1.Key scientific issues and breakthrough paths to eliminate the harm of hepatitis B virus infection
Yixue WANG ; Bo PENG ; Lei WEI ; Quanxin LONG ; Yuchen XIA ; Yinyan SUN ; Wenhui LI
Journal of Clinical Hepatology 2026;42(1):2-6
Hepatitis B virus (HBV) exclusively infects liver parenchymal cells and forms covalently closed circular DNA (cccDNA) within their nuclei. HBV cccDNA serves as the essential template for viral gene transcription, the sole source of progeny virus production, and the key driver of viral antigen expression, and it is the molecular basis for the persistence of HBV infection. Therefore, elimination and/or functional silencing of cccDNA is the key to eradicate chronic HBV infection. This article discusses the critical scientific issues that need to be solved during elimination of the harm of HBV infection from the perspectives of the synthesis, transcription, and clearance of cccDNA, as well as the impact of nonparenchymal cells on cccDNA, in order to provide a reference for eradicating HBV infection in the future.
2.Comparative Study on Effect of Jingui Shenqiwan and Liuwei Dihuangwan on Reproductive Ability and Brain Function of Normal Mice
Hong SUN ; Fan LEI ; Chenggong LI ; Rui LUO ; Shixian HU ; Bin REN ; Juan HAO ; Yi DING ; Lijun DU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):1-14
ObjectiveTo explore the effects of Jingui Shenqiwan (JSW) and Liuwei Dihuangwan (LDW) on the reproductive ability and brain function of normal mice and compare the actions of the two medications. MethodsSeven groups of female and male mice were divided at a ratio of 2∶1. Except for the control group, the other six groups were as follows: a group of both males and females receiving JSW (3.0 g·kg-1), a group of both males and females receiving LDW (4.5 g·kg-1), a group of males receiving water and females receiving JSW, a group of males receiving water while females receiving LDW, a group of females receiving water while males receiving JSW, and a group of females receiving water while males receiving LDW. Each group was administered the drug for 14 days and then caged together at a 2∶1 (female∶male) ratio to detect the number of pregnant mice and calculate the pregnancy rate. Pregnant mice continued receiving the drug until they naturally gave birth, which was followed by the observation of newborn mice, calculation of their average number, and the measurement of the offspring's preference for sugar water and neonatal recognition index. At the end of the experiment, the weights of the thymus and spleen were measured to calculate the organ coefficients, and mRNA or protein expression was analyzed in the brain and testes or ovaries. A 1% sucrose solution was used to examine the euphoria of their brain reward systems, while novel object recognition test (NOR) was applied to assess their memory capabilities. mRNA expression was detected using real-time quantitative polymerase chain reaction (Real-time PCR) assay, and protein expression was analyzed with Western blot. ResultsCompared with the control group, oral administration of JSW to both male and female mice for 14 days significantly increased the pregnancy rate of female mice on day 2 after being caged together (P<0.05), while LDW showed a trend but no statistical significance. Additionally, compared with the control group, JSW could upregulate the gene expression of gonadotropin-releasing hormone (GnRH) in the thalamus, as well as reproductive stem cell factor (SCF) and tyrosine kinase receptor (c-Kit) in the testes and reproductive stem cell marker mouse vasa homologue (MVH) in the ovaries, upregulate the expression of proteins influencing neuronal functional activity, such as brain-derived neurotrophic factor (BDNF), in hippocampal neurons (P<0.05), and enhance sucrose preference in male mice (P<0.05). Compared with the control group, JSW significantly increased sucrose preference and novel object recognition index in offspring mice (P<0.05), which was related to the upregulation of hippocampal dopamine D1 receptor (D1R) and N-methyl-D-aspartate receptor (Nmdar) gene expression. Compared with the control group, both JSW and LDW could upregulate the protein expression of glucocorticoid receptor (GR), BDNF, and tyrosine kinase receptor B (TrkB) in the hippocampus of offspring mice (P<0.05). ConclusionJSW significantly enhances the reproductive ability of normal mice, which is not only related to the release of gonadotropin but also associated with its regulation of brain function. Additionally, JSW has a certain regulatory effect on the brain function of the offspring mice.
3.Zuoguiwan Mitigates Oxidative Stress in Rat Model of Hyperthyroidism Due to Kidney-Yin Deficiency via DRD4/NOX4 Pathway
Ling LIN ; Qianming LIANG ; Changsheng DENG ; Li RU ; Zhiyong XU ; Chao LI ; Mingshun SHEN ; Yueming YUAN ; Muzi LI ; Lei YANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):43-51
ObjectiveTo decipher the mechanism by which Zuoguiwan (ZGW) treat hyperthyroidism in rats with kidney-Yin deficiency based on the dopamine receptor D4 (DRD4)/nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) signaling pathway. MethodsThe rat model of kidney-Yin deficiency was induced by unilateral intramuscular injection of dexamethasone (0.35 mg·kg-1). After successful modeling, the rats were randomized into model, methimazole (positive control, 5 mg·kg-1), low-, medium-, and high-dose (1.85, 3.70, 7.40 g·kg-1, respectively) ZGW, and normal control groups. After 21 days of continuous gavage, the behavioral indexes and body weight changes of rats were evaluated. The pathological changes of the renal tissue were observed by hematoxylin-eosin staining. The serum levels of thyroid hormones [triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH)], renal function indexes [serum creatine (Scr) and blood urea nitrogen (BUN)], energy metabolism markers [cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP)], and oxidative stress-related factors [superoxide dismutase (SOD), malondialdehyde (MDA), and NADPH)] were measured by enzyme-linked immunosorbent assay (ELISA). Western blot was employed to analyze the expression of DRD4, NOX4, mitochondrial respiratory chain complex proteins [NADH:ubiquinone oxidoreductase subunit S4 (NDUFS4) and cytochrome C oxidase subunit 4 (COX4)], and inflammation-related protein [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), p38 mitogen-activated protein kinase (MAPK)] pathway in the renal tissue. ResultsCompared with the normal group, the model group showed mental malaise, body weight decreases (P<0.01), inflammatory cell infiltration in the renal tissue, a few residual parotid glands in the thyroid, elevations in serum levels of T3, T4, Scr, BUN, cAMP, cAMP/cGMP, MDA, and NADPH (P<0.01), down-regulation in protein levels of TSH, SOD, and DRD4 (P<0.05, P<0.01), and up-regulation in expression of NOX4, p-p38 MAPK/p38 MAPK, and inflammatory factors (P<0.01). Compared with the model group, ZGW increased the body weight (P<0.05, P<0.01), reduced the infiltration of renal interstitial inflammatory cells, restored the thyroid structure and follicle size, lowered the serum levels of T3, T4, Scr, BUN, cAMP, cAMP/cGMP, MDA and NADPH (P<0.05, P<0.01), up-regulated the expression of TSH, SOD and DRD4 (P<0.05, P<0.01), and down-regulated the expression of NOX4, p-p38 MAPK/p38 MAPK, and inflammatory factors (P<0.05, P<0.01). Moreover, high-dose ZGW outperformed methimazole (P<0.05). ConclusionBy activating DRD4, ZGW can inhibit the expression of NOX4 mediated by the p38 MAPK pathway, reduce oxidative stress and inflammatory response, thereby ameliorating the pathological state of hyperthyroidism due to kidney-Yin deficiency. This study provides new molecular mechanism support for the clinical application of ZGW.
4.Mechanism of Action of Guishenwan in Treatment of Ovarian Insufficiency Diseases: A Review
Yao CHEN ; Sainan TIAN ; Bin'an WANG ; Shengyu WANG ; Wen'e LIU ; Lei LEI ; Li TANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):317-324
Guishenwan (GSW), originating from Jingyue Quanshu (Zhang Jingyue's Complete Works), is a classic traditional Chinese medicine (TCM) formula with a history of over 400 years. Designed for kidney essence deficiency syndrome, it is clinically applied to treat diseases associated with essence-blood deficiency, such as ovarian insufficiency diseases in women, oligospermia-induced infertility in men, and lumbar disc herniation. Numerous studies have confirmed its significant efficacy and advantages in managing ovarian insufficiency diseases, including diminished ovarian reserve (DOR), premature ovarian insufficiency (POI), and premature ovarian failure (POF). According to recent literature, the therapeutic mechanisms of GSW in treating ovarian insufficiency diseases involve regulating the hypothalamic-pituitary-ovarian axis (HPOA) function, ameliorating reproductive endocrine disorders, improving ovarian function, modulating relevant signaling pathways, and exerting immunoregulatory and anti-inflammatory effects. A review of GSW in clinical treatment revealed that clinical applications of GSW, particularly in combination with Western medicine, not only alleviate symptoms but also compensate for the limitations of hormone replacement therapy, thereby reducing recurrence, minimizing adverse reactions, and enhancing safety. This review aims to provide a scientific basis for the rational clinical use of GSW in ovarian insufficiency diseases, offer innovative TCM strategies for developing novel ovarian-protective drugs, promote the integration of TCM and Western medicine in reproductive medicine, and ultimately contribute a Chinese approach to global management of ovarian insufficiency diseases.
5.Mechanisms of Sini San in Regulation of Gut Microbiota Against Depression and Liver Injury in CUMS Rats
Junling LI ; Yan ZHANG ; Lei WANG ; Fang QI ; Zhenzhen CHEN ; Tianxing CHEN ; Yuhang LIU ; Xueying WANG ; Xianwen TANG ; Yubo LI
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):33-40
ObjectiveTo explore the efficacy and mechanisms of Sini San in the treatment of depression and liver injury based on gut microbiota. MethodsThirty-two male Sprague-Dawley (SD) rats were randomly divided into a normal group, model group (M), Sini San group (MS, 2.5 g·kg-1), and fluoxetine group (MF, 2 mg·kg-1). Except for the normal group, rats in the other three groups were subjected to chronic unpredictable mild stress (CUMS). After 8 weeks, the open-field test and sucrose preference test were conducted. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum corticosterone (CORT), adrenocorticotropic hormone (ACTH), corticotropin-releasing factor (CRF), lipopolysaccharide (LPS), Zonulin, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), γ-aminobutyric acid (GABA) levels in the hippocampus and prefrontal cortex, and brain-derived neurotrophic factor (BDNF) levels in the hippocampus. Real-time quantitative polymerase chain reaction (Real-time PCR) was used to detect hippocampal BDNF mRNA expression. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured using the ultraviolet lactate dehydrogenase method. The ultrastructure of the intestinal epithelium was observed by electron microscopy, and gut microbiota in rat feces were analyzed using 16S rDNA high-throughput sequencing. ResultsCompared with the normal group, the sucrose preference of rats in the model group was significantly reduced (P0.01), whereas it was significantly increased in the Sini San group compared with the model group (P0.05). Compared with the normal group, hippocampal GABA protein levels and BDNF mRNA expression in the model group were significantly decreased (P0.05), and compared with the model group, both were significantly increased in the Sini San group (P0.05, P0.01). Compared with the normal group, serum LPS and Zonulin levels in the model group were significantly increased (P0.05, P0.01), and compared with the model group, Zonulin levels in the Sini San group were significantly decreased (P0.05). No obvious changes were observed in the ultrastructure of the jejunal mucosa among groups. Compared with the normal group, widened and blurred tight junctions, sparse and shortened microvilli, and mitochondrial swelling with cristae disruption in epithelial cells were observed in the ileal and colonic mucosa of the model group, which were markedly improved in the Sini San and fluoxetine groups. The results of 16S rDNA high-throughput sequencing showed that Sini San improved CUMS-induced dysbiosis of Bacteroidetes and Proteobacteria. Correlation analysis indicated that Bacteroidetes and Proteobacteria were significantly correlated with depression-related indicators, liver function, and intestinal mucosal permeability. ConclusionSini San exerts antidepressant and hepatoprotective effects by improving Bacteroidetes and Proteobacteria and inhibiting the increase in intestinal mucosal permeability in CUMS rats.
6.Molecular Mechanism of Programmed Cell Death in Chronic Obstructive Pulmonary Disease and Traditional Chinese Medicine Intervention: A Review
Xin PENG ; Yunhui LI ; Lei LIANG ; Zheyu LUAN ; Hanxiao WANG ; Haotian XU ; Ziming DANG ; Jihong FENG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):304-313
Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease that poses a significant threat to global health, exhibiting high morbidity, disability and mortality rate, with its prevention and treatment situation becoming increasingly critical. The pathogenesis of COPD is complex, and the underlying cellular and molecular biological mechanisms remain incompletely elucidated. Programmed cell death (PCD) is the process wherein cells actively undergo demise to maintain internal environmental stability in response to certain signals or specific stimuli. Contemporary medical research indicates that the dysregulation of PCD patterns such as apoptosis, necroptosis, pyroptosis, autophagy, and ferroptosis is closely related to the onset and progression of COPD. Clarifying the molecular mechanisms of PCD in COPD may provide novel perspectives for in-depth understanding and prevention of the disease. Traditional Chinese medicine (TCM) is characterized by holistic regulation. In recent years, extensive research has been conducted in the TCM field focusing on modulating apoptosis, necroptosis, pyroptosis, autophagy, and ferroptosis for the treatment of COPD, yielding remarkable achievements. Therefore, this study systematically explored the molecular mechanism of PCD in COPD and reviewed the potential mechanisms and intervention status of TCM targeting PCD in COPD, aiming to provide insights and references for the clinical prevention, treatment and in-depth research of COPD.
7.Therapeutic effects of adipose-derived mesenchymal stem cells and their exosomes on dexamethasone-induced sarcopenia in mice
Weiyuan YUAN ; Qinhui LEI ; Xiuqi LI ; Tiezhu LU ; Ziwen FU ; Zhili LIANG ; Shaoyang JI ; Yijia LI ; Yu REN
Chinese Journal of Tissue Engineering Research 2026;30(1):58-67
BACKGROUND:Sarcopenia is an age-related condition characterized by the loss of skeletal muscle mass,strength,and/or physical function.Currently,effective treatments for sarcopenia remain limited.A new therapeutic approach to improve symptoms and prognosis of sarcopenia patients clinically was important.OBJECTIVE:To explore the effects of canine adipose-derived mesenchymal stem cells and their exosomes on a dexamethasone-induced sarcopenia in mice.METHODS:Mesenchymal stem cells were isolated and cultured from canine adipose tissue,and identified and functionally evaluated through flow cytometry and differentiation assays for osteogenesis,adipogenesis,and chondrogenesis.Subsequently,exosomes from adipose-derived mesenchymal stem cells were extracted and characterized using transmission electron microscopy,western blot assay,and nanocoulter tracking analysis.In vitro,the effects of canine adipose-derived mesenchymal stem cells and their exosomes on myotube growth and the expression of muscle atrophy-related genes were investigated using dexamethasone-induced C2C12 myotube atrophy and aging C2C12 models.In vivo,a dexamethasone-induced mouse sarcopenia model was established and received intraperitoneal or intravenous injection of canine adipose-derived mesenchymal stem cells.Therapeutic efficacy was assessed through mouse rotarod performance,histopathological analysis,and muscle atrophy-related genes testing.RESULTS AND CONCLUSION:(1)The isolated canine adipose-derived mesenchymal stem cells highly expressed CD73,CD90,and CD105,and lowly expressed MHC-Ⅱ,CD14,CD19,CD34,and CD45,and successfully differentiated into osteoblasts,adipocytes,and chondrocytes in vitro.(2)The adipose-derived mesenchymal stem cells-derived exosomes met the identification criteria in terms of particle size,electron microscopy morphology,and positive expression of specific markers.(3)Compared to the dexamethasone-induced C2C12 atrophy group,treatment with adipose-derived mesenchymal stem cells and their exosomes promoted the recovery and growth of myotubes,inhibited the expression of muscle atrophy-related genes MuRF1 and Atrogin-1.(4)Compared to the aging C2C12 group,adipose-derived mesenchymal stem cells and their exosomes significantly enhanced the recovery and growth of aged muscle tubes in aging cells.(5)Compared to the control group,the rotarod time in dexamethasone-induced sarcopenia model mice was significantly decreased(P<0.01).After 7 days(P<0.01,P<0.01)and 10 days(P<0.01,P<0.05)of adipose-derived mesenchymal stem cells treatment via intraperitoneal and intravenous injection,rotarod time was significantly increased,respectively.After 14 days,all treatment groups showed longer rotarod times than the model group,although with no significant differences between them.(6)Compared to the control group,the cross-sectional area of anterior tibial muscle in the model group was significantly reduced(P<0.01),and it was significantly increased after intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells(P<0.05,P<0.01).(7)Compared to the model group,intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells significantly inhibited the mRNA expression of MuRF1 and Atrogin-1 genes(P<0.01,P<0.01,P<0.01,P<0.01).The results indicated that adipose-derived mesenchymal stem cells and their exosomes promoted recovery and growth of atrophic myotube cells by inhibiting the expression of muscle atrophy-related genes,and both intraperitoneal and intravenous administration of adipose-derived mesenchymal stem cells provided good therapeutic effects on sarcopenia in mice.
8.Postmenopausal osteoporosis:predictive values of muscle mass,grip strength,and appendicular skeletal muscle index
Zhijie YANG ; Rui ZHAO ; Haolin YANG ; Xiaoyun LI ; Yangbo LI ; Jiachun HUANG ; Yanping LIN ; Lei WAN ; Hongxing HUANG
Chinese Journal of Tissue Engineering Research 2026;30(5):1073-1080
BACKGROUND:The prevalence of osteoporosis is high in postmenopausal women,but muscle mass,grip strength,and how these factors affect osteoporosis are understudied,and the exact link between them has not been clarified.OBJECTIVE:To investigate the correlation between muscle mass,grip strength,appendicular skeletal muscle index and bone mineral density in postmenopausal women with osteoporosis and to assess the potential values of these indices in predicting and diagnosing postmenopausal osteoporosis.METHODS:Eighty-three postmenopausal women were collected from the outpatient clinic of the Third Affiliated Hospital of Guangzhou University of Chinese Medicine from February 2023 to January 2024.General data were collected.Bone mineral density was detected.T-value,muscle mass of each part,grip strength were recorded.The body mass index and appendicular skeletal muscle index were calculated.The patients were categorized into non-osteoporosis group(n=17)and postmenopausal osteoporosis group(n=66)according to T value and fracture history,and were statistically analyzed accordingly.RESULTS AND CONCLUSION:(1)The body mass,body mass index,bone mineral density of the overall lumbar spine,muscle mass and appendicular skeletal muscle index were higher in the non-osteoporosis group than the osteoporosis group(P<0.05).(2)Muscle mass was positively correlated with bone mineral density of the overall lumbar spine and individual vertebrae(P<0.05).(3)Multiple stepwise linear regression analysis showed that body mass and grip strength were linearly and positively correlated with muscle mass;body height and muscle mass were linearly and positively correlated with grip strength,and body mass was linearly and negatively correlated with grip strength.Body mass index was linearly and positively correlated with bone mineral density,and age was linearly and negatively correlated with bone mineral density.(4)Analysis by receiver operating characteristic curve showed that:muscle mass(the area under the curve,sensitivity,specificity and critical value of muscle mass were 0.744,76.50%,74.20%and 36.50 kg,respectively,with P=0.002)and appendicular skeletal muscle index(the area under the curve,sensitivity,specificity and critical value of appendicular skeletal muscle index were 0.739,82.40%,62.10%and 5.81 kg/m2,respectively,and P=0.002)had good predictive value for postmenopausal osteoporosis.To conclude,a reduction in muscle mass and appendicular skeletal muscle index can help to predict the risk of postmenopausal osteoporosis,and the possibility of osteoporosis should be taken into account in postmenopausal women when muscle mass is<36.50 kg or appendicular skeletal muscle index is<5.81 kg/m2,in order to prevent the occurrence of postmenopausal osteoporosis.
9.Mechanisms by which aerobic and resistance exercises improve obesity-related cognitive impairment
Yu LIU ; Senlin LEI ; Jintao ZHOU ; Hui LIU ; Xianhui LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1171-1183
BACKGROUND:Obesity is not only related to metabolic diseases such as diabetes and cardiovascular disease,but also closely related to the increased risk of cognitive decline,dementia and other neurodegenerative diseases.Studies have found that aerobic exercise and resistance exercise can help improve obesity-related cognitive impairment,but their therapeutic effects and related mechanisms of action are still unclear.OBJECTIVE:To explore the protective effects of aerobic and resistance exercises on the nervous center of obesity-related cognitive impairment mice.METHODS:Forty-eight 8-week-old C57BL/6J wild-type male mice were randomly divided into four groups:a control group was fed normally for 20 weeks;a high fat group was fed with high fat diet(60%fat energy)for 20 weeks;an aerobic exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of aerobic exercise;and a resistance exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of resistance exercise.After the exercise intervention,body mass was weighed,insulin tolerance and glucose tolerance were tested to evaluate insulin resistance,and cognitive function of mice in each group was detected by new object recognition experiment and Y-maze experiment.The morphology of hippocampal and cortical tissue cells was observed by hematoxylin-eosin staining.The mRNA relative expression levels of tumor necrosis factor-α and interleukin-6 were detected by real-time fluorescence quantitative PCR,and the protein expressions of Bax,Bcl-2,nuclear factor-κB,Cleaved Caspase-1,Caspase-3,synapsin 1 and brain-derived neurotrophic factor were detected by western blot.RESULTS AND CONCLUSION:(1)Compared with the control group,the body mass of mice increased in the high-fat group(P<0.05),accompanied by insulin resistance and cognitive dysfunction,the expression levels of nuclear factor-κB,Bax,Caspase-3,Cleaved Caspase-1 in the hippocampus were significantly increased(P<0.05),the expression levels of brain-derived neurotrophic factor,synapsin 1and Bcl-2 proteins were significantly decreased(P<0.05),Bcl-2/Bax ratio was significantly decreased(P<0.05),and the mRNA levels of inflammatory cytokines,tumor necrosis factor-α and interleukin-6,were significantly up-regulated(P<0.05).(2)Compared with the high-fat group,the above indexes were significantly improved in the aerobic exercise group(P<0.05),while in the resistance exercise group,the body mass of mice was significantly decreased,the levels of inflammatory cytokines tumor necrosis factor-α and interleukin-6 mRNA were significantly decreased(P<0.05),the protein expression of Caspase-3 was significantly decreased(P<0.05),and the protein expression of brain-derived neurotrophic factor was significantly up-regulated(P<0.05),but no significant changes were observed in the other indexes(P>0.05).In conclusion,long-term exercise can reduce insulin resistance,down-regulate the expression of nuclear factor-κB pathway,weaken inflammatory response,inhibit neuronal apoptosis and improve synaptic plasticity,resulting in neuroprotective effects,and effectively alleviate obesity-related cognitive dysfunction in obese mice.The therapeutic effect of aerobic exercise is superior to that of resistance exercise.
10.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.

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