Associations of Cognitive Impairment with All-Cause and Cardiovascular Mortality Among Individuals with Diabetes: A Prospective Cohort Study.

This study explored the association between diabetes, cognitive imFpairment (CI), and mortality in a cohort of 2931 individuals aged 60 and above from the 2011 to 2014 NHANES. Mortality data was gathered through 2019, and multivariable Cox proportional hazards models were used to determine the association between diabetes, CI, and mortality adjusting for sociodemographic characteristics, lifestyle factors, and comorbidity conditions. The study spanned up to 9.17 years, observing 579 deaths, with individuals having both diabetes and CI showing the highest all-cause mortality (23.6 events per 100 patient-years). Adjusted analysis revealed a 2.34-fold higher risk of all-cause mortality for this group, surpassing those with diabetes or CI alone. These results held after a series of stratified and sensitivity analyses. In conclusion, CI was linked to higher all-cause mortality in individuals with diabetes, emphasizing the need to address cognitive dysfunction in diabetic patients.

Effect of blood pressure on mortality in patients with cognitive impairment: a prospective cohort study.

Background: Cognitive impairment is a prevalent condition that substantially elevates mortality rates among the elderly. The impact of hypertension on mortality in older adults with cognitive impairment is a subject of contention. This study aims to examine the influence of hypertension on both all-cause and CVD-specific mortality in elderly individuals experiencing cognitive impairment within a prospective cohort. Methods: This study encompassed 2,925 participants (weighted 53,086,905) aged 60 years or older from National Health and Nutrition Examination Survey (NHANES) spanning 2011-2014. Incidence of all-cause and CVD-specific mortality was ascertained through linkage with National Death Index records until 31 December 2019. Survival was performed employing the Kaplan-Meier method. Hazard ratios (HRs) were calculated via Cox proportional hazards regression models. Results: Over the follow-up period of up to 9.17 years [with a median (IQR) time to death of 6.58 years], equivalent to 18,731.56 (weighted 3.46 × 108) person-years, there were a total of 576 recorded deaths. Participants with CI exhibited a 1.96-fold higher risk of all-cause mortality (95% CI: 1.55-2.49; p < 0.01) and a 2.8-fold higher risk of CVD-specific mortality (95% CI: 1.83-4.29; p < 0.01) in comparison to participants without CI. Among participants with CI, concurrent hypertension comorbidity was linked to a 2.73-fold elevated risk of all-cause mortality (95% CI: 1.78-4.17; p < 0.01) and a 5.3-fold elevated risk of CVD-specific mortality (95% CI: 2.54-11.04; p < 0.01). Further stratified analyses revealed that the combined effects of hypertension and CI on all-cause and CVD-specific mortality were more pronounced in participants aged 60-69 years compared to those aged 70-80 years (p for interaction <0.01). The primary findings exhibited resilience across a series of sensitivity analyses. Conclusions: Participants with CI exhibited a markedly elevated risk of all-cause and CVD-specific mortality when coexisting with hypertension. Appropriate management of hypertension in patients with CI may be helpful in reducing the excess risk of death.

Z-Guggulsterone attenuates cognitive defects and decreases neuroinflammation in APPswe/PS1dE9 mice through inhibiting the TLR4 signaling pathway.

Growing evidence indicates that inflammatory damage is implicated in the pathogenesis of Alzheimer's disease (AD). Z-Guggulsterone (Z-GS) is a natural steroid, which is extracted from Commiphora mukul and has anti-inflammatory effects in vivo and in vitro. In the present study, we investigated the disease-modifying effects of chronic Z-GS administration on the cognitive and neuropathological impairments in the transgenic mouse models of AD. We found that chronic Z-GS administration prevented learning and memory deficits in the APPswe/PS1dE9 mice. In addition, Z-GS treatment significantly decreased cerebral amyloid-ß (Aß) levels and plaque burden via inhibiting amyloid precursor protein (APP) processing by reducing beta-site APP cleaving enzyme 1 (BACE1) expression in the APPswe/PS1dE9 mice. We also found that Z-GS treatment markedly alleviated neuroinflammation and reduced synaptic defects in the APPswe/PS1dE9 mice. Furthermore, the activated TLR4/NF-κB signaling pathways in APPswe/PS1dE9 mice were remarkably inhibited by Z-GS treatment, which was achieved via suppressing the phosphorylation of JNK. Collectively, our data demonstrate that chronic Z-GS treatment restores cognitive defects and reverses multiple neuropathological impairments in the APPswe/PS1dE9 mice. This study provides novel insights into the neuroprotective effects and neurobiological mechanisms of Z-GS on AD, indicating that Z-GS is a promising disease-modifying agent for the treatment of AD.

A comparison of the diagnostic accuracy of the Mini-Cog and AD8 in identifying cognitive impairment in a geriatric health screening population in China.

The present study aimed to evaluate and compare the discriminative abilities of the Mini-Cog and AD8 tests in detecting cognitive impairment in a Chinese health screening population. 160 geriatric participants were enrolled at an academic medical center . The Mini-Cog, AD8, and Mini-Mental State Examination (MMSE) were used to assess the possibility of cognitive impairment. Logistic regression and receiver operator characteristic curve analyses were performed to evaluate the discriminative abilities of the tests. The prevalence of cognitive impairment was 41.25%. Logistic regression modeling showed that the Mini-Cog (odds ratio (OR) = 0.34, 95% confidence interval (CI): 0.25-0.46) and MMSE (OR = 0.58, 95%CI: 0.49-0.69) predicted cognitive impairment with 79.4% and 80.6% correct classification, respectively. While the AD8 (OR = 1.56, 95% CI: 1.32-1.85) predicted cognitive impairment with 72.5% correct classification. The areas under the receiver operating characteristic curves of the Mini-Cog, AD8 and MMSE for detecting cognitive impairment were 0.79 (95% CI: 0.72-0.85), 0.66 (95% CI: 0.58-0.73) and 0.80 (95% CI: 0.73-0.86). Both sensitivity and specificity of the Mini-Cog were superior to those of the AD8 (sensitivity 78.79% vs. 56.06%; specificity 79.79% vs. 75.53%). Cognitive screening is crucial to maintain the quality of life of older adults. Compared with the AD8, the Mini-Cog test is a more effective tool for screening cognitive impairment in older adults.

Acetyl-11-keto-ß-boswellic acid ameliorates cognitive deficits and reduces amyloid-ß levels in APPswe/PS1dE9 mice through antioxidant and anti-inflammatory pathways.

Alzheimer's disease (AD) is a complex disease involved oxidative stress and inflammation in its pathogenesis. Acetyl-11-keto-ß-boswellic acid (AKBA) is an active triterpenoid compound from extracts of Boswellia serrata, which has been widely used as an antioxidant and anti-inflammatory agent. The present study was to determine whether AKBA, a novel candidate, could protect against cognitive and neuropathological impairments in AD. We found that AKBA treatment resulted in a significant improvement of learning and memory deficits, a dramatic decrease in cerebral amyloid-ß (Aß) levels and plaque burden, a profound alleviation in oxidative stress and inflammation, and a marked reduction in activated glial cells and synaptic defects in the APPswe/PS1dE9 mice. Furthermore, amyloid precursor protein (APP) processing was remarkably suppressed with AKBA treatment by inhibiting beta-site APP cleaving enzyme 1 (BACE1) protein expression to produce Aß in the APPswe/PS1dE9 mice brains. Mechanistically, AKBA modulated antioxidant and anti-inflammatory pathways via increasing nuclear erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression, and via declining phosphorylation of inhibitor of nuclear factor-kappa B alpha (IκBα) and p65. Collectively, our findings provide evidence that AKBA protects neurons against oxidative stress and inflammation in AD, and this neuroprotective effect involves the Nrf2/HO-1 and nuclear factor-kappa B (NF-κB) signaling pathways.

A case report of disseminated nocardiosis with ocular involvement in a myasthenia gravis patient and literature review.

BACKGROUND: Nocardiosis is a rare and life-threatening opportunistic infection in immunocompromised patients. Myasthenia gravis (MG) patients are potentially at risk of nocardia infection because of the use of immunosuppressive agents. To date, only 7 patients with MG have been reported to have nocardiosis. Disseminated nocardiosis with ocular involvement has not been reported in MG patients. CASE PRESENTATION: A 66-year-old man with MG who was receiving treatment with methylprednisolone and azathioprine was found to have a respiratory infection. He also had heterogeneous symptoms with skin, brain and ocular manifestations. Nocardia bacteria verified by the culture of puncture fluid, and a diagnosis of disseminated nocardiosis was made. Except for left eye blindness, the patient completely recovered from the disease with combination antibiotic therapy. To further understand nocardiosis in patients with MG, we reviewed the previous relevant literature. According to the literature, this is the first report of disseminated nocardiosis with ocular involvement in an MG patient. CONCLUSIONS: MG patients with immunosuppressant treatments are potentially at risk of a rare nocardia infection, and a favourable prognosis can be achieved through early diagnosis and appropriate antibiotic therapy.

A SIRT1 agonist reduces cognitive decline in type 2 diabetic rats through antioxidative and anti­inflammatory mechanisms.

Sirtuin 1 (SIRT1) is an NAD+­dependent protein deacetylase that is involved in cell differentiation, aging, apoptosis, physiological rhythms, metabolic regulation, oxidative stress and numerous other important biological processes. In the present study, the ability of a sirtuin­1 (SIRT1) agonist, SRT1720, to reduce cognitive decline in type 2 diabetes mellitus (T2DM) was investigated. Streptozotocin­induced male Sprague­Dawley rats were used to establish a T2DM model and the protective effect of SRT1720 and its underlying mechanisms were investigated. Body weight and fasting blood glucose (FBG) were recorded and cognitive function was measured with the Morris water maze. Levels of oxidative stress, inflammation, caspase­3 activity and nuclear factor κB (NF­κB) mRNA expression were detected with a series of commercial assay kits and reverse transcription­quantitative polymerase chain reaction, respectively. Western blot analysis was performed to determine the protein expression of NF­κB, endothelial nitric oxide synthase (eNOS), peroxisome proliferator­activated receptor γ (PPARγ), AMP­activated protein kinase (AMPK), heat shock 70 kDa protein (HSP70), SIRT1, nuclear factor erythroid 2­related factor 2 (Nrf2) and heme oxygenase 1 (HO­1). The results revealed that SRT1720 significantly increased body weight, decreased FBG, improved cognitive function and reduced the levels of proteins associated with oxidative stress and inflammation damage in T2DM rats. Additionally, SRT1720 significantly decreased NF­κB p65 mRNA expression and increased eNOS and PPARγ expression. SRT1720 significantly reduced caspase­3 activity and HSP70 protein expression, and increased p­AMPK, SIRT1, Nrf2 and HO­1 protein expression. Collectively, the results indicate that SRT1720 may reduce cognitive decline in T2DM rats through antioxidative and anti­inflammatory action via NF­κB and AMPK­dependent mechanisms.

Activation of Wnt3a signaling promotes myogenic differentiation of mesenchymal stem cells in mdx mice.

AIM: Duchenne muscular dystrophy (DMD) is an X-linked genetic muscular disorder with no effective treatment at present. Mesenchymal stem cell (MSC) transplantation has been used to treat DMD, but the efficiency is low. Our previous studies show that activation of Wnt3a signaling promotes myogenic differentiation of MSCs in vitro. Here we report an effective MSC transplantation therapy in mdx mice by activation of Wnt3a signaling. METHODS: MSCs were isolated from mouse bone marrow, and pretreated with Wnt3a-conditioned medium (Wnt3a-CM), then transplanted into mdx mice. The recipient mice were euthanized at 4, 8, 12, 16 weeks after the transplantation, and muscle pathological changes were examined. The expression of dystrophin in muscle was detected using immunofluorescence staining, RT-PCR and Western blotting. RESULTS: Sixteen weeks later, transplantation of Wnt3a-pretreated MSCs in mdx mice improved the characteristics of dystrophic muscles evidenced by significant reductions in centrally nucleated myofibers, the variability range of cross-sectional area (CSA) and the connective tissue area of myofibers. Furthermore, transplantation of Wnt3a-pretreated MSCs in mdx mice gradually and markedly increased the expression of dystrophin in muscle, and improved the efficiency of myogenic differentiation. CONCLUSION: Transplantation of Wnt3a-pretreated MSCs in mdx mice results in long-term amelioration of the dystrophic phenotype and restores dystrophin expression in muscle. The results suggest that Wnt3a may be a promising candidate for the treatment of DMD.

Rapid eye movement sleep behavior disorder in patients with probable Alzheimer's disease.

BACKGROUND AND AIMS: Rapid eye movement (REM) sleep behavior disorder (RBD) is commonly associated with neurodegenerative disorders characterized by α-synuclein deposition, including Parkinson's disease, multiple system atrophy, and Lewy body dementia. However, this tendency in tauopathy-mediated diseases is rare and only sporadically reported. We systematically illustrate the occurrence of RBD and sleep features among a cohort of patients with Alzheimer's disease (AD), a non-synucleinopathy. METHODS: We recruited 105 clinically probable AD patients. Fifteen clinically probable AD patients with suspected RBD underwent a video-polysomnography (vPSG) examination. RESULTS: Five patients with probable AD exhibited RBD. One of the patients performed repeated touching of the head and the face with his hands and flailed his arms. Three patients exhibited hand twisting, exploring, prominent limb kicking, and jerking. The fifth patient exhibited all of the characteristics of RBD (he recalled a dream about fighting animals), and his wife was awakened by his screaming. Of these five patients, one patient took the acetylcholinesterase inhibitor drug donepezil. The patients with AD + RBD demonstrated increases in both tonic and phasic electromyography activity during REM sleep, but sleep architecture did not differ between the AD + RBD and AD-alone groups. CONCLUSION: RBD can occur in patients with AD. The occurrence of RBD does not change the sleep architecture of AD patients.

Longitudinal alteration of amygdalar functional connectivity in mild cognitive impairment subjects revealed by resting-state FMRI.

Mild cognitive impairment (MCI) is considered to be the prodromal stage of Alzheimer's disease. The amygdala, which is considered to be a hub, has been shown to have widespread brain connections with many cortical regions. Longitudinal alterations in the functional connectivity of the amygdala remain unclear in MCI. We hypothesized that the impairment in the amygdala-cortical loop would be more severe in a follow-up MCI group than in a baseline MCI group and that these alterations would be related to the disease processes. To test this hypothesis, we used resting-state functional magnetic resonance imaging to investigate alterations in amygdalar connectivity patterns based on longitudinal data from 13 MCI subjects (8 males and 5 females). Compared to the baseline, decreases in functional connectivity were mainly found located between the amygdala and regions at the conjunction of the temporal-occipital system and the regions included in the default mode network in the follow-up MCI individuals. The alterations in the functional connectivity of the identified regions were validated in an independent dataset. Specifically, reduced amygdalar connectivity was significantly correlated with cognitive abilities. These findings indicate that impairments in the functional connectivity of the amygdala may be potential biomarkers of the progression of MCI.

Cerebral microbleeds are associated with deep white matter hyperintensities, but only in hypertensive patients.

Cerebral microbleeds (CMBs) and white matter hyperintensities (WMH) are the most common manifestations of small vessel disease, and often co-occur in patients with cerebral vascular disease. Hypertension is widely accepted as a risk factor for both CMBs and WMH. However, the effect of hypertension on the association between CMBs and WMH remains unclear. We hypothesized that the relationship between CMBs and WMH is determined by hypertension. One hundred forty-eight patients with acute cerebrovascular disease who were admitted to PLA general hospital in Beijing, China from February 2010 to May 2011 were recruited in this study. CMBs on T2*-weighted angiography (SWAN) were assessed using the Brain Observer Microbleed Rating Scale criteria. The severity of the WMH was separately assessed as either peri-ventricular hyperintensities (PVH) or deep white matter hyperintensities (DWMH). The association among CMBs and the severity of WMH, and hypertension were determined. CMBs were found in 65 (43.9%) patients. The frequency of CMBs was related to the severity of DWMH and PVH. CMBs were more frequently observed in patients with hypertension compared to patients without hypertension (51.3% vs. 20.0%, p = 0.001). Hypertension was an independent risk factor for CMBs (odds ratio 5.239, p = 0.001) and DWMH (odds ratio 2.373, p = 0.040). Furthermore, the relationship between the presence of CMBs and the severity of DWMH was only found in patients with hypertension (r = 0.298, p<0.01). However, CMBs were associated with PVH independently of hypertension. This study demonstrated that hypertension determined the association between CMBs and DWMH.

[Application of A(2)DS(2) score for predicting post-stroke pneumonia in elderly patients].

OBJECTIVE: To investigate the risk factors for post-stroke pneumonia and assess the value of A(2)DS(2) score in predicting post-stroke pneumonia in elderly stroke patients. METHODS: The clinical data were retrospectively collected from elderly stroke patients from January, 2007 to December, 2012. A(2)DS(2) score was then assigned using the clinical information from the medical record. The ability of the score to discriminate between patients with post-stroke pneumonia and those without was quantified using ROC analysis. The calibration of the score was analyzed using Hosmer-Lemeshow goodness-of-fit test. RESULTS: A total of 131 elderly male stroke patients were enrolled in this study, among whom the incidence of post-stroke pneumonia was 29.01%. The independent risk factors for post-stroke pneumonia identified included moderate (P=0.0081, OR: 5.6089; 95%CI: 1.5663-20.0854) and severe (P=0.0048, OR: 44.4827; 95%CI: 3.1847-621.3126) neurological impairment, dysphagia (P=0.0005, OR: 7.5265; 95%CI: 2.4282-23.3292), and atrial fibrillation (P=0.0226, OR: 4.1778; 95%CI: 1.2221-14.2825). The incidence of post-stroke pneumonia ranged from 2.2% in patients with a A(2)DS(2) score less than 3 to 75% in those with a score higher than 8. The C-statistic of A(2)DS(2) score for predicting post-stroke pneumonia was 0.86 (95%CI: 0.784-0.911) by the ROC analysis. The A(2)DS(2) score was well calibrated to predict post-stroke pneumonia in elderly patients by Hosmer-Lemeshow test (7.083, P=0.528). CONCLUSION: The A(2)DS(2) score can be useful for predicting post-stroke pneumonia and for routine monitoring of high-risk elderly stroke patients in the clinical setting.

[A follow-up study on cognitive changes of mild cognitive impairment in the elderly].

OBJECTIVE: To observe and assess the cognitive changes of mild cognitive impairment (MCI) in the elderly. METHODS: A cohort study design was conducted among 47 patients with MCI and 21 control selected from the same convalescent camp, Montreal cognitive assessment (MoCA), mini mental state examination (MMSE) and clock drawing test (CDT) were performed to all subjects at the onset of study and 12 months later. RESULTS: The score of MMSE, CDT, MoCA and its subitems including visuospatial skill and delayed recall of MCI group were lower than the baseline after 12 months, with significantly decline in the score of MoCA (P = 0.041) and delay recall (P = 0.003). There was no obvious difference in the score of control between the baseline and that after 12 months. CONCLUSION: The decline of delayed recall occurred early and significantly, which may be a predictor in the conversion of mild cognitive impairment to dementia.

[A cross-sectional study of neurological disease in the veterans of military communities in Beijing].

OBJECTIVE: To investigate the prevalence of cognitive and motor disorders as well as emotional and sleep abnormality in the veterans from military communities in Beijing. METHODS: The participants underwent a comprehensive in-person evaluation including detailed neuropsychological testing, Hospital Anxiety and Depression Scale and special questionnaires for movement and sleep disorders. RESULTS: The overall prevalence of cognitive impairment, extrapyramidal diseases was 32.7%, 8.8%. The prevalence of mild cognitive impairment, dementia, Parkinson disease, essential tremor, anxiety and depression was 26.2%, 6.5%, 2.0%, 6.1%, 1.4% and 4.1% respectively. Prevalence of all kinds of sleep disorders ranged from 10.3% to 53.9%. The prevalence of cognitive impairment had no significant difference of sex, but were correlated to age and education, the correlation coefficient was 0.326 and -0.221 (P<0.01). CONCLUSION: Veterans from military communities had higher prevalence of cognitive impairment, extrapyramidal diseases and sleep disorders and lower that of anxiety and depression relatively.

Inhibition of myostatin promotes myogenic differentiation of rat bone marrow-derived mesenchymal stromal cells.

BACKGROUND AIMS: Mesenchymal stromal cells (MSC) have been thought to be attractive candidates for the treatment of Duchenne muscular dystrophy (DMD), but the rate of MSC myogenesis is very low. Thus MSC treatment for DMD is restricted. Myostatin (Mstn), a negative regulator of myogenesis, is known to be responsible for limiting skeletal muscle regeneration. We hypothesized that inhibition of Mstn by using anti-Mstn antibody (Ab) would ameliorate the myogenic differentiation of MSC in vitro and in vivo. METHODS: MSC were isolated from rat bone marrow. Induced rat MSC (rMSC) were treated with various concentrations of anti-Mstn Ab. The expression of myogenic differentiation antigen (MyoD), myogenin and myosin heavy chain-type alpha (MHC-alpha) were estimated by immunofluorescence analysis and reverse transcription-polymerase chain reaction (RT-PCR). Adipogenic differentiation of rMSC inhibited by anti-Mstn Ab was evaluated by Oil Red O staining. The expression of dystrophin was detected 16 weeks after anti-Mstn Ab injection and rMSC transplantation by immunofluorescence staining, RT-PCR and Western blot. Motor function, serum creatine kinase (CK) and histologic changes were also evaluated. RESULTS: Five-azacytidine-mediated myogenic differentiation induced significant endogenous Mstn expression. Anti-Mstn Ab improved the expression of MyoD, myogenin and MHC-alpha and inhibited adipocyte formation. Sixteen weeks after transplantation, the inhibition of Mstn had improved motor function and muscle mass. In accordance with the increased motor function and muscle mass, dystrophin expression had increased. Furthermore, serum CK and centrally nucleated fiber (CNF) levels decreased slightly, suggesting specific pathologic features of the dystrophic muscle were partially restored. CONCLUSIONS: Using anti-Mstn Ab, we found that inhibition of Mstn improved myogenic differentiation of rMSC in vitro and in vivo. A combination of Mstn blockade and MSC transplantation may provide a pharmacologic and cell-based strategy for the treatment of DMD.

[Comparison of transduction efficiencies of various gene vectors in human bone-marrow-derived mesenchymal stem cells].

OBJECTIVE: To compare the transduction efficiencies of adenoviral vector, adeno-associated viral vector, baculoviral vector, and plasmid vector in human bone-marrow-derived mesenchymal stem cells (hBMSCs). METHODS: The hBMSCs were cultured in vitro and transducted with the adenoviral vector, adeno-associated viral vector, baculoviral vector, and plasmid vector. The expression of target protein was observed by inverted fluorescent microscopy and flow cytometry. RESULTS: Inverted fluorescent microscopy showed that some of the hBMSCs after transduction expressed the green fluorescent protein (GFP) and the hBMSCs transducted with baculoviral vector expressed more GFP than those of other three vectors. Flow cytometry showed that the transduction efficiencies and mean fluorescence intensities of the adenoviral vector, adeno-associated viral vector, and plasmid vector were 42%, 37%, and 22% and 158, 115, and 77, respectively, which were significantly lower than those of baculoviral vector (70%, P < 0.01; 212, P < 0.05; respectively). CONCLUSION: Compared with the adenoviral vector, adeno-associated viral vector, and plasmid vector, the baculoviral vector has higher transduction efficiency in hBMSCs and therefore may be a more suitable gene vector for research in human gene therapy.

Comparative study of mesenchymal stem cells from C57BL/10 and mdx mice.

BACKGROUND: Human mesenchymal stem cells (MSCs) have been studied and applied extensively because of their ability to self-renew and differentiate into various cell types. Since most human diseases models are murine, mouse MSCs should have been studied in detail. The mdx mouse - a Duchenne muscular dystrophy model - was produced by introducing a point mutation in the dystrophin gene. To understand the role of dystrophin in MSCs, we compared MSCs from mdx and C57BL/10 mice, focusing particularly on the aspects of light and electron microscopic morphology, immunophenotyping, and differentiation potential. RESULTS: Our study showed that at passage 10, mdx-MSCs exhibited increased heterochromatin, larger vacuoles, and more lysosomes under electron microscopy compared to C57BL/10-MSCs. C57BL/10-MSCs formed a few myotubes, while mdx-MSCs did not at the same passages. By passage 21, mdx-MSCs but not C57BL/10-MSCs had gradually lost their proliferative ability. In addition, a significant difference in the expression of CD34, not Sca-1 and CD11b, was observed between the MSCs from the 2 mice. CONCLUSION: Our current study reveals that the MSCs from the 2 mice, namely, C57BL/10 and mdx, exhibit differences in proliferative and myogenic abilities. The results suggest that the changes in mouse MSC behavior may be influenced by lack of dystrophin protein in mdx mouse.

Wnt3a signaling promotes proliferation, myogenic differentiation, and migration of rat bone marrow mesenchymal stem cells.

AIM: To investigate the effects of the wingless-related MMTV integration site 3A (Wnt3a) signaling on the proliferation, migration, and the myogenic and adipogenic differentiation of rat bone marrow mesenchymal stem cells (rMSC). METHODS: Primary MSC were isolated and cultured from Sprague-Dawley rats and characterized by flow cytometry. Mouse L cells were transfected with Wnt3a cDNA, and conditioned media containing active Wnt3a proteins were prepared. Cell proliferation was evaluated by cell count and 5-bromodeoxyuridine incorporation assay. The migration of rMSC was performed by using a transwell migration and wound healing assay. The myogenic and adipogenic differentiation in rMSC were examined by light microscopy, immunofluorescence, and RT-PCR at different time points after myogenic or adipogenic introduction. RESULTS: Wnt3a signaling induced beta-catenin nuclear translocation and activated the Wnt pathway in rMSC. In the presence of Wnt3a, rMSC proliferated more rapidly than the control cells, keeping their differentiation potential. Moreover, Wnt3a signaling induced 2.62% and 3.76% of rMSC-expressed desmin and myosin heavy chain after being cultured in myogenic medium. The myogenic differentiation genes, including Pax7, MyoD, Myf5, Myf4, and myogenin, were activated after Wnt3a treatment. On the other hand, Wnt3a inhibited the adipogenic differentiation in rMSC through the downregulated expression of CCAAT/enhancer-binding protein alpha (C/EBPalpha) and peroxisome proliferator-activated receptor gamma (PPARgamma). Furthermore, Wnt3a promoted the migration capacity of rMSC. CONCLUSION: The results indicate that Wnt3a signaling can induce myogenic differentiation in rMSC. Wnt3a signaling is also involved in the regulation of the proliferation and migration of rMSC. These results could provide a rational foundation for cell-based tissue repair in humans.

Enhanced effect of microdystrophin gene transfection by HSV-VP22 mediated intercellular protein transport.

BACKGROUND: Duchenne muscular dystrophy (DMD) is an X-linked recessive disease caused by mutations of dystrophin gene, there is no effective treatment for this disorder at present. Plasmid-mediated gene therapy is a promising therapeutical approach for the treatment of DMD. One of the major issues with plasmid-mediated gene therapy for DMD is poor transfection efficiency and distribution. The herpes simplex virus protein VP22 has the capacity to spread from a primary transduced cell to surrounding cells and improve the outcome of gene transfer. To improve the efficiency of plasmid-mediated gene therapy and investigate the utility of the intercellular trafficking properties of VP22-linked protein for the treatment for DMD, expression vectors for C-terminal versions of VP22-microdystrophin fusion protein was constructed and the VP22-mediated shuttle effect was evaluated both in vitro and in vivo. RESULTS: Our results clearly demonstrate that the VP22-microdystrophin fusion protein could transport into C2C12 cells from 3T3 cells, moreover, the VP22-microdystrophin fusion protein enhanced greatly the amount of microdystrophin that accumulated following microdystrophin gene transfer in both transfected 3T3 cells and in the muscles of dystrophin-deficient (mdx) mice. CONCLUSION: These results highlight the efficiency of the VP22-mediated intercellular protein delivery for potential therapy of DMD and suggested that protein transduction may be a potential and versatile tool to enhance the effects of gene delivery for somatic gene therapy of DMD.