ABSTRACT
Textbook question answering (TQA) task aims to infer answers for given questions from a multimodal context, including text and diagrams. The existing studies have aggregated intramodal semantics extracted from a single modality but have yet to capture the intermodal semantics between different modalities. A major challenge in learning intermodal semantics is maintaining lossless intramodal semantics while bridging the gap of semantics caused by heterogeneity. In this article, we propose an intermodal relation-aware heterogeneous graph network (IMR-HGN) to extract the intermodal semantics for TQA, which aggregates different modalities while learning features rather than representing them independently. First, we design a multidomain consistent representation (MDCR) to eliminate semantic gaps by capturing intermodal features while maintaining lossless intramodal semantics in multidomains. Furthermore, we present neighbor-based relation inpainting (NRI) to reduce semantic ambiguity via repairing fuzzy relations with correlations of relations. Finally, we propose hierarchical multisemantics aggregation (HMSA) to guarantee the completeness of semantics by aggregating features of nodes and relations with a reconstruction network (RN). Experimental results show that IMR-HGN could extract the intermodal semantics of answers, achieving a 2.16% improvement on the validation set of the TQA dataset and a 3.04% increase on the test set of the AI2D dataset.
ABSTRACT
Impacts occur everywhere, and they pose a serious threat to human health and production safety. Flexible materials with efficient cushioning and energy absorption are ideal candidates to provide protection from impacts. Despite the high demand, the cushioning capacity of protective materials is still limited. In this study, an integrated bionic strategy is proposed, and a bioinspired structural composite material with highly cushioning performance is developed on the basis of this strategy. The results demonstrated that the integrated bionic material, an S-spider web-foam, has excellent energy storage and dissipation as well as cushioning performance. Under impact loading, S-spider web-foam can reduce peak impact forces by a factor of 3.5 times better than silicone foam, achieving unprecedented cushioning performance. The results of this study deepen the understanding of flexible cushioning materials and may provide new strategies and inspiration for the preparation of high-performance flexible cushioning materials.
ABSTRACT
Human heel pads commonly undergo cyclic loading during daily activities. Low cyclic loadings such as daily human walking tend to have less effect on the mechanical properties of heel pads. However, the impact of cyclic loading on cushion performance, a vital biomechanical property of heel pads, under engineering test condition remains unexplored. Herein, dynamic mechanical measurements and finite element (FE) simulations were employed to explore this phenomenon. It was found that the wavy collagen fibers in the heel pad will be straightened under cycle compression loading, which resulted in increased stiffness of the heel pad. The stiffness of the heel pads demonstrated an inclination to escalate over a span of 50,000 loading cycles, consequently resulting in a corresponding increase in peak impact force over the same loading cycles. Sustained cyclic loading has the potential to result in the fracturing of the straightened collagen fibers, this collagen breakage may diminish the stiffness of the heel pad, leading to a reduction in peak impact force. This work enhances understanding of the biomechanical functions of human heel pad and may provide potential inspirations for the innovative development of healthcare devices for foot complex.
ABSTRACT
Second-hand smoking evokes inflammation and cardiovascular diseases. Recent evidence has revealed a pivotal role for deranged autophagy in smoke exposure-induced cardiac anomalies. This study evaluated the impact of haploinsufficiency of the mTOR-independent autophagy protein Beclin1 on side-stream smoke exposure-induced cardiac anomalies and mechanism(s) involved. Adult WT and Beclin1 haploinsufficiency (Becn+/-) mice were exposed to cigarette smoke for 1 h daily for 90 days. Echocardiographic, cardiomyocyte function, intracellular Ca2+, autophagy, mitophagy, apoptosis and inflammation were examined. DHE staining was employed to evaluate O2- level. Our data revealed that Beclin1 deficiency exacerbated smoke exposure-induced myocardial anomalies in geometry, fractional shortening, cardiomyocyte function, intracellular Ca2+ handling, TEM ultrastructure, and inflammation along with pronounced apoptosis and O2- production. Side-stream smoke provoked excessive autophagy/mitophagy, mtDNA release, and activation of innate immune response signals cyclic GMP-AMP synthase (cGAS) and its effector - stimulator of interferon genes (STING), the effect was abolished or unaffected by Becn haploinsufficiency. STING phosphorylation was overtly promoted by smoke exposure in Becn+/- mice. Smoke exposure also suppressed phosphorylation of mTOR although it facilitated that of ULK1 in both groups. In vitro data revealed that inhibition of cGAS or STING failed to affect smoke extract-induced mitophagy although they abrogated smoke extract-induced cardiomyocyte dysfunction except cGAS inhibition in Becn+/- mice. These data suggest that Beclin1 is integral in the maintenance of cardiac homeostasis under side-stream smoke exposure via a STING-mediated mechanism.
Subject(s)
Beclin-1/genetics , Haploinsufficiency/genetics , Membrane Proteins/metabolism , Myocardial Contraction , Myocardium/pathology , Tobacco Smoke Pollution , Ventricular Remodeling , Animals , Animals, Newborn , Apoptosis , Autophagy , Autophagy-Related Protein-1 Homolog/metabolism , Beclin-1/deficiency , Biomarkers/metabolism , Biomechanical Phenomena , DNA, Mitochondrial/metabolism , Electrocardiography , Inflammation/pathology , Mice , Mitophagy , Myocardium/ultrastructure , Myocytes, Cardiac/metabolism , Nucleotidyltransferases/metabolism , Organelle Biogenesis , Phosphorylation , Signal Transduction , Superoxides/metabolism , TOR Serine-Threonine Kinases/metabolismABSTRACT
Hypoxia is a common pathological process caused by insufficient oxygen. Long noncoding RNAs (lncRNAs) have been proven to participate in this pathology. Hypoxia is reported to significantly reduce the secretion of tissue inhibitor of metalloproteinase 2 (TIMP2) and TIMP2 induces pheochromocytoma-12 (PC12) cell cycle arrest. Thus, our study aimed to explore the mechanism by which lncRNA maternally expressed gene 3 (MEG3) was implicated in hypoxia-induced PC12 cell injury through TIMP2 promoter methylation. To elucidate the potential biological significance of MEG3 and the regulatory mechanism between MEG3 and TIMP2, a hypoxia-induced PC12 cell injury model was generated. The hypoxia-exposed cells were subjected to a series of overexpression plasmids and short hairpin RNAs, followed by the measurement of levels of MEG3, TIMP2, lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS), Bcl-2-associated X protein, B-cell lymphoma-2, and caspase-3, as well as the changes in MMP, cell proliferation, apoptosis, and cell cycle progression. On the basis of the findings, MEG3 was upregulated in hypoxia-injured PC12 cells. MEG3 recruited methylation proteins DNMT3a, DNMT3b, and MBD1 and accelerated TIMP2 promoter methylation, which in turn inhibited its expression. Moreover, PC12 cells following MEG3 silencing and TIMP2 overexpression exhibited significantly decreased levels of LDH, MDA, and ROS along with cell apoptosis, yet increased SOD and MMP levels, as well as cell cycle entry to the S phase and cell proliferation. In conclusion, MEG3 silencing suppresses hypoxia-induced PC12 cell injury by inhibiting TIMP2 promoter methylation. This study may provide novel therapeutic targets for hypoxia-induced injury.
Subject(s)
Cell Hypoxia/genetics , Gene Expression Regulation/genetics , RNA, Long Noncoding/genetics , Tissue Inhibitor of Metalloproteinase-2/genetics , Animals , DNA Methylation/genetics , PC12 Cells , Promoter Regions, Genetic/genetics , RatsABSTRACT
OBJECTIVE: To investigate the effectiveness of neuromuscular electrical stimulation (NMES) with or without other interventions in improving lower limb activity after chronic stroke. DATA SOURCES: Electronic databases, including PubMed, EMBase, Cochrane Library, PEDro (Physiotherapy Evidence Database), and PsycINFO, were searched from the inception to January 2017. STUDY SELECTION: We selected the randomized controlled trials (RCTs) involving chronic stroke survivors with lower limb dysfunction and comparing NMES or combined with other interventions with a control group of no electrical stimulation treatment. DATA EXTRACTION: The primary outcome was defined as lower limb motor function, and the secondary outcomes included gait speed, Berg Balance Scale, timed Up and Go, 6-minute walk test, Modified Ashworth Scale, and range of motion. DATA SYNTHESIS: Twenty-one RCTs involving 1481 participants were identified from 5759 retrieved articles. Pooled analysis showed that NMES had a moderate but statistically significant benefit on lower limb motor function (standard mean difference 0.42, 95% confidence interval 0.26-0.58), especially when NMES was combined with other interventions or treatment time within either 6 or 12 weeks. NMES also had significant benefits on gait speed, balance, spasticity, and range of motion but had no significant difference in walking endurance after NMES. CONCLUSIONS: NMES combined with or without other interventions has beneficial effects in lower limb motor function in chronic stroke survivors. These data suggest that NMES should be a promising therapy to apply in chronic stroke rehabilitation to improve the capability of lower extremity in performing activities.
Subject(s)
Electric Stimulation Therapy/methods , Hemiplegia/rehabilitation , Stroke Rehabilitation/methods , Stroke/complications , Chronic Disease , Hemiplegia/etiology , Hemiplegia/physiopathology , Humans , Lower Extremity/physiopathology , Physical Therapy Modalities , Range of Motion, Articular , Recovery of Function , Stroke/physiopathology , Treatment Outcome , Walk Test , Walking/physiology , Walking SpeedABSTRACT
Functional electrical stimulation can improve motor function after stroke. The mechanism may involve activity-dependent plasticity and brain remodeling. The aim of our study was to investigate the effectiveness of a patterned electrical stimulation FES mimic to gait in motor recovery among stroke survivors and to investigate possible mechanisms through brain fMRI. Forty-eight subjects were recruited and randomly assigned to a four-channel FES group (n = 18), a placebo group (n = 15), or a dual-channel FES group (n = 15). Stimulation lasted for 30 minutes in each session for 3 weeks. All of the subjects were assessed at baseline and after weeks 1, 2, and 3. The assessments included the Fugl-Meyer Assessment, the Postural Assessment Scale for Stroke Patients, Brunel's Balance Assessment, the Berg Balance Scale, and the modified Barthel Index. Brain fMRI were acquired before and after the intervention. All of the motor assessment scores significantly increased week by week in all the three groups. The four-channel group showed significantly better improvement than the dual-channel group and placebo groups. fMRI showed that fractional anisotropy was significantly increased in both the four-channel and dual-channel groups compared with the placebo group and fiber bundles had increased significantly on the ipsilateral side, but not on the contralateral side in the group given four-channel stimulation. In conclusion, when four-channel FES induces cycling movement of the lower extremities based on a gait pattern, it may be more effective in promoting motor recovery and induce more plastic changes and brain remodeling than two-channel stimulation. This trial is registered with clinical trial registration unique identifier ChiCTR-TRC-11001615.
Subject(s)
Electric Stimulation Therapy/methods , Stroke Rehabilitation/methods , Stroke/therapy , Adult , Aged , Brain/physiopathology , China , Electric Stimulation/methods , Female , Gait/physiology , Humans , Lower Extremity/physiopathology , Male , Middle Aged , Motor Skills/physiology , Physical Therapy Modalities/instrumentation , Recovery of Function/physiologyABSTRACT
OBJECTIVES: Functional electrical stimulation (FES) may induce involuntary exercise and make beneficial effects on vascular dementia (VD) by strengthening the BDNF-pCREB-mediated pathway and hippocampal plasticity. Whether FES improves recognition memory and synaptic plasticity in the prefrontal cortex (PFC) was investigated by establishing a VD model. METHODS: The VD rats were administered with two weeks of voluntary exercise, forced exercise, or involuntary exercise induced with FES. Sham-operated and control groups were also included. The behavioral changes were assessed with the novel object recognition test and novel object location test. The expression levels of key proteins related to synaptic plasticity in the PFC were also detected. RESULTS: All types of exercise improved the rats' novel object recognition index, but only voluntary exercise and involuntary exercise induced with FES improved the novel object location index. Any sort of exercise enhanced the expression of key proteins in the PFC. CONCLUSION: Involuntary exercise induced with FES can improve recognition memory in VD better than forced exercise. The mechanism is associated with increased synaptic plasticity in the PFC. FES may be a useful alternative tool for cognitive rehabilitation.
Subject(s)
Dementia, Vascular , Memory Disorders/etiology , Memory Disorders/rehabilitation , Neuronal Plasticity/physiology , Physical Conditioning, Animal/methods , Prefrontal Cortex/pathology , Recognition, Psychology/physiology , Animals , Dementia, Vascular/complications , Dementia, Vascular/pathology , Dementia, Vascular/rehabilitation , Disease Models, Animal , Exploratory Behavior , Gene Expression Regulation/physiology , Male , Membrane Proteins/metabolism , Nerve Tissue Proteins/metabolism , Rats , Rats, WistarABSTRACT
BACKGROUND The role of nicotinic acetylcholine receptor alpha7 subunit (a7nAchR) in the treatment of acute cerebral ischemia by VNS has not been thoroughly clarified to date. Therefore, this study aimed to investigate the specific role of a7nAchR and explore whether this process is involved in the mechanisms of VNS-induced neuroprotection in rats undergoing permanent middle cerebral artery occlusion (PMCAO) surgery. MATERIAL AND METHODS Rats received a7nAChR antagonist (A) or antagonist placebo injection for control (AC), followed by PMCAO and VNS treatment, whereas the a7nAChR agonist (P) was utilized singly without VNS treatment but only with PMCAO pretreatment. The rats were randomly divided into 6 groups: sham PMCAO, PMCAO, PMCAO+VNS, PMCAO+VNS+A, PMCAO+VNS+AC, and PMCAO+P. Neurological function and cerebral infarct volume were measured to evaluate the level of brain injury at 24 h after PMCAO or PMCAO-sham. Moreover, the related proteins levels of a7nAChR, p-JAK2, and p-STAT3 in the ischemic penumbra were assessed by Western blot analysis. RESULTS Rats pretreated with VNS had significantly improved neurological function and reduced cerebral infarct volume after PMCAO injury (p<0.05). In addition, VNS enhanced the levels of a7nAchR, p-JAK2, and p-STAT3 in the ischemic penumbra (p<0.05). However, inhibition of a7nAchR not only attenuated the beneficial neuroprotective effects induced by VNS, but also decreased levels of p-JAK2 and p-STAT3. Strikingly, pharmacological activation of a7nAchR can partially substitute for VNS-induced beneficial neurological protection. CONCLUSIONS These results suggest that a7nAchR is a pivotal mediator of VNS-induced neuroprotective effects on PMCAO injury, which may be related to suppressed inflammation via activation of the a7nAchR/JAK2 anti-inflammatory pathway.
Subject(s)
Brain Ischemia/therapy , Janus Kinase 2/metabolism , Vagus Nerve Stimulation/methods , alpha7 Nicotinic Acetylcholine Receptor/metabolism , Animals , Brain Injuries/drug therapy , Brain Ischemia/drug therapy , Brain Ischemia/metabolism , Disease Models, Animal , Infarction, Middle Cerebral Artery/metabolism , Infarction, Middle Cerebral Artery/surgery , Inflammation/drug therapy , Male , Neuroprotective Agents/therapeutic use , Rats , Rats, Sprague-Dawley , STAT3 Transcription Factor/metabolism , Vagus Nerve/metabolism , alpha7 Nicotinic Acetylcholine Receptor/agonists , alpha7 Nicotinic Acetylcholine Receptor/antagonists & inhibitorsABSTRACT
Neural stem cells (NSCs) are important in rehabilitation following stroke. Electroacupuncture (EA) treatment has been observed to promote the recovery of neurological functions subsequent to stroke, however, the effects of EA on the proliferation and differentiation of NSCs and its potential mechanisms remain to be elucidated. In the present study, rats, in which a stroke was induced through middle cerebral artery occlusion (MCAO), were treated with EA or control manipulation for 21 days. The modified Neurological Severity score and Morris water maze tests were used to assess the neurological functions of the rats. Bromodeoxyuridine (BrdU)/glial fibrillary acidic protein (GFAP) or BrdU/neuronal marker (NeuN) double immunofluorescence staining were used to examine the proliferation and differentiation of the NSCs. Reverse transcription quantitative polymerase chain reaction (RTqPCR) and western blot analyses were performed to detect the expression levels of Notch1 and Hes1 in the dentate gyrus (DG) of the hippocampus of rats following MCAO. The results demonstrated that EA treatment significantly improved the neurological functional recovery of rats following stroke. A significant increase was observed in the number of BrdU+/GAFP+ and BrdU+/NeuN+ cells in the DG area in the EAtreated rats compared with that of the control group. RTqPCR analysis revealed that EA treatment significantly increased the expression levels of Notch1 and Hes1, which may account for the enhanced proliferation and differentiation of NSCs. In conclusion, to the best of our knowledge, the present study was the first to demonstrate that EA treatment promoted NSC proliferation and neurogenesis in the DG area through the upregulation of Notch signaling following a stroke; therefore, EA may be a useful novel therapeutic strategy in future stroke treatment.
Subject(s)
Cell Proliferation , Dentate Gyrus/cytology , Electroacupuncture , Neural Stem Cells/cytology , Neurogenesis , Stroke/therapy , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Dentate Gyrus/metabolism , Dentate Gyrus/physiopathology , Electroacupuncture/methods , Homeodomain Proteins/genetics , Male , Neural Stem Cells/metabolism , Neural Stem Cells/pathology , Rats , Rats, Sprague-Dawley , Receptor, Notch1/genetics , Stroke/genetics , Stroke/physiopathology , Transcription Factor HES-1 , Up-RegulationABSTRACT
Previous studies have shown that proliferation of endogenous neural precursor cells cannot alone compensate for the damage to neurons and axons. From the perspective of neural plasticity, we observed the effects of functional electrical stimulation treatment on endogenous neural precursor cell proliferation and expression of basic fibroblast growth factor and epidermal growth factor in the rat brain on the infarct side. Functional electrical stimulation was performed in rat models of acute middle cerebral artery occlusion. Simultaneously, we set up a placebo stimulation group and a sham-operated group. Immunohistochemical staining showed that, at 7 and 14 days, compared with the placebo group, the numbers of nestin (a neural precursor cell marker)-positive cells in the subgranular zone and subventricular zone were increased in the functional electrical stimulation treatment group. Western blot assays and reverse-transcription PCR showed that total protein levels and gene expression of epidermal growth factor and basic fibroblast growth factor were also upregulated on the infarct side. Prehensile traction test results showed that, at 14 days, prehension function of rats in the functional electrical stimulation group was significantly better than in the placebo group. These results suggest that functional electrical stimulation can promote endogenous neural precursor cell proliferation in the brains of acute cerebral infarction rats, enhance expression of basic fibroblast growth factor and epidermal growth factor, and improve the motor function of rats.
ABSTRACT
Recent evidence has suggested that cigarette smoking is associated with an increased prevalence of heart diseases. Given that cigarette smoking triggers proinflammatory response via stimulation of the capsaicin-sensitive transient receptor potential cation channel TRPV1, this study was designed to evaluate the effect of an essential α,ß-unsaturated aldehyde from cigarette smoke crotonaldehyde on myocardial function and the underlying mechanism with a focus on TRPV1 and mitochondria. Cardiomyocyte mechanical and intracellular Ca2+ properties were evaluated including peak shortening (PS), maximal velocity of shortening/relengthening (±dL/dt), time-to-PS (TPS), time-to-90% relengthening (TR90), fura-2 fluorescence intensity (FFI), intracellular Ca2+ decay and SERCA activity. Apoptosis and TRPV1 were evaluated using Western blot analysis. Production of reactive oxygen species (ROS) and DNA damage were measured using the intracellular fluoroprobe 5-(6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate and 8-hydroxy-2'-deoxyguanosine (8-OHdG), respectively. Our data revealed that crotonaldehyde interrupted cardiomyocyte contractile and intracellular Ca2+ property including depressed PS, ±dL/dt, ΔFFI and SERCA activity, as well as prolonged TR90 and intracellular Ca2+ decay. Crotonaldehyde exposure increased TRPV1 and NADPH oxidase levels, promoted apoptosis, mitochondrial injury (decreased aconitase activity, PGC-1α and UCP-2) as well as production of ROS and 8-OHdG. Interestingly, crotonaldehyde-induced cardiac defect was obliterated by the ROS scavenger glutathione and the TRPV1 inhibitor capsazepine. Capsazepine (not glutathione) ablated crotonaldehyde-induced mitochondrial damage. Capsazepine, glutathione and the NADPH inhibitor apocynin negated crotonaldehyde-induced ROS accumulation. Our data suggest a role of crotonaldehyde compromises cardiomyocyte mechanical function possibly through a TRPV1- and mitochondria-dependent oxidative stress mechanism.
Subject(s)
Aldehydes/pharmacology , Mitochondria, Heart/drug effects , Myocytes, Cardiac/drug effects , TRPV Cation Channels/metabolism , 8-Hydroxy-2'-Deoxyguanosine , Aconitate Hydratase/metabolism , Animals , Calcium/metabolism , Caspase 3/metabolism , Cells, Cultured , DNA Damage , Deoxyguanosine/analogs & derivatives , Deoxyguanosine/metabolism , Male , Mice, Inbred C57BL , Mitochondria, Heart/metabolism , Myocardial Contraction , Myocytes, Cardiac/physiology , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , SmokingABSTRACT
Huoxue Huayu (HXHY) has been widely used in traditional Chinese medicine (TCM) as a key therapeutic principle for osteoarthritis (OA), and related herbs have been widely prescribed to treat OA in the clinic. The aims of the present study were to explore a multi-target therapy for OA using 10 common HXHY herbs and to investigate their potential applications for treatment of other diseases. A novel computational simulation approach that integrates chemical structure, ligand clusters, chemical space and druglikeness evaluations, as well as docking and network analysis, was used to investigate the properties and effects of the herbs. The compounds contained in the studied HXHY herbs were divided into 10 clusters. Comparison of the chemical properties of these compounds to those of other compounds described in the DrugBank database indicated that the properties of the former are more diverse than those of the latter and that most of the HXHY-derived compounds do not violate the 'Lipinski's rule of five'. Docking analysis allowed for the identification of 39 potential bioactive compounds from HXHY herbs and 11 potential targets for these compounds. The identified targets were closely associated with 49 diseases, including neoplasms, musculoskeletal, nervous system and cardiovascular diseases. Ligandtarget (LT) and ligandtargetdisease (LTD) networks were constructed in order to further elucidate the pharmacological effects of the herbs. Our findings suggest that a number of compounds from HXHY herbs are promising candidates for multtarget therapeutic application in OA and may exert diverse pharmacological effects, affecting additional diseases besides OA.
Subject(s)
Drugs, Chinese Herbal/therapeutic use , Osteoarthritis/drug therapy , Cluster Analysis , Databases, Factual , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/metabolism , Humans , Ligands , Medicine, Chinese Traditional , Molecular Docking Simulation , Plant Extracts/chemistry , Plant Extracts/therapeutic useABSTRACT
The aim of the present study was to examine the effects of acute infrasound exposure on oxidative damage and investigate the underlying mechanisms in rat cardiomyocytes. Neonatal rat cardiomyocytes were cultured and exposed to infrasound for several days. In the study, the expression of CAT, GPx, SOD1, and SOD2 and their activities in rat cardiomyocytes in infrasound exposure groups were significantly decreased compared to those in the various time controls, along with significantly higher levels of O2 (-) and H2O2. Decreased cardiac cell viability was not observed in various time controls. A significant reduction in cardiac cell viability was observed in the infrasound group compared to the control, while significantly increased cardiac cell viability was observed in the infrasound exposure and rosiglitazone pretreatment group. Compared to the control, rosiglitazone significantly upregulated CAT, GPx, SOD1, and SOD2 expression and their activities in rat cardiomyocytes exposed to infrasound, while the levels of O2 (-) or H2O2 were significantly decreased. A potential link between a significant downregulation of PPAR-γ expression in rat cardiomyocytes in the infrasound group was compared to the control and infrasound-induced oxidative stress. These findings indicate that infrasound can induce oxidative damage in rat cardiomyocytes by inactivating PPAR-γ.
Subject(s)
Myocytes, Cardiac/metabolism , Myocytes, Cardiac/radiation effects , Oxidative Stress/physiology , Oxidative Stress/radiation effects , PPAR gamma/biosynthesis , Sound/adverse effects , Animals , Cells, Cultured , Gene Expression Regulation , Male , Rats , Rats, Sprague-DawleyABSTRACT
Angiotensin-(1-7) displays antihypertensive and antiproliferative properties although its effect on cardiac remodeling and hypertrophy in hypertension has not been fully elucidated. The present study was designed to examine the effect of chronic angiotensin-(1-7) treatment on myocardial remodeling, cardiac hypertrophy and underlying mechanisms in spontaneous hypertension. Adult male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were treated with or without angiotensin-(1-7) or the angiotensin-(1-7) antagonist A-779 for 24 weeks. Mean arterial pressure, left ventricular geometry, expression of the hypertrophic markers ANP and ß-MHC, collagen contents (type I and III), collagenase (MMP-1), matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of MMPs-1 (TIMP-1) were evaluated in WKY and SHR rats with or without treatment. Our data revealed that chronic angiotensin-(1-7) treatment significantly suppressed hypertension, left ventricular hypertrophy, expression of ANP and ß-MHC as well as myocardial fibrosis in SHR rats, the effects of which were nullified by the angiotensin-(1-7) receptor antagonist A-779. In addition, angiotensin-(1-7) treatment significantly counteracted hypertension-induced changes in the mRNA expression of MMP-2 and TIMP-1 and collagenase activity, the effects of which were blunted by A-779. In vitro study revealed that angiotensin-(1-7) directly increased the activity of MMP-2 and MMP-9 while decreasing the content of TIMP-1 and TIMP-2. Taken together, our results revealed a protective effect of angiotensin-(1-7) against cardiac hypertrophy and collagen deposition, which may be related to concerted changes in MMPs and TIMPs levels. These data indicated the therapeutic potential of angiotensin-(1-7) in spontaneous hypertension-induced cardiac remodeling.
Subject(s)
Angiotensin I/pharmacology , Antihypertensive Agents/pharmacology , Cardiomegaly/prevention & control , Hypertension/drug therapy , Matrix Metalloproteinase 2/physiology , Matrix Metalloproteinase 9/physiology , Myocardium/pathology , Peptide Fragments/pharmacology , Tissue Inhibitor of Metalloproteinases/physiology , Animals , Atrial Natriuretic Factor/analysis , Atrial Natriuretic Factor/genetics , Blood Pressure/drug effects , Collagen/metabolism , Collagenases/metabolism , Fibrosis , Hypertension/metabolism , Hypertension/pathology , Male , Matrix Metalloproteinase 2/analysis , Matrix Metalloproteinase 9/analysis , Myocardium/metabolism , Myosin Heavy Chains/analysis , Myosin Heavy Chains/genetics , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Tissue Inhibitor of Metalloproteinases/analysisABSTRACT
This study was designed to examine the effect of infrasound exposure (5 Hz at 130 dB) on whole-cell L-type Ca2+ currents (WLCC) in rat ventricular myocytes and the underlying mechanism(s) involved. Thirty-two adult Sprague-Dawley rats were randomly assigned to infrasound exposure and control groups. [Ca2+](i), WLCC, mRNA expression of the a(1c) subunit of L-type Ca2+ channels (LCC), and SERCA2 protein were examined on day 1, 7, and 14 after initiation of infrasound exposure. Fluo-3/AM fluorescence and the laser scanning confocal microscope techniques were used to measure [Ca2+](i) in freshly isolated ventricular myocytes. The Ca2+ fluorescence intensity (FI), denoting [Ca2+](i) in cardiomyocytes, was significantly elevated in a time-dependent manner in the exposure groups. There was a significant increase in WLCC in the 1-day group and a further significant increase in the 7- and 14-day groups. LCC mRNA expression measured by RT-PCR revealed a significant rise in the 1-day group and a significant additional rise in the 7- and 14-day groups compared with control group. SERCA2 expression was significantly upregulated in the 1-day group followed by an overt decrease in the 7- and 14-day groups. Prolonged exposure of infrasound altered WLCC in rat cardiomyocytes by shifting the steady-state inactivation curves to the right (more depolarized direction) without altering the slope and biophysical properties of I (Ca,L). Taken together, our data suggest that changes in [Ca2+](I) levels as well as expression of LCC and SERCA2 may contribute to the infrasound exposure-elicited cardiac response.
Subject(s)
Acoustic Stimulation/adverse effects , Action Potentials/physiology , Calcium Channels, L-Type/physiology , Myocytes, Cardiac/physiology , Acoustic Stimulation/methods , Animals , Male , Myocytes, Cardiac/cytology , Rats , Rats, Sprague-DawleyABSTRACT
MicroRNAs (miRNAs) are small noncoding RNAs of 19-24 nucleotides in length and involved in gene expression regulation. They are associated with cell proliferation, differentiation, apoptosis, and carcinogenesis. The specific expression profiles of miRNAs have been found in many human cancers, but there are few studies on endometrioid adenocarcinoma. We found the miRNA expression profile in 10 pairs of endometrioid adenocarcinoma and adjacent nontumorous endometrium using human miRNA microarray. Seventeen miRNAs exhibited higher expression and six miRNAs exhibited lower expression in endometrioid adenocarcinoma samples than those in the nontumorous samples in the microarray. Of those, the miR-205, miR-449, and miR-429 were greatly enriched; in contrast the miR-204, miR-99b, and miR-193b were greatly downregulated in adenocarcinoma tissues. The expressions of these six miRNAs were validated using real time reverse transcription-PCR. This information may provide the candidate miRNA genome for further confirming the role of miRNAs in carcinogenesis of endometrioid adenocarcinoma and potentially serving as a diagnostic or therapeutic tool in endometrioid adenocarcinoma.
Subject(s)
Carcinoma, Endometrioid/genetics , Endometrial Neoplasms/genetics , Gene Expression Profiling , MicroRNAs/genetics , Animals , Carcinoma, Endometrioid/diagnosis , Endometrial Neoplasms/diagnosis , False Positive Reactions , Female , Gene Expression Regulation, Neoplastic , Humans , Mammals/genetics , Mice , Oligonucleotide Array Sequence AnalysisABSTRACT
Osteosarcoma is the most frequent primary malignant tumor of the skeleton and occurs mainly in children and adolescent. The prognosis of osteosarcoma is very poor due to its aggressive and no effective treatment. This study is the first to investigate the anti-cancer effects of antisense pEGFP-C1-Survivin on human osteosarcoma cells. It was shown in our results that Survivin blockaded could significantly induce apoptosis and inhibit the invasive of osteosarcoma cells line MG-63. The effects were probably produced by the decreased expression of Survivin induced by antisense pEGFP-C1-Survivin which was examined by RT-PCR and western blotting. All these suggested that Survivin should be very important in the development of osteosarcoma and Survivin blockaded by using antisense pEGFP-C1-Survivin could markedly inhibit the proliferation and invasion of osteosarcoma cells line MG-63, partially reversed their malignant phenotype. Targeting Survivin might be a promising option in the treatment of osteosarcoma.
Subject(s)
Apoptosis , Bone Neoplasms/therapy , Microtubule-Associated Proteins/antagonists & inhibitors , Oligonucleotides, Antisense/metabolism , Osteosarcoma/therapy , Blotting, Western , Bone Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation , Down-Regulation/genetics , Humans , Inhibitor of Apoptosis Proteins , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/physiology , Osteosarcoma/pathology , RNA Interference , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Survivin , TransfectionABSTRACT
Recent interest in adverse effects of infrasound on organisms arises from health concerns. We assessed the association between infrasound exposure of 5 Hz at 130 dB and changes of cardiac ultrastructure and function in rats. Thirty-two Sprague-Dawley rats were randomized into control, 1, 7, and 14 days groups for 2 h of infrasound once daily according to planned schedules. Changes of cardiac ultrastructure, hemodynamics indices, intracellular Ca(2+) concentrations ([Ca(2+)](i)), and sarcoplasmic reticulum Ca(2+)-ATPase 2 (SERCA2) were detected. Heart rates in 1 day group were significantly increased compared with control group and no significant changes in other groups. Left ventricular systolic pressures were significantly increased with time. Left ventricular diastolic end pressure and maximum rising rates of left ventricular pressure (+dl/dt) were significantly increased in 7 and 14 days groups and not changed in 1 day group, compared with control group. Maximum dropping rates of left ventricular pressure (-dl/dt) were significantly decreased in 7 and 14 days groups and not changed in 1 day group, compared with control group. In heart cells, there were several swelled mitochondria in 1 day group, more swelled mitochondria in 7 days group, platelet aggregation in the intercellular substance in 14 days group. [Ca(2+)](i) were significantly increased with time. There was a significant increase in SERCA2 in 1 day group, while a significant decrease in 7 and 14 days groups, compared with control group. Infrasound of 5 Hz at 130 dB can damage cardiac ultrastructure and function. Changes of [Ca(2+)](i) and SERCA2 play an important role in the secondary cardiac damage.
Subject(s)
Heart Ventricles/physiopathology , Myocardium/ultrastructure , Sound/adverse effects , Animals , Calcium/metabolism , Cells, Cultured , Male , Microscopy, Electron, Transmission , Mitochondria, Heart/ultrastructure , Myocardium/metabolism , Myocytes, Cardiac/metabolism , Rats , Rats, Sprague-Dawley , Sarcoplasmic Reticulum/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolismABSTRACT
To investigate some bioeffects of infrasound on copulation as well as underlying mechanisms, we inspected the changes of sexual behavior, serum testosterone concentration and mRNA expression levels of steroidogenic factor 1 (SF-1), steroidogenic acute regulatory protein (StAR) and cytochrome P450 cholesterol side chain cleavage enzyme (P450scc) in testes of rats exposed to infrasound of 8Hz at 90 or 130dB for 1, 7, 14 and 21 days (2h/day), respectively. Rats exposed to 90dB exhibited significant decrement in sexual behavior, serum testosterone levels and mRNA expression levels of StAR and P450scc at the time point of 1 day but not at the rest time points, and no significantly change of SF-1 mRNA expression was observed over the period of 21 days in spite of mild fluctuation. Rats exposed to 130dB exhibited significant decrement in all aspects above, which became more profound with prolonged exposure. Our conclusion is that adverse bioeffects of infrasound on reproduction depend on some exposure parameters, the mechanism of which could involve in the decreased expression of some key enzymes or regulator for testosterone biosynthesis.