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1.
Bone Res ; 12(1): 27, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714649

RESUMO

Tendon adhesion is a common complication after tendon injury with the development of accumulated fibrotic tissues without effective anti-fibrotic therapies, resulting in severe disability. Macrophages are widely recognized as a fibrotic trigger during peritendinous adhesion formation. However, different clusters of macrophages have various functions and receive multiple regulation, which are both still unknown. In our current study, multi-omics analysis including single-cell RNA sequencing and proteomics was performed on both human and mouse tendon adhesion tissue at different stages after tendon injury. The transcriptomes of over 74 000 human single cells were profiled. As results, we found that SPP1+ macrophages, RGCC+ endothelial cells, ACKR1+ endothelial cells and ADAM12+ fibroblasts participated in tendon adhesion formation. Interestingly, despite specific fibrotic clusters in tendon adhesion, FOLR2+ macrophages were identified as an antifibrotic cluster by in vitro experiments using human cells. Furthermore, ACKR1 was verified to regulate FOLR2+ macrophages migration at the injured peritendinous site by transplantation of bone marrow from Lysm-Cre;R26RtdTomato mice to lethally irradiated Ackr1-/- mice (Ackr1-/- chimeras; deficient in ACKR1) and control mice (WT chimeras). Compared with WT chimeras, the decline of FOLR2+ macrophages was also observed, indicating that ACKR1 was specifically involved in FOLR2+ macrophages migration. Taken together, our study not only characterized the fibrosis microenvironment landscape of tendon adhesion by multi-omics analysis, but also uncovered a novel antifibrotic cluster of macrophages and their origin. These results provide potential therapeutic targets against human tendon adhesion.


Assuntos
Movimento Celular , Macrófagos , Regeneração , Humanos , Animais , Macrófagos/metabolismo , Camundongos , Tendões/metabolismo , Tendões/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Traumatismos dos Tendões/patologia , Traumatismos dos Tendões/metabolismo , Traumatismos dos Tendões/genética , Proteômica , Feminino , Multiômica
2.
NPJ Regen Med ; 9(1): 14, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561335

RESUMO

Osteoarthritis affects 15% of people over 65 years of age. It is characterized by articular cartilage degradation and inflammation, leading to joint pain and disability. Osteoarthritis is incurable and the patients may eventually need joint replacement. An emerging treatment is mesenchymal stromal cells (MSCs), with over two hundred clinical trials being registered. However, the outcomes of these trials have fallen short of the expectation, due to heterogeneity of MSCs and uncertain mechanisms of action. It is generally believed that MSCs exert their function mainly by secreting immunomodulatory and trophic factors. Here we used knee osteoarthritis mouse model to assess the therapeutic effects of MSCs isolated from the white adipose or dermal adipose tissue of Prrx1-Cre; R26tdTomato mice and Dermo1-Cre; R26tdTomato mice. We found that the Prrx1-lineage MSCs from the white adipose tissues showed the greatest in vitro differentiation potentials among the four MSC groups and single cell profiling showed that the Prrx1-lineage MSCs contained more stem cells than the Dermo1 counterpart. Only the Prrx1-lineage cells isolated from white adipose tissues showed long-term therapeutic effectiveness on early-stage osteoarthritis models. Mechanistically, Prrx1-lineage MSCs differentiated into Col2+ chondrocytes and replaced the damage cartilage, activated Col1 expressing in resident chondrocytes, and inhibited synovial inflammation. Transcriptome analysis showed that the articular chondrocytes derived from injected MSCs expressed immunomodulatory cytokines, trophic factors, and chondrocyte-specific genes. Our study identified a MSC population genetically marked by Prrx1 that has great multipotentiality and can differentiate into chondrocytes to replace the damaged cartilage.

3.
Heliyon ; 10(5): e27114, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38434304

RESUMO

Aims: Retinal ischemia/reperfusion (I/R) injury is implicated in the etiology of various ocular disorders. Prior research has demonstrated that bone marrow tyrosine kinase on chromosome X (BMX) contributes to the advancement of ischemic disease and inflammatory reactions. Consequently, the current investigation aims to evaluate BMX's impact on retinal I/R injury and clarify its implied mechanism of action. Main methods: This study utilized male and female systemic BMX knockout (BMX-/-) mice to conduct experiments. The utilization of Western blot assay and immunofluorescence labeling techniques was employed to investigate variations in the expression of protein and tissue localization. Histomorphological changes were observed through H&E staining and SD-OCT examination. Visual function changes were assessed through electrophysiological experiments. Furthermore, apoptosis in the retina was identified using the TUNEL assay, as well as the ELISA technique, which has been utilized to determine the inflammatory factors level. Key findings: Our investigation results revealed that the knockdown of BMX did not yield a significant effect on mouse retina. In mice, BMX knockdown mitigated the negative impact of I/R injury on retinal tissue structure and visual function. BMX knockdown effectively reduced apoptosis, suppressed inflammatory responses, and decreased inflammatory factors subsequent to I/R injury. The outcomes of the current investigation revealed that BMX knockdown partially protected the retina through downregulating phosphorylation of AKT/ERK/STAT3 pathway. Significance: Our investigation showed that BMX-/- reduces AKT, ERK, and STAT3 phosphorylation, reducing apoptosis and inflammation. Thus, this strategy protected the retina from structural and functional damage after I/R injury.

4.
Open Forum Infect Dis ; 11(2): ofad649, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38312215

RESUMO

Background: Due to scarce therapeutic options, hospital-acquired infections caused by Klebsiella pneumoniae (KP), particularly carbapenem-resistant KP (CRKP), pose enormous threat to patients' health worldwide. This study aimed to characterize the epidemiology and risk factors of CRKP among nosocomial KP infections. Method: MEDLINE, Embase, PubMed, and Google Scholar were searched for studies reporting CRKP prevalence from inception to 30 March 2023. Data from eligible publications were extracted and subjected to meta-analysis to obtain global, regional, and country-specific estimates. To determine the cause of heterogeneity among the selected studies, prespecified subgroup analyses and meta-regression were also performed. Odds ratios of CRKP-associated risk factors were pooled by a DerSimonian and Laird random-effects method. Results: We retained 61 articles across 14 countries and territories. The global prevalence of CRKP among patients with KP infections was 28.69% (95% CI, 26.53%-30.86%). South Asia had the highest CRKP prevalence at 66.04% (95% CI, 54.22%-77.85%), while high-income North America had the lowest prevalence at 14.29% (95% CI, 6.50%-22.0%). In the country/territory level, Greece had the highest prevalence at 70.61% (95% CI, 56.77%-84.45%), followed by India at 67.62% (95% CI, 53.74%-81.79%) and Taiwan at 67.54% (95% CI, 58.65%-76.14%). Hospital-acquired CRKP infections were associated with the following factors: hematologic malignancies, corticosteroid therapies, intensive care unit stays, mechanical ventilations, central venous catheter implantations, previous hospitalization, and antibiotic-related exposures (antifungals, carbapenems, quinolones, and cephalosporins). Conclusions: Study findings highlight the importance of routine surveillance to control carbapenem resistance and suggest that patients with nosocomial KP infection have a very high prevalence of CRKP.

5.
Environ Microbiol Rep ; 16(1): e13223, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38124298

RESUMO

Soil pathogens play important roles in shaping soil microbial diversity and controlling ecosystem functions. Though climate and local environmental factors and their influences on fungal pathogen communities have been examined separately, few studies explore the relative contributions of these factors. This is particularly crucial in eco-fragile regions, which are more sensitive to environmental changes. Herein we investigated the diversity and community structure of putative soil fungal pathogens in cold and dry grasslands on the Tibetan Plateau, using high-throughput sequencing. The results showed that steppe soils had the highest diversity of all pathogens and plant pathogens; contrastingly, meadow soils had the highest animal pathogen diversity. Structural equation modelling revealed that climate, plant, and soil had similar levels of influence on putative soil fungal pathogen diversity, with total effects ranging from 52% to 59% (all p < 0.001), with precipitation exhibiting a stronger direct effect than plant and soil factors. Putative soil fungal pathogen community structure gradually changed with desert, steppe, and meadow, and was primarily controlled by the interactions of climate, plant, and soil factors rather than by distinct factors individually. This finding contrasts with most studies of soil bacterial and fungal community structure, which generally report dominant roles of individual environmental factors.


Assuntos
Ecossistema , Pradaria , Solo/química , Microbiologia do Solo , Plantas
6.
Injury ; 54(12): 110984, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37922833

RESUMO

BACKGROUND: Road collisions are a significant source of traumatic brain injury (TBI). We aimed to determine the pattern of road injury related TBI (RI-TBI) incidence, as well as its temporal trends. METHODS: We collected detailed information on RI-TBI between 1990 and 2019, derived from the Global Burden of Disease Study 2019. Estimated annual percentage changes (EAPCs) of RI-TBI age standardized incidence rate (ASIR), by sex, region, and cause of road injuries, were assessed to quantify the temporal trends of RI-TBI burden. RESULTS: Globally, incident cases of RI-TBI increased 68.1% from 6,900,000 in 1990 to 11,600,000 in 2019. The overall ASIR increased by an average of 0.43% (95% CI 0.30%-0.56%) per year during this period. The ASIR of RI-TBI due to cyclist, motorcyclist and other road injuries increased between 1990 and 2019; the corresponding EAPCs were 0.56 (95% CI 0.37-0.75), 1.60 (95% CI 1.35-1.86), and 0.75 (95% CI 0.59-0.91), respectively. In contrast, the ASIR of RI-TBI due to motor vehicle and pedestrian decreased with an EAPC of -0.12 and -0.14 respectively. The changing pattern for RI-TBI was heterogeneous across countries and regions. The most pronounced increases were observed in Mexico (EAPC = 3.74), followed by China (EAPC = 2.45) and Lesotho (EAPC = 1.91). CONCLUSIONS: RI-TBI remains a major public health concern worldwide, although road safety legislations have contributed to the decreasing incidence in some countries. We found an unfavorable trend in several countries with a relatively low socio-demographic index, suggesting that much more targeted and specific approaches should be adopted in these areas to forestall the increase in RI-TBI.


Assuntos
Lesões Encefálicas Traumáticas , Carga Global da Doença , Humanos , Incidência , Lesões Encefálicas Traumáticas/epidemiologia , China , México , Saúde Global , Anos de Vida Ajustados por Qualidade de Vida
7.
BMC Surg ; 23(1): 274, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37700315

RESUMO

BACKGROUND: Septic shock is one of the leading causes of mortality in intensive care units. This retrospective study was carried out to evaluate the association of clinical available factors with 28-day mortality. PATIENTS AND METHOD: In this observational study, patients with perioperative septic shocks secondary to intra-abdominal infection caused by enteric perforation were included. A total of 328 sepsis patients were admitted to the surgical intensive care units from January 2012 to December 2016. A total of 138 patients met the enrolment criteria and were included in the study. The data of demographic, clinical and laboratory were all recorded. RESULT: All these 138 patients received abdominal surgery prior to surgical intensive care units caused by acute enteric perforation. These patients were all met the diagnostic criteria of septic shock according to Sepsis-3. Statistical analysis showed that lactic acid, blood platelet, fibrinogen, creatinine and activated partial thromboplastin time were found to be associated with 28-day mortality. A combination of serum activated partial thromboplastin time combined with fibrinogen and creatinine could predict in-hospital 28-day mortality. The area under the curve of serum activated partial thromboplastin time combined with fibrinogen and creatinine is 0.875 (0.806-0.944). CONCLUSION: In conclusion, this pilot study demonstrated that these factors can predict the prognosis of septic shock caused by enteric perforation. In order to reduce the mortality, surgeons and intensive care units physician may consider these data in perioperative period.


Assuntos
Hemostáticos , Sepse , Choque Séptico , Humanos , Fibrinogênio , Tempo de Tromboplastina Parcial , Creatinina , Choque Séptico/complicações , Projetos Piloto , Prognóstico , Estudos Retrospectivos
8.
BMC Biol ; 21(1): 169, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37553612

RESUMO

BACKGROUND: The nutrient-absorbing villi of small intestines are renewed and repaired by intestinal stem cells (ISCs), which reside in a well-organized crypt structure. Genetic studies have shown that Wnt molecules secreted by telocytes, Gli1+ stromal cells, and epithelial cells are required for ISC proliferation and villus homeostasis. Intestinal stromal cells are heterogeneous and single-cell profiling has divided them into telocytes/subepithelial myofibroblasts, myocytes, pericytes, trophocytes, and Pdgfralow stromal cells. Yet, the niche function of these stromal populations remains incompletely understood. RESULTS: We show here that a Twist2 stromal lineage, which constitutes the Pdgfralow stromal cell and trophocyte subpopulations, maintains the crypt structure to provide an inflammation-restricting niche for regenerating ISCs. Ablating Twist2 lineage cells or deletion of one Wntless allele in these cells disturbs the crypt structure and impairs villus homeostasis. Upon radiation, Wntless haplo-deficiency caused decreased production of anti-microbial peptides and increased inflammation, leading to defective ISC proliferation and crypt regeneration, which were partially rescued by eradication of commensal bacteria. In addition, we show that Wnts secreted by Acta2+ subpopulations also play a role in crypt regeneration but not homeostasis. CONCLUSIONS: These findings suggest that ISCs may require different niches for villus homeostasis and regeneration and that the Twist2 lineage cells may help to maintain a microbe-restricted environment to allow ISC-mediated crypt regeneration.


Assuntos
Linhagem da Célula , Homeostase , Intestinos , Nicho de Células-Tronco , Células-Tronco , Células-Tronco/citologia , Células-Tronco/metabolismo , Intestinos/citologia , Intestinos/metabolismo , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Animais , Camundongos
9.
Nat Genet ; 54(12): 1946-1958, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36456880

RESUMO

Specialized connective tissues, including bone and adipose tissues, control various physiological activities, including mineral and energy homeostasis. However, the identity of stem cells maintaining these tissues throughout adulthood remains elusive. By conducting genetic lineage tracing and cell depletion experiments in newly generated knock-in Cre/CreERT2 lines, we show here that rare Prrx1-expressing cells act as stem cells for bone, white adipose tissue and dermis in adult mice, which are indispensable for the homeostasis and repair of these tissues. Single-cell profiling reveals the cycling and multipotent nature of Prrx1-expressing cells and the stemness of these cells is further validated by transplantation assays. Moreover, we identify the cell surface markers for Prrx1-expressing stem cells and show that the activities of these stem cells are regulated by Wnt signaling. These findings expand our knowledge of connective tissue homeostasis/regeneration and may help improve stem-cell-based therapies.


Assuntos
Tecido Adiposo Branco , Células-Tronco , Camundongos , Animais
10.
Mol Immunol ; 146: 18-26, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35421737

RESUMO

BACKGROUND: Acute kidney injury caused by sepsis has become a hotspot of scientific research in recent years. Since the kidney is the most abundant of all organs with vascular endothelium, activation and injury of vascular endothelial cells is a main reason to renal dysfunction. In our research, we identify that miRNA-449c-5p can alleviate HUVECs injury through inhibiting the NF-κb signaling pathway activation by targeting TAK1 with the method of bioinformatics and in vitro experiment. METHODS: Datasets of GSE28750 and GSE94717 were obtained from the GEO database. Differential analysis was performed on the two data sets using the GEO2R tool of the GEO database, and the miRNA-mRNA network was further constructed. Lipopolysaccharide (LPS) against Human umbilical vein endothelial cells induced an in vitro model of AKI were used for verification. RT-PCR, Western blotting, ELISA, CCK8, EDU and luciferase reporter genes were used to verify whether miR-449c-5p could alleviate the apoptosis of vascular endothelial cells and the release of inflammatory factors during the progression of sepsis by inhibiting the expression of TAK1. RESULTS: TAK1 was identified as a direct target of miR-449c-5p by luciferase reporter gene assay, and TAK1 expression was negatively regulated by miR-449c-5p. Overexpression of miR-449c-5p promoted cell viability, inhibited apoptosis rate and inhibited the expression of inflammatory cytokines in HUVECs after LPS stimulation. Moreover, miR-449c-5p deactivated NF-κB signaling by targeting TAK1. CONCLUSION: In cell model experiments, it was found that miRNA-449c-5p could inhibit the release of LPS induced inflammatory cytokine, inhibit the occurrence of apoptosis and promote cell proliferation by inhibiting the expression of TAK1. Therefore, thus miRNA-449c-5p played a protective role on vascular endothelial cells.


Assuntos
MAP Quinase Quinase Quinases/genética , MicroRNAs , Sepse , Apoptose/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , MicroRNAs/genética , NF-kappa B/metabolismo , Sepse/genética , Sepse/metabolismo , Transdução de Sinais
11.
Autophagy ; 18(8): 1822-1840, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34870550

RESUMO

Acquired chemotherapy resistance is one of the main culprits in the relapse of breast cancer. But the underlying mechanism of chemotherapy resistance remains elusive. Here, we demonstrate that a small adaptor protein, SH3BGRL, is not only elevated in the majority of breast cancer patients but also has relevance with the relapse and poor prognosis of breast cancer patients. Functionally, SH3BGRL upregulation enhances the chemoresistance of breast cancer cells to the first-line doxorubicin treatment through macroautophagic/autophagic protection. Mechanistically, SH3BGRL can unexpectedly bind to ribosomal subunits to enhance PIK3C3 translation efficiency and sustain ATG12 stability. Therefore, inhibition of autophagy or silence of PIK3C3 or ATG12 can effectively block the driving effect of SH3BGRL on doxorubicin resistance of breast cancer cells in vitro and in vivo. We also validate that SH3BGRL expression is positively correlated with that of PIK3C3 or ATG12, as well as the constitutive occurrence of autophagy in clinical breast cancer tissues. Taken together, our data reveal that SH3BGRL upregulation would be a key driver to the acquired chemotherapy resistance through autophagy enhancement in breast cancer while targeting SH3BGRL could be a potential therapeutic strategy against breast cancer.Abbreviations: ABCs: ATP-binding cassette transporters; Act D: actinomycin D; ACTB/ß-actin: actin beta; ATG: autophagy-related; Baf A1: bafilomycin A1; CASP3: caspase 3; CHX: cycloheximide; CQ: chloroquine; Dox: doxorubicin; FBS: fetal bovine serum; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GEO: gene expression omnibus; GFP: green fluorescent protein; G6PD: glucose-6-phosphate dehydrogenase; GSEA: gene set enrichment analysis; IHC: immunochemistry; KEGG: Kyoto Encyclopedia of Genes and Genomes; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; 3-MA: 3-methyladenine; mRNA: messenger RNA; PIK3C3: phosphatidylinositol 3-kinase catalytic subunit type 3; SH3BGRL: SH3 domain binding glutamate-rich protein-like; SQSTM1/p62: sequestosome 1; ULK1: unc-51 like autophagy activating kinase 1.


Assuntos
Proteína 12 Relacionada à Autofagia , Autofagia , Neoplasias da Mama , Classe III de Fosfatidilinositol 3-Quinases , Autofagia/fisiologia , Proteína 12 Relacionada à Autofagia/genética , Proteína 12 Relacionada à Autofagia/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Recidiva Local de Neoplasia , Proteínas
13.
Sci Transl Med ; 13(603)2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34290057

RESUMO

Inflammatory bowel disease (IBD) affects 0.3% of the global population, yet the etiology remains poorly understood. Anti-inflammation therapy has shown great success, but only 60% of patients with IBD benefit from it, indicating that new targets are needed. Here, we report the discovery of an intrinsic counter regulatory mechanism in colitis pathogenesis that may be targeted for IBD treatment. In response to microbial invasion, resident Vimentin+ stromal cells, connective tissue cells genetically marked by Twist2, are activated during the propagation phase of the disease, but not during initiation and resolution phases, and become a primary source of prostaglandin E2 (PGE2). PGE2 induction requires a nuclear factor κB-independent, TLR4-p38MAPK-Cox2 pathway activation. Ablation of each of the pathway genes, but not Rela or Tgfb1, in Twist2 cells enhanced M1 macrophage polarization and granulocyte/T helper 1 (TH1)/TH17 infiltration and aggravated colitis development. PGE2 administration ameliorated colitis in mouse models with defective PGE2 production but not in animals with normal PGE2 induction. Analysis of clinical samples and public domain data revealed increased expression of Cox2, the rate-limiting enzyme of PGE2 biosynthesis, in inflamed tissues, and especially in colon Vimentin+Twist2+ stromal cells, in about 60% of patients with active Crohn's disease or ulcerative colitis. Moreover, Cox2 protein expression was negatively correlated with disease severity, suggesting an involvement of stromal cells in IBD pathogenesis. Thus, the study uncovers an active immune pathway in colitic inflammation that may be targeted to treat patients with IBD with defects in PGE2 production.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Animais , Colo , Humanos , Imunidade Inata , Camundongos , Células Estromais
14.
Oncogene ; 40(38): 5677-5690, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34331014

RESUMO

Metastatic recurrence is still a major challenge in breast cancer treatment, but the underlying mechanisms remain unclear. Here, we report that a small adaptor protein, SH3BGRL, is upregulated in the majority of breast cancer patients, especially elevated in those with metastatic relapse, indicating it as a marker for the poor prognosis of breast cancer. Physiologically, SH3BGRL can multifunctionally promote breast cancer cell tumorigenicity, migration, invasiveness, and efficient lung colonization in nude mice. Mechanistically, SH3BGRL downregulates the acting-binding protein profilin 1 (PFN1) by accelerating the translation of the PFN1 E3 ligase, STUB1 via SH3BGRL interaction with ribosomal proteins, or/and enhancing the interaction of PFN1 with STUB1 to accelerate PFN1 degradation. Loss of PFN1 consequently contributes to downstream multiple activations of AKT, NF-kB, and WNT signaling pathways. In contrast, the forced expression of compensatory PFN1 in SH3BGRL-high cells efficiently neutralizes SH3BGRL-induced metastasis and tumorigenesis with PTEN upregulation and PI3K-AKT signaling inactivation. Clinical analysis validates that SH3BGRL expression is negatively correlated with PFN1 and PTEN levels, but positively to the activations of AKT, NF-kB, and WNT signaling pathways in breast patient tissues. Our results thus suggest that SH3BGRL is a valuable prognostic factor and a potential therapeutic target for preventing breast cancer progression and metastasis.


Assuntos
Neoplasias da Mama/patologia , Profilinas/química , Proteínas/genética , Ubiquitina-Proteína Ligases/metabolismo , Regulação para Cima , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , Metástase Neoplásica , Transplante de Neoplasias , Prognóstico , Proteólise , Análise de Sobrevida
15.
Chem Asian J ; 16(15): 2107-2112, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34117722

RESUMO

Molybdenum carbide possessing a Pt-like d-band electronic structure is considered as one of potential candidates of electrocatalysts and it shows intrinsic catalytic property. However, a high carbonizing temperature easily leads to the coalescence of nanoparticles (NPs). Here, we propose a simple sol-gel route to achieve high dispersity of carbide NPs by designing a Mo-involved xerogel. The results show that molybdenum carbide NPs are dispersed and anchored on the nitrogen-doped carbon nanosheets (Mo2 C@NC). Ultrathin carbon layers resemble graphene and the network structures act as a support of carbide NPs, which can hinder NPs' coalescence effectively. Nanpoparticles cross-coupled on network-structure nanosheets display the grid shapes. Electrochemical studies indicate that Mo2 C@NC material exhibits outstanding hydrogen evolution performance in alkaline electrolyte.

16.
FASEB J ; 35(4): e21345, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33715219

RESUMO

Obesity is common in the middle aged population and it increases the risks of diabetes, cardiovascular diseases, certain cancers, and dementia. Yet, its etiology remains incompletely understood. Here, we show that ectopic expression of HB-EGF, an important regulator of neurogenesis, in Nestin+ neuroepithelial progenitors with the Cre-LoxP system leads to development of spontaneous middle age obesity in male mice accompanied by hyperglycemia and insulin resistance. The Nestin-HB-EGF mice show decreases in food uptake, energy expenditure, and physical activity, suggesting that reduced energy expenditure underlies the pathogenesis of this obesity model. However, HB-EGF expression in appetite-controlling POMC or AgRP neurons or adipocytes fails to induce obesity. Mechanistically, HB-EGF suppresses expression of Hypocretin/Orexin, an orexigenic neuropeptide hormone, in the hypothalamus of middle aged Nestin-HB-EGF mice. Hypothalamus Orexin administration alleviates the obese and hyperglycemic phenotypes in Nestin-HB-EGF mice. This study uncovers an important role for HB-EGF in regulating Orexin expression and energy expenditure and establishes a midlife obesity model whose pathogenesis involves age-dependent changes in hypothalamus neurons.


Assuntos
Fator de Crescimento Semelhante a EGF de Ligação à Heparina/metabolismo , Nestina/metabolismo , Células-Tronco Neurais/metabolismo , Obesidade/metabolismo , Orexinas/metabolismo , Adiponectina/sangue , Envelhecimento , Animais , Composição Corporal , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/genética , Humanos , Insulina/sangue , Leptina/sangue , Camundongos , Nestina/genética , Orexinas/genética
17.
Stem Cell Res Ther ; 12(1): 25, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413643

RESUMO

Umbilical cord mesenchymal stem cells (UC-MSCs) have certain advantages over other MSCs and about 300 clinical trials have been registered using UC-MSCs to treat diseases such as osteoarthritis, autoimmune diseases, and degenerative disorders, yet, only limited success has been achieved. One reason is that in vitro expanded UC-MSCs show tremendous heterogeneity and their relationship to in vivo UC-MSCs remains unknown. Here, we investigated freshly isolated, uncultured UC-MSCs by single-cell RNA sequencing (scRNA-seq) and found two populations of UC-MSCs. Although UC-MSCs share many expressed genes and may have the same origin, they can be clearly separated based on differentially expressed genes including CD73 and other markers. Moreover, group 1 MSCs are enriched in expression of genes in immune response/regulatory activities, muscle cell proliferation and differentiation, stemness, and oxidative stress while group 2 MSCs are enriched with gene expression in extracellular matrix production, osteoblast and chondrocytes differentiation, and bone and cartilage growth. These findings suggest that UC-MSCs should be separated right after isolation and individually expanded in vitro to treat different diseases.


Assuntos
Células-Tronco Mesenquimais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Perfilação da Expressão Gênica , Humanos , Análise de Célula Única , Cordão Umbilical
18.
ACS Appl Mater Interfaces ; 13(1): 622-630, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33356099

RESUMO

We developed a robust ternary PdO-CeO2-OMS-2 catalyst with excellent catalytic performance in the selective reduction of NO with CO using a strategy based on combining components that synergistically interact leading to an effective abatement of these toxic gases. The catalyst affords 100% selectivity to N2 at the nearly full conversion of NO and CO at 250 °C, high stability in the presence of H2O, and a remarkable SO2 tolerance. To unravel the origin of the excellent catalytic performance, the structural and chemical properties of the PdO-CeO2-OMS-2 nanocomposite were analyzed in the as-prepared and used state of the catalyst, employing a series of pertinent characterization methods and specific catalytic tests. The experimental as well as theoretical results, based on density-functional theory calculations suggest that CO and NO follow different reaction pathways, CO is preferentially adsorbed and oxidized at Pd sites (PdII and Pd0), while NO decomposes on the ceria surface. Lattice oxygen vacancies at the interfacial perimeter of PdO-CeO2 and PdO-OMS-2, and the diffusion of oxygen and oxygen vacancies are proposed to play a critical role in this multicenter reaction system.

19.
Front Genet ; 11: 930, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922440

RESUMO

Accumulating evidence show that Poly C Binding Protein 1 (PCBP1) is deleted in distinct types of tumors as a novel tumor suppressor, but its tumor suppression mechanism remains elusive. Here, we firstly describe that downregulation of PCBP1 is significantly associated with clinical ovarian tumor progression. Mechanistically, PCBP1 overexpression affects various autophagy-related genes expression at various expression levels to attenuate the intrinsic cell autophagy, including the autophagy-initiating ULK, ATG12, ATG7 as well as the bona fide marker of autophagosome, LC3B. Accordingly, knockdown of the endogenous PCBP1 in turn enhances autophagy and less cell death. Meanwhile, PCBP1 upregulates p62/SQSTM1 via inhibition p62/SQSTM1 autophagolysome and proteasome degradation as well as its mRNA stability, consequently accompanying with the caspase 3 or 8 activation for tumor cell apoptosis. Importantly, clinical ovary cancer sample analysis consistently validates the relevance of PCBP1 expression to both p62/SQSTM1 and caspase-8 to overall survival, and indicates PCBP1 may be a master player to repress tumor initiation. Taken together, our results uncover the tumorigenic mechanism of PCBP1 depletion and suggest that inhibition of tumor cell autophagy with autophagic inhibitors could be an effective therapeutical strategy for PCBP1-deficient tumor.

20.
ACS Appl Mater Interfaces ; 12(35): 39092-39097, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32805824

RESUMO

Silicon (Si)-based Schottky junction photoelectrodes have attracted considerable attention for photoelectrochemical (PEC) water splitting in recent years. To realize highly efficient Si-based Schottky junction photoelectrodes, the critical challenge is to enable the photoelectrodes to not only have a high Schottky barrier height (SBH), by which a high photovoltage can be obtained, but also ensure an efficient charge transport. Here, we propose and demonstrate a strategy to fabricate a high-performance NiSi/n-Si Schottky junction photoanode by metal silicidation in conjunction with dopant segregation (DS). The metal silicidation produces photoanodes with a high-quality NiSi/Si interface without a disordered SiO2 layer, which ensures highly efficient charge transport, and thus a high saturated photocurrent density of 33 mA cm-2 was attained for the photoanode. The subsequent DS gives the photoanodes a high SBH of 0.94 eV through the introduction of electric dipoles at the NiSi/n-Si interface. As a result, a high photovoltage and favorable onset potential of 1.03 V vs RHE was achieved. In addition, the strong alkali corrosion resistance of NiSi also endows the photoanode with a high stability during PEC operation in 1 M KOH. Our work provides a universal strategy to fabricate metal-silicide/Si Schottky junction photoelectrodes for high-performance PEC water splitting.

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