Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
J Am Chem Soc ; 146(31): 21568-21582, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39051165

RESUMO

The heterogeneity of hepatocellular carcinoma (HCC) can prevent effective treatment, emphasizing the need for more effective therapies. Herein, we employed arsenene nanosheets coated with manganese dioxide and polyethylene glycol (AMPNs) for the degradation of Pin1, which is universally overexpressed in HCC. By employing an "AND gate", AMPNs exhibited responsiveness toward excessive glutathione and hydrogen peroxide within the tumor microenvironment, thereby selectively releasing AsxOy to mitigate potential side effects of As2O3. Notably, AMPNs induced the suppressing Pin1 expression while simultaneously upregulation PD-L1, thereby eliciting a robust antitumor immune response and enhancing the efficacy of anti-PD-1/anti-PD-L1 therapy. The combination of AMPNs and anti-PD-1 synergistically enhanced tumor suppression and effectively induced long-lasting immune memory. This approach did not reveal As2O3-associated toxicity, indicating that arsenene-based nanotherapeutic could be employed to amplify the response rate of anti-PD-1/anti-PD-L1 therapy to improve the clinical outcomes of HCC patients and potentially other solid tumors (e.g., breast cancer) that are refractory to anti-PD-1/anti-PD-L1 therapy.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Compostos de Manganês , Peptidilprolil Isomerase de Interação com NIMA , Óxidos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Óxidos/química , Óxidos/farmacologia , Humanos , Peptidilprolil Isomerase de Interação com NIMA/antagonistas & inibidores , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Compostos de Manganês/química , Compostos de Manganês/farmacologia , Nanoestruturas/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Arsenicais/química , Arsenicais/farmacologia , Arsenicais/uso terapêutico , Camundongos , Animais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Linhagem Celular Tumoral , Polietilenoglicóis/química
2.
J Virol ; 94(23)2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-32967957

RESUMO

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus which has become a global epidemic threat due to its rapid spread and association with serious consequences of infection, including neonatal microcephaly. Inositol-requiring enzyme 1α (IRE1α) is an endoplasmic reticulum (ER)-related transmembrane protein that mediates unfolded protein response (UPR) pathway and has been indicated to play an important role in flavivirus replication. However, the mechanism of how IRE1α affects ZIKV replication remains unknown. In this study, we explored the role of IRE1α in ZIKV infection in vitro and in vivo by using CRISPR/Cas9-based gene knockout and RNA interference-based gene knockdown techniques. Both knockout and knockdown of IRE1α dramatically reduced ZIKV replication levels, including viral RNA levels, protein expression, and titers in different human cell lines. Trans-complementation with IRE1α restored viral replication levels decreased by IRE1α depletion. Furthermore, the proviral effect of IRE1α was dependent on its kinase and RNase activities. Importantly, we found that IRE1α promoted the replication of ZIKV through upregulating the accumulation of monounsaturated fatty acid (MUFA) rate-limiting enzyme stearoyl coenzyme A (stearoyl-CoA) desaturase 1 (SCD1), which further affected the production of oleic acid (OA) and lipid droplet. Finally, our data demonstrated that in the brain tissues of ZIKV-infected mice, the replication levels of ZIKV and virus-related lesions were significantly suppressed by both the kinase and RNase inhibitors of IRE1α. Taken together, our results identified IRE1α as a ZIKV dependency factor which promotes viral replication through affecting SCD1-mediated lipid metabolism, potentially providing a novel molecular target for the development of anti-ZIKV agents.IMPORTANCE Zika virus (ZIKV) has been linked to serious neurologic disorders and causes widespread concern in the field of global public health. Inositol requiring enzyme 1α (IRE1α) is an ER-related transmembrane protein that mediates unfolded protein response (UPR) pathway. Here, we revealed that IRE1α is a proviral factor for ZIKV replication both in culture cells and mice model, which relies on its kinase and RNase activities. Importantly, we further provided evidence that upon ZIKV infection, IRE1α is activated and splices XBP1 mRNA which enhances the expression of monounsaturated fatty acids rate-limiting enzyme stearoyl coenzyme A (stearoyl-CoA) desaturase 1 (SCD1) and subsequent lipid droplet production. Our data uncover a novel mechanism of IRE1α proviral effect by modulating lipid metabolism, providing the first evidence of a close relationship between IRE1α-mediated UPR, lipid metabolism, and ZIKV replication and indicating IRE1α inhibitors as potentially effective anti-ZIKV agents.


Assuntos
Endorribonucleases/metabolismo , Inositol/metabolismo , Metabolismo dos Lipídeos/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Estearoil-CoA Dessaturase/metabolismo , Infecção por Zika virus/metabolismo , Zika virus/metabolismo , Células A549 , Animais , Encéfalo/patologia , Encéfalo/virologia , Sistemas CRISPR-Cas , Linhagem Celular , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Endorribonucleases/genética , Edição de Genes , Técnicas de Inativação de Genes , Humanos , Camundongos , Ácido Oleico/metabolismo , Proteínas Serina-Treonina Quinases/genética , Estearoil-CoA Dessaturase/genética , Resposta a Proteínas não Dobradas , Replicação Viral/fisiologia , Infecção por Zika virus/patologia
3.
J Biol Chem ; 294(48): 18168-18180, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31636123

RESUMO

Zika virus (ZIKV) is a mosquito-borne flavivirus that has emerged as a threat to global health. The family of adenosine deaminases acting on dsRNA (ADARs) are human host factors important for the genetic diversity and evolution of ZIKV. Here, we further investigated the role of ADAR1 in ZIKV replication by utilizing CRISPR/Cas9-based gene editing and RNAi-based gene knockdown techniques. Both ADAR1 knockout and knockdown significantly reduced ZIKV RNA synthesis, protein levels, and viral titers in several human cell lines. Trans-complementation with the full-length ADAR1 form p150 or the shorter form p110 lacking the Zα domain restored viral replication levels suppressed by the ADAR1 knockout. Moreover, we observed that the nuclear p110 form was redistributed to the cytoplasm in response to ZIKV infection. ADAR1 was not involved in viral entry but promoted viral protein translation by impairing ZIKV-induced activation of protein kinase regulated by dsRNA (PKR). Of note, the RNA-editing activity of ADAR1 was not required to promote ZIKV replication. We also found that the proviral role of ADAR1 was partially mediated through its ability to suppress IFN production and PKR activation. Our work identifies ADAR1 as a proviral factor involved in ZIKV replication, suggesting that ADAR1 could be a potential antiviral target.


Assuntos
Adenosina Desaminase/metabolismo , Biossíntese de Proteínas/fisiologia , Proteínas de Ligação a RNA/metabolismo , Proteínas Virais/biossíntese , Replicação Viral/fisiologia , Zika virus/fisiologia , eIF-2 Quinase/metabolismo , Células A549 , Adenosina Desaminase/genética , Animais , Chlorocebus aethiops , Ativação Enzimática , Células HEK293 , Humanos , Proteínas de Ligação a RNA/genética , Células Vero , Proteínas Virais/genética , eIF-2 Quinase/genética
4.
Retrovirology ; 14(1): 56, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29258557

RESUMO

BACKGROUND: MOV10 protein has ATP-dependent 5'-3' RNA helicase activity and belongs to the UPF1p superfamily. It can inhibit human immunodeficiency virus type 1 (HIV-1) replication at multiple stages and interact with apolipoprotein-B-mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G or A3G), a member of the cytidine deaminase family that exerts potent inhibitory effects against HIV-1 infection. However, HIV-1-encoded virion infectivity factor (Vif) protein specifically mediates the degradation of A3G via the ubiquitin-proteasome system (UPS). RESULTS: We demonstrate that MOV10 counteracts Vif-mediated degradation of A3G by inhibiting the assembly of the Vif-CBF-ß-Cullin 5-ElonginB-ElonginC complex. Through interference with UPS, MOV10 enhances the level of A3G in HIV-1-infected cells and virions, and synergistically inhibits the replication and infectivity of HIV-1. In addition, the DEAG-box of MOV10 is required for inhibition of Vif-mediated A3G degradation as the DEAG-box mutant significantly loses this ability. CONCLUSIONS: Our results demonstrate a novel mechanism involved in the anti-HIV-1 function of MOV10. Given that both MOV10 and A3G belong to the interferon antiviral system, their synergistic inhibition of HIV-1 suggests that these proteins may play complicated roles in antiviral functions.


Assuntos
Desaminase APOBEC-3G/metabolismo , Infecções por HIV/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , RNA Helicases/metabolismo , Produtos do Gene vif do Vírus da Imunodeficiência Humana/metabolismo , Antivirais/metabolismo , Linhagem Celular Transformada , Células HEK293 , Infecções por HIV/enzimologia , Infecções por HIV/virologia , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Mutação , RNA Helicases/genética , Transdução de Sinais , Ubiquitina/metabolismo , Replicação Viral
5.
Stem Cells Int ; 2024: 7045341, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39478978

RESUMO

Dental trauma is highly prevalent in children and adolescents, alongside tooth decay. This condition mainly induces pulp contamination, pulp necrosis, and tooth avulsion in the clinical context. The disturbance to root growth is prone to occur in immature permanent teeth. However, conventional endodontic treatment may not achieve favorable outcomes in these cases, necessitating conducting relevant exploration. Therefore, this study was performed to examine the impact of Annexin A1 (ANXA1) on the vascular repair of dental pulp using human dental pulp stem cells (DPSCs). Specifically, RNA sequencing (RNA-Seq) and functional clustering analyses were employed to identify key genes involved in pulp regeneration. ANXA1 was detected in DPSCs and may correlate with pulp restoration. However, it remains undefined about the potential of ANXA1 to promote the angiogenetic differentiation of DPSCs. The results of this study revealed that the addition of ANXA1 significantly enhanced the secretion of vascular endothelial growth factor-A (VEGF-A) in DPSCs. Moreover, the incubation of DPSCs with ANXA1 resulted in a higher expression level of endothelial markers and promoted vessel formation through the upregulation of the phosphorylated p38 (p-p38) pathway. The in vivo results corroborated that the ANXA1 group exhibited more blood vessels and an increased ratio of positive staining for CD31. In conclusion, these findings indicate that ANXA1 enhances the in vivo and in vitro vascularization of DPSCs, and the activation of p-p38 may play a pivotal role in mediating the differentiation process.

6.
Research (Wash D C) ; 7: 0511, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39449854

RESUMO

Various lipid metabolism-related factors are essential for Zika virus (ZIKV) replication. In this study, we revealed a crucial role of diacylglycerol O-acyltransferase 2 (DGAT2) in ZIKV replication using a short hairpin RNA-based gene knockdown technique. The replication of ZIKV was significantly inhibited by DGAT2 depletion in multiple cell lines and restored by trans-complementation with DGAT2. Mechanistically, DGAT2 is recruited in the viral replication complex by interacting with non-structural (NS) proteins. Among them, both human and murine DGAT2s can be cleaved by NS2B3 at the 122R-R-S124 site. Interestingly, the cleavage product of DGAT2 becomes more stable and is sufficient to promote the lipid droplet (LD) formation independent of its enzymatic activity. This work identifies DGAT2 as a novel target of the viral protease NS2B3 and elucidates that DGAT2 is recruited by viral proteins into the replication complex, thereby playing a proviral role by promoting LD formation, which advances our understanding of host-flavivirus interaction.

7.
Comb Chem High Throughput Screen ; 26(7): 1337-1350, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35792123

RESUMO

BACKGROUND: Dental pulp stem cells (DPSCs) refer to a type of stem cells, which is characterized by great differentiation potential and is easy to obtain. DPSCs are able to be employed for treating immune diseases and tissue regeneration. However, the differentiation ability exhibited by aging DPSCs is reduced, thereby limiting the application. As speculated by the microarray analysis, different expressions of miRNAs might be involved in DPSC senescence, whereas comprehensive transcriptome level detection has been rare. OBJECTIVE AND METHODS: To gain insights into the molecular mechanisms involved, RNA-sequencing, pathway enrichment and Gene Ontology Analysis were conducted on aging and young DPSCs. RESULTS: In this study, the differences in long non-coding RNA (lncRNA) and messenger RNA (mRNA expressions) of the aging and young DPSCs were demonstrated, and the vital factors and the relevant pathways were speculated. On the whole, 18950 mRNAs and 21854 lncRNAs were detected, among which 14 mRNAs and 7 lncRNAs were differentially expressed. Furthermore, hsa-miR-6724-5p may be a vital node in the aging process of DPSCs, and its target genes was involved in the dopaminergic synapse. CONCLUSION: In brief, the aging of DPSCs was significantly dependent of differentially expressed genes (DEGs) which is related to dopaminergic synapse. However, the specific function and internal relationship of the DEGs should be verified in depth.


Assuntos
MicroRNAs , RNA Longo não Codificante , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Polpa Dentária , Proliferação de Células/genética , Diferenciação Celular , MicroRNAs/genética , MicroRNAs/metabolismo , Células-Tronco/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células Cultivadas
8.
Heliyon ; 9(4): e15188, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37096002

RESUMO

Patients with diabetic osteoporosis (DOP) often suffer from poor osseointegration of artificial implants, which is a challenge that affects implant outcomes. The osteogenic differentiation ability of human jaw bone marrow mesenchymal stem cells (JBMMSCs) is the key to implant osseointegration. Studies have shown that the microenvironment of hyperglycemia affects the osteogenic differentiation of mesenchymal stem cells (MSC), but the mechanism is still unclear. Therefore, the aim of this study was to isolate and culture JBMMSCs from surgically derived bone fragments from DOP patients and control patients to investigate the differences in their osteogenic differentiation ability and to elucidate its mechanisms. The results showed that the osteogenic ability of hJBMMSCs was significantly decreased in the DOP environment. Mechanism study showed that the expression of senescence marker gene P53 was significantly increased in DOP hJBMMSCs compared to control hJBMMSCs according to RNA-sequencing result. Further, DOP hJBMMSCs were found to display significant senescence using ß-galactosidase staining, mitochondrial membrane potential and ROS assay, qRT-PCR and WB analysis. Overexpression of P53 in hJBMMSCs, knockdown of P53 in DOP hJBMMSCs, and knockdown followed by overexpression of P53 significantly affected the osteogenic differentiation ability of hJBMMSCs. These results suggest that MSC senescence is an important reason for decreasing osteogenic capacity in DOP patients. P53 is a key target in regulating hJBMMSCs aging, and knocking down P53 can effectively restore the osteogenic differentiation ability of DOP hJBMMSCs and promote osteosynthesis in DOP dental implants. It provided a new idea to elucidate the pathogenesis and treatment of diabetic bone metabolic diseases.

9.
Stem Cells Dev ; 32(19-20): 652-666, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37282516

RESUMO

The alveolar bone marrow mesenchymal stem cells (ABM-MSCs) play an important role in oral bone healing and regeneration. Insulin is considered to improve impaired oral bones due to local factors, systemic factors and pathological conditions. However, the effect of insulin on bone formation ability of ABM-MSCs still needs to be elucidated. The aim of this study was to determine the responsiveness of rat ABM-MSCs to insulin and to explore the underlying mechanism. We found that insulin promoted ABM-MSCs proliferation in a concentration-dependent manner, in which 10-6 M insulin exerted the most significant effect. 10-6 M insulin significantly promoted the type I collagen (COL-1) synthesis, alkaline phosphatase (ALP) activity, osteocalcin (OCN) expression, and mineralized matrix formation in ABM-MSCs, significantly enhanced the gene and protein expressions of intracellular COL-1, ALP, and OCN. Acute insulin stimulation significantly promoted insulin receptor (IR) phosphorylation, IR substrate-1 (IRS-1) protein expression, and mammalian target of rapamycin (mTOR) phosphorylation, but chronic insulin stimulation decreased these values, while inhibitor NT219 could attenuate these responses. When seeded on ß-tricalcium phosphate (ß-TCP), ABM-MSCs adhered and grew well, during the 28-day culture period, ABM-MSCs+ß-TCP +10-6 M insulin group showed significantly higher extracellular total COL-1 amino-terminus prolongation peptide content, ALP activity, OCN secretion, and Ca and P concentration. When implanted subcutaneously in severe combined immunodeficient mice for 1 month, the ABM-MSCs+ß-TCP +10-6 M insulin group obtained the most bone formation and blood vessels. These results showed that insulin promoted the proliferation and osteogenic differentiation of ABM-MSCs in vitro, and enhance osteogenesis and angiogenesis of ABM-MSCs in vivo. Inhibition studies demonstrated that the insulin-induced osteogenic differentiation of ABM-MSCs was dependent of insulin/mTOR signaling. It suggests that insulin has a direct anabolic effect on ABM-MSCs.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Camundongos , Ratos , Animais , Insulina/farmacologia , Insulina/metabolismo , Diferenciação Celular , Colágeno/metabolismo , Osteocalcina/genética , Osteocalcina/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Células da Medula Óssea , Células Cultivadas , Fosfatase Alcalina/metabolismo , Mamíferos/metabolismo
10.
Acta Biomater ; 166: 470-484, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37253416

RESUMO

Metabolic dysregulation contributes not only to cancer development but also to a tumor immune microenvironment (TIME), which poses great challenges to chemo- and immunotherapy. Targeting metabolic reprogramming has recently emerged as a promising strategy for cancer treatment, but the lethality against solid tumors appears to be fairly restricted, partially due to the poor solubility of small molecule drugs. Herein, we construct a versatile biomimetic nanoplatform (referred to as HM-BPT) employing pH-sensitive tumor-tropism hybrid membrane-coated Manganese oxide (MnO2) nanoparticles for the delivery of BPTES, a glutamine metabolism inhibitor. Basically, hybrid membranes consisting of mesenchymal stem cell membranes (MSCm) and pH-sensitive liposomes (pSL) enable the biomimetic nanoplatform to target TME and escape from endo/lysosomes after endocytosis. The results reveal that HM-BPT treatment leads to remarkable tumor inhibition, cytotoxic T lymphocyte (CTL) infiltration, as well as M1 phenotype repolarization and stimulator of IFN genes (STING) pathway activation in macrophages in a 4T1 xenograft model. Furthermore, glutathione (GSH) depletion and oxygen (O2) supply synergistically ameliorate the immunosuppressive status of the TME, boosting potent antitumor immune responses. Overall, our study explores an integrated therapeutic platform for TME reprogramming and immune activation, offering tremendous promise for cancer combination therapy. STATEMENT OF SIGNIFICANCE: Metabolic abnormalities and the tumor immune microenvironment (TIME) lead to hyporesponsiveness to conventional therapies, ultimately resulting in refractory malignancies. In the current work, a biomimetic nanoplatform (HM-BPT) was developed for TME metabolic reprogramming in favor of immunotherapy. Particularly, hybrid membrane camouflage endowed the nanoplatform with TME targeting, endo/lysosomal escape, and sensitive release properties. The impact of hybrid membrane fusion ratio on cellular uptake and cell viability was explored, yielding beneficial references for the future development of bioactive nanomaterials. Intravenous administration of HM-BPT substantially relieved tumor burden and restored innate and acquired immune activation in 4T1 xenograft models. In conclusion, the created HM-BPT system has the potential to be a promising nanoplatform for combining cancer therapies.


Assuntos
Nanopartículas , Neoplasias , Humanos , Animais , Compostos de Manganês/farmacologia , Microambiente Tumoral , Óxidos , Lisossomos , Imunoterapia , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Linhagem Celular Tumoral
11.
Stem Cells Dev ; 30(8): 441-457, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33798004

RESUMO

Dental stem/progenitor cells are a promising cell sources for alveolar bone (AB) regeneration because of their same embryonic origin and superior osteogenic potential. However, their molecular processes during osteogenic differentiation remain unclear. The objective of this study was to identify the responsiveness of dental follicle cells (DFCs) and AB marrow-derived mesenchymal stem cells (ABM-MSCs) to recombinant human bone morphogenetic protein-2 (rhBMP-2). These cells expressed vimentin and MSC markers and did not express cytokeratin and hematopoietic stem cell markers and showed multilineage differentiation potential under specific culture conditions. DFCs exhibited higher proliferation and colony-forming unit-fibroblast efficiency than ABM-MSCs; rhBMP-2 induced DFCs to differentiate toward a cementoblast/osteoblast phenotype and ABM-MSCs to differentiate only toward a osteoblast phenotype; and rhBMP-2-induced DFCs exhibited higher osteogenic differentiation potential than ABM-MSCs. These cells adhered, grew, and produced extracellular matrix on nanohydroxyapatite/collagen/poly(l-lactide) (nHAC/PLA). During a 14-day culture on nHAC/PLA, the extracellular alkaline phosphatase (ALP) activity of DFCs decreased gradually and that of ABM-MSCs increased gradually; rhBMP-2 enhanced their extracellular ALP activity, intracellular osteocalcin (OCN), and osteopontin (OPN) protein expression; and DFCs exhibited higher extracellular ALP activity and intracellular OCN protein expression than ABM-MSCs. When implanted subcutaneously in severe combined immunodeficient mice for 3 months, DFCs+nHAC/PLA+rhBMP-2 obtained higher percentage of bone formation area, OCN, and cementum attachment protein expression and lower OPN expression than ABM-MSCs+nHAC/PLA+rhBMP-2. These results showed that DFCs possessed superior proliferation and osteogenic differentiation potential in vitro, and formed higher quantity and quality bones in vivo. It suggested that DFCs might exhibit a more sensitive responsiveness to rhBMP-2, so that DFCs enter a relatively mature stage of osteogenic differentiation earlier than ABM-MSCs after rhBMP-2 induction. The findings imply that these dental stem/progenitor cells are alternative sources for AB engineering in regenerative medicine, and developing dental tissue may provide better source for stem/progenitor cells.


Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Diferenciação Celular/efeitos dos fármacos , Saco Dentário/citologia , Células-Tronco Mesenquimais/citologia , Osteogênese/efeitos dos fármacos , Células-Tronco/citologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Diferenciação Celular/genética , Células Cultivadas , Colágeno/metabolismo , Durapatita/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/ultraestrutura , Microscopia Eletrônica de Varredura , Osteocalcina/genética , Osteocalcina/metabolismo , Osteogênese/genética , Osteopontina/genética , Osteopontina/metabolismo , Poliésteres/metabolismo , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Células-Tronco/metabolismo , Células-Tronco/ultraestrutura
12.
Stem Cells Int ; 2021: 6616240, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33505470

RESUMO

Dental pulp stem cells (DPSCs) are ideal seed cells for the regeneration of dental tissues. However, DPSC senescence restricts its clinical applications. Metformin (Met), a common prescription drug for type 2 diabetes, is thought to influence the aging process. This study is aimed at determining the effects of metformin on DPSC senescence. Young and aging DPSCs were isolated from freshly extracted human teeth. Flow cytometry confirmed that DPSCs expressed characteristic surface antigen markers of mesenchymal stem cells (MSCs). Cell Counting Kit-8 (CCK-8) assay showed that a concentration of 100 µM metformin produced the highest increase in the proliferation of DPSCs. Metformin inhibited senescence in DPSCs as evidenced by senescence-associated ß-galactosidase (SA-ß-gal) staining and the expression levels of senescence-associated proteins. Additionally, metformin significantly suppressed microRNA-34a-3p (miR-34a-3p) expression, elevated calcium-binding protein 39 (CAB39) expression, and activated the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway. Dual-luciferase reporter assay confirmed that CAB39 is a direct target for miR-34a-3p. Furthermore, transfection of miR-34a-3p mimics promoted the senescence of DPSCs, while metformin treatment or Lenti-CAB39 transfection inhibited cellular senescence. In conclusion, these results indicated that metformin could alleviate the senescence of DPSCs by downregulating miR-34a-3p and upregulating CAB39 through the AMPK/mTOR signaling pathway. This study elucidates on the inhibitory effect of metformin on DPSC senescence and its potential as a therapeutic target for senescence treatment.

13.
Stem Cells Int ; 2021: 4465022, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34447439

RESUMO

The microenvironment, or niche, regulates stem cell fate and improves differentiation efficiency. Human umbilical cord mesenchymal stem cells (hUC-MSCs) are ideal cell source for bone tissue engineering. However, the role of the microenvironments in hUC-MSC-based bone regeneration is not yet fully understood. This study is aimed at investigating the effects of the in vitro culture microenvironment (hUC-MSCs, nano-hydroxyapatite/collagen/poly (L-lactide) (nHAC/PLA), osteogenic media (OMD), and recombinant human bone morphogenetic protein-7 (rhBMP-7)) and the in vivo transplanted microenvironment (ectopic and orthotopic) on bone regeneration ability of hUC-MSCs. The isolated hUC-MSCs showed self-renewal potential and MSCs' characteristics. In the in vitro two-dimensional culture microenvironment, OMD or OMD with rhBMP-7 significantly enhanced hUC-MSCs' osteocalcin immunofluorescence staining, alkaline phosphatase, and Alizarin red staining; OMD with rhBMP-7 exhibited the highest ALP secretion and mineralized matrix formation. In the in vitro three-dimensional culture microenvironment, nHAC/PLA supported hUC-MSCs' adhesion, proliferation, and differentiation; the microenvironment containing OMD or OMD and rhBMP-7 shortened cell proliferation progression and made osteogenic differentiation progression advance; rhBMP-7 significantly attenuated the inhibiting effect of OMD on hUC-MSCs' proliferation and significantly enhanced the promoting effect of OMD on gene expression and protein secretion of osteogenic differentiation markers, calcium and phosphorous concentration, and mineralized matrix formation. The in vitro three-dimensional culture microenvironment containing OMD and rhBMP-7 induced hUC-MSCs to form the most new bones in ectopic or orthotopic microenvironment as proved by microcomputed tomography and hematoxylin and eosin staining, but bone formation in orthotopic microenvironment was significantly higher than that in ectopic microenvironment. The results indicated that the combination of in vitro hUC-MSCs+nHAC/PLA+OMD+rhBMP-7 microenvironment and in vivo orthotopic microenvironment provided a more optimized niche for bone regeneration of hUC-MSCs. This study elucidates that hUC-MSCs and their local microenvironment, or niche, play an important role in hUC-MSC-based bone regeneration. The endogenously produced BMP may serve an important regulatory role in the process.

14.
Artigo em Inglês | MEDLINE | ID: mdl-32039055

RESUMO

Zika virus (ZIKV) is an emerging arthropod-borne virus and belongs to the Flaviviridae family. The infection of ZIKV has become the global health crisis because of its rapid spread and association with severe neurological disorders, including congenital microcephaly and Guillain-Barre Syndrome. To identify host factors contributing to ZIKV pathogenesis, transcriptomic landscape in ZIKV-infected cells was examined with mRNA microarray analysis and we observed that the expression of hydroxycarboxylic acid receptor 2 (HCAR2) could be significantly induced by ZIKV infection. By utilizing two IRE1 inhibitors and XBP1-specific shRNAs, we revealed that the up-regulation of HCAR2 expression induced by ZIKV was dependent on the IRE1-XBP1 pathway. Through the CRISPR/Cas9 system, we generated HCAR2-deficient cell clones in two cell types (human lung carcinoma epithelial A549 cell and human hepatoma Huh7.5 cell). We found that the depletion of HCAR2 significantly increased the replication level of ZIKV, including RNA levels, protein expression levels, and viral titers. In addition, our data demonstrated that the antiviral effect of HCAR2 was not involved in viral entry process and was not dependent on its antilipolytic effect on nicotinic acid/HCAR2-mediated signaling pathway. Taken together, our results indicated that HCAR2 could function as a restriction factor in control of ZIKV replication, potentially providing a novel molecular target for anti-ZIKV therapeutics.


Assuntos
Endorribonucleases/metabolismo , Fatores Imunológicos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Proteína 1 de Ligação a X-Box/metabolismo , Infecção por Zika virus/imunologia , Linhagem Celular , Edição de Genes , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Análise em Microsséries , Mapas de Interação de Proteínas , Replicação Viral , Zika virus/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA