1.Clinical analysis of 6 cases of diffuse panbronchiolitis in children.
Li-Xin DENG ; De-Hui CHEN ; Yu-Neng LIN ; Shang-Zhi WU ; Jia-Xing XU ; Zhan-Hang HUANG ; Ying-Ying GU ; Jun-Xiang FENG
Chinese Journal of Contemporary Pediatrics 2025;27(3):334-339
OBJECTIVES:
To analyze the clinical characteristics of diffuse panbronchiolitis (DPB) in children and to enhance the clinical diagnosis and treatment of this disease.
METHODS:
A retrospective analysis was conducted on the clinical data of 6 children diagnosed with DPB who were hospitalized at The First Affiliated Hospital of Guangzhou Medical University from January 2011 to December 2019.
RESULTS:
Among the 6 patients, there were 2 males and 4 females; the age at diagnosis ranged from 7 to 12 years. All patients presented with cough, sputum production, and exertional dyspnea, and all had a history of sinusitis. Two cases showed positive serum cold agglutinin tests, and 5 cases exhibited pathological changes consistent with chronic bronchiolitis. High-resolution chest CT in all patients revealed centrilobular nodules diffusely distributed throughout both lungs with a tree-in-bud appearance. Five patients received low-dose azithromycin maintenance therapy, but 3 showed inadequate treatment response. After empirical anti-tuberculosis treatment, non-tuberculous Mycobacteria were found in the bronchoalveolar lavage fluid. Follow-up over 2 years showed 1 case cured, 3 cases significantly improved, and 2 cases partially improved.
CONCLUSIONS
The clinical presentation of DPB is non-specific and can easily lead to misdiagnosis. In cases where DPB is clinically diagnosed but does not show improvement with low-dose azithromycin treatment, special infections should be considered.
Humans
;
Male
;
Female
;
Bronchiolitis/drug therapy*
;
Retrospective Studies
;
Child
;
Haemophilus Infections/diagnosis*
2.Efficacy Prediction of Platelet Count Trajectories after Induction Therapy with Venetoclax Combined with Azacitidine in Newly Diagnosed AML Patients.
Qian-Ying MA ; Xiao-Rui JING ; Han-Chun WANG ; Hui-Rong WU ; Juan CHENG
Journal of Experimental Hematology 2025;33(2):331-338
OBJECTIVE:
To investigate platelet count trajectories after induction therapy with venetoclax combined with azacitidine (VA regimen) in newly diagnosed AML patients and further analyze its clinical significance.
METHODS:
Clinical date of 50 newly diagnosed AML patients who received VA treatment from March 2020 to July 2023 in Department of Hematology of the First Hospital of Lanzhou University were retrospectively collected. The platelet trajectories after induction chemotherapy were constructed by using group-based trajectory modeling. To study the association between diverse trajectories of platelet counts and compound complete remission (cCR) rate, overall response rate (ORR), minimal residual disease (MRD) negative rate and overall survival (OS) rate. The Cox proportional hazard model was used to evaluate the relationship between platelet trajectory and OS. The logistic regression was used to analyze the influence of individual characteristics on platelet trajectory.
RESULTS:
Two platelet trajectories were identified based on the model, including platelet slowly increased group (n=31, 62.0%) and platelet rapidly increased group (n=19, 38.0%). There were statistically significant differences in cCR rate, ORR and OS rate between platelet slowly increased group and platelet rapidly increased group (all P < 0.05). The Cox regression analysis showed that platelet rapidly increased group was associated with a decreased risk of mortality compared with platelet slowly increased group (HR=0.153, 95%CI : 0.045-0.527, P =0.003). Logistic regression analysis showed that IDH1/2 mutation (OR =3.908, 95%CI : 1.023-14.923, P =0.046) and platelet transfusion (OR =0.771, 95%CI : 0.620-0.959, P =0.020) were independent influencing factors of platelet trajectory.
CONCLUSION
The dynamic trajectory of platelet counts in newly diagnosed AML patients who received VA treatment can serve as a significant indicator to observe the efficacy and prognosis. The platelet rapidly increased is an independent protective factor for good prognosis. TheIDH1 /2 mutation and platelet transfusion are independent influencing factors of platelet trajectory.
Humans
;
Leukemia, Myeloid, Acute/blood*
;
Sulfonamides/administration & dosage*
;
Azacitidine/therapeutic use*
;
Platelet Count
;
Retrospective Studies
;
Bridged Bicyclo Compounds, Heterocyclic/administration & dosage*
;
Male
;
Female
;
Antineoplastic Combined Chemotherapy Protocols/therapeutic use*
;
Induction Chemotherapy
;
Survival Rate
3.Efficacy and Safety of Diagnostic-Driven Therapy for Invasive Fungal Disease in Patients with Myeloid Hematologic Malignancies.
Hui XIAO ; Fan WU ; Ying PAN ; Fu-Run AN ; Zhi-Min ZHAI
Journal of Experimental Hematology 2025;33(5):1524-1528
OBJECTIVE:
To investigate the efficacy and safety of diagnostic-driven therapy for invasive fungal disease(IFD) in patients with myeloid hematologic malignancies.
METHODS:
A retrospective analysis was conducted on the clinical data of 91 patients with myeloid hematologic malignancies who received diagnostic-driven therapy for IFD at the Second Hospital of Anhui Medical University from January 1, 2020 to December 31, 2023. The patients were divided into two groups based on medication: 44 patients in the caspofungin group and 47 patients in the voriconazole group. The clinical efficacy and adverse reactions of the two groups were compared and analyzed.
RESULTS:
The overall response rates in the caspofungin and voriconazole groups were 67.4% and 60.0%, respectively. Among patients who transitioned to diagnostic-driven therapy following prophylactic or empirical treatment with triazole antifungal agents, the response rate of the caspofungin group was significantly higher than that of the voriconazole group (76.9% vs 35.3%, P <0.05). A total of 9 patients in both groups experienced adverse reactions, and no grade III or higher adverse reactions occurred. The incidence of grade I-II adverse reactions in the caspofungin group was lower than in the voriconazole group (2.3% vs 17.0%, P <0.05).
CONCLUSION
In patients with myeloid hematologic malignancies, caspofungin and voriconazole demonstrate comparable clinical efficacy in diagnostic-driven therapy for IFD, but caspofungin is associated with a lower incidence of adverse reactions. Caspofungin exhibits significant effectiveness when initiating diagnostic-driven therapy after prophylactic or empirical treatment with broad-spectrum triazole antifungal agents.
Humans
;
Retrospective Studies
;
Hematologic Neoplasms/complications*
;
Antifungal Agents/therapeutic use*
;
Voriconazole/therapeutic use*
;
Caspofungin/therapeutic use*
;
Invasive Fungal Infections/diagnosis*
;
Male
;
Female
;
Mycoses/drug therapy*
;
Middle Aged
;
Treatment Outcome
;
Aged
;
Adult
4.Bear Bile Powder Ameliorates LPS-Induced Acute Lung Injury by Inhibiting CD14 Pathway and Improving Intestinal Flora: Exploration of "Fei (Lung)-Dachang (Large Intestine) Interaction" Theory.
Long CHENG ; Hui-Ling TIAN ; Hong-Yuan LEI ; Ying-Zhou WANG ; Ma-Jing JIAO ; Yun-Hui LIANG ; Zhi-Zheng WU ; Xu-Kun DENG ; Yong-Shen REN
Chinese journal of integrative medicine 2025;31(9):821-829
OBJECTIVE:
To explore the effect of bear bile powder (BBP) on acute lung injury (ALI) and the underlying mechanism.
METHODS:
The chemical constituents of BBP were analyzed by ultra-high-pressure liquid chromatography-mass spectrometry (UPLC-MS). After 7 days of adaptive feeding, 50 mice were randomly divided into 5 groups by a random number table (n=10): normal control (NC), lipopolysaccharide (LPS), dexamethasone (Dex), low-, and high-dose BBP groups. The dosing cycle was 9 days. On the 12th and 14th days, 20 µL of Staphylococcus aureus solution (bacterial concentration of 1 × 10-7 CFU/mL) was given by nasal drip after 1 h of intragastric administration, and the mice in the NC group was given the same dose of phosphated buffered saline (PBS) solution. On the 16th day, after 1 h intragastric administration, 100 µL of LPS solution (1 mg/mL) was given by tracheal intubation, and the same dose of PBS solution was given to the NC group. Lung tissue was obtained to measure the myeloperoxidase (MPO) activity, the lung wet/dry weight ratio and expressions of CD14 and other related proteins. The lower lobe of the right lung was obtained for pathological examination. The concentrations of inflammatory cytokines including interleukin (IL)-6, tumour necrosis factor α (TNF-α ) and IL-1β in the bronchoalveolar lavage fluid (BALF) were detected by enzyme linked immunosorbent assay, and the number of neutrophils was counted. The colonic contents of the mice were analyzed by 16 sRNA technique and the contents of short-chain fatty acids (SCFAs) were measured by gas chromatograph-mass spectrometer (GC-MS).
RESULTS:
UPLC-MS revealed that the chemical components of BBP samples were mainly tauroursodeoxycholic acid and taurochenodeoxycholic acid sodium salt. BBP reduced the activity of MPO, concentrations of inflammatory cytokines, and inhibited the expression of CD14 protein, thus suppressing the activation of NF-κB pathway (P<0.05). The lung histopathological results indicated that BBP significantly reduced the degree of neutrophil infiltration, cell shedding, necrosis, and alveolar cavity depression. Moreover, BBP effectively regulated the composition of the intestinal microflora and increased the production of SCFAs, which contributed to its treatment effect (P<0.05).
CONCLUSIONS
BBP alleviates lung injury in ALI mouse through inhibiting activation of NF-κB pathway and decreasing expression of CD14 protein. BBP may promote recovery of ALI by improving the structure of intestinal flora and enhancing metabolic function of intestinal flora.
Animals
;
Acute Lung Injury/pathology*
;
Lipopolysaccharides
;
Ursidae
;
Gastrointestinal Microbiome/drug effects*
;
Bile/chemistry*
;
Lipopolysaccharide Receptors/metabolism*
;
Powders
;
Male
;
Lung/drug effects*
;
Mice
;
Peroxidase/metabolism*
;
Signal Transduction/drug effects*
;
Cytokines/metabolism*
5.Antithrombotic effect in zebrafish of a fibrinolytic protein EPF3 from Dilong (Pheretima vulgaris Chen) and its transport mechanism in Caco-2 monolayer through cell bypass pathway.
Wan-Ling ZHONG ; Jian-Qiong YANG ; Hai LIU ; Ya-Li WU ; Hui-Juan SHEN ; Peng-Yue LI ; Shou-Ying DU
Journal of Integrative Medicine 2025;23(4):415-428
OBJECTIVE:
EPF3 is a fibrinolysin monomer isolated and purified from Pheretima vulgaris Chen, an earthworm used in traditional Chinese medicine as Dilong for treating blood stasis syndrome. Its composition, anticoagulant and fibrinolytic activities, and relevant mechanisms have been confirmed through in vitro experiments. However, whether it has antithrombotic effects in vivo and can be absorbed by the gastrointestinal tract is unknown. This study evaluates the antithrombotic effect in zebrafish and investigates the gastrointestinal stability and intestinal absorption mechanism of this protein in vitro.
METHODS:
The antithrombotic effect of EPF3 in vivo was verified using the zebrafish thrombus model induced by arachidonic acid and FeCl3. Then, the protein bands of EPF3 incubated with simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and homogenate of Caco-2 cells (HC2C) were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to evaluate its gastrointestinal stability. Finally, the transport behavior and absorption mechanism of EPF3 were studied using Caco-2 cell monolayer.
RESULTS:
EPF3 could significantly enhance the returned blood volume and blood flow velocity in zebrafish with platelet aggregation thrombus induced by arachidonic acid. It could also prolong the formation time of tail artery thrombus and increase the blood flow velocity in zebrafish with vessel injury thrombus induced by FeCl3. EPF3 was stable in SIF and HC2C and unstable in SGF. The permeability of EPF3 in Caco-2 monolayer was time-dependent and concentration-dependent. The efflux ratio was less than 1.2 during transport, and the transport behavior was not affected by inhibitors. EPF3 could reversibly reduce the expression of tight junction-related proteins, including zonula occludens-1, occludin, and claudin-1 in Caco-2 cells.
CONCLUSION
EPF3 could play a thrombolytic and antithrombotic role in zebrafish. It could be transported and absorbed into the intestine through cellular bypass pathway by opening the intestinal epithelium tight junction. This study provides a scientific explanation for the antithrombotic effect of earthworm and provides a basis for the feasibility of subsequent development of EPF3 as an antithrombotic enteric-soluble preparation. Please cite this article as: Zhong WL, Yang JQ, Liu H, Wu YL, Shen HJ, Li PY, Du SY. Antithrombotic effect in zebrafish of a fibrinolytic protein EPF3 from Dilong (Pheretima vulgaris Chen) and its transport mechanism in Caco-2 monolayer through cell bypass pathway. J Integr Med. 2025; 23(4): 415-428.
Animals
;
Zebrafish
;
Humans
;
Caco-2 Cells
;
Fibrinolytic Agents/pharmacology*
;
Thrombosis/drug therapy*
;
Intestinal Absorption
6.Identification and Potential Clinical Utility of Common Genetic Variants in Gestational Diabetes among Chinese Pregnant Women
Claudia Ha-ting TAM ; Ying WANG ; Chi Chiu WANG ; Lai Yuk YUEN ; Cadmon King-poo LIM ; Junhong LENG ; Ling WU ; Alex Chi-wai NG ; Yong HOU ; Kit Ying TSOI ; Hui WANG ; Risa OZAKI ; Albert Martin LI ; Qingqing WANG ; Juliana Chung-ngor CHAN ; Yan Chou YE ; Wing Hung TAM ; Xilin YANG ; Ronald Ching-wan MA
Diabetes & Metabolism Journal 2025;49(1):128-143
Background:
The genetic basis for hyperglycaemia in pregnancy remain unclear. This study aimed to uncover the genetic determinants of gestational diabetes mellitus (GDM) and investigate their applications.
Methods:
We performed a meta-analysis of genome-wide association studies (GWAS) for GDM in Chinese women (464 cases and 1,217 controls), followed by de novo replications in an independent Chinese cohort (564 cases and 572 controls) and in silico replication in European (12,332 cases and 131,109 controls) and multi-ethnic populations (5,485 cases and 347,856 controls). A polygenic risk score (PRS) was derived based on the identified variants.
Results:
Using the genome-wide scan and candidate gene approaches, we identified four susceptibility loci for GDM. These included three previously reported loci for GDM and type 2 diabetes mellitus (T2DM) at MTNR1B (rs7945617, odds ratio [OR], 1.64; 95% confidence interval [CI],1.38 to 1.96]), CDKAL1 (rs7754840, OR, 1.33; 95% CI, 1.13 to 1.58), and INS-IGF2-KCNQ1 (rs2237897, OR, 1.48; 95% CI, 1.23 to 1.79), as well as a novel genome-wide significant locus near TBR1-SLC4A10 (rs117781972, OR, 2.05; 95% CI, 1.61 to 2.62; Pmeta=7.6×10-9), which has not been previously reported in GWAS for T2DM or glycaemic traits. Moreover, we found that women with a high PRS (top quintile) had over threefold (95% CI, 2.30 to 4.09; Pmeta=3.1×10-14) and 71% (95% CI, 1.08 to 2.71; P=0.0220) higher risk for GDM and abnormal glucose tolerance post-pregnancy, respectively, compared to other individuals.
Conclusion
Our results indicate that the genetic architecture of glucose metabolism exhibits both similarities and differences between the pregnant and non-pregnant states. Integrating genetic information can facilitate identification of pregnant women at a higher risk of developing GDM or later diabetes.
7.Identification and Potential Clinical Utility of Common Genetic Variants in Gestational Diabetes among Chinese Pregnant Women
Claudia Ha-ting TAM ; Ying WANG ; Chi Chiu WANG ; Lai Yuk YUEN ; Cadmon King-poo LIM ; Junhong LENG ; Ling WU ; Alex Chi-wai NG ; Yong HOU ; Kit Ying TSOI ; Hui WANG ; Risa OZAKI ; Albert Martin LI ; Qingqing WANG ; Juliana Chung-ngor CHAN ; Yan Chou YE ; Wing Hung TAM ; Xilin YANG ; Ronald Ching-wan MA
Diabetes & Metabolism Journal 2025;49(1):128-143
Background:
The genetic basis for hyperglycaemia in pregnancy remain unclear. This study aimed to uncover the genetic determinants of gestational diabetes mellitus (GDM) and investigate their applications.
Methods:
We performed a meta-analysis of genome-wide association studies (GWAS) for GDM in Chinese women (464 cases and 1,217 controls), followed by de novo replications in an independent Chinese cohort (564 cases and 572 controls) and in silico replication in European (12,332 cases and 131,109 controls) and multi-ethnic populations (5,485 cases and 347,856 controls). A polygenic risk score (PRS) was derived based on the identified variants.
Results:
Using the genome-wide scan and candidate gene approaches, we identified four susceptibility loci for GDM. These included three previously reported loci for GDM and type 2 diabetes mellitus (T2DM) at MTNR1B (rs7945617, odds ratio [OR], 1.64; 95% confidence interval [CI],1.38 to 1.96]), CDKAL1 (rs7754840, OR, 1.33; 95% CI, 1.13 to 1.58), and INS-IGF2-KCNQ1 (rs2237897, OR, 1.48; 95% CI, 1.23 to 1.79), as well as a novel genome-wide significant locus near TBR1-SLC4A10 (rs117781972, OR, 2.05; 95% CI, 1.61 to 2.62; Pmeta=7.6×10-9), which has not been previously reported in GWAS for T2DM or glycaemic traits. Moreover, we found that women with a high PRS (top quintile) had over threefold (95% CI, 2.30 to 4.09; Pmeta=3.1×10-14) and 71% (95% CI, 1.08 to 2.71; P=0.0220) higher risk for GDM and abnormal glucose tolerance post-pregnancy, respectively, compared to other individuals.
Conclusion
Our results indicate that the genetic architecture of glucose metabolism exhibits both similarities and differences between the pregnant and non-pregnant states. Integrating genetic information can facilitate identification of pregnant women at a higher risk of developing GDM or later diabetes.
8.Identification and Potential Clinical Utility of Common Genetic Variants in Gestational Diabetes among Chinese Pregnant Women
Claudia Ha-ting TAM ; Ying WANG ; Chi Chiu WANG ; Lai Yuk YUEN ; Cadmon King-poo LIM ; Junhong LENG ; Ling WU ; Alex Chi-wai NG ; Yong HOU ; Kit Ying TSOI ; Hui WANG ; Risa OZAKI ; Albert Martin LI ; Qingqing WANG ; Juliana Chung-ngor CHAN ; Yan Chou YE ; Wing Hung TAM ; Xilin YANG ; Ronald Ching-wan MA
Diabetes & Metabolism Journal 2025;49(1):128-143
Background:
The genetic basis for hyperglycaemia in pregnancy remain unclear. This study aimed to uncover the genetic determinants of gestational diabetes mellitus (GDM) and investigate their applications.
Methods:
We performed a meta-analysis of genome-wide association studies (GWAS) for GDM in Chinese women (464 cases and 1,217 controls), followed by de novo replications in an independent Chinese cohort (564 cases and 572 controls) and in silico replication in European (12,332 cases and 131,109 controls) and multi-ethnic populations (5,485 cases and 347,856 controls). A polygenic risk score (PRS) was derived based on the identified variants.
Results:
Using the genome-wide scan and candidate gene approaches, we identified four susceptibility loci for GDM. These included three previously reported loci for GDM and type 2 diabetes mellitus (T2DM) at MTNR1B (rs7945617, odds ratio [OR], 1.64; 95% confidence interval [CI],1.38 to 1.96]), CDKAL1 (rs7754840, OR, 1.33; 95% CI, 1.13 to 1.58), and INS-IGF2-KCNQ1 (rs2237897, OR, 1.48; 95% CI, 1.23 to 1.79), as well as a novel genome-wide significant locus near TBR1-SLC4A10 (rs117781972, OR, 2.05; 95% CI, 1.61 to 2.62; Pmeta=7.6×10-9), which has not been previously reported in GWAS for T2DM or glycaemic traits. Moreover, we found that women with a high PRS (top quintile) had over threefold (95% CI, 2.30 to 4.09; Pmeta=3.1×10-14) and 71% (95% CI, 1.08 to 2.71; P=0.0220) higher risk for GDM and abnormal glucose tolerance post-pregnancy, respectively, compared to other individuals.
Conclusion
Our results indicate that the genetic architecture of glucose metabolism exhibits both similarities and differences between the pregnant and non-pregnant states. Integrating genetic information can facilitate identification of pregnant women at a higher risk of developing GDM or later diabetes.
9.Clinical and pathological characteristics of adrenal cortical carcinoma:a single-center retrospective study
Qing-Zheng WU ; Ming-Xiu YANG ; Bing LI ; Shu-Ying LI ; Zi-Xin GUO ; Yi-Jun LI ; Ya-Qi YIN ; Ya-Jing WANG ; Kang CHEN ; Li ZANG ; Wei-Jun GU ; Yi-Ming MU ; Zhao-Hui LYU
Medical Journal of Chinese People's Liberation Army 2025;50(7):786-792
Objective To investigate the clinical and pathological characteristics of adrenal cortical carcinoma(ACC),compare differences between hypercortisolism and non-functional ACC,and assess the diagnostic value of indicators such as Ki-67 index.Methods The clinical data of 57 ACC patients admitted to the First Medical Center of Chinese PLA General Hospital from January 2015 to March 2025 were retrospectively analyzed.According to the results of endocrine function assessment,47 of these patients were divided into hypercortisolism group(n=19)and non-functional group(n=28).The differences in clinical and pathological characteristics between the two groups were compared,and non-parametric tests and Spearman correlation analysis were used to explore the relationship between Ki-67 index and tumor stage as well as imaging features.Results Among the 57 patients,there were 20 males and 37 females,with a male-to-female ratio of 1:1.85.The age ranged from 16 to 76 years,and the age at diagnosis was(48.7±13.3)years.The tumor diameter was(10.53±4.14)cm.The tumors were located on the right side in 12 cases(21.1%),on the left side in 34 cases(59.6%),and bilaterally in 11 cases(19.3%).Among them,16 cases(28.1%)were complicated with glucose metabolism disorders,31 cases(54.3%)had hypertension,and 20 cases(35.1%)had hypokalemia.According to ENSAT staging,there were 0 cases in stage Ⅰ,15 cases(26.3%)in stage Ⅱ,24 cases(42.1%)in stage Ⅲ,and 18 cases(31.6%)in stage Ⅳ.Endocrine function assessment was completed in 47 of the 57 patients,including 28 cases(59.6%)of non-functional ACC and 19 cases(40.4%)of hypercortisolism(including 1 case of hypercortisolism combined with increased sex hormone secretion).Compared with non-functional group,hypercortisolism group had a significantly higher prevalence of hypertension(P=0.014),later ENSAT stage(P=0.010),and a higher proportion of hypervascularization(P=0.048).The median Ki-67 index was 20%(10%-40%),showing no significant correlation with either the maximum tumor diameter or SUVmax value,but it was related to ENSAT staging,with Ki-67 index in stageⅣ patients being significantly higher than that in stage Ⅱ(P=0.032).Immunohistochemistry results showed that the positive rate of Inhibin-α was 84.8%,and the positive rate of Melan-A was 40.9%.Conclusions ACC is a rare malignant endocrine tumor.ACC patients with hypercortisolism are more likely to be complicated with hypertension,have later staging,and more common hypervascular manifestations.Clinically,their endocrine function should be prioritized for assessment,and more active treatment strategies should be adopted.Diagnosis should be combined with imaging characteristics(such as hypervascularization)and immunohistochemical indicators(Ki-67,Inhibin-α,Melan-A).The significant increase in Ki-67 is in the advanced stage can serve as an important prognostic indicator to guide individualized treatment.
10.Eccentric treadmill exercise promotes adaptive hypertrophy of gastrocnemius in rats.
Zhi-Qiang DAI ; Yu KE ; Yan ZHAO ; Ying YANG ; Hui-Wen WU ; Hua-Yu SHANG ; Zhi XIA
Acta Physiologica Sinica 2025;77(3):449-464
The present study aimed to investigate the effects of eccentric treadmill exercise on adaptive hypertrophy of skeletal muscle in rats. Thirty-two 3-month-old Sprague Dawley (SD) rats were selected and randomly assigned to one of the four groups based on their body weights: 2-week quiet control group (2C), 2-week downhill running exercise group (2E), 4-week quiet control group (4C), and 4-week downhill running exercise group (4E). The downhill running protocol for rats in the exercise groups involved slope of -16°, running speed of 16 m/min, training duration of 90 min, and 5 training sessions per week. Twenty-four hours after the final session of training, all the four groups of rats underwent an exhaustion treadmill exercise. After resting for 48 h, all the rats were euthanized and their gastrocnemius muscles were harvested for analysis. HE staining was used to measure the cross-sectional area (CSA) and diameter of muscle fibers. Transmission electron microscope was used to observe the ultrastructural changes in muscle fibers. Purithromycin surface labeling translation method was used to measure protein synthesis rate. Immunofluorescence double labeling was used to detect the colocalization levels of lysosomal-associated membrane protein 2 (Lamp2)-leucyl-tRNA synthetase (LARS) and Lamp2-mammalian target of rapamycin (mTOR). Western blot was used to measure the protein expression levels of myosin heavy chain (MHC) IIb and LARS, as well as the phosphorylation levels of mTOR, p70 ribosomal protein S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1). The results showed that, compared with the 2C group rats, the 2E group rats showed significant increases in wet weight of gastrocnemius muscle, wet weight/body weight ratio, running distance, running time, pre- and post-exercise blood lactate levels, myofibrillar protein content, colocalization levels of Lamp2-LARS and Lamp2-mTOR, and LARS protein expression. Besides these above changes, compared with the 4C group, the 4E group further exhibited significantly increased fiber CSA, fiber diameter, protein synthesis rate, and phosphorylation levels of mTOR, p70S6K, and 4E-BP1. Compared with the quiet control groups, the exercise groups exhibited ultrastructural damage of rat gastrocnemius muscle, which was more pronounced in the 4E group. These findings suggest that eccentric treadmill exercise may promote mTOR translocation to lysosomal membrane, activating mTOR signaling via up-regulating LARS expression. This, in turn, increases protein synthesis rate through the mTOR-p70S6K-4E-BP1 signaling pathway, promoting protein deposition and inducing adaptive skeletal muscle hypertrophy. Although the ultrastructural changes of skeletal muscle are more pronounced, the relatively long training cycles during short-term exercise periods have a more significant effect on promoting gastrocnemius muscle protein synthesis and adaptive hypertrophy.
Animals
;
Rats, Sprague-Dawley
;
Physical Conditioning, Animal/physiology*
;
Rats
;
Muscle, Skeletal/metabolism*
;
TOR Serine-Threonine Kinases/metabolism*
;
Male
;
Hypertrophy
;
Adaptation, Physiological/physiology*
;
Adaptor Proteins, Signal Transducing/metabolism*
;
Ribosomal Protein S6 Kinases, 70-kDa/metabolism*
;
Intracellular Signaling Peptides and Proteins

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