Optimization of Diagnosis-Related Groups for 14,246 Patients with Uterine Leiomyoma in a Single Center in Western China Using a Machine Learning Model.

Background: Uterine leiomyoma (UL) is one of the most common benign tumors in women, and its incidence is gradually increasing in China. The clinical complications of UL have a negative impact on women's health, and the cost of treatment poses a significant burden on patients. Diagnosis-related groups (DRG) are internationally recognized as advanced healthcare payment management methods that can effectively reduce costs. However, there are variations in the design and grouping rules of DRG policies across different regions. Therefore, this study aims to analyze the factors influencing the hospitalization costs of patients with UL and optimize the design of DRG grouping schemes to provide insights for the development of localized DRG grouping policies. Methods: The Mann-Whitney U-test or the Kruskal-Wallis H-test was employed for univariate analysis, and multiple stepwise linear regression analysis was utilized to identify the primary influencing factors of hospitalization costs for UL. Case combination classification was conducted using the exhaustive chi-square automatic interactive detection (E-CHAID) algorithm within a decision tree framework. Results: Age, occupation, number of hospitalizations, type of medical insurance, Transfer to other departments, length of stay (LOS), type of UL, admission condition, comorbidities and complications, type of primary procedure, other types of surgical procedures, and discharge method had a significant impact on hospitalization costs (P<0.05). Among them, the type of primary procedure, other types of surgical procedures, and LOS were the main factors influencing hospitalization costs. By incorporating the type of primary procedure, other types of surgical procedures, and LOS into the decision tree model, patients were divided into 11 DRG combinations. Conclusion: Hospitalization costs for UL are mainly related to the type of primary procedure, other types of surgical procedures, and LOS. The DRG case combinations of UL based on E-CHAID algorithm are scientific and reasonable.

A tumor suppressor protein encoded by circKEAP1 inhibits osteosarcoma cell stemness and metastasis by promoting vimentin proteasome degradation and activating anti-tumor immunity.

BACKGROUND: Osteosarcoma (OS) is one of most commonly diagnosed bone cancer. Circular RNAs (circRNAs) are a class of highly stable non-coding RNA, the majority of which have not been characterized functionally. The underlying function and molecular mechanisms of circRNAs in OS have not been fully demonstrated. METHOD: Microarray analysis was performed to identify circRNAs that are differentially-expressed between OS and corresponding normal tissues. The biological function of circKEAP1 was confirmed in vitro and in vivo. Mass spectrometry and western blot assays were used to identify the circKEAP1-encoded protein KEAP1-259aa. The molecular mechanism of circKEAP1 was investigated by RNA sequencing and RNA immunoprecipitation analyses. RESULTS: Here, we identified a tumor suppressor circKEAP1, originating from the back-splicing of exon2 of the KEAP1 gene. Clinically, circKEAP1 is downregulated in OS tumors and associated with better survival in cancer patients. N6-methyladenosine (m6A) at a specific adenosine leads to low expression of circKEAP1. Further analysis revealed that circKEAP1 contained a 777 nt long ORF and encoded a truncated protein KEAP1-259aa that reduces cell proliferation, invasion and tumorsphere formation of OS cells. Mechanistically, KEAP1-259aa bound to vimentin in the cytoplasm to promote vimentin proteasome degradation by interacting with the E3 ligase ARIH1. Moreover, circKEAP1 interacted with RIG-I to activate anti-tumor immunity via the IFN-γ pathway. CONCLUSION: Taken together, our findings characterize a tumor suppressor circKEAP1 as a key tumor suppressor regulating of OS cell stemness, proliferation and migration, providing potential therapeutic targets for treatment of OS.

Alleviating sleep disturbances and modulating neuronal activity after ischemia: Evidence for the benefits of zolpidem in stroke recovery.

AIMS: Sleep disorders are prevalent among stroke survivors and impede stroke recovery, yet they are still insufficiently considered in the management of stroke patients, and the mechanisms by which they occur remain unclear. There is evidence that boosting phasic GABA signaling with zolpidem during the repair phase improves stroke recovery by enhancing neural plasticity; however, as a non-benzodiazepine hypnotic, the effects of zolpidem on post-stroke sleep disorders remain unclear. METHOD: Transient ischemic stroke in male rats was induced with a 30-minute middle cerebral artery occlusion. Zolpidem or vehicle was intraperitoneally delivered once daily from 2 to 7 days after the stroke, and the electroencephalogram and electromyogram were recorded simultaneously. At 24 h after ischemia, c-Fos immunostaining was used to assess the effect of transient ischemic stroke and acute zolpidem treatment on neuronal activity. RESULTS: In addition to the effects on reducing brain damage and mitigating behavioral deficits, repeated zolpidem treatment during the subacute phase of stroke quickly ameliorated circadian rhythm disruption, alleviated sleep fragmentation, and increased sleep depth in ischemic rats. Immunohistochemical staining showed that in contrast to robust activation in para-infarct and some remote areas by 24 h after the onset of focal ischemia, the activity of the ipsilateral suprachiasmatic nucleus, the biological rhythm center, was strongly suppressed. A single dose of zolpidem significantly upregulated c-Fos expression in the ipsilateral suprachiasmatic nucleus to levels comparable to the contralateral side. CONCLUSION: Stroke leads to suprachiasmatic nucleus dysfunction. Zolpidem restores suprachiasmatic nucleus activity and effectively alleviates post-stroke sleep disturbances, indicating its potential to promote stroke recovery.

The allocation and fairness of health human resources in Chinese maternal and child health care institutions: a nationwide longitudinal study.

BACKGROUND: In response to an aging population, the Chinese government implemented the three-child policy in 2021 based on the comprehensive two-child policy. With the implementation of the new birth policy, people's maternal and child health (MCH) needs will also increase. The allocation and fairness of MCH human resources directly affect people's access to MCH services. The purpose of this study is to analyze the allocation of health human resources in Chinese maternal and child health care institutions, evaluate the fairness of the allocation, to provide a reference for the rational allocation of MCH human resources. METHODS: The data of health technicians, licensed (assistant) physicians, and registered nurses in maternal and child health care institutions nationwide from 2016 to 2020 were included. The health resource density index (HRDI) is used to evaluate the allocation level of MCH human resources. The Gini coefficient (G) and Theil index (T) are used to evaluate the fairness of the allocation of MCH human resources from the perspectives of population and geographic area. RESULTS: From 2016 to 2020, the average annual growth rate of the number of health technicians, licensed (assistant) physicians, and registered nurses in Chinese maternal and child health care institutions was 7.53, 6.88, and 9.12%, respectively. The Gini coefficient (G) of the three types of MCH human resources allocated by population were all below 0.23, and the Gini coefficient (G) allocated by geographical area were all above 0.65. The Theil index (T) of the three types of MCH human resources allocated by population was all lower than 0.06, and the Theil index (T) allocated by geographical area was all higher than 0.53. In addition, the three types of MCH human resources allocated by population and geographic area contributed more than 84% of the Theil index within the group (Tintra) to the Theil index (T). CONCLUSIONS: China's MCH human resources were fair in terms of population allocation, but unfair in terms of geographical area allocation. In the future, more attention should be paid to the geographical accessibility of MCH human resources, and the allocation of resources should comprehensively consider the two factors of serving the population and geographical area.

Melatonin supplementation in the subacute phase after ischemia alleviates postischemic sleep disturbances in rats.

BACKGROUND: Sleep disorders are highly prevalent among stroke survivors and impede stroke recovery. It is well established that melatonin has neuroprotective effects in animal models of ischemic stroke. However, as a modulator of endogenous physiological circadian rhythms, the effects of melatonin on poststroke sleep disorders remain unclear. In the present study, we investigated how melatonin delivered intraperitoneally once daily in the subacute phase after stroke onset, influencing neuronal survival, motor recovery, and sleep-wake profiles in rats. METHODS: Transient ischemic stroke in male Sprague-Dawley rats was induced with 30 min occlusion of the middle cerebral artery. Melatonin or vehicle was delivered intraperitoneally once daily in the subacute phase, from 2 to 7 days after stroke. Electroencephalogram and electromyogram recordings were obtained simultaneously. RESULTS: Compared to the effects observed in the vehicle-treated ischemic group, after 6 daily consecutive treatment of melatonin at 10 mg/kg starting at ischemic/reperfusion day 2, the infarct volume was significantly decreased (from 39.6 to 26.2%), and the degeneration of axons in the ipsilateral striatum and the contralateral corpus callosum were significantly alleviated. Sensorimotor performances were obviously improved as evidenced by significant increases in the latency to falling off the wire and in the use of the impaired forelimb. In addition to those predictable results of reducing brain tissue damage and mitigating behavioral deficits, repeated melatonin treatment during the subacute phase of stroke also alleviated sleep fragmentation through reducing sleep-wake stage transitions and stage bouts, together with increasing stage durations. Furthermore, daily administration of melatonin at 9 a.m. significantly increased the nonrapid eye movement sleep delta power during both the light and dark periods and decreased the degree of reduction of the circadian index. CONCLUSIONS: Melatonin promptly reversed ischemia-induced sleep disturbances. The neuroprotective effects of melatonin on ischemic injury may be partially associated with its role in sleep modulation.

Noninvasive Ultrasound Stimulation of Ventral Tegmental Area Induces Reanimation from General Anaesthesia in Mice.

Evidence in animals suggests that deep brain stimulation or optogenetics can be used for recovery from disorders of consciousness (DOC). However, these treatments require invasive procedures. This report presents a noninvasive strategy to stimulate central nervous system neurons selectively for recovery from DOC in mice. Through the delivery of ultrasound energy to the ventral tegmental area, mice were aroused from an unconscious, anaesthetized state in this study, and this process was controlled by adjusting the ultrasound parameters. The mice in the sham group under isoflurane-induced, continuous, steady-state general anaesthesia did not regain their righting reflex. On insonation, the emergence time from inhaled isoflurane anaesthesia decreased (sham: 13.63 ± 0.53 min, ultrasound: 1.5 ± 0.19 min, p < 0.001). Further, the induction time (sham: 12.0 ± 0.6 min, ultrasound: 17.88 ± 0.64 min, p < 0.001) and the concentration for 50% of the maximal effect (EC50) of isoflurane (sham: 0.6%, ultrasound: 0.7%) increased. In addition, ultrasound stimulation reduced the recovery time in mice with traumatic brain injury (sham: 30.38 ± 1.9 min, ultrasound: 7.38 ± 1.02 min, p < 0.01). This noninvasive strategy could be used on demand to promote emergence from DOC and may be a potential treatment for such disorders.

Impact of smoking on the income level of Chinese urban residents: a two-wave follow-up of the China Family Panel Study.

OBJECTIVES: This study attempts to analyse the impact of smoking on the income level of Chinese urban residents to provide a reference for creating informed regulations on cigarette smoking. DESIGN: A population-based cohort study. METHOD: Two waves of panel data in 2014 and 2016 from the China Family Panel Study were used. A total of 8025 urban adults were identified. The Hausman-Taylor model was used to analyse the theoretical relationship between smoking and income. RESULTS: The percentage of current smokers decreased from 27.39% (2014) to 26.24% (2016), while the percentage of former smokers rose from 9.78% to 11.78%. The results from the Hausman-Taylor model showed that current smokers and former smokers are associated with statistically significant decrease in the income of urban residents of 37.70% and 44.00%, respectively, compared with that of non-smokers. After eliminating the impact of smoking on income, the poverty rate among urban residents decreased from 15.33% to 13.63%. CONCLUSIONS: Smoking can significantly reduce the income of Chinese urban residents, resulting in immense negative impacts on Chinese society. Therefore, the government should raise the tax rate on tobacco, include smoking cessation treatment in medical insurance coverage, promote publicity campaigns on the awareness of tobacco hazards and encourage smokers to quit smoking early.

Catastrophic health expenditure: A comparative analysis of smoking and non-smoking households in China.

INTRODUCTION: Smoking is hazardous to health and places a heavy economic burden on individuals and their families. Clearly, smoking in China is prevalent since China is the largest consumer of tobacco in the world. Chinese smoking and nonsmoking households were compared in terms of the incidence and intensity of Catastrophic Health Expenditures (CHEs). The factors associated with catastrophic health expenditures were analyzed. METHODS: Data for this study were collected from two waves of panel data in 2011 and 2013 from the national China Health and Retirement Longitudinal Study (CHARLS). A total of 8073 households with at least one member aged above 45 were identified each year. Catastrophic health expenditure was measured by the ratio of a household's out-of-pocket healthcare payments (OOP) to the household's Capacity to Pay (CTP). A panel logit random-effects model was used to examine correlates with catastrophic health expenditure. RESULTS: The incidence of catastrophic health expenditures for Chinese households with members aged 45 and above in 2011 and 2013 were 12.99% and 15.56%, respectively. The mean gaps (MGs) were 3.16% and 4.88%, respectively, and the mean positive gaps (MPGs) were 24.36% and 31.40%, respectively. The incidences of catastrophic health expenditures were 17.41% and 20.03% in former smoking households, 12.10% and 15.09% in current smoking households, and 12.72% and 13.64% in nonsmoking households. In the panel logit regression model analysis, former smoking households (OR = 1.444, P<0.001) were more prone to catastrophic health expenditures than nonsmoking households. Risk factors for catastrophic health expenditures included members with chronic diseases (OR = 4.359, P<0.001), hospitalized patients (OR = 8.60, P<0.001), elderly people aged above 65 (OR = 1.577, P<0.001), or persons with disabilities (OR = 1.275, P<0.001). Protective factors for catastrophic health expenditures included being in an urban household, having a larger family size, and having a higher household income. CONCLUSIONS: The incidence of catastrophic health expenditures in Chinese households is relatively high. Smoking is one of the primary risk factors for catastrophic health expenditures. Stronger interventions against smoking should be made in time to reduce the occurrence of health issues caused by smoking and the financial losses for individuals, families and society.

Cloning and characterization of the rat Slo3 (KCa 5.1) channel: From biophysics to pharmacology.

BACKGROUND AND PURPOSE: The Slo3 potassium (KCa 5.1) channel, which is specifically expressed in the testis and sperm, is essential for mammalian male fertilization. The sequence divergence of the bovine, mouse and human Slo3 α-subunit revealed a rapid evolution rate across different species. The rat Slo3 (rSlo3) channel has not been cloned and characterized previously. EXPERIMENTAL APPROACH: We used molecular cloning, electrophysiology (inside-out patches and outside-out patches) and mutagenesis to investigate the biophysical properties and pharmacological characteristics of the rSlo3 channel. KEY RESULTS: The rat Slo3 channel (rSlo3) is gated by voltage and cytosolic pH rather than intracellular calcium. The characteristics of voltage-dependent, pH-sensitivity and activation kinetics of the rSlo3 channel differ from the characteristics of other Slo3 orthologues. In terms of pharmacology, the 4-AP blockade of the rSlo3 channel also shows properties distinct from its blockade of the mSlo3 channel. Iberiotoxin and progesterone weakly inhibit the rSlo3 channel. Finally, we found that propofol, one of the widely used general anaesthetics, blocks the rSlo3 channel from both intracellular and extracellular sides, whereas ketamine only blocks the rSlo3 channel at the extracellular side. CONCLUSION AND IMPLICATIONS: Our findings suggest that the rSlo3 channel possesses unique biophysical and pharmacological properties. Our results provide new insights into the diversities of the Slo3 family of channels, which are valuable for estimating the effects of the use of these drugs to improve sperm quality.

Comprehensive analysis of the expression profile of circRNAs and their predicted protein-coding ability in the muscle of mdx mice.

Duchenne muscular dystrophy (DMD) is an X-linked genetic neuromuscular disease that is characterized by progressive muscle wasting and by defects in the regenerative capacity and inflammatory infiltration of muscle. Many noncoding RNAs (ncRNAs) participate in the pathophysiological mechanisms of this disease. To explore the role of circular RNAs (circRNAs), a type of ncRNAs, in DMD, microarray analysis was performed to explore the expression patterns of circRNAs in the gastrocnemius muscles in mdx mice, a DMD animal model, and C57 mice. The microarray data were validated by qRT-PCR. Further, gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to predict the function of the differentially expressed circRNAs (DEcRNAs). A circRNA/microRNA (miRNA) interaction network was predicted by bioinformatics. We also predicted the protein-coding ability of the circRNAs based on their N6-methyladenosine motifs and open-reading frames. We identified 197 differentially expressed circRNAs between mdx mice and C57 mice. Of the 197 DEcRNAs, 6 circRNAs were randomly selected to validate the microarray data, and twenty-two circRNAs were randomly selected to construct a circRNA/miRNA interaction network. Bioinformatics analysis showed that the linear counterparts of the DEcRNAs were mainly associated with muscle structure, nervous system development, and the cAMP signaling pathway. A total of 189 circRNAs were predicted to have protein-coding potential, and there were 98 circRNAs that could potentially be translated into polypeptides with 150 or more amino acids. This work described the expression pattern of circRNAs in mdx mice and indicated that circRNAs may play pivotal roles in the pathophysiological mechanisms of DMD.

Long-term treatment of blepharospasm with botulinum toxin A: a service-based study over a 16-year follow-up in southern China.

OBJECTIVE: To elucidate the effect of long-term treatment with botulinum toxin A (BTX-A) for blepharospasm. Prevalence data and clinical features in southern China and influencing factors for selecting BTX-A treatment were explored. METHODS: We collected data retrospectively from 338 consecutive patients diagnosed with blepharospasm over 16 years to assess prevalence data and clinical features. Thereafter, all patients were classified into BTX-A (n = 135) or non-BTX-A (n = 203) treatment groups according to the patients' requests in order to explore the factors influencing whether BTX-A treatment was chosen. Furthermore, dynamic follow-up data were analyzed to evaluate the long-term efficacy in the BTX-A group. RESULTS: The prevalence was 23.3 per million, with an onset age of 50.3 ± 12.3 years and a female:male ratio of 2.4:1; the most common symptom was excessive blinking (91.2%). The symptom severity and psychological assessment scores were significantly decreased by treatment with BTX-A (p < 0.01), and there was no significant difference in response duration with the prolongation of BTX-A injections. Adverse events occurred 52 times (5.0%) among 1038 injections. The symptom severity and psychological assessment scores and the occurrence of eye-opening difficulty were higher, and medical expenses and the symptom tolerability rate were lower in the BTX-A group than in the non-BTX-A group (p < 0.05). CONCLUSION: The onset age was earlier than that in Western countries. However, starting BTX-A treatment early is justified, even though a higher dosage was needed to maintain reliable long-term efficacy. Additionally, symptom severity and medical expenses are the primary factors affecting whether patients select BTX-A treatment.

Nigrostriatal and mesolimbic control of sleep-wake behavior in rat.

The midbrain dopamine system via the dorsal and ventral striatum regulates a wide range of behaviors. To dissect the role of dopaminergic projections to the dorsal striatum (nigrostriatal projection) and ventral striatum (mesolimbic projection) in sleep-wake behavior, we selectively chemogenetically stimulated nigrostriatal or mesolimbic projections and examined the resulting effects on sleep in rats. Stimulation of nigrostriatal pathways increased sleep and EEG delta power, while stimulation of mesolimbic pathways decreased sleep and reduced cortical EEG power. These results indicate that midbrain dopamine signaling in the dorsal or ventral striatum promotes sleep or wake, respectively.

Upregulation of microRNA-205 is a potential biomarker for intracranial aneurysms.

Inhibition of microRNA-205 is considered to be a therapeutic target for abdominal aortic aneurysm in animal model. Hepatocyte growth factor also plays pivotal roles in the pathogenesis of intracranial aneurysms, and its expression can be regulated by different miRNAs in different processes. We investigated the involvement of microRNA-205 in intracranial aneurysms and explored is potential interaction with hepatocyte growth factor. We found that blood levels of microRNA-205 were significantly higher in patients with intracranial aneurysms than in healthy controls. High blood levels of microRNA-205 showed diagnostic values for intracranial aneurysms. MicroRNA-205 and hepatocyte growth factor were negatively correlated in patients with intracranial aneurysms. MicroRNA-205 overexpression inhibited hepatocyte growth factor expression and reduced cell viability. Therefore, microRNA-205 may participate in intracranial aneurysms and may serve as a diagnostic marker for this disease.

MiR-16 attenuates ß-amyloid-induced neurotoxicity through targeting ß-site amyloid precursor protein-cleaving enzyme 1 in an Alzheimer's disease cell model.

The aberrant deposition of ß-amyloid (Aß) is closely linked to the pathogenesis and development of Alzheimer's disease (AD). MiR-16 was abnormally downregulated and may be related to the development of AD. However, the functional role and molecular mechanism of miR-16 in AD pathogenesis are still not well elucidated. The expressions of miR-16 and ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1) mRNA and protein levels in AD brain tissues and Aß-treated PC12 cellular AD model were examined by qRT-PCR and western blot analyses. Luciferase reporter assay was used to verify the potential target of miR-16. The cell viability, apoptosis, and caspase-3 activity in PC12 cells were determined by the MTT assay, flow cytometry analysis, and caspase-3 activity assay, respectively. Downregulation of miR-16 and upregulation of BACE1 existed in AD tissues and the cellular AD model of PC12. In addition, miR-16 directly suppressed BACE1 expression. Moreover, miR-16 overexpression and BACE1 knockdown facilitated Aß-induced cell toxicity, apoptosis, and caspase-3 activity in N2a cells, which was partially eliminated by overexpression of BACE1. In contrast, BACE1 knockdown reversed the miR-16 inhibition-mediated inhibitory effect on Aß-induced cell toxicity, apoptosis, and caspase-3 activity in PC12 cells. Collectively, miR-16 attenuated Aß-induced neurotoxicity through targeting BACE1 in an Aß insult cellular AD model, providing a potential therapeutic target for AD treatment.

STAT1, IGF1, RAC1, and MDM2 Are Associated with Recurrence of Giant Cell Tumor of Bone.

BACKGROUND: In our previous study, mouse double minute 2 homolog (MDM2), insulin-like growth factor 1 (IGF1), signal transducer and activator of transcription 1 (STAT1), and Rac family small GTPase 1 (RAC1) were correlated with the recurrence of giant cell tumor of bone (GCT). The aim of this study is to use a large cohort study to confirm the involvement of these four genes in GCT recurrence. METHODS: The expression of these four genes was detected and compared between GCT patients with or without recurrence. The correlation between the expression of these four genes and clinical characteristics was evaluated. Protein-protein interaction (PPI) network was constructed for functional enrichment analysis. RESULTS: It showed that the expression levels of MDM2, IGF1, STAT1, and RAC1 in GCT patients with recurrence were significantly higher than those in GCT patients without recurrence (P < 0.05). Multivariate logistic regression analysis suggested that several clinical characteristics may influence prognosis. A PPI network was constructed using the four genes as hub genes. Functional enrichment analysis showed that this network involves many important biological progress mediated by these four genes, including immune response. CONCLUSION: MDM2, IGF1, STAT1, and RAC1 are associated with GCT recurrence, which might serve as biomarkers for GCT recurrence.

TGF-ß1 activates the canonical NF-κB signaling to promote cell survival and proliferation in dystrophic muscle fibroblasts in vitro.

Activated fibroblasts continue to proliferate at injury sites, leading to progressive muscular fibrosis in Duchenne muscular dystrophy (DMD). TGF-ß1 is a dominant profibrotic mediator thought to play a critical role in muscle fibrosis; however, the implicated mechanisms are not fully understood. Here we showed that TGF-ß1 increased the resistance to apoptosis and stimulated cell cycle progression in dystrophic muscle fibroblasts under serum deprivation conditions in vitro. TGF-ß1 treatment activated the canonical NF-κB pathway; and we found that pharmacological inhibition of IKKß with IMD-0354 and RelA gene knockdown with siRNA attenuated these effects of TGF-ß1 on dystrophic muscle fibroblasts. Collectively, our data suggest that TGF-ß1 prevents apoptosis and cell cycle arrest in dystrophic muscle fibroblasts through the canonical NF-κB signaling pathway.

Inhibition of glycogen synthase kinase-3ß attenuates glucocorticoid-induced suppression of myogenic differentiation in vitro.

Glucocorticoids are the only therapy that has been demonstrated to alter the progress of Duchenne muscular dystrophy (DMD), the most common muscular dystrophy in children. However, glucocorticoids disturb skeletal muscle metabolism and hamper myogenesis and muscle regeneration. The mechanisms involved in the glucocorticoid-mediated suppression of myogenic differentiation are not fully understood. Glycogen synthase kinase-3ß (GSK-3ß) is considered to play a central role as a negative regulator in myogenic differentiation. Here, we showed that glucocorticoid treatment during the first 48 h in differentiation medium decreased the level of phosphorylated Ser9-GSK-3ß, an inactive form of GSK-3ß, suggesting that glucocorticoids affect GSK-3ß activity. We then investigated whether GSK-3ß inhibition could regulate glucocorticoid-mediated suppression of myogenic differentiation in vitro. Two methods were employed to inhibit GSK-3ß: pharmacological inhibition with LiCl and GSK-3ß gene knockdown. We found that both methods resulted in enhanced myotube formation and increased levels of muscle regulatory factors and muscle-specific protein expression. Importantly, GSK-3ß inhibition attenuated glucocorticoid-induced suppression of myogenic differentiation. Collectively, these data suggest the involvement of GSK-3ß in the glucocorticoid-mediated impairment of myogenic differentiation. Therefore, the inhibition of GSK-3ß may be a strategy for preventing glucocorticoid-induced muscle degeneration.

Identification of differentially expressed genes and their subpathways in recurrent versus primary bone giant cell tumors.

Giant cell tumor (GCT) of the bone is a benign but locally aggressive bone neoplasm with a strong tendency to develop local recurrent and metastatic disease. Thus, it provides a useful model system for the identification of biological mechanisms involved in bone tumor progression and metastasis. This study profiled 24 cases of recurrent versus primary bone GCT tissues using QuantiGene 2.0 Multiplex Arrays that included Human p53 80-Plex Panels and Human Stem Cell 80-Plex Panels. A total of 32 differentially expressed genes were identified, including the 20 most upregulated genes and the 12 most downregulated genes in recurrent GCT. The genes identified are related to cell growth, adhesion, apoptosis, signal transduction and bone formation. Furthermore, iSubpathwayMiner analyses were performed to identify significant biological pathway regions (subpathway) associated with this disease. The pathway analysis identified 11 statistically significant enriched subpathways, including pathways in cancer, p53 signaling pathway, osteoclast differentiation pathway and Wnt signaling pathway. Among these subpathways, four genes (IGF1, MDM2, STAT1 and RAC1) were presumed to play an important role in bone GCT recurrence. The differentially expressed MDM2 protein was immunohistochemically confirmed in the recurrent versus primary bone GCT tissues. This study identified differentially expressed genes and their subpathways in recurrent GCT, which may serve as potential biomarkers for the prediction of GCT recurrence.

Effects of matrix metalloproteinase-1 on the myogenic differentiation of bone marrow-derived mesenchymal stem cells in vitro.

Matrix metalloproteinase-1 (MMP-1) is a member of the family of zinc-dependent endopeptidases that are capable of degrading extracellular matrix (ECM) and certain non-matrix proteins. It has been shown that MMP-1 can enhance muscle regeneration by improving the differentiation and migration of myoblasts. However, it is still not known whether MMP-1 can promote the myogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). To address this question, we isolated BMSCs from C57BL/6J mice and investigated the effects of MMP-1 on their proliferation and myogenic differentiation. Our results showed that MMP-1 treatment, which had no cytotoxic effects on BMSCs, increased the mRNA and protein levels of MyoD and desmin in a dose-dependent manner, indicating that MMP-1 promoted myogenic differentiation of BMSCs in vitro. These results suggest that BMSCs may have a therapeutic potential for treating muscular disorders.