-temperature environment. MethodsA mouse model of exercise-induced fatigue was established under high-temperature (35°C) to simulate heat stress. The subjects were divided into 3 distinct groups based on their carbohydrate intake order: the “mixed intake” group (HOT_MIX), where all macronutrients (carbohydrates, proteins, and fats) were consumed in a balanced ratio; the “carbohydrate-first intake” group (HOT_CHO), where carbohydrates were consumed first followed by other macronutrients; the “carbohydrate-later intake” group (HOT_PRO), where proteins and fats were consumed prior to carbohydrates. Each group underwent a 7 d intervention period with daily intake according to their designated group. Exercise performance was assessed using rotarod retention time test, and biomarkers of muscle damage, such as lactate dehydrogenase (LDH), creatine kinase (CK), lactate (LD), alanine aminotransferase (ALT), and non-esterified fatty acids (NEFA), were measured. Furthermore, targeted metabolomics analyses were conducted to investigate metabolic shifts in response to different dietary strategies, and KEGG pathway enrichment analysis was employed to explore the biological mechanisms underlying these changes. ResultsThe findings demonstrated that the HOT_PRO group exhibited a significantly improved performance in the rotarod test, with a longer retention time compared to both the HOT_MIX and HOT_CHO groups (P<0.05). Additionally, this group showed significantly reduced levels of muscle damage markers such as LDH and CK, indicating that the carbohydrate-later intake strategy helped alleviate exercise-induced muscle injury. Metabolomic profiling of the HOT_PRO group showed marked increases in alanine, creatine, and flavin adenine dinucleotide (FAD), indicating shifts in amino acid metabolism and oxidative metabolism. Conversely, metabolites such as spermidine, cholesterol sulfate, cholesterol, and serine were significantly reduced in the HOT_PRO group, pointing to alterations in lipid and sterol metabolism. Further analysis of the differential metabolites revealed that these changes were primarily associated with key metabolic pathways, including glycine-serine-threonine metabolism, primary bile acid biosynthesis, taurine and hypotaurine metabolism, and steroid hormone biosynthesis. These pathways are essential for energy production, antioxidant defense, and muscle recovery, suggesting that the carbohydrate-later feeding strategy may promote metabolic homeostasis and improve exercise recovery by enhancing these critical metabolic processes. ConclusionThe results of this study support the hypothesis that consuming carbohydrates after proteins and fats during exercise recovery enhances metabolic homeostasis and accelerates recovery under heat stress. This strategy effectively modulates energy, amino acid, and lipid-related pathways, which are crucial for improving endurance performance and mitigating fatigue in high-temperature environments. The findings suggest that carbohydrate-later intake could be a promising nutritional strategy for athletes and individuals exposed to heat during physical activity. Furthermore, the study provides valuable insights into how different nutrient timing strategies can impact exercise recovery and metabolic regulation, paving the way for more personalized and effective nutritional interventions in extreme environmental conditions.

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