1.Innovative Development and Cutting-edge Applications of Split Intein Technology
Jin-Qiu GAN ; Xiang-Yu DENG ; Xin-Yan WANG ; Jia-Bin LI
Progress in Biochemistry and Biophysics 2026;53(6):1520-1540
Inteins are unique protein insertion sequences capable of self-excision, enabling the covalent ligation of flanking extein peptides via amide bond formation. This process proceeds spontaneously without requiring external enzymes, cofactors, or chemical reagents, granting inteins exceptional biocompatibility and traceless performance in protein engineering applications. Split inteins represent a specialized and versatile subclass whose splicing domains are encoded by two separate gene fragments rather than a single continuous open reading frame. These fragments, known as the N-terminal (IntN) and C-terminal (IntC) split inteins, associate through non-covalent interactions including hydrophobic forces, hydrogen bonds, and van der Waals forces to assemble into an active three-dimensional structure, which then drives efficient extein ligation and enables protein trans-splicing. Protein trans-splicing mediated by split inteins has become a cornerstone for traceless protein ligation owing to its high specificity and irreversibility, fundamentally reshaping strategies for protein modification, assembly, and functional regulation. Compared with traditional chemical ligation methods, split intein systems require no complex chemical derivatization of peptide fragments and can operate efficiently at micromolar concentrations under physiological conditions, thus avoiding structural and functional damage caused by organic reagents. In contrast to enzymatic ligation tools such as sortase, split inteins eliminate the need for additional enzymes or cofactors, simplifying reaction systems, reducing costs, and minimizing non-specific side products. These distinctive advantages render split inteins highly promising for applications in chemical biology, synthetic biology, and biopharmaceutical development. In recent years, deepened mechanistic understanding has established structure-guided rational design as the primary approach to overcoming key limitations of split inteins, including intrinsic aggregation propensity, strict extein sequence dependence, and limited splicing efficiency. Bioinformatic tools have been used to identify aggregation-prone regions in the IntN fragment, and site-directed mutagenesis of hydrophobic residues, relocation of split sites, or removal of misfolding-prone sequences has substantially reduced in vitro aggregation and improved soluble expression and assembly activity. Rational engineering of catalytic residues and adjacent flexible loops has relaxed strict amino acid preferences at extein junctions, enhancing sequence tolerance and reducing the risk of functional impairment in target proteins. Consensus design based on multiple sequence alignments has yielded ultra-fast splicing variants such as Cfa DnaE and Cat-TerL, which exhibit significantly accelerated kinetics and improved tolerance to denaturing conditions. Meanwhile, advances in structural biology have further clarified the conformational dynamics and catalytic mechanisms of splicing, supporting the precise design of high-performance intein modules. On this basis, electrostatic interaction tuning and metagenomic screening have yielded multiple mutually orthogonal split intein pairs, enabling selective multi-fragment protein ligation and providing new routes for the efficient synthesis of large multi-domain functional proteins. With these engineered split inteins offering continuously improved performance and expanded applicability, protein trans-splicing has been widely applied in numerous cutting-edge areas of protein research and biomedicine. In gene delivery, split intein-based systems overcome the packaging limit of adeno-associated viral vectors, enabling the accurate reconstitution of large therapeutic proteins and base editors in target cells, thereby enhancing the efficacy and scope of gene therapy for genetic diseases. In internal protein sequence editing, split inteins mediate precise sequence replacement and modification in flexible regions or loops of target proteins, without the need for complex multi-step ligation and protein refolding involved in traditional protein semisynthesis. In protein-protein interaction studies, intein-mediated splicing covalently captures transient and weak intracellular complexes, enabling sensitive, high-throughput interaction detection and drug screening. In synthetic biology, conditionally controllable splicing systems support the construction of diverse intracellular and cell-surface biological logic gates for the precise regulation of cellular behavior. In mechanistic biochemical research, split inteins enable photocatalytic proximity labeling and site-specific tagging, allowing the preparation of homogeneous protein samples carrying precise post-translational modifications such as ubiquitination and polyglutamylation for chromatin interactome analysis and epigenetic studies. Moreover, covalent trapping strategies using split inteins stabilize transient enzymatic intermediates, providing unprecedented insights into molecular mechanisms such as nucleosome ubiquitination that are difficult to elucidate using conventional methods. This review systematically summarizes key technological advances in split inteins over the past decade, highlighting engineering strategies, mechanistic insights, and the development of orthogonal components. It comprehensively surveys emerging applications at the frontiers of protein research, analyzes current core challenges, and proposes future directions, particularly emphasizing artificial intelligence-driven de novo design and novel splicing pathways to break existing technical bottlenecks. By enabling traceless, efficient, and versatile protein manipulation, split inteins continue to serve as indispensable tools that drive innovation in protein engineering and fundamental life science research.
2.SIRT5 Potentiates Hepatocarcinogenesis by Modulating Protein Acylation in Mice
Yu ZHANG ; Feng-Rui REN ; Jia-Yun LI ; Xiang-Yu CHEN ; Zi-Yi WANG ; Qi SUN ; Jun-Cheng ZHAO ; Ye ZHANG ; Zhen HUANG ; Hao HU ; Tao-Tao WEI ; Min XIAO
Progress in Biochemistry and Biophysics 2026;53(6):1712-1722
ObjectiveHepatocellular carcinoma (HCC) represents 90% of all primary liver cancers. The main risk factors associated with HCC include viral hepatitis (B and/or C), alcohol abuse, and metabolic dysfunction-associated steatotic liver disease (MASLD), which progressively advance to liver fibrosis, cirrhosis, and ultimately evolve into HCC. Surgical resection represents the most effective treatment for HCC, while recent advances in immunotherapy, including immune checkpoint inhibitors and adoptive cell therapies, have provided improved treatment prospects for patients with unresectable HCC. However, the complex metabolic heterogeneity of HCC limits the therapeutic efficacy. Metabolic intermediates acyl-CoA not only provide energy and substrates for numerous biochemical reactions but also serve as donors for protein lysine acylation, a major class of post-translational modification (PTM). Therefore, a deeper understanding of the molecular mechanisms underlying protein lysine acylation and hepatocarcinogenesis is urgently needed. MethodsThe levels of protein lysine acylation and silence information regulator 5 (SIRT5) expression levels in clinical HCC samples were analyzed by Western blot. Quantitative malonylome and succinylome of HCC samples were analyzed by antibody-based affinity enrichment coupled with tandem mass spectrometry. The proliferation of HCC cells was analyzed with Cell Counting Kit-8 (CCK-8) assays, the apoptosis was quantified by Annexin V-FITC/propidium iodide (PI) staining coupled with flow cytometry, and the ability of cells to migrate was assayed by Transwell assays. The enzymatic activity of glutathione S-transferase Mu 1 (GSTM1) was quantified. Transgenic mice with hepatic overexpression of SIRT5 were constructed using CRISPR-Cas9, and primary hepatocarcinogenesis was induced by administration of diethylnitrosamine. ResultsWestern blot analysis indicated that the expression level of SIRT5 was elevated in clinical samples from HCC patients, and the levels of lysine malonylation, glutarylation, and succinylation were significantly reduced in HCC tissues. Knockout of SIRT5 in MHCC-97H and MHCC-97L hepatoma cells suppressed cell proliferation, and increased the percentage of apoptotic cells significantly. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the differentially malonylome and succinylome of HCC samples revealed significant enrichment in two major classes of biological processes: core energy metabolism (e.g., glycolysis/gluconeogenesis, tricarboxylic acid metabolic process, fatty acid beta oxidation) and detoxification and oxidative stress response (e.g., response to toxic substance, chemical carcinogenesis, reactive oxygen species (ROS)). SIRT5 removes malonylation from lysine residues in GSTM1 and restores its detoxification activity, which is crucial for the survival of hepatocytes under stressed conditions. More importantly, in vivo experiment indicated that hepatic-specific overexpression of SIRT5 in mice accelerated diethylnitrosamine-induced liver fibrosis and hepatocarcinogenesis, indicating the critical role of SIRT5 in HCC progression. ConclusionThis study highlights the previously unrecognized SIRT5-GSTM1 axis as a key regulator in hepatocarcinogenesis, and suggests a potential target for the treatment of patients with HCC.
3.Pseudolaric Acid B-linked Double-network Hydrogel Alleviates Pruritus by Inhibiting The Growth of Staphylococcus aureus
Ye YOU ; Yan YANG ; Tong-Yu LI ; Cheng-Long CAI ; Ting WANG ; Chan ZHU ; Zong-Xiang TANG
Progress in Biochemistry and Biophysics 2026;53(6):1734-1745
ObjectiveThis study aimed to elucidate the mechanistic role of Staphylococcus aureus in the pathogenesis of atopic dermatitis (AD), a chronic inflammatory skin disorder characterized by pruritus and barrier dysfunction. A key focus was screening traditional Chinese medicine (TCM) active components with dual antibacterial and antipruritic efficacy, followed by systematic evaluation of their in vitro antibacterial activity. Additionally, a novel drug delivery system was constructed to enable localized efficient drug delivery, inhibiting S. aureus proliferation and alleviating its induced pruritus, thereby providing new strategies for targeted AD therapy. MethodsMale C57BL/6J mice aged 6-8 weeks (body weight 18-22 g) were used to establish an AD model via repeated oxazolone sensitization. On day 14, microbial samples were collected from the lesional area (1 cm²) using sterile cotton swabs, followed by vortex mixing, serial dilution, and plating on 5% sheep blood agar plates (incubated at 37°C for 24 h). Single colonies with complete transparent β-hemolytic zones were isolated and identified as vancomycin-intermediate S. aureus (VISA) via 16S rRNA sequencing. An S. aureus mono-infection animal model was then established by applying gauze saturated with bacterial suspension (McFarland turbidity 0.1) to the nape and back skin of mice. The pruritic phenotype and inflammatory cell infiltration induced by S. aureus were evaluated using comprehensive approaches including behavioral assays (e.g., scratching frequency recording), hematoxylin-eosin (HE) staining, and toluidine blue staining. The in vitro antibacterial efficacy of the TCM monomer pseudolaric acid B (PAB) and double network hydrogel (DN) was separately assessed by disk diffusion assay, while the minimum inhibitory concentration (MIC) of PAB was determined via broth dilution method. Further validation of the pharmacodynamic characteristics of the composite system (PAB@DN, composed of PAB and DN) was conducted through behavioral assays, HE staining, and dermatitis scoring, with its drug release profile evaluated by mass spectrometry analysis. Based on scratching behavioral analysis and dermatitis scoring, the optimal ratio and concentration of PAB@DN were optimized. ResultsThe S. aureus load in AD lesional tissues was significantly higher than in normal skin ((5.3±0.33)×10⁶ CFU vs. (3.6±0.26)×10⁷ CFU, P<0.001). In the S. aureus mono-infection group, mice exhibited a 6.7-fold increase in scratching frequency compared to the control group. HE staining revealed marked epidermal thickening ((10.4±2.39) μm vs. (85.6±1.95) μm, P<0.000 1), and toluidine blue staining showed a 23-fold increase in mast cell degranulation. Pseudolaric acid B exhibited a significant concentration-dependent inhibitory effect onS. aureus growth, with its in vitro antibacterial effect being 57% that of the antibiotic cefepime (inhibition zone diameter: PAB (1.885±0.036) cm vs. cefepime (3.636±0.005) cm, P<0.000 1) and a minimum inhibitory concentration (MIC) of 1 g/L. The carrier double network hydrogel (DN) itself lacked direct antibacterial activity (no significant difference in inhibition zone diameter compared to the control) but effectively ameliorated the dry symptoms of AD-like lesions. The PAB@DN composite system demonstrated a synergistic effect compared to individual components, resulting in a 50% reduction in scratching behavior, an 86% decrease in dermatitis score, and a 60% reduction in epidermal thickening. It also reduced the S. aureus load in mouse skin by approximately 34%, with the optimal effective formulation being PAB at 1 g/L loaded onto DN. ConclusionS. aureus colonization plays a critical driving role in the onset and progression of AD. Using an S. aureus infection model, this study confirmed that the pseudolaric acidB-hydrogel composite delivery system (PAB@DN) can effectively alleviate S. aureus-induced pruritus and skin damage, providing experimental evidence for microbiota-targeted therapy of AD.
4.Effect of Acupuncture at Neiguan (PC6) on Improving Autism by Promoting Myelination Through The METTL14/m⁶A/PTEN Axis Based on “Xuanfu-Suiqiao” Theory
Wei-Li DANG ; Lü-Yuan LIANG ; Yu-Xin LI ; Zhi-Yao LI ; Sai-Dan LIU ; Jia-Lei CAO ; Rong-Ze MA ; Yun-Kai WANG ; Xiao-Qing YANG ; Bing-Qi WEI ; Bing-Xiang MA
Progress in Biochemistry and Biophysics 2026;53(5):1165-1177
ObjectiveTo clarify whether METTL14 mediates the core role of acupuncture at Neiguan (PC6) in promoting myelination and improving behavior in young autistic rats through gene intervention technology. MethodsThe ASD model was established by intraperitoneal injection of valproic acid (VPA) in pregnant rats. Male offspring were intracerebroventricularly injected with adenovirus-packaged METTL14 shRNA (sh-METTL14) or its control (sh-NC) on postnatal day 1, with a model group set as well. Subsequently, the juvenile rats were divided into model group, acupuncture group, acupuncture+sh-NC group, and acupuncture+sh-METTL14 group. The acupuncture group received acupuncture at Neiguan (PC6) from postnatal day 7, once daily for 21 consecutive days. Neurobehavioral changes were evaluated by behavioral tests; METTL14 knockdown efficiency and the expression of METTL14, METTL3, and PTEN were detected by quantitative real-time PCR (qRT-PCR) and Western blot (WB); PTEN m6A levels were measured by RNA immunoprecipitation-qPCR (RIP-qPCR); myelin ultrastructure, expression of myelin basic protein (MBP) and neurofascin 155 (NF155), and dendritic spine density were observed using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), immunofluorescence, qRT-PCR, and primary neuron culture. ResultsBehaviorally, knockdown of METTL14 significantly counteracted the beneficial effects of acupuncture in improving self-grooming, open field exploration, three-chamber social interaction, and Morris water maze learning and memory (P<0.05, P<0.01). Compared with the acupuncture+sh-NC group, the acupuncture+sh-METTL14 group showed significantly decreased mRNA and protein expression of hippocampal METTL14 (P<0.01), and the upregulating effects of acupuncture on METTL3 and PTEN expression were reversed (P<0.01). Meanwhile, knockdown of METTL14 significantly inhibited the acupuncture-induced increase in PTEN m6A levels (P<0.01). Morphologically, knockdown of METTL14 attenuated the improvement of myelin structure by acupuncture, reversed the downregulation of MBP and upregulation of NF155 induced by acupuncture, and blocked the increase in dendritic spine density (P<0.05, P<0.01). ConclusionMETTL14 is a key molecule mediating the therapeutic effect of acupuncture at Neiguan. Acupuncture at Neiguan upregulates METTL14, thereby enhancing m6A methylation modification of PTEN mRNA to stabilize its expression, ultimately promoting myelin development and improving behavioral symptoms in ASD juvenile rats. This preliminarily reveals the modern biological connotation of “opening Xuanfu and dredging myelin”.
5.Epigenetic mechanism of Diwu Yanggan Capsule in improving liver regeneration microenvironment in a rat model of liver cancer
Minggang WANG ; Jiamei DONG ; Zhihua YE ; Xiang GAO ; Qi CHEN ; Xiaoqiao YU ; Hanmin LI
Journal of Clinical Hepatology 2026;42(2):362-371
ObjectiveTo investigate the epigenetic mechanism of Diwu Yanggan Capsule in improving liver regeneration microenvironment in a rat model of liver cancer by regulating DNA methylation, and to provide a basis for scientific clinical medication. MethodsA total of 48 specific pathogen-free Sprague-Dawley rats were divided into normal group, model group, and Diwu Yanggan Capsule group using a random number table, with 16 rats in each group. The Solt-Farber two-step method was used to establish a rat model of liver cancer. The rats in the Diwu Yanggan Capsule group were given Diwu Yanggan Capsule at a dose of 750 mg/kg/d by gavage, and those in the normal group and the model group were given an equal volume of normal saline by gavage. Liver tissue samples were collected from each group of rats after 16 weeks of continuous intervention; DNA methylation chips were used to analyze the change in DNA methylation in liver tissue, and gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used for data analysis. In addition, the MeDIP-PCR technique was used to detect the changes in candidate differentially methylated genes such as YWHAB, ADCK2, ERLIN2, SEMA3B, and TPH2 in the liver tissue of rats, and Western blot and RT-qPCR were used to verify the expression of key methylated genes. The independent-samples t test was used for comparison of continuous data between two groups, and a one-way analysis of variance was used for comparison between multiple groups, while the least significant difference t-test was used for further comparison between two groups. ResultsThe DNA methylation chip analysis showed that compared with the normal group, the model group had significant methylation changes in the promoter region of 2 422 genes in liver tissue of rats. The GO functional enrichment analysis and the KEGG pathway enrichment analysis showed that these differentially methylated genes were significantly enriched in metabolic pathways such as steroid hormone biosynthesis and drug metabolism-cytochrome P450. Compared with the model group, the Diwu Yanggan Capsule group had significant reversal of promoter methylation in 1 650 genes, and the KEGG enrichment analysis showed that these genes were mainly involved in the pathways closely associated with cell proliferation, apoptosis, and microenvironment regulation, such as the calcium ion signaling pathway, the cAMP signaling pathway, and the extracellular factor signaling pathway. Compared with the model group, the Diwu Yanggan Capsule group had a significant increase in the promoter methylation level of the ADCK2 gene (P<0.05) and significant reductions in the promoter methylation levels of the ERLIN2 and TPH2 genes (all P<0.05). Compared with the model group, the Diwu Yanggan Capsule group had significant reductions in the mRNA expression levels and the protein expression levels of the ADCK2 (all P<0.05). ConclusionAbnormal DNA methylation in liver tissue participates in the development and progression of liver cancer. The effect of Diwu Yanggan Capsule on DNA methylation level is an important epigenetic mechanism for its effect in the prevention and treatment of liver cancer.
6.Preliminary evaluation of the effect of comprehensive health management on the prevention and treatment of ischemic stroke
Shuai ZHU ; Genming ZHAO ; Yiying ZHANG ; Dongni LIANG ; Hongjie YU ; Qian PENG ; Fang XIANG ; Na WANG
Journal of Public Health and Preventive Medicine 2026;37(2):89-93
Objective To evaluate the short-term effects of comprehensive health management interventions for stroke high-risk population screening on the prevention and treatment of ischemic stroke, and to provide reference and basis for improving and exploring health management and prevention strategies for stroke high-risk population. Methods From 2018 to 2022, 13 community health service centers in Jiading District, Shanghai were selected in the present study. Based on information push platform, stroke risk assessment and health intervention follow-up were conducted for community residents through convenience sampling. The residents were divided into a full course intervention group (intervention group) and a routine intervention group (control group) according to different health intervention measures and forms. The incidence of ischemic stroke in the two groups of survey subjects was tracked within 36 months. Results A total of 52144 subjects were included in the study. The total number of patients in the full course intervention group was 14227, with an incidence density of 577.32/100 000 (556.49/100 000-598.12/100 000), which was lower than that of the conventional intervention group (37 917), with an incidence density of 1 485.47/100 000 (1 464.99/100 000-1 505.94/100 000) (χ2=2490.212, P<0.001). The relative risk of the full course intervention group was 0.39, and the relative risk of stroke risk factors in the full course intervention group from low to high was 0.33, 0.43, 0.45, and 0.49, respectively. The incidence density of males in the full course intervention group was 660.76 (627.46/100 000 - 694.05/100 000), with a relative risk of 0.43, and the incidence density of female patients was 509.71/100 000 (483.37/100 000 - 536.05/100 000), with a relative risk of 0.35. The overall incidence density of the population under 62 years old gourp, 62-75 years old group and over 75 years old group was 197.45/100 000 (173.09/100 000 -221.80/100 000), 608.36/100 000 (580.19/100 000-636.54/100 000), and 1 025.06/100 000 (958.51/100 000-1 091.61/100 000), with relative risks of 0.51, 0.44, and 0.38, respectively. Conclusion Comprehensive health management measures can effectively reduce the short-term risk of ischemic stroke, and should be further promoted and improved to enhance the effectiveness of stroke prevention and control.
7.Zuogui Jiangtang Shuxin Prescription Ameliorates Lipid Deposition in Diabetic Cardiomyopathy of MKR Mice by Regulating AMPK/FoxO1/CD36 Signaling Pathway
Xiu LIU ; Juping WANG ; Jiawang HUANG ; Junju ZOU ; Qin XIANG ; Yunfeng YU ; Rong YU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):134-142
ObjectiveTo investigate the ameliorative effects and related mechanisms of the Zuogui Jiangtang Shuxin prescription (ZJSP) on glucose and lipid metabolism disorders in MKR mice with diabetic cardiomyopathy (DCM), with a focus on elucidating its regulatory role on the adenosine monophosphate-activated protein kinase (AMPK)/forkhead box protein O1 (FoxO1)/cluster of differentiation 36 (CD36) signaling pathway and lipid deposition. MethodsFifty 8-week-old male MKR mice were fed a high-fat diet for four weeks and then intraperitoneally injected with streptozotocin (STZ) while maintaining a high-fat diet to establish a DCM model. The mice were randomly divided into the model group, the low-dose(14.43 g·kg-1)and high-dose(28.86 g·kg-1) ZJSP groups, and the metformin group (0.25 g·kg-1), with age-matched FVB mice as a normal control group. Each group received intragastric administration of normal saline or corresponding concentrations of ZJSP at equal volumes. After four weeks, fasting blood glucose (FBG) and cardiac function were measured. Blood was collected from the eyeballs under anesthesia to detect fasting insulin (FINS) and blood lipid levels. Myocardial tissue morphology was observed by hematoxylin-eosin (HE) staining, and lipid deposition in the heart was assessed using oil red O staining. Real-time quantitative polymerase chain reaction (Real-time PCR) was used to measure the mRNA expression levels of AMPK, FoxO1, and CD36 in myocardial tissues. Western blot was employed to detect the protein expression levels of AMPK, p-AMPK, FoxO1, p-FoxO1, and CD36. ResultsCompared with the control group, the model group showed significantly increased levels of FBG and FINS (P<0.01), elevated levels of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) (P<0.01), and significantly decreased left ventricular ejection fraction (EF) and fractional shortening (FS) values (P<0.01). HE staining revealed marked cardiomyocyte hypertrophy, disarray, and widened intercellular spaces in myocardial tissues. Oil Red O staining showed extensive red deposition areas and fine lipid droplet accumulation in the myocardial tissue. AMPK mRNA expression was decreased, while FoxO1 and CD36 mRNA expressions were significantly increased (P<0.01). The p-AMPK/AMPK protein expression ratio in myocardial tissues was significantly reduced, while the p-FoxO1/FoxO1 protein expression ratio and CD36 protein expression levels were significantly increased (P<0.01). Compared with the model group, all treatment groups exhibited significantly reduced FBG (P<0.01), decreased FINS and blood lipid levels (TG, TC, LDL-C) (P<0.05, P<0.01), improved cardiac function (P<0.05), noticeable amelioration of myocardial histopathological morphology and lipid deposition, increased AMPK mRNA expression (P<0.01), with significantly downregulated FoxO1 and CD36 mRNA expressions (P<0.01), elevated p-AMPK/AMPK protein expression levels in myocardial tissue (P<0.05), significantly decreased p-FoxO1/FoxO1 ratios (P<0.01), and downregulated CD36 protein expression levels (P<0.05, P<0.01). ConclusionZJSP exerts a protective effect on the heart in type 2 DCM of MKR mice, and its mechanism may be associated with the regulation of the AMPK/FoxO1/CD36 signaling pathway.
8.Zuogui Jiangtang Shuxin Prescription Ameliorates Lipid Deposition in Diabetic Cardiomyopathy of MKR Mice by Regulating AMPK/FoxO1/CD36 Signaling Pathway
Xiu LIU ; Juping WANG ; Jiawang HUANG ; Junju ZOU ; Qin XIANG ; Yunfeng YU ; Rong YU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):134-142
ObjectiveTo investigate the ameliorative effects and related mechanisms of the Zuogui Jiangtang Shuxin prescription (ZJSP) on glucose and lipid metabolism disorders in MKR mice with diabetic cardiomyopathy (DCM), with a focus on elucidating its regulatory role on the adenosine monophosphate-activated protein kinase (AMPK)/forkhead box protein O1 (FoxO1)/cluster of differentiation 36 (CD36) signaling pathway and lipid deposition. MethodsFifty 8-week-old male MKR mice were fed a high-fat diet for four weeks and then intraperitoneally injected with streptozotocin (STZ) while maintaining a high-fat diet to establish a DCM model. The mice were randomly divided into the model group, the low-dose(14.43 g·kg-1)and high-dose(28.86 g·kg-1) ZJSP groups, and the metformin group (0.25 g·kg-1), with age-matched FVB mice as a normal control group. Each group received intragastric administration of normal saline or corresponding concentrations of ZJSP at equal volumes. After four weeks, fasting blood glucose (FBG) and cardiac function were measured. Blood was collected from the eyeballs under anesthesia to detect fasting insulin (FINS) and blood lipid levels. Myocardial tissue morphology was observed by hematoxylin-eosin (HE) staining, and lipid deposition in the heart was assessed using oil red O staining. Real-time quantitative polymerase chain reaction (Real-time PCR) was used to measure the mRNA expression levels of AMPK, FoxO1, and CD36 in myocardial tissues. Western blot was employed to detect the protein expression levels of AMPK, p-AMPK, FoxO1, p-FoxO1, and CD36. ResultsCompared with the control group, the model group showed significantly increased levels of FBG and FINS (P<0.01), elevated levels of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) (P<0.01), and significantly decreased left ventricular ejection fraction (EF) and fractional shortening (FS) values (P<0.01). HE staining revealed marked cardiomyocyte hypertrophy, disarray, and widened intercellular spaces in myocardial tissues. Oil Red O staining showed extensive red deposition areas and fine lipid droplet accumulation in the myocardial tissue. AMPK mRNA expression was decreased, while FoxO1 and CD36 mRNA expressions were significantly increased (P<0.01). The p-AMPK/AMPK protein expression ratio in myocardial tissues was significantly reduced, while the p-FoxO1/FoxO1 protein expression ratio and CD36 protein expression levels were significantly increased (P<0.01). Compared with the model group, all treatment groups exhibited significantly reduced FBG (P<0.01), decreased FINS and blood lipid levels (TG, TC, LDL-C) (P<0.05, P<0.01), improved cardiac function (P<0.05), noticeable amelioration of myocardial histopathological morphology and lipid deposition, increased AMPK mRNA expression (P<0.01), with significantly downregulated FoxO1 and CD36 mRNA expressions (P<0.01), elevated p-AMPK/AMPK protein expression levels in myocardial tissue (P<0.05), significantly decreased p-FoxO1/FoxO1 ratios (P<0.01), and downregulated CD36 protein expression levels (P<0.05, P<0.01). ConclusionZJSP exerts a protective effect on the heart in type 2 DCM of MKR mice, and its mechanism may be associated with the regulation of the AMPK/FoxO1/CD36 signaling pathway.
9.Syndrome Differentiation and Treatment Mechanisms of Inflammatory Injury in Diabetic Cardiomypathy from Theory of "Gaozhuo"
Xiaoyue WANG ; Yunfeng YU ; Xiangning HUANG ; Yixin XIANG ; Sihao ZHANG ; Qin XIANG ; Rong YU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):235-244
Diabetic cardiomyopathy (DCM) is one of the most common complications of diabetes mellitus and is a major threat to global health. As a key mechanism in the occurrence and progression of DCM, the inflammatory response persists throughout the entire course of the DCM. The Gaozhuo theory suggests that the basic pathogenesis of inflammatory injury in DCM is the Qi deficiency of spleen and kidney and Gaozhuo invasion, and divides the pathological process into three phases: Gaozhuo invasion, turbid heat damage to the channels, and turbid blood stasis and heat junction. Among them, the Qi deficiency of spleen and kidney and the endogenous formation of Gaozhuo represent the process of inflammatory factor formation induced by glucose metabolism disorders. Turbid heat damage to the channels refers to the process of myocardial inflammatory injury mediated by inflammatory factors, and turbid blood stasis and heat junction are the process of myocardial injury developing toward myocardial fibrosis and ventricular remodeling. As the disease continues to progress, it eventually develops into a depletion of the heart Yang, leading to the ultimate regression of heart failure. According to the theory of Gaozhuo, traditional Chinese medicine (TCM) should regulate inflammatory injury in DCM by strengthening the spleen and tonifying the kidney to address the root cause, and resolving dampness and lowering turbidity to treat the symptoms. If the turbidity has been stored for a long time and turns into heat, strengthening the spleen and tonifying the kidney, and clearing heat and resolving turbidity should be the therapy. If the turbidity, stasis, and heat are knotted in the heart and collaterals, strengthening the spleen and tonifying the kidney, and resolving stasis and lowering turbidity should be the therapy. TCM compounds and monomers can regulate the inflammatory response in DCM. TCM compounds can be divided into the categories for benefiting Qi to resolve turbidity, benefiting Qi and clearing heat to resolve turbidity, and benefiting Qi and activating blood to reduce turbidity. The compounds can inhibit upstream signals of inflammation and expression of inflammatory factors, improve the inflammatory damage to myocardium and blood vessels, myocardial fibrosis, and cardiac systole and diastole, and thus slow down the onset and progression of DCM.
10.Syndrome Differentiation and Treatment Mechanisms of Hepatic Stellate Cell Activation in Type 2 Diabetes Mellitus Combined with Non-alcoholic Fatty Liver Disease Based on Theory of "Gaozhuo"
Yixin XIANG ; Yunfeng YU ; Xiaoyue WANG ; Xiangning HUANG ; Qin XIANG ; Rong YU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):253-260
Non-alcoholic fatty liver disease (NAFLD) is one of the most common complications of type 2 diabetes mellitus (T2DM), and hepatic stellate cell (HSC) activation is the key link in the progression of NAFLD to liver fibrosis. According to the theory of "Gaozhuo", spleen deficiency and Qi stagnation, along with Gaozhuo invasion, are the causes of NAFLD progression to liver fibrosis, which reveals the pathogenesis essence of HSC activation in traditional Chinese medicine (TCM). Among them, spleen deficiency and Qi stagnation are the root causes of the endogenous formation of Gaozhuo. Spleen deficiency indicates the insulin sensitivity decrease and glucose metabolism disorders, and Qi stagnation means the dysregulation of hepatic glucose and lipid metabolism, which creates the preconditions for HSC activation. Gaozhuo invasion is the direct cause of HSC activation, including three stages: Internal retention of Gaozhuo, turbidity and stasis stagnation, and toxic stasis and consolidation. Internal retention of Gaozhuo refers to the abnormal metabolism and deposition of hepatic lipids, as well as the microcirculatory disorders. Turbidity and stasis stagnation is the process by which lipotoxicity stimulates the transformation of HSC into myofibroblast (MFB), and toxic stasis and consolidation represent the secretion of a large amount of extracellular matrix (ECM) by MFB to promote the fibrosis. According to the theory of Gaozhuo and the activation process of HSC, syndromes for T2DM combined with NAFLD can be classified into spleen deficiency and Qi stagnation with internal retention of Gaozhuo, spleen Qi deficiency with turbidity and stasis stagnation, and spleen Qi deficiency with toxic stasis and consolidation. Clinically, the treatment principle is to strengthen the spleen and promote Qi, resolve turbidity, and eliminate blood stasis. Both TCM compounds and monomers can effectively inhibit the HSC activation. TCM compounds can be classified into categories for regulating spleen and harmonizing liver, resolving turbidity and removing stasis, and detoxifying and removing stasis. They mainly work by improving lipid metabolism, reducing lipid accumulation in the liver, alleviating inflammatory and oxidative stress responses, inhibiting the activation and proliferation of HSC, and reducing ECM deposition, thereby delaying the progression of liver fibrosis.


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