Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
Add more filters











Publication year range
1.
Life Sci ; 355: 122973, 2024 Oct 15.
Article in English | MEDLINE | ID: mdl-39142510

ABSTRACT

AIMS: Microglial cells are integral to the pathogenesis of Alzheimer's disease (AD). The observed sex disparity in AD prevalence, with a notable predominance in women, implies a potential influence of sex hormones, such as androgens, on disease mechanisms. Despite this, the specific effects of androgens on microglia remain unclear. This study is designed to delineate the interplay between androgens and the survival and inflammatory profile of microglial cells, as well as to explore their contribution to the progression of AD. METHODS AND KEY FINDINGS: To create a chronic androgen deficiency model, 3-month-old wild-type (WT) mice and APP/PS1 mice underwent bilateral orchiectomy (ORX), with age-matched sham-operated controls. Cognitive and memory were evaluated at 5 and 12 months, paralleled by assessments of amyloid-beta (Aß) and microglial morphology in hippocampal and cortical areas. The ORX treatment in mice resulted in diminished microglial populations and morphological alterations, alongside an increase in Aß plaques and a concomitant decline in cognitive performance that exacerbated over time. In vitro, dihydrotestosterone (DHT) was found to stimulate microglial proliferation and ameliorate Aß1-42-induced apoptosis. SIGNIFICANCE: These findings suggested that androgens may exert a protective role, maintaining the normal proliferation and functionality of microglial cells. This preservation could potentially slow the progression of AD. As a result, our study provided a conceptual framework for the development of novel therapeutic strategies for AD.


Subject(s)
Alzheimer Disease , Androgens , Mice, Transgenic , Microglia , Animals , Microglia/pathology , Microglia/metabolism , Microglia/drug effects , Alzheimer Disease/pathology , Alzheimer Disease/metabolism , Male , Mice , Androgens/pharmacology , Androgens/metabolism , Androgens/deficiency , Orchiectomy , Amyloid beta-Peptides/metabolism , Mice, Inbred C57BL , Dihydrotestosterone/pharmacology , Disease Models, Animal , Hippocampus/pathology , Hippocampus/metabolism , Apoptosis/drug effects , Cell Proliferation/drug effects , Age Factors , Plaque, Amyloid/pathology , Plaque, Amyloid/metabolism
2.
Immunol Invest ; : 1-17, 2024 Jul 23.
Article in English | MEDLINE | ID: mdl-39042045

ABSTRACT

BACKGROUND: Allergic rhinitis (AR) is a non-infectious inflammatory disease of the nasal mucosa mediated by IgE and involving a variety of immune cells such as mast cells. In previous studies, AR was considered as an isolated disease of the immune system. However, recent studies have found that the nervous system is closely related to the development of AR. Bidirectional communication between the nervous and immune systems plays an important role in AR. SUMMARY: The nervous system and immune system depend on the anatomical relationship between nerve fibers and immune cells, as well as various neurotransmitters, cytokines, inflammatory mediators, etc. to produce bidirectional connections, which affect the development of AR. KEY MESSAGES: This article reviews the impact of neuro-immune interactions in AR on the development of AR, including neuro-immune cell units.

3.
Brain Behav Immun ; 120: 499-512, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38944162

ABSTRACT

The gut microbiota and neurological development of neonatal mice are susceptible to environmental factors that may lead to altered behavior into adulthood. However, the role that changed gut microbiota and neurodevelopment early in life play in this needs to be clarified. In this study, by modeling early-life environmental changes by cross-fostering BALB/c mice, we revealed the effects of the environment during the critical period of postnatal development on adult social behavior and their relationship with the gut microbiota and the nervous system. The neural projections exist between the ascending colon and oxytocin neurons in the paraventricular nuclei (PVN), peripheral oxytocin levels and PVN neuron numbers decreased after cross-fostering, and sex-specific alteration in gut microbiota and its metabolites may be involved in social impairments and immune imbalances brought by cross-fostering via the gut-brain axis. Our findings also suggest that social cognitive impairment may result from a combination of PVN oxytocinergic neurons, gut microbiota, and metabolites.


Subject(s)
Brain-Gut Axis , Gastrointestinal Microbiome , Mice, Inbred BALB C , Neurons , Oxytocin , Paraventricular Hypothalamic Nucleus , Social Behavior , Animals , Gastrointestinal Microbiome/physiology , Mice , Oxytocin/metabolism , Male , Female , Paraventricular Hypothalamic Nucleus/metabolism , Brain-Gut Axis/physiology , Neurons/metabolism , Brain/metabolism , Behavior, Animal/physiology , Colon/metabolism , Colon/microbiology , Animals, Newborn
4.
J Psychiatry Neurosci ; 49(3): E192-E207, 2024.
Article in English | MEDLINE | ID: mdl-38816029

ABSTRACT

BACKGROUND: Recent studies have identified empathy deficit as a core impairment and diagnostic criterion for people with autism spectrum disorders; however, the improvement of empathy focuses primarily on behavioural interventions without the target regulation. We sought to compare brain regions associated with empathy-like behaviours of fear and pain, and to explore the role of the oxytocin-oxytocin receptor system in fear empathy. METHODS: We used C57BL mice to establish 2 models of fear empathy and pain empathy. We employed immunofluorescence histochemical techniques to observe the expression of c-Fos throughout the entire brain and subsequently quantified the number of c-Fos-positive cells in different brain regions. Furthermore, we employed chemogenetic technology to selectively manipulate these neurons in Oxt-Cre-/+ mice to identify the role of oxytocin in this process. RESULTS: The regions activated by fear empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, paraventricular nucleus (PVN), lateral habenula, and ventral and dorsal hippocampus. The regions activated by pain empathy were the anterior cingulate cortex, basolateral amygdala, nucleus accumbens, and lateral habenula. We found that increasing the activity of oxytocin neurons in the PVN region enhanced the response to fear empathy. This enhancement may be mediated through oxytocin receptors. LIMITATIONS: This study included only male animals, which restricts the broader interpretation of the findings. Further investigations on circuit function need to be conducted. CONCLUSION: The brain regions implicated in the regulation of fear and pain empathy exhibit distinctions; the activity of PVN neurons was positively correlated with empathic behaviour in mice. These findings highlight the role of the PVN oxytocin pathway in regulating fear empathy and suggest the importance of oxytocin signalling in mediating empathetic responses.


Subject(s)
Empathy , Fear , Mice, Inbred C57BL , Neurons , Oxytocin , Paraventricular Hypothalamic Nucleus , Animals , Oxytocin/metabolism , Male , Paraventricular Hypothalamic Nucleus/metabolism , Fear/physiology , Empathy/physiology , Neurons/metabolism , Mice , Receptors, Oxytocin/metabolism , Proto-Oncogene Proteins c-fos/metabolism , Pain/physiopathology , Pain/psychology , Mice, Transgenic
5.
J Epidemiol Glob Health ; 14(2): 433-443, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38353918

ABSTRACT

PURPOSE: This study aims to raise awareness of the disparities in survival predictions among races in head and neck cancer (HNC) patients by developing and validating population-based prognostic models specifically tailored for Taiwanese and Asian populations. METHODS: A total of 49,137 patients diagnosed with HNCs were included from the Taiwan Cancer Registry (TCR). Six prognostic models, divided into three categories based on surgical status, were developed to predict both overall survival (OS) and cancer-specific survival using the registered demographic and clinicopathological characteristics in the Cox proportional hazards model. The prognostic models underwent internal evaluation through a tenfold cross-validation among the TCR Taiwanese datasets and external validation across three primary racial populations using the Surveillance, Epidemiology, and End Results database. Predictive performance was assessed using discrimination analysis employing Harrell's c-index and calibration analysis with proportion tests. RESULTS: The TCR training and testing datasets demonstrated stable and favorable predictive performance, with all Harrell's c-index values ≥ 0.7 and almost all differences in proportion between the predicted and observed mortality being < 5%. In external validation, Asians exhibited the best performance compared with white and black populations, particularly in predicting OS, with all Harrell's c-index values > 0.7. CONCLUSIONS: Survival predictive disparities exist among different racial groups in HNCs. We have developed population-based prognostic models for Asians that can enhance clinical practice and treatment plans.


Subject(s)
Epidemiological Models , Head and Neck Neoplasms , Routinely Collected Health Data , Head and Neck Neoplasms/epidemiology , Head and Neck Neoplasms/mortality , Taiwan , Survival Analysis , Humans , Male , Female , Middle Aged , Racial Groups/statistics & numerical data
6.
CNS Neurosci Ther ; 29(12): 3980-3994, 2023 12.
Article in English | MEDLINE | ID: mdl-37402694

ABSTRACT

AIMS: As the ovaries age and women transition to menopause and postmenopause, reduced estradiol levels are associated with anxiety and depression. Exercise contributes to alleviate anxiety and depression and the bone-derived hormone osteocalcin has been reported to be necessary to prevent anxiety-like behaviors. The aim of this study was to investigate the effects of exercise on anxiety behaviors in climacteric mice and whether it was related to osteocalcin. METHODS: Menopausal mouse model was induced by intraperitoneal injection of 4-vinylcyclohexene diepoxide (VCD). Open field, elevated plus maze, and light-dark tests were used to detect anxious behavior in mice. The content of serum osteocalcin was measured and its correlation with anxiety behavior was analyzed. BRDU and NEUN co-localization cells were detected with immunofluorescence. Western blot was applied to obtain apoptosis-related proteins. RESULTS: The VCD mice showed obvious anxiety-like behaviors and 10 weeks of treadmill exercise significantly ameliorated the anxiety and increased circulating osteocalcin in VCD mice. Exercise increased the number of BRDU and NEUN co-localization cells in hippocampal dentate gyrus, reduced the number of impaired hippocampal neurons, inhibited the expression of BAX, cleaved Caspase3, and cleaved PARP, promoted the expression of BCL-2. Importantly, circulating osteocalcin levels were positively associated with the improvements of anxiety, the number of BRDU and NEUN co-localization cells in hippocampal dentate gyrus and negatively related to impaired hippocampal neurons. CONCLUSION: Exercise ameliorates anxiety behavior, promotes hippocampal dentate gyrus neurogenesis, and inhibits hippocampal cell apoptosis in VCD-induced menopausal mice. They are related to circulating osteocalcin, which are increased by exercise.


Subject(s)
Anxiety , Neuroprotection , Humans , Mice , Animals , Female , Osteocalcin/metabolism , Osteocalcin/pharmacology , Bromodeoxyuridine/metabolism , Anxiety/chemically induced , Menopause , Hippocampus/metabolism , Neurogenesis/physiology
7.
J Bone Miner Metab ; 41(5): 606-620, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37418073

ABSTRACT

INTRODUCTION: The increase of ATP concentration in the extracellular space represents one of the effective signals that stimulate the physiological activities of cells when the bone is exposed to external mechanical stimulation such as stretching and shear stress force throughout life. However, the effects of ATP on osteoblast differentiation and related mechanisms are not well understood. MATERIALS AND METHODS: In this study, the roles of extracellular ATP on osteoblast differentiation, intracellular calcium ([Ca2+]i) levels, metabolomics, and the expression of proteins related to energy metabolism were investigated. RESULTS: Our results showed that 100 µM extracellular ATP initiated intracellular calcium ([Ca2+]i) oscillations via the calcium-sensing receptor (P2R) and promoted the differentiation of MC3T3-E1 cells. Metabolomics analysis showed that the differentiation of MC3T3-E1 cells depended on aerobic oxidation, but little glycolysis. Moreover, the differentiation of MC3T3-E1 cells and aerobic oxidation were suppressed with the inhibition of AMP-activated protein kinase (AMPK). CONCLUSION: These results indicate that calcium oscillations triggered by extracellular ATP can activate aerobic oxidation through AMPK-related signaling pathways and thus promote osteoblast differentiation.


Subject(s)
Calcium Signaling , Calcium , Calcium/metabolism , AMP-Activated Protein Kinases/metabolism , AMP-Activated Protein Kinases/pharmacology , Cell Differentiation , Osteoblasts/metabolism , Adenosine Triphosphate/metabolism
8.
Int J Mol Sci ; 24(5)2023 Mar 05.
Article in English | MEDLINE | ID: mdl-36902420

ABSTRACT

During bone remodeling, high extracellular calcium levels accumulated around the resorbing bone tissue as soon as the activation of osteoclasts. However, if and how calcium is involved in the regulation of bone remodeling remains unclear. In this study, the effect of high extracellular calcium concentrations on osteoblast proliferation and differentiation, intracellular calcium ([Ca2+]i) levels, metabolomics, and the expression of proteins related to energy metabolism were investigated. Our results showed that high extracellular calcium levels initiated a [Ca2+]i transient via the calcium-sensing receptor (CaSR) and promoted the proliferation of MC3T3-E1 cells. Metabolomics analysis showed that the proliferation of MC3T3-E1 cells was dependent on aerobic glycolysis, but not the tricarboxylic acid cycle. Moreover, the proliferation and glycolysis of MC3T3-E1 cells were suppressed following the inhibition of AKT. These results indicate that calcium transient triggered by high extracellular calcium levels activated glycolysis via AKT-related signaling pathways and ultimately promoted the proliferation of osteoblasts.


Subject(s)
Calcium , Osteoblasts , Proto-Oncogene Proteins c-akt , Calcium/metabolism , Calcium, Dietary/pharmacology , Cell Differentiation , Cell Proliferation , Osteoblasts/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Animals , Mice , Cell Line
9.
J. physiol. biochem ; 78(1): 61-72, feb. 2022.
Article in English | IBECS | ID: ibc-215873

ABSTRACT

Weight-bearing training, as one of resistance exercises, is beneficial to bone health. Myostatin (MSTN) is a negative regulator of skeletal muscle growth and development. Animals lacking MSTN show increased bone mineral density (BMD). The aim of this study was to investigate the preventive effect of weight-bearing training on bone loss in ovariectomized rats and whether it was related to MSTN. In this study, the rats were randomly assigned to three group: Sham-ovariectomized (Sham), ovariectomized (OVX), ovariectomized and weight-bearing training (OWT). The rats in the OWT group ran at 20-m/min bearing with 35% of their body weight for 6 days/week. After 10 weeks, compared with the OVX group, weight-bearing training increased the BMD of total femur and trabecular bone by 8.13% and 57.44%, respectively. The OVX-induced destruction of bone microarchitecture including the thickness and number of trabeculae and bone volume fraction was all significantly improved (9.26%, 47.68%, 63.03%) in the OWT group. The OVX-induced degradation of bone mechanical properties was significantly enhanced in the OWT group (maximum load increased by 35.46%, stiffness increased by 89.19%, energy absorption increased by 53.4%; elastic modulus increased by 26.3%). Ten-week weight-bearing training also significantly upregulated the mRNA and protein expression of Wnt1 and β-catenin, which is crucial in bone development. Compared with the Sham group, MSTN in serum and muscle increased in the OVX group, but it decreased in the OWT group compared with the OVX group. Its receptor ActRIIB and downstream molecules Smad2/3 in the OVX group were downregulated in bone by weight-bearing training. The results indicated that MSTN is an important myokine for weight-bearing training to attenuate bone loss in ovariectomized rats. (AU)


Subject(s)
Animals , Rats , Myostatin , Bone Density , Osteoporosis/prevention & control , Weight-Bearing , Femur , Ovariectomy
10.
J Physiol Biochem ; 78(1): 61-72, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34453705

ABSTRACT

Weight-bearing training, as one of resistance exercises, is beneficial to bone health. Myostatin (MSTN) is a negative regulator of skeletal muscle growth and development. Animals lacking MSTN show increased bone mineral density (BMD). The aim of this study was to investigate the preventive effect of weight-bearing training on bone loss in ovariectomized rats and whether it was related to MSTN. In this study, the rats were randomly assigned to three group: Sham-ovariectomized (Sham), ovariectomized (OVX), ovariectomized and weight-bearing training (OWT). The rats in the OWT group ran at 20-m/min bearing with 35% of their body weight for 6 days/week. After 10 weeks, compared with the OVX group, weight-bearing training increased the BMD of total femur and trabecular bone by 8.13% and 57.44%, respectively. The OVX-induced destruction of bone microarchitecture including the thickness and number of trabeculae and bone volume fraction was all significantly improved (9.26%, 47.68%, 63.03%) in the OWT group. The OVX-induced degradation of bone mechanical properties was significantly enhanced in the OWT group (maximum load increased by 35.46%, stiffness increased by 89.19%, energy absorption increased by 53.4%; elastic modulus increased by 26.3%). Ten-week weight-bearing training also significantly upregulated the mRNA and protein expression of Wnt1 and ß-catenin, which is crucial in bone development. Compared with the Sham group, MSTN in serum and muscle increased in the OVX group, but it decreased in the OWT group compared with the OVX group. Its receptor ActRIIB and downstream molecules Smad2/3 in the OVX group were downregulated in bone by weight-bearing training. The results indicated that MSTN is an important myokine for weight-bearing training to attenuate bone loss in ovariectomized rats.


Subject(s)
Bone Density , Myostatin , Osteoporosis/prevention & control , Weight-Bearing , Animals , Female , Femur/metabolism , Myostatin/genetics , Myostatin/metabolism , Ovariectomy , Rats
11.
Ultrasonics ; 113: 106360, 2021 May.
Article in English | MEDLINE | ID: mdl-33561635

ABSTRACT

Low-intensity pulsed ultrasound (LIPUS) with an intensity (spatial average temporal average, ISATA) of 30 mW/cm2 has been widely proved to be effective on impaired bone healing, but showing little effectiveness in the treatment of osteoporosis. We hypothesized that the intensity of LIPUS may be a key factor in explaining this difference, thus two intensity levels, the widely used 30 mW/cm2 and a higher 150 mW/cm2, were used to simultaneously treat osteoporosis and osteoporotic bone defect in ovariectomized (OVX) rats with a 1-mm drill hole on their left femurs.Results showed that 150 mW/cm2 LIPUS augmented the healing rate of the drill hole than 30 mW/cm2 after 3-week LIPUS treatment, although did not further enhance the healing rate after 6-week LIPUS treatment. For ameliorating osteoporosis, 150 mW/cm2 LIPUS achieved more advantages over 30 mW/cm2 in improving bone density, microstructure and biomechanics 6 weeks after LIPUS intervention. In conclusion, LIPUS with an intensity of 30 mW/cm2 was sufficient to facilitate bone defect healing, but a higher intensity can be considered as a rapid trigger for osteoporotic bone repair. In addition, improving the intensity of LIPUS may be a potentially effective consideration for alleviation of osteoporosis, and the LIPUS regimen in the treatment of osteoporosis remains to be optimized.


Subject(s)
Osteoporosis/therapy , Osteoporotic Fractures/therapy , Ultrasonic Waves , Animals , Bone Density , Disease Models, Animal , Female , Femur , Fracture Healing , Ovariectomy , Rats , Rats, Sprague-Dawley
12.
Ultrasound Med Biol ; 46(1): 108-121, 2020 01.
Article in English | MEDLINE | ID: mdl-31587953

ABSTRACT

This study investigated the effects of low-intensity pulsed ultrasound (LIPUS) of different spatial-average-temporal-average intensity (ISATA) ranging from 15-150 mW/cm2 on the treatment of osteoporosis in ovariectomized rats. Healthy 3-mo-old female Sprague-Dawley rats were randomly divided into nine groups (n = 12 per group): sham-ovariectomy (OVX) control group, OVX control group and OVX groups treated with LIPUS at seven different intensities (ISATA: 15, 30, 50, 75, 100, 125 and 150 mW/cm2, respectively). LIPUS was applied to bilateral femurs 12 wk post-OVX for 20 min/d for 6 wk. Micro-computed tomography, biomechanical tests, serum biochemical analysis and grip strength tests were performed to evaluate the therapeutic effects of LIPUS at different intensities. Results revealed that LIPUS intensity yielded strong correlations with bone mineral density and bone microstructure (R2 = 0.57-0.83) and bone mechanical strength (R2 = 0.80-0.97), and that the intensity of 150 mW/cm2, instead of the 30 mW/cm2 widely used in bone fracture healing, was most effective in maintaining bone mass among all the LIPUS signals between 15 and 150 mW/cm2. This suggests that higher ultrasound intensity (i.e., 150 mW/cm2) may be more effective than lower intensity in mitigation of osteopenia and osteoporosis.


Subject(s)
Osteoporosis/therapy , Ultrasonic Therapy/methods , Animals , Female , Ovariectomy , Random Allocation , Rats , Rats, Sprague-Dawley
13.
J Bone Miner Metab ; 38(1): 14-26, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31414284

ABSTRACT

INTRODUCTION: Menopause can lead to osteoporosis, which is characterized by destruction of bone microstructure, poor mechanical properties, and prone to fracture. LIPUS can effectively promote bone formation and fracture healing. MSTN is a transforming growth factor-ß family member that acts as a negative regulator of skeletal muscle growth. A MSTN deficiency also has a positive effect on bone formation. However, whether LIPUS could inhibit bone loss and promote healing of bone injury of menopause through the inhibition of the MSTN signaling pathway has not been previously investigated. We herein investigated the effects of LIPUS on bone architecture, mechanical properties, the healing of bone defects, and its potential molecular mechanisms in ovariectomized rats. MATERIALS AND METHODS: The rats were randomly divided into three groups: sham ovariectomized group (Sham), ovariectomized model group (OVX), ovariectomized model with LIPUS therapy group (OVX + LIPUS). The OVX + LIPUS rats were treated with LIPUS (1.5 MHz, 30 mW/cm2) on the femur for 20 min/day that lasted for 19 days. RESULTS: LIPUS effectively improved the bone microstructure, increased mechanical properties and promoted the healing of bone defects in ovariectomized rats. Moreover, LIPUS effectively decreased the MSTN content in serum and quadriceps muscle in ovariectomized rats, and inhibited the expression of MSTN downstream signaling molecules and activated the Wnt signaling pathway in the femur. CONCLUSIONS: The present study shows that LIPUS improved osteoporosis and promoted bone defect healing in the ovariectomized rats may through the inhibition of the MSTN signal pathway.


Subject(s)
Bone Resorption/prevention & control , Myostatin/metabolism , Ovariectomy , Signal Transduction , Ultrasonic Waves , Alkaline Phosphatase/blood , Animals , Biomechanical Phenomena , Body Weight , Bone Resorption/blood , Female , Femur/diagnostic imaging , Femur/physiology , Gene Expression Regulation , Muscle Fibers, Skeletal/pathology , Muscles/pathology , Organ Size , Rats, Sprague-Dawley , Tartrate-Resistant Acid Phosphatase/blood , Uterus/pathology , Wnt Signaling Pathway
14.
Exp Ther Med ; 16(4): 3686-3693, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30233727

ABSTRACT

Myostatin (MSTN) is not only a key negative regulator of skeletal muscle secretion, however is also an endocrine factor that is transmitted to bone. To investigate the effect and possible mechanism of weight-bearing treadmill running on bone with poorly controlled Type 1 diabetes, rats were randomly divided into three groups: Normal control (NC), diabetic mellitus (DM) and diabetic exercise training groups (DM-WTR). The DM-WTR rats were trained with weight-bearing running. The results demonstrated that the levels of serum insulin, body weight, bone mass, muscle mass, grip strength, and serum calcium in the DM-WTR rats were significantly increased, whereas the levels of blood glucose, alkaline phosphatase, and tartrate-resistant acid phosphatase were markedly reduced in the DM-WTR rats compared with the DM rats. Weight-bearing running inhibited streptozocin (STZ)-induced MSTN mRNA and protein expression in the diabetic rats. The mRNA and protein expression levels of activin type IIB receptor and mothers against decapentaplegic homolog 2/3 and its phosphorylation in femur DM-WTR rats were reduced compared with DM rats. In addition, weight-bearing running enhanced the STZ-induced Wnt and ß-catenin expression levels and reduced the STZ-induced glycogen synthase kinase (GSK)-3ß expression in diabetic rats' femora. In conclusion, the results suggested that weight-bearing running could partially ameliorate STZ-induced femur atrophy via MSTN downregulation, and this may be associated with the inactivation of Activin A Receptor Type 2B/Smad2/3 signaling pathways and the activation of the Wnt/GSK3ß/ß-catenin signaling pathway. Further studies are needed to verify these conclusions.

15.
Mol Med Rep ; 18(1): 1127-1133, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29845230

ABSTRACT

Diabetic muscle atrophy causes a reduction of skeletal muscle size and strength, which affects normal daily activities. However, pulsed electromagnetic fields (PEMFs) can retard the atrophy of type II fibers (ActRIIB) in denervated muscles. Therefore, the purpose of the present study was to determine whether PEMFs can alleviate streptozotocin (STZ)­induced diabetic muscle atrophy. To do this, 40 Sprague­Dawley (SD) rats were randomly divided into four groups (n=10 per group): The normal control group (NC; nondiabetic rats without treatment); the diabetic mellitus group (DM; STZ­induced rats without treatment); the diabetic insulin­treated group (DT; diabetic rats on insulin treatment, 6­8 U/d twice a day for 6 weeks) as a positive control; and the diabetic PEMFs therapy group (DP; diabetic rats with PEMFs exposure treatment, 15 Hz, 1.46 mT, 30 min/day for 6 weeks). Body weight, muscle strength, muscle mass and serum insulin level were significantly increased in the DP group compared with the DM group. PEMFs also decreased the blood glucose level and altered the activity of metabolic enzymes. PEMFs significantly increased the cross­sectional area of muscle fiber. In addition, PEMFs significantly activated protein kinase B (Akt) and mammalian target of rapamycin (mTOR), and inhibited the activity of myostatin (MSTN), ActRIIB and forkhead box protein O1 (FoxO1) compared with the DM group. Thus indicating that the Akt/mTOR and Akt/FoxO1 signaling pathways may be involved in the promotion of STZ­induced diabetic muscle atrophy by PEMFs. The results of the present study suggested that PEMFs stimulation may alleviate diabetic muscle atrophy in the STZ model, and that this is associated with alterations in multiple signaling pathways in which MSTN may be an integral factor. MSTN­associated signaling pathways may provide therapeutic targets to attenuate severe diabetic muscle wasting.


Subject(s)
Diabetes Complications/therapy , Diabetes Mellitus, Experimental/therapy , Electromagnetic Fields , Magnetic Field Therapy , Muscular Atrophy/therapy , Animals , Diabetes Complications/metabolism , Diabetes Complications/pathology , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Male , Muscle Proteins/metabolism , Muscle Strength , Muscular Atrophy/etiology , Muscular Atrophy/metabolism , Muscular Atrophy/pathology , Nerve Tissue Proteins/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Sprague-Dawley , Signal Transduction , TOR Serine-Threonine Kinases/metabolism
16.
Skelet Muscle ; 7(1): 29, 2017 12 22.
Article in English | MEDLINE | ID: mdl-29273088

ABSTRACT

BACKGROUND: Type 1 diabetes mellitus (T1DM) induces serious skeletal muscle atrophy. Low-intensity pulsed ultrasound (LIPUS) is a common treatment for skeletal muscle injury and is effective in accelerating the rate of muscle growth. However, to the best of our knowledge, whether LIPUS can improve skeletal muscle atrophy in type 1 diabetic rats has not been investigated. METHODS: The rats were randomly divided into four groups: the normal control group (NC); the sham-treated diabetic control group (DC); the diabetic, insulin-treated group (DI) as a positive control; and the diabetic LIPUS therapy group (DL). The DL rats were treated with LIPUS (1 MHz, 30 mW/cm2) on the gastrocnemius for 20 min/day. RESULTS: After 6 weeks, the rats in the DC group showed severe muscle atrophy. However, LIPUS significantly improved type 1 diabetes-induced muscle atrophy, as evidenced by significantly enhanced muscle cross-sectional area, muscle mass, and strength. Moreover, compared with the DC group, LIPUS significantly activated Akt and upregulated the expression of mTOR, and LIPUS downregulated the expression of MSTN, its receptor ActRIIB, and FoxO1. CONCLUSIONS: These results indicate that LIPUS improved muscle atrophy induced by type 1 diabetes, and the MSTN/Akt/mTOR&FoxO1 signaling pathway may play a role in this improvement.


Subject(s)
Diabetes Mellitus, Type 1/complications , Muscular Atrophy/metabolism , Muscular Atrophy/therapy , Ultrasonic Waves , Animals , Disease Models, Animal , Gene Expression , Male , Muscle Strength , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Muscular Atrophy/etiology , RNA, Messenger/metabolism , Rats, Sprague-Dawley , Signal Transduction
17.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 33(5): 436-440, 2017 May 08.
Article in Chinese | MEDLINE | ID: mdl-29926589

ABSTRACT

OBJECTIVE: To investigate the effects of climb ladder and aerobic treadmill exercise on learning memory ability in diabetic rats and explore its possible mechanisms. METHODS: Forty male rats were randomly divided into normal control group (NC), diabetic control group (DC), diabetic loading ladder group (DL) and diabetic aerobic treadmill group (DA), diabetes was induced by a single intraperitoneal injection of STZ. In the evening, the DL group were trained three cycle (10 times/cycle) with weight-bearing climbing ladder, 2 min intervals, 6 days/week, lasted for six weeks. The DA group was trained on a motor-driven treadmill at a speed of 20 m/min (0 incline), 30 min/day, 6 days/week, lasted for six weeks. Morris water maze was used to detect the learning and memory ability of rats after modeling success and after exercise intervention. After the last water maze test, the rats were killed to obtain the hippocampus. RT-QPCR was used to detect the gene expressions of brain derived neurophic factor (BDNF), tropomyosin receptor kinase B (TrkB) and cAMP-response element binding protein (CREB). RESULTS: Compared with NC group, the expressions of BDNF and CREB gene in hippocampus of DC group and the learning and memory ability were significantly decreased. Compared with DC group, the expression of BDNF and CREB in hippocampus of DL and DA rats was significantly up-regulated and the learning ability was significantly increased. The TrkB gene of hippocampus in DL rats was significantly up-regulated and the spatial memory ability was significantly improved. Compared with the DA group, the TRKB and CREB genes in the hippocampus of DL group were significantly up-regulated. CONCLUSIONS: Aerobic treadmill exercise and weight-bearing ladder exercise have a positive effect on the learning ability of diabetic rats, while the weight-bearing ladder exercise improves the memory ability of diabetic rats better than aerobic exercise. These effects may be related to the up-regulation of BDNF/TrkB/CREB signaling pathway.


Subject(s)
Diabetes Mellitus, Experimental , Learning , Memory , Physical Conditioning, Animal , Weight-Bearing , Animals , Brain-Derived Neurotrophic Factor/metabolism , Cyclic AMP Response Element Modulator/metabolism , Hippocampus/metabolism , Male , Rats , Receptor, trkB/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL