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1.
Sci Transl Med ; 16(731): eadf4590, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38266107

RESUMO

The infrapatellar fat pad (IPFP) and synovium play essential roles in maintaining knee joint homeostasis and in the progression of osteoarthritis (OA). The cellular and transcriptional mechanisms regulating the function of these specialized tissues under healthy and diseased conditions are largely unknown. Here, single-cell and single-nuclei RNA sequencing of human IPFP and synovial tissues were performed to elucidate the cellular composition and transcriptional profile. Computational trajectory analysis revealed that dipeptidyl peptidase 4+ mesenchymal cells function as a common progenitor for IPFP adipocytes and synovial lining layer fibroblasts, suggesting that IPFP and synovium represent an integrated tissue unit. OA induced a profibrotic and inflammatory phenotype in mesenchymal lineage cells with biglycan+ intermediate fibroblasts as a major contributor to OA fibrosis. Apolipoprotein E (APOE) signaling from intermediate fibroblasts and macrophages was identified as a critical regulatory factor. Ex vivo incubation of human cartilage with soluble APOE accelerated proteoglycan degeneration. Inhibition of APOE signaling by intra-articular injection of an anti-APOE neutralizing antibody attenuated the progression of collagenase-induced OA in mice, demonstrating a detrimental effect of APOE on cartilage. Our studies provide a framework for designing further therapeutic strategies for OA by describing the cellular and transcriptional landscape of human IPFP and synovium in healthy versus OA joints.


Assuntos
Apolipoproteínas E , Transdução de Sinais , Humanos , Animais , Camundongos , Membrana Sinovial , Anticorpos Neutralizantes , Tecido Adiposo
2.
Adv Sci (Weinh) ; 11(3): e2303614, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38036301

RESUMO

Infrapatellar fat pad (IPFP) is closely associated with the development and progression of knee osteoarthritis (OA), but the underlying mechanism remains unclear. Here, it is find that IPFP from OA patients can secret small extracellular vesicles (sEVs) and deliver them into articular chondrocytes. Inhibition the release of endogenous osteoarthritic IPFP-sEVs by GW4869 significantly alleviated IPFP-sEVs-induced cartilage destruction. Functional assays in vitro demonstrated that IPFP-sEVs significantly promoted chondrocyte extracellular matrix (ECM) catabolism and induced cellular senescence. It is further demonstrated that IPFP-sEVs induced ECM degradation in human and mice cartilage explants and aggravated the progression of experimental OA in mice. Mechanistically, highly enriched let-7b-5p and let-7c-5p in IPFP-sEVs are essential to mediate detrimental effects by directly decreasing senescence negative regulator, lamin B receptor (LBR). Notably, intra-articular injection of antagomirs inhibiting let-7b-5p and let-7c-5p in mice increased LBR expression, suppressed chondrocyte senescence and ameliorated the progression of experimental OA model. This study uncovers the function and mechanism of the IPFP-sEVs in the progression of OA. Targeting IPFP-sEVs cargoes of let-7b-5p and let-7c-5p can provide a potential strategy for OA therapy.


Assuntos
Cartilagem Articular , Vesículas Extracelulares , Osteoartrite do Joelho , Humanos , Camundongos , Animais , Cartilagem Articular/metabolismo , Articulação do Joelho/metabolismo , Tecido Adiposo/metabolismo , Osteoartrite do Joelho/metabolismo , Vesículas Extracelulares/metabolismo
3.
Rev Cardiovasc Med ; 23(2): 65, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35229556

RESUMO

BACKGROUND: Renal denervation (RDN) is effective to lower systolic blood pressure (SBP) in essential hypertension. However, patient selection under medications remains an important unmet clinical need. METHODS: This multicenter study aimed at observing whether preprocedural features associated with increased renin-angiotensin-aldosterone activity influence RDN response. This study enrolled the patients who underwent RDN for uncontrolled hypertension. Medical records were reviewd and patients were divided into 2 groups depending by meeting any of the following conditions prior to RDN: (1) >10 mmHg of office SBP reduction after aldosterone inhibition, (2) aldosterone-renin ratio >30 or (3) slow flow on the renal angiogram. RDN responders were defined by a reduction in 24-hour mean ≥6 mmHg or by ≥1 class of antihypertensive drug withdraw. RESULTS: A total of 46 patients were enrolled, of which 27 (59%) were in control group A and 19 (41%) in group B. The baseline age, gender, office and 24-hour SBP (mean 140.0 ± 12.8 mmHg vs. 144.0 ± 16.5 mmHg, p = 0.577) were comparable, while the number of prescribed drug classes was fewer in group A (4.0 ± 1.3 vs. 4.9 ± 0.9, p = 0.014). The proportion patients with prescribed aldosterone antagonist or high aldosterone-renin ratios were higher in group B. At 12 months post RDN, the results were significantly better in group B in terms of mean change in office SBP (12.4 ± 23.5 mmHg vs. 29.9 ± 25.5 mmHg, p = 0.046) and the proportion of RDN responders (51.9% vs. 89.5%, p < 0.001). CONCLUSION: RDN was more effective in patients with any of 3 clinical indices.


Assuntos
Anti-Hipertensivos , Hipertensão , Anti-Hipertensivos/efeitos adversos , Pressão Sanguínea , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/cirurgia , Rim , Simpatectomia/efeitos adversos , Simpatectomia/métodos , Resultado do Tratamento
4.
J Formos Med Assoc ; 121(9): 1786-1797, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35115197

RESUMO

BACKGROUND/PURPOSE: Pharmacogenetics is a potential driver of the "East Asian paradox," in which East Asian acute coronary syndrome (ACS) patients receiving dual antiplatelet therapy (DAPT) with clopidogrel following percutaneous coronary intervention (PCI) demonstrate higher levels of platelet reactivity on treatment than Western patients, yet have lower ischemic risk and higher bleeding risk at comparable doses. However, the impact of pharmacogenetics, particularly regarding CYP2C19 genotype, on the pharmacodynamics of P2Y12 inhibitors has not been extensively studied in Taiwanese ACS patients as yet. METHODS: CYP2C19 genotyping and pharmacogenetic analysis was conducted on 102 subjects from the Switch Study, a multicenter, single-arm, open-label intervention study that examined the effects on platelet activity and clinical outcomes of switching from clopidogrel (75 mg daily) to low-dose prasugrel (3.75 mg daily) for maintenance DAPT after PCI in 203 Taiwanese ACS patients. RESULTS: Genotyping results revealed that 43.1% were CYP2C19 extensive metabolizers (EM), while 56.9% were reduced metabolizers (RM). After switching to prasugrel, mean P2Y12 reaction units (PRU) values were significantly reduced in both EM and RM populations, while the proportion of high on-treatment platelet reactivity (HPR) patients significantly declined in RM patients. No increase in bleeding risk after switching was observed during follow-up. Multivariate analysis indicated that for RM patients, low estimated glomerular filtration rate (eGFR) and low hemoglobin were associated with greater HPR risk on clopidogrel, but not after switching to prasugrel. CONCLUSION: Switching to low-dose prasugrel from clopidogrel reduced mean PRU levels and proportion of HPR patients, with more significant reduction in RM patients.


Assuntos
Síndrome Coronariana Aguda , Intervenção Coronária Percutânea , Clopidogrel , Citocromo P-450 CYP2C19 , Humanos , Inibidores da Agregação Plaquetária , Cloridrato de Prasugrel , Ticlopidina
6.
Cardiovasc Interv Ther ; 37(2): 269-278, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33813727

RESUMO

The recommended maintenance dose of prasugrel for East Asian populations (i.e., Japanese and Taiwanese) is 3.75 mg as part of dual antiplatelet therapy (DAPT) for the prevention of recurrent ischemia and stent thrombosis in acute coronary syndrome (ACS). This modified dosage regimen has been established in studies conducted in Japan; however, the efficacy and safety of switching from clopidogrel to prasugrel DAPT among Taiwanese patients remain to be explored. In this phase IV, multicenter, single-arm, open-label study, we evaluated the 4-week pharmacodynamic response, and the 48-week safety outcomes of prasugrel 3.75 mg after a switch from clopidogrel in Taiwanese ACS patients. A total of 203 prasugrel-naïve ACS patients (over 90% male) who had received post-PCI clopidogrel DAPT for at least 2 weeks were enrolled from ten medical centers in Taiwan and subsequently switched to prasugrel 3.75 mg DAPT. Four weeks after the switch, P2Y12 reaction unit (PRU) values were significantly decreased in the total cohort (mean - 18.2 ± 48.1; 95% confidence interval - 24.9 to - 11.5, p < 0.001), and there was an overall consistent antiplatelet response in the treated subjects. The proportion of patients with high on-treatment platelet reactivity (HPR; PRU > 208) dropped from 23.5 to 10% (p < 0.001). Female sex was associated with a greater PRU reduction with prasugrel, whereas HPR at baseline, age ≥ 65 years, and body mass index ≥ 25 best predicted HPR at Week 4. Throughout the 48-week treatment with prasugrel, the incidences of MACE (1.0%) and TIMI major bleeding (2.0%) were rather low, accompanying an acceptable safety profile of TIMI minor (6.4%) and non-major, non-minor clinically relevant bleeding (3.0%). Overall, switching to the maintenance dose of prasugrel (3.75 mg) was observed to be effective and well tolerated among post-PCI ACS patients in Taiwan. Clinical Trial Registration Number: NCT03672097.


Assuntos
Síndrome Coronariana Aguda , Intervenção Coronária Percutânea , Síndrome Coronariana Aguda/tratamento farmacológico , Síndrome Coronariana Aguda/cirurgia , Idoso , Clopidogrel/efeitos adversos , Feminino , Humanos , Masculino , Intervenção Coronária Percutânea/efeitos adversos , Inibidores da Agregação Plaquetária/efeitos adversos , Cloridrato de Prasugrel/efeitos adversos , Ticlopidina/uso terapêutico , Resultado do Tratamento
7.
Am J Cardiol ; 150: 77-81, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34006371

RESUMO

Since 1953, sinus tachycardia has been defined as a heart rate (HR) in sinus rhythm of >100 beats per minute (bpm). However, this number has never been formally evaluated, and no established threshold values for special groups, such as those with heart failure (HF) accompanied by a reduced ejection fraction (HFrEF). Herein, we provided evidence that lowering the HR of patients with HFrEF to <70 bpm with medications such as ivabradine improves outcomes. Numerous large-scale trials and smaller clinical studies have shown that reducing the HR in patients with HFrEF improves cardiovascular and overall outcomes. Evidence suggests that a HR of <70 bpm is appropriate for patients with HFrEF. Examination of HF registries indicates that in a large proportion of these patients the HR exceeds 80 bpm, and no consideration is given to lowering the HR, due in large part to lack of physician awareness of the benefits of a lower HR. Evidence indicates that the first-line medication for lowering HR in patients with HFrEF is ivabradine. In conclusion, the improved prognosis following appropriate HR management in patients with HFrEF suggest that the cut-off value for sinus tachycardia in these patients should be redefined as 75 bpm. Maintaining a HR of <70 bpm in patients with HFrEF is associated with improved cardiovascular and overall outcomes.


Assuntos
Fármacos Cardiovasculares/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Frequência Cardíaca/fisiologia , Volume Sistólico/fisiologia , Taquicardia/tratamento farmacológico , Taquicardia/fisiopatologia , Digoxina/uso terapêutico , Humanos , Ivabradina/uso terapêutico
8.
Acta Cardiol Sin ; 36(4): 326-334, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32675924

RESUMO

BACKGROUND: Temporary mechanical support, including percutaneous cardiopulmonary support (PCPS), is crucial for reversing patients' compromised hemodynamic function. Knowledge about whether cardiologists can directly manage patients receiving PCPS and about the predictive values of different prognostic scores is insufficient. METHODS: We examined the data and in-hospital mortality of 45 eligible patients receiving cardiologist-managed PCPS from July 2012 to January 2019 in our institute. We compared different prognostic scores [namely Survival After Veno-arterial ECMO (SAVE), modified SAVE, prEdictioN of Cardiogenic shock OUtcome foR acute myocardial infarction patients salvaGed by VA-ECMO (ENCOURAGE), and Sequential Organ Failure Assessment (SOFA) scores] through area under the receiver operating characteristic curve (AUC) analysis. RESULTS: The patients' mean age was 64.3 ± 11.3 years, and 71.1% were men. The overall in-hospital survival rate was 35.6%. Compared to survivors, nonsurvivors were more likely to have an ischemic etiology, cardiopulmonary resuscitation, and higher lactate levels. Survivors had higher SAVE (-5.9 vs. -11.4) and modified SAVE (4.2 vs. -7.1) scores than nonsurvivors (both p = 0.001), but SOFA (9.7 vs. 10.3) and ENCOURAGE (24.8 vs. 26.8) scores were similar (both p > 0.1). In multivariate models, only modified SAVE score remained statistically significant (hazard ratio: 0.96, 95% confidence interval: 0.93-1.00; p = 0.047). Modified SAVE score showed the best risk discrimination (AUC = 0.78). CONCLUSIONS: Establishing regular and continual training protocols can enable cardiologists to perform emergency PCPS (without on-site surgery) and daily care for patients with refractory cardiogenic shock. The modified SAVE score facilitates risk stratification and future decision-making processes.

9.
Stem Cell Res Ther ; 11(1): 33, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31973760

RESUMO

The original article [1] contains an error in Fig. 5 whereby sub-Fig. 5c, d & 5e are mistakenly mixed-up.

10.
Biochem Biophys Res Commun ; 522(2): 322-327, 2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-31761321

RESUMO

BACKGROUND: Hepcidin is a key regulator of iron homeostasis. Some studies showed that exogenous hepcidin decreased the expression of divalent metal transporter (DMT1) rather than ferroportin(FPN1) to regulate renal iron metabolism. This study explored the effects of hepcidin synthesized by the kidney and its mechanism of iron regulation. METHODS: In the in vivo experiments, mice were divided into a unilateral ureter obstruction (UUO) model group and a sham operation group, and mice in the UUO model group were sacrificed on days 1, 3, 5 and 7. The expression of renal hepcidin, FPN1, DMT1 and the retention of renal iron were studied. In the in vitro experiments, we overexpressed hepcidin in HK-2 cells. Then we tested the expression of renal hepcidin, FPN1, DMT1 and observed the production of intracellular ferrous ions. RESULTS: Renal hepcidin expression was consistently higher in the UUO group than in the sham group from the first day. The expression of FPN1 gradually decreased, and the expression of DMT1 gradually increased in the UUO model. Intracellular ferrous ions significantly increased on the first day of the UUO model. In hepcidin overexpressed HK-2 cells, the expression of FPN1 was decreased, while the expression of DMT1 has no significant change. In addition, production of intracellular ferrous ions increased. CONCLUSION: local hepcidin can regulate iron metabolism in the kidney by adjusting the expression of FPN1.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Hepcidinas/metabolismo , Espaço Intracelular/metabolismo , Sobrecarga de Ferro/metabolismo , Rim/metabolismo , Animais , Ferritinas/metabolismo , Ferro/metabolismo , Masculino , Camundongos Endogâmicos C57BL
11.
Stem Cell Res Ther ; 10(1): 357, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31779679

RESUMO

BACKGROUND: The degenerative disc disease (DDD) is a major cause of low back pain. The physiological low-glucose microenvironment of the cartilage endplate (CEP) is disrupted in DDD. Glucose influences protein O-GlcNAcylation via the hexosamine biosynthetic pathway (HBP), which is the key to stem cell fate. Thiamet-G is an inhibitor of O-GlcNAcase for accumulating O-GlcNAcylated proteins while 6-diazo-5-oxo-L-norleucine (DON) inhibits HBP. Mechanisms of DDD are incompletely understood but include CEP degeneration and calcification. We aimed to identify the molecular mechanisms of glucose in CEP calcification in DDD. METHODS: We assessed normal and degenerated CEP tissues from patients, and the effects of chondrogenesis and osteogenesis of the CEP were determined by western blot and immunohistochemical staining. Cartilage endplate stem cells (CESCs) were induced with low-, normal-, and high-glucose medium for 21 days, and chondrogenic and osteogenic differentiations were measured by Q-PCR, western blot, and immunohistochemical staining. CESCs were induced with low-glucose and high-glucose medium with or without Thiamet-G or DON for 21 days, and chondrogenic and osteogenic differentiations were measured by Q-PCR, western blot, and immunohistochemical staining. Sox9 and Runx2 O-GlcNAcylation were measured by immunofluorescence. The effects of O-GlcNAcylation on the downstream genes of Sox9 and Runx2 were determined by Q-PCR and western blot. RESULTS: Degenerated CEPs from DDD patients lost chondrogenesis, acquired osteogenesis, and had higher protein O-GlcNAcylation level compared to normal CEPs from LVF patients. CESC chondrogenic differentiation gradually decreased while osteogenic differentiation gradually increased from low- to high-glucose differentiation medium. Furthermore, Thiamet-G promoted CESC osteogenic differentiation and inhibited chondrogenic differentiation in low-glucose differentiation medium; however, DON acted opposite role in high-glucose differentiation medium. Interestingly, we found that Sox9 and Runx2 were O-GlcNAcylated in differentiated CESCs. Finally, O-GlcNAcylation of Sox9 and Runx2 decreased chondrogenesis and increased osteogenesis in CESCs. CONCLUSIONS: Our findings demonstrate the effect of glucose concentration on regulating the chondrogenic and osteogenic differentiation potential of CESCs and provide insight into the mechanism of how glucose concentration regulates Sox9 and Runx2 O-GlcNAcylation to affect the differentiation of CESCs, which may represent a target for CEP degeneration therapy.


Assuntos
Cartilagem/metabolismo , Diferenciação Celular/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Glucose/farmacologia , Lâmina de Crescimento/metabolismo , Osteogênese/efeitos dos fármacos , Fatores de Transcrição SOX9/metabolismo , Células-Tronco/metabolismo , Adulto , Cartilagem/citologia , Feminino , Glicosilação , Lâmina de Crescimento/citologia , Humanos , Masculino , Pessoa de Meia-Idade , Células-Tronco/citologia
12.
Comput Methods Programs Biomed ; 177: 175-182, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31319946

RESUMO

BACKGROUND AND OBJECTIVE: In the United States, lung cancer is the leading cause of cancer death. The survival rate could increase by early detection. In recent years, the endobronchial ultrasonography (EBUS) images have been utilized to differentiate between benign and malignant lesions and guide transbronchial needle aspiration because it is real-time, radiation-free and has better performance. However, the diagnosis depends on the subjective judgment from doctors. In some previous studies, which using the grayscale image textures of the EBUS images to classify the lung lesions but it belonged to semi-automated system which still need the experts to select a part of the lesion first. Therefore, the main purpose of this study was to achieve full automation assistance by using convolution neural network. METHODS: First of all, the EBUS images resized to the input size of convolution neural network (CNN). And then, the training data were rotated and flipped. The parameters of the model trained with ImageNet previously were transferred to the CaffeNet used to classify the lung lesions. And then, the parameter of the CaffeNet was optimized by the EBUS training data. The features with 4096 dimension were extracted from the 7th fully connected layer and the support vector machine (SVM) was utilized to differentiate benign and malignant. This study was validated with 164 cases including 56 benign and 108 malignant. RESULTS: According to the experiment results, applying the classification by the features from the CNN with transfer learning had better performance than the conventional method with gray level co-occurrence matrix (GLCM) features. The accuracy, sensitivity, specificity, and the area under ROC achieved 85.4% (140/164), 87.0% (94/108), 82.1% (46/56), and 0.8705, respectively. CONCLUSIONS: From the experiment results, it has potential ability to diagnose EBUS images with CNN.


Assuntos
Brônquios/diagnóstico por imagem , Diagnóstico por Computador , Neoplasias Pulmonares/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Ultrassonografia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Área Sob a Curva , Humanos , Pessoa de Meia-Idade , Redes Neurais de Computação , Reconhecimento Automatizado de Padrão , Curva ROC , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
13.
Stem Cells Int ; 2019: 8404168, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31249601

RESUMO

Stem cell therapies for intervertebral disc degeneration have been demonstrated as a promising strategy. Previous studies have shown that human nucleus pulposus cell- (NPC-) derived exosomes can induce the differentiation of mesenchymal stem cells (MSCs) into NP-like cells in vitro. However, the mechanism of MSC differentiation into NP-like cells with the induction of NPC exosomes is still unclear. Here, we verified the induction effects of NPC exosomes on the differentiation of MSCs into NP-like cells. In addition, the Notch1 pathway was downregulated in this process. Then, DAPT and soluble Jagged1 (SJAG) were applied to inhibit or enhance the expression of the Notch1 pathway, respectively, resulting in the upregulation or downregulation of collagen II, aggrecan, and Sox9 in MSCs. Knocking down of Notch1 protein facilitated the effects of NPC exosomes on the differentiation of MSCs into NP-like cells. NPC exosomes were more effective than an indirect coculture system in terms of the differentiation of MSCs into NP-like cells. Inhibition of NPC exosome secretion with Rab27a siRNA prevented the induction effects of an indirect coculture system on the differentiation of MSCs into NP-like cells. Transwell migration assays revealed that NPC exosomes could promote the migration of MSCs. Taken together, the Notch1 pathway was negatively associated with the differentiation of MSCs into NP-like cells with the treatments of NPC exosomes. Inhibition of the Notch1 pathway facilitates NPC exosome-induced differentiation of MSCs into NP-like cells in vitro. NPC exosomes play a key role in the differentiation of MSCs into NP-like cells in an indirect coculture system of NPCs and MSCs.

14.
Stem Cell Res Ther ; 10(1): 118, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30987681

RESUMO

BACKGROUND: Adult stem cells exist in a quiescent state (G0) within the in vivo niche; the loss of quiescence often leads to a decrease in the number and function of adult stem cells, impairing tissue regeneration and repair. Endogenous repair by nucleus pulposus-derived stem cells has recently shown promising regenerative potential for the treatment of intervertebral disc degeneration (IDD). However, the number and function of nucleus pulposus stem cells (NPSCs) declined throughout the process of IDD. This effect may have a specific relationship with quiescence. However, the biology of the quiescent NPSCs has not been reported. METHODS: First, we established an in vitro model for NPSC quiescence with serum starvation. The induction of G0 was confirmed by flow cytometry analyses of dual staining with Hoechst 33342 and Pyronin Y, immunofluorescent staining with Ki67 and Western blot analysis of P27 expression. NPSCs were cultured under serum starvation conditions for a long time period (21 days). To examine the functional phenotype of quiescent NPSCs, the cells were reactivated with 10% serum and differentiated into osteogenic and chondrogenic lineages in vitro. The number of colony-forming units was also estimated. To elucidate the role of autophagy in the quiescence of NPSCs, we activated and inhibited autophagy in starved cells with rapamycin and chloroquine, respectively. Then, the expression of P27 was evaluated by Western blot analysis, and the immunofluorescence of Ki67 was assessed. Finally, we assessed the role of P27 siRNA in NPSC quiescence by flow cytometry analyses and 5-ethynyl-20-deoxyuridine incorporation assays under normal and serum-starved conditions. RESULTS: NPSC quiescence was induced by 48 h of serum starvation, and they maintained quiescence for up to 21 days. Upon reactivation with serum, the quiescent NPSCs re-entered the cell cycle and exhibited enhanced clonogenic self-renewal, osteogenic differentiation and chondrogenic differentiation potentials compared to control NPSCs under normal culture conditions. We also found that autophagy underlay serum starvation-induced NPSC quiescence. Further study demonstrated that autophagy mediated the quiescence of NPSCs by regulating P27. CONCLUSIONS: Serum starvation efficiently induces quiescence in NPSCs. Quiescent NPSCs maintain stem cell properties. Our study reveals that autophagy plays a role in maintaining NPSC quiescence and that autophagy mediates the quiescence of NPSCs by regulating P27. We conclude that the induction of quiescence in cultured NPSCs provides a useful model for the analysis of mechanisms that might be relevant to the biology of NPSCs in vivo.


Assuntos
Células-Tronco Adultas/metabolismo , Morte Celular Autofágica , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Núcleo Pulposo/metabolismo , Células-Tronco Adultas/patologia , Animais , Núcleo Pulposo/patologia , Ratos , Ratos Sprague-Dawley
15.
Stem Cell Res Ther ; 10(1): 30, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30646958

RESUMO

BACKGROUND: Radiotherapy to cancer patients is inevitably accompanied by normal tissue injury, and the bone is one of the most commonly damaged tissues. Damage to bone marrow mesenchymal stem cells (BM-MSCs) induced by radiation is thought to be a major cause of radiation-induced bone loss. Exosomes exhibit great therapeutic potential in the treatment of osteoporosis, but whether exosomes are involved in radiation-induced bone loss has not been thoroughly elucidated to date. The main purpose of this study is to investigate the role of exosomes derived from BM-MSCs in restoring recipient BM-MSC function and alleviating radiation-induced bone loss. METHODS: BM-MSC-derived exosomes were intravenously injected to rats immediately after irradiation. After 28 days, the left tibiae were harvested for micro-CT and histomorphometric analysis. The effects of exosomes on antioxidant capacity, DNA damage repair, proliferation, and cell senescence of recipient BM-MSCs were determined. Osteogenic and adipogenic differentiation assays were used to detect the effects of exosomes on the differentiation potential of recipient BM-MSCs, and related genes were measured by qRT-PCR and Western blot analysis. ß-Catenin expression was detected at histological and cytological levels. RESULTS: BM-MSC-derived exosomes can attenuate radiation-induced bone loss in a rat model that is similar to mesenchymal stem cell transplantation. Exosome-treated BM-MSCs exhibit reduced oxidative stress, accelerated DNA damage repair, and reduced proliferation inhibition and cell senescence-associate protein expression compared with BM-MSCs that exclusively received irradiation. Following irradiation, exosomes promote ß-catenin expression in BM-MSCs and restore the balance between adipogenic and osteogenic differentiation. CONCLUSIONS: Our findings indicate that BM-MSC-derived exosomes take effects by restoring the function of recipient BM-MSCs. Therefore, exosomes may represent a promising cell-free therapeutic approach for the treatment of radiation-induced bone loss.

16.
World Neurosurg ; 112: e255-e260, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29325949

RESUMO

OBJECTIVE: To compare the efficacy and safety of minimally endoscopic discectomy (MED) and percutaneous endoscopic lumbar discectomy (PELD) in the treatment of adolescent lumbar disc herniation (ALDH). METHODS: We retrospectively collected data from 30 patients with ALDH who underwent MED and 48 patients with ALDH who underwent PELD at our hospital between January 2010 and January 2012. Baseline data included age, sex, symptom duration, and surgical segment. Perioperative data included duration of surgery duration, blood loss, and duration of postoperative hospitalization. The Oswestry Disability Index (ODI) and visual analog scale (VAS) for both the lower back and leg were recorded as surgical outcomes. All surgical outcomes were recorded before surgery, at 1 week after surgery, at 6 months after surgery, and at final follow-up. RESULTS: There were no significant differences in baseline data between the MED and PELD groups. Both groups showed improvements in ODI and VAS scores before surgery and at the final follow-up time point (P < 0.05); however, the MED group had a higher mean ODI score at 1 week (12.44 ± 6.39 vs. 7.25 ± 6.40; P = 0.02) and 6 months (9.33 ± 7.43 vs. 3.97 ± 7.64; P = 0.04) after surgery. In addition, mean VAS scores for lower back pain were higher in the MED group at 1 week (1.93 ± 1.39 vs. 0.91 ± 0.85; P = 0.01), 6 months (1.80 ± 1.15 vs. 0.61 ± 0.94; P = 0.00), and final follow-up (1.87 ± 1.46 vs. 0.65 ± 0.88; P = 0.00), as was mean VAS score for radicular pain at 1 week after surgery (1.48 ± 0.76 vs. 0.74 ± 0.81; P = 0.01). One patient in each group experienced recurrent lumbar disc herniation. No other complications were reported in either group. CONCLUSIONS: Both PELD and MED are effective and safe surgical techniques for the treatment of ALDH; however, compared with MED, PELD is more advantageous for lower back pain and provides more rapid resolution of radicular pain.


Assuntos
Discotomia Percutânea/métodos , Endoscopia/métodos , Deslocamento do Disco Intervertebral/cirurgia , Adolescente , Discotomia/métodos , Feminino , Seguimentos , Humanos , Vértebras Lombares/cirurgia , Masculino , Estudos Retrospectivos , Resultado do Tratamento
17.
Am J Physiol Heart Circ Physiol ; 301(3): H1166-72, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21622817

RESUMO

Gap junctions play a key role in maintaining the functional integrity of the vascular wall. Using carbenoxolone (CBX) as a gap junction blocker, we aimed to assess the contribution of gap junctions in the vascular wall to flow-mediated vasodilatation (FMD) in healthy adults. Percentage FMD (%FMD) and circulating vasoactive molecules/activity, including atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), aldosterone, cortisol, plasma renin activity (PRA), and endothelin (ET-1), were measured in 25 healthy volunteers (mean age: 30.1 ± 5.4 yr; 14 males) before and after oral administration of CBX (100 mg). %FMD decreased after ingestion of CBX (9.71 ± 3.1 vs. 3.40 ± 2.0%; P < 0.0001). The levels of ANP, BNP, cortisol, and ET-1 remained stationary, while both PRA and aldosterone decreased (P < 0.005) after CBX ingestion. Blood pressure and heart rate were minimally changed by CBX. Inhibition of gap junctional communication by CBX impairs FMD in healthy persons, suggesting that physiologically, vascular gap junctions participate in the maintenance of FMD. CBX does not induce the release of vasoconstricting molecules or enhance vasoconstriction, suggesting that inhibition of gap junctional communication by CBX underlies the impairment of FMD. Therefore, administering CBX in FMD examination can be a way to follow the effect of gap junctions on endothelial function, but further work remains to verify the specificity of CBX effect.


Assuntos
Artéria Braquial/efeitos dos fármacos , Carbenoxolona/farmacologia , Endotélio Vascular/efeitos dos fármacos , Junções Comunicantes/efeitos dos fármacos , Hiperemia/fisiopatologia , Vasodilatação/efeitos dos fármacos , Administração Oral , Adulto , Aldosterona/sangue , Fator Natriurético Atrial/sangue , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/metabolismo , Artéria Braquial/fisiopatologia , Carbenoxolona/administração & dosagem , Endotelina-1/sangue , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Junções Comunicantes/metabolismo , Humanos , Hidrocortisona/sangue , Hiperemia/sangue , Hiperemia/diagnóstico por imagem , Modelos Lineares , Masculino , Peptídeo Natriurético Encefálico/sangue , Fluxo Sanguíneo Regional/efeitos dos fármacos , Renina/sangue , Fatores de Tempo , Ultrassonografia
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