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1.
Cancer Biol Ther ; 25(1): 2338955, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38680092

RESUMO

Gliomas are the most common type of primary brain tumor. Despite advances in treatment, it remains one of the most aggressive and deadly tumor of the central nervous system (CNS). Gliomas are characterized by high malignancy, heterogeneity, invasiveness, and high resistance to radiotherapy and chemotherapy. It is urgent to find potential new molecular targets for glioma. The TRPM channels consist of TRPM1-TPRM8 and play a role in many cellular functions, including proliferation, migration, invasion, angiogenesis, etc. More and more studies have shown that TRPM channels can be used as new therapeutic targets for glioma. In this review, we first introduce the structure, activation patterns, and physiological functions of TRPM channels. Additionally, the pathological mechanism of glioma mediated by TRPM2, 3, 7, and 8 and the related signaling pathways are described. Finally, we discuss the therapeutic potential of targeting TRPM for glioma.


•TRPM channels are widely expressed in the human body and play an important role in gliomas.• Abnormal expression of TRPM2, 3, 7, and 8 channels in gliomas is associated with disease severity and prognosis.•TRPM2, 3, 7, and 8 channels are effective targets in glioma.


Assuntos
Neoplasias Encefálicas , Glioma , Canais de Cátion TRPM , Humanos , Glioma/metabolismo , Glioma/patologia , Glioma/genética , Glioma/tratamento farmacológico , Canais de Cátion TRPM/metabolismo , Canais de Cátion TRPM/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Transdução de Sinais , Animais
2.
Neuro Oncol ; 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38554116

RESUMO

BACKGROUND: The mesenchymal (MES) subtype of glioblastoma (GBM) is believed to be influenced by both cancer cell-intrinsic alterations and extrinsic cellular interactions, yet the underlying mechanisms remain unexplored. METHODS: Identification of microglial heterogeneity by bioinformatics analysis. Transwell migration, invasion assays, and tumor models were used to determine gene function and the role of small molecule inhibitors. RNA sequencing, chromatin immunoprecipitation, and dual-luciferase reporter assays were performed to explore the underlying regulatory mechanisms. RESULTS: We identified the inflammatory microglial subtype of tumor-associated microglia (TAM) and found that its specific gene ITGB2 was highly expressed in TAM of MES GBM tissues. Mechanistically, the activation of ITGB2 in microglia promoted the interaction between the SH2 domain of STAT3 and the cytoplasmic domain of ITGB2, thereby stimulating the JAK1/STAT3/IL-6 signaling feedback to promote the MES transition of GBM cells. Additionally, microglia communicated with GBM cells through the interaction between the receptor ITGB2 on microglia and the ligand ICAM-1 on GBM cells, while an increased secretion of ICAM-1 was induced by the proinflammatory cytokine LIF. Further studies demonstrated that inhibition of CDK7 substantially reduced the recruitment of SNW1 to the super-enhancer of LIF, resulting in transcriptional inhibition of LIF. We identified notoginsenoside R1 as a novel LIF inhibitor that exhibited synergistic effects in combination with temozolomide. CONCLUSIONS: Our research reveals that the epigenetic-mediated interaction of GBM cells with TAM drives the MES transition of GBM and provides a novel therapeutic avenue for patients with MES GBM.

3.
J Exp Clin Cancer Res ; 42(1): 183, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37501079

RESUMO

Super-enhancers (SEs) consist of multiple typical enhancers enriched at high density with transcription factors, histone-modifying enzymes and cofactors. Oncogenic SEs promote tumorigenesis and malignancy by altering protein-coding gene expression and noncoding regulatory element function. Therefore, they play central roles in the treatment of cancer. Here, we review the structural characteristics, organization, identification, and functions of SEs and the underlying molecular mechanism by which SEs drive oncogenic transcription in tumor cells. We then summarize abnormal SE complexes, SE-driven coding genes, and noncoding RNAs involved in tumor development. In summary, we believe that SEs show great potential as biomarkers and therapeutic targets.


Assuntos
Elementos Facilitadores Genéticos , Neoplasias , Humanos , Neoplasias/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Histonas/metabolismo , Carcinogênese/genética
4.
Cancer Lett ; 562: 216189, 2023 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-37076042

RESUMO

P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a novel class of small regulatory RNAs (approximately 24-31 nucleotides in length) that often bind to members of the PIWI protein family. piRNAs regulate transposons in animal germ cells; piRNAs are also specifically expressed in many human tissues and regulate pivotal signaling pathways. Additionally, the abnormal expression of piRNAs and PIWI proteins has been associated with various malignant tumours, and multiple mechanisms of piRNA-mediated target gene dysregulation are involved in tumourigenesis and progression, suggesting that they have the potential to serve as new biomarkers and therapeutic targets for tumours. However, the functions and potential mechanisms of action of piRNAs in cancer have not yet been elucidated. This review summarises the current findings on the biogenesis, function, and mechanisms of piRNAs and PIWI proteins in cancer. We also discuss the clinical significance of piRNAs as diagnostic or prognostic biomarkers and therapeutic tools for cancer. Finally, we present some critical questions regarding piRNA research that need to be addressed to provide insight into the future development of the field.


Assuntos
Neoplasias , RNA de Interação com Piwi , Masculino , Animais , Humanos , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Proteínas/metabolismo , Carcinogênese , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo
5.
Adv Drug Deliv Rev ; 195: 114726, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36754285

RESUMO

Variable domains of heavy chain-only antibodies (VHH), also known as nanobodies (Nbs), are monomeric antigen-binding domains derived from the camelid heavy chain-only antibodies. Nbs are characterized by small size, high target selectivity, and marked solubility and stability, which collectively facilitate high-quality drug development. In addition, Nbs are readily expressed from various expression systems, including E. coli and yeast cells. For these reasons, Nbs have emerged as preferred antibody fragments for protein engineering, disease diagnosis, and treatment. To date, two Nb-based therapies have been approved by the U.S. Food and Drug Administration (FDA). Numerous candidates spanning a wide spectrum of diseases such as cancer, immune disorders, infectious diseases, and neurodegenerative disorders are under preclinical and clinical investigation. Here, we discuss the structural features of Nbs that allow for specific, versatile, and strong target binding. We also summarize emerging technologies for identification, structural analysis, and humanization of Nbs. Our main focus is to review recent advances in using Nbs as a modular scaffold to facilitate the engineering of multivalent polymers for cutting-edge applications. Finally, we discuss remaining challenges for Nb development and envision new opportunities in Nb-based research.


Assuntos
Escherichia coli , Anticorpos de Domínio Único , Estados Unidos , Escherichia coli/genética , Escherichia coli/metabolismo , Engenharia de Proteínas
6.
Diabetes Metab Res Rev ; 39(2): e3592, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36401613

RESUMO

AIMS: This study investigated insulinoma-associated-2 autoantibody (IA-2A) and zinc transporter 8 autoantibody (ZnT8A) distribution in patients with type 1 diabetes (T1D) and latent autoimmune diabetes (LAD) and the autoantibodies' association with clinical characteristics and HLA-DR-DQ genes. MATERIALS AND METHODS: This cross-sectional study recruited 17,536 patients with diabetes from 46 hospitals across China. A total of 189 patients with T1D and 58 patients with LAD with IA-2A positivity, 126 patients with T1D and 86 patients with LAD with ZnT8A positivity, and 231 patients with type 2 diabetes (T2D) were selected to evaluate islet autoantibodies, clinical phenotypes, and HLA-DR-DQ gene frequency. RESULTS: IA-2A was bimodally distributed in patients with T1D and LAD. Patients with low IA-2A titre LAD had lower fasting C-peptide (FCP) (p < 0.01), lower postprandial C-peptide (PCP) (p < 0.001), and higher haemoglobin A1c (HbA1c) levels (p < 0.05) than patients with T2D. Patients with high IA-2A titre LAD were younger than patients with low IA-2A titre LAD (p < 0.05). Patients with low IA-2A titre T1D had lower FCP (p < 0.01), lower PCP (p < 0.01), and higher HbA1c levels (p < 0.05) than patients with high IA-2A titre LAD. HLA-DR-DQ genetic analysis demonstrated that the frequency of susceptible HLA haplotypes was higher in IA-2A-positive patients (p < 0.001) than in patients with T2D. Patients with high ZnT8A titre LAD had lower FCP (p = 0.045), lower PCP (p = 0.023), and higher HbA1c levels (p = 0.009) and a higher frequency of total susceptible haplotypes (p < 0.001) than patients with low ZnT8A titre LAD. CONCLUSIONS: IA-2A in patients with T1D and LAD was bimodally distributed, and the presence of IA-2A could demonstrate partial LAD clinical characteristics. ZnT8A titre had a certain predictive value for islet functions in patients with LAD.


Assuntos
Proteínas de Transporte de Cátions , Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Intolerância à Glucose , Insulinoma , Neoplasias Pancreáticas , Humanos , Diabetes Mellitus Tipo 1/genética , Transportador 8 de Zinco , Autoanticorpos , Estudos Transversais , Peptídeo C , Hemoglobinas Glicadas , Proteínas de Transporte de Cátions/genética , Antígenos HLA-DR , Glutamato Descarboxilase
7.
Front Immunol ; 13: 968798, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36451831

RESUMO

Objective: Fulminant type 1 diabetes may uniquely occur as a fatal adverse event during immune checkpoint inhibitor (ICI) therapy. We investigated the clinical and immunological characteristics of ICI-associated fulminant type 1 diabetes (IFD). Research design and methods: We enrolled 80 patients with IFD (77 cases from the literature), 56 patients with ICI-associated type 1 diabetes (IT1D) (55 cases from the literature), 45 patients with traditional fulminant type 1 diabetes (TFD), and 43 patients with acute-onset type 1 diabetes for comprehensive analysis including islet autoantibodies and subgroup analysis based on ethnic origin. Results: Patients with IFD accounted for 58.8% (80/136) of patients with ICI-related diabetes. IFD had a more rapid onset than IT1D after ICI therapy (90.5 days vs. 120 days, p <0.05). The onset time and number of infusions after ICI therapy initiation were lower in the antibody-positive IFD group than that in the antibody-negative IFD group (both p <0.001). IFD had a more rapid onset and more serious among Caucasians than that among Asians (p <0.01, p <0.05, respectively), and the prevalence of islet autoantibody positivity in the Caucasian IFD were prominently higher than those in the Asian IFD (p <0.05). Onset age and plasma glucose levels were significantly higher in the IFD group than those in the TFD and acute-onset type 1 diabetes groups. HbA1c levels were slightly higher in patients with IFD than those with TFD. Conclusions: IFD is relatively common in Caucasian population where TFD is very rare or almost absent. IFD occurrence is significantly related to islet autoantibody status and ethnic origin.


Assuntos
Diabetes Mellitus Tipo 1 , Doenças do Sistema Endócrino , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Etnicidade , Autoanticorpos
8.
Proc Natl Acad Sci U S A ; 119(12): e2116251119, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35290126

RESUMO

RNA modifications regulate a variety of cellular processes including DNA repair.The RNA methyltransferase TRDMT1 generates methyl-5-cytosine (m5C) on messen-ger RNA (mRNA) at DNA double-strand breaks (DSBs) in transcribed regions, pro-moting transcription-coupled homologous recombination (HR). Here, we identifiedthat Fragile X mental retardation protein (FMRP) promotes transcription-coupled HRvia its interaction with both the m5C writer TRDMT1 and the m5C eraser ten-eleventranslocation protein 1 (TET1). TRDMT1, FMRP, and TET1 function in a temporalorder at the transcriptionally active sites of DSBs. FMRP displays a higher affinity forDNA:RNA hybrids containing m5C-modified RNA than for hybrids without modifica-tion and facilitates demethylation of m5C by TET1 in vitro. Loss of either the chroma-tin- or RNA-binding domain of FMRP compromises demethylation of damage-inducedm5C in cells. Importantly, FMRP is required for R-loop resolving in cells. Due to unre-solved R-loop and m5C preventing completion of DSB repair, FMRP depletion or lowexpression leads to delayed repair of DSBs at transcriptionally active sites and sensitizescancer cells to radiation in a BRCA-independent manner. Together, ourfindings presentan m5C reader, FMRP, which acts as a coordinator between the m5C writer and eraserto promote mRNA-dependent repair and cell survival in cancer.


Assuntos
Proteína do X Frágil da Deficiência Intelectual , Síndrome do Cromossomo X Frágil , Citosina , Desmetilação , Proteína do X Frágil da Deficiência Intelectual/genética , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Síndrome do Cromossomo X Frágil/genética , Recombinação Homóloga , Humanos , Oxigenases de Função Mista/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , RNA/genética , RNA/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
9.
Eur J Endocrinol ; 185(6): 819-829, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34519671

RESUMO

BACKGROUND: Obesity is associated with impaired immune function and chronic low-grade inflammation. Metabolic surgery is one of the most effective therapies for treating obesity and related metabolic disorders. We aimed to explore the pathophysiological roles of peripheral dendritic cells (DCs) and T lymphocytes in metabolic surgery. METHOD: In this observational cohort study, a total of 106 individuals, including obese participants with or without T2DM, overweight subjects and normal controls, were recruited. All obese participants underwent laparoscopic sleeve gastrectomy surgery and returned for the evaluation of the clinical indicators after surgery. We evaluated the frequencies of circulating DCs subsets (myeloid (mDCs) and plasmacytoid (pDCs)), the pro-inflammatory (Th1 and Th17) and anti-inflammatory (Th2 and Treg) T cell subsets by flow cytometry. RESULTS: Compared with normal controls, the frequencies of mDCs, Th1 and Th17 cells increased, while Treg and Th2 cells decreased in the obese participants. The frequency of mDCs and Th1 cells consistently declined after surgery compared with baseline in the obese patients and were restored to the levels observed in the normal controls after surgery. Moreover, the frequency of Treg cells was increased at 6 months after surgery in the obese patients with T2DM, and Th17 cells declined at 6 months after surgery in the severely obese patients without T2DM. CONCLUSION: This study indicates that metabolic surgery can effectively improve imbalanced immune cells in peripheral blood and restore the proportion of immune cells to a normal range during a 12-month follow-up.


Assuntos
Cirurgia Bariátrica , Células Dendríticas/imunologia , Diabetes Mellitus Tipo 2/cirurgia , Obesidade/cirurgia , Linfócitos T/imunologia , Adulto , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/imunologia , Feminino , Humanos , Masculino , Células Mieloides/imunologia , Obesidade/complicações , Obesidade/imunologia , Sobrepeso/imunologia , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia
10.
iScience ; 24(9): 103014, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34522857

RESUMO

Therapeutic and diagnostic efficacies of small biomolecules and chemical compounds are hampered by suboptimal pharmacokinetics. Here, we developed a repertoire of robust and high-affinity antihuman serum albumin nanobodies (NbHSA) that can be readily fused to small biologics for half-life extension. We characterized the thermostability, binding kinetics, and cross-species reactivity of NbHSAs, mapped their epitopes, and structurally resolved a tetrameric HSA-Nb complex. We parallelly determined the half-lives of a cohort of selected NbHSAs in an HSA mouse model by quantitative proteomics. Compared to short-lived control nanobodies, the half-lives of NbHSAs were drastically prolonged by 771-fold. NbHSAs have distinct and diverse pharmacokinetics, positively correlating with their albumin binding affinities at the endosomal pH. We then generated stable and highly bioactive NbHSA-cytokine fusion constructs "Duraleukin" and demonstrated Duraleukin's high preclinical efficacy for cancer treatment in a melanoma model. This high-quality and versatile Nb toolkit will help tailor drug half-life to specific medical needs.

11.
NAR Cancer ; 3(1): zcab010, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33778494

RESUMO

The RNA methyltransferase TRDMT1 has recently emerged as a key regulator of homologous recombination (HR) in the transcribed regions of the genome, but how it is regulated and its relevance in cancer remain unknown. Here, we identified that TRDMT1 is poly-ubiquitinated at K251 by the E3 ligase TRIM28, removing TRDMT1 from DNA damage sites and allowing completion of HR. Interestingly, K251 is adjacent to G155 in the 3D structure, and the G155V mutation leads to hyper ubiquitination of TRDMT1, reduced TRDMT1 levels and impaired HR. Accordingly, a TRDMT1 G155V mutation in an ovarian cancer super responder to platinum treatment. Cells expressing TRDMT1-G155V are sensitive to cisplatin in vitro and in vivo. In contrast, high expression of TRDMT1 in patients with ovarian cancer correlates with platinum resistance. A potent TRDMT1 inhibitor resensitizes TRDMT1-high tumor cells to cisplatin. These results suggest that TRDMT1 is a promising therapeutic target to sensitize ovarian tumors to platinum therapy.

12.
J Autoimmun ; 111: 102452, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32291137

RESUMO

The emergent outbreak of coronavirus disease 2019 (COVID-19) has caused a global pandemic. Acute respiratory distress syndrome (ARDS) and multiorgan dysfunction are among the leading causes of death in critically ill patients with COVID-19. The elevated inflammatory cytokines suggest that a cytokine storm, also known as cytokine release syndrome (CRS), may play a major role in the pathology of COVID-19. However, the efficacy of corticosteroids, commonly utilized antiinflammatory agents, to treat COVID-19-induced CRS is controversial. There is an urgent need for novel therapies to treat COVID-19-induced CRS. Here, we discuss the pathogenesis of severe acute respiratory syndrome (SARS)-induced CRS, compare the CRS in COVID-19 with that in SARS and Middle East respiratory syndrome (MERS), and summarize the existing therapies for CRS. We propose to utilize interleukin-6 (IL-6) blockade to manage COVID-19-induced CRS and discuss several factors that should be taken into consideration for its clinical application.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Infecções por Coronavirus/patologia , Síndrome da Liberação de Citocina/terapia , Interleucina-6/antagonistas & inibidores , Pneumonia Viral/patologia , Anti-Inflamatórios/uso terapêutico , Betacoronavirus/patogenicidade , COVID-19 , Humanos , Imunomodulação/efeitos dos fármacos , Interleucina-6/sangue , Pandemias , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/patologia
13.
Nat Commun ; 9(1): 4115, 2018 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-30297739

RESUMO

Actively transcribed regions of the genome are protected by transcription-coupled DNA repair mechanisms, including transcription-coupled homologous recombination (TC-HR). Here we used reactive oxygen species (ROS) to induce and characterize TC-HR at a transcribed locus in human cells. As canonical HR, TC-HR requires RAD51. However, the localization of RAD51 to damage sites during TC-HR does not require BRCA1 and BRCA2, but relies on RAD52 and Cockayne Syndrome Protein B (CSB). During TC-HR, RAD52 is recruited by CSB through an acidic domain. CSB in turn is recruited by R loops, which are strongly induced by ROS in transcribed regions. Notably, CSB displays a strong affinity for DNA:RNA hybrids in vitro, suggesting that it is a sensor of ROS-induced R loops. Thus, TC-HR is triggered by R loops, initiated by CSB, and carried out by the CSB-RAD52-RAD51 axis, establishing a BRCA1/2-independent alternative HR pathway protecting the transcribed genome.


Assuntos
DNA Helicases/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Recombinação Homóloga , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transcrição Gênica , Sequência de Aminoácidos , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Sequência de Bases , Linhagem Celular Tumoral , DNA/genética , DNA/metabolismo , Dano ao DNA , DNA Helicases/genética , Reparo do DNA , Enzimas Reparadoras do DNA/genética , Células HEK293 , Humanos , Proteínas de Ligação a Poli-ADP-Ribose/genética , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Proteína Rad52 de Recombinação e Reparo de DNA/genética , Proteína Rad52 de Recombinação e Reparo de DNA/metabolismo , Homologia de Sequência de Aminoácidos
14.
J Diabetes Res ; 2017: 5052812, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28491871

RESUMO

B lymphocytes are involved in inflammation and are related to insulin resistance in obesity and type 2 diabetes (T2D). This study investigated the phenotype and frequency of B-lymphocyte subsets in subjects recently diagnosed with T2D (n = 60), impaired glucose regulation (IGR, n = 73), and normal glucose tolerance (NGT, n = 169) by flow cytometry. T2D subjects had an increased percentage of CD19+CD23+ (B-2) cells and a decreased percentage of CD19+CD23- (B-1) cells attributing to CD19+CD23-CD5- (B-1b) cells, but not CD19+CD23-CD5+ (B-1a) cells, compared to NGT and IGR subjects. The proportion of CD19+CD5+CD1dhi (B10) cells did not differ between the IGR or T2D group and NGT controls. Of note, HbA1c and triglyceride showed a positive correlation with B-2 cells but an inverse correlation with B-1 and B-1b cells, which were independently associated with the presence of T2D by logistic regression models. In summary, this study shows an unbalanced proinflammatory phenotype of B-cell subsets correlated with glycemia and lipidemia in patients with T2D. Our data provide new insight into chronic activation of the immune system and subclinical inflammation in T2D. Further prospective studies are warranted to confirm our observations.


Assuntos
Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Diabetes Mellitus Tipo 2/imunologia , Intolerância à Glucose/imunologia , Adulto , Antígenos CD19/imunologia , Glicemia/metabolismo , Antígenos CD5/imunologia , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Citometria de Fluxo , Intolerância à Glucose/metabolismo , Hemoglobinas Glicadas/metabolismo , Humanos , Resistência à Insulina , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Receptores de IgE/imunologia , Triglicerídeos/metabolismo
15.
Diabetes Care ; 39(3): 434-40, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26721817

RESUMO

OBJECTIVE: B lymphocytes play an important role in the immunopathogenesis of autoimmune diabetes. We hypothesized that the altered B-cell subset phenotype is associated with autoimmune diabetes. RESEARCH DESIGN AND METHODS: Patients with type 1 diabetes (T1D) (n = 81), latent autoimmune diabetes in adults (LADA) (n = 82), or type 2 diabetes (T2D) (n = 95) and healthy control subjects (n = 218) with normal glucose tolerance (NGT) were recruited. We determined the percentage of circulating B-lymphocyte subsets, including CD19(+)CD23(-)CD21(+) (marginal zone B [MZB]), CD19(+)CD23(+)CD21(-) (follicular B [FoB]), and CD19(+)CD5(+)CD1d(hi) (interleukin-10-producing regulatory B [B10]) cells by flow cytometry. RESULTS: Patients with T1D or LADA had increased percentages of MZB cells and decreased percentages of FoB cells compared with healthy control subjects with NGT and patients with T2D. Moreover, patients with T1D showed the lowest frequency of B10 cells compared with patients with LADA or T2D, whereas healthy control subjects expressed the highest frequency of B10 cells. Of note, the frequency of MZB cells was negatively associated and the frequency of FoB cells was positively associated with fasting C-peptide (FCP). The frequency of B10 cells was positively correlated with FCP and negatively correlated with hemoglobin A(1c). CONCLUSIONS: The data show that patients with T1D or LADA express an altered frequency of B-cell subsets, which is associated with islet function and glycemia. These findings suggest that B lymphocytes may be involved in loss of self-tolerance and ß-cell destruction and could be used as a biomarker and potential target for immunological intervention.


Assuntos
Subpopulações de Linfócitos B/imunologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 2/imunologia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
16.
PLoS One ; 8(10): e76172, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24204601

RESUMO

OBJECTIVE: Mitochondrial oxidative stress is the basis for pancreatic ß-cell apoptosis and a common pathway for numerous types of damage, including glucotoxicity and lipotoxicity. We cultivated mice pancreatic ß-cell tumor Min6 cell lines in vitro and observed pancreatic ß-cell apoptosis and changes in mitochondrial function before and after the addition of Exendin-4. Based on these observations, we discuss the protective role of Exendin-4 against mitochondrial oxidative damage and its relationship with Ca(2+)-independent phospholipase A2. METHODS: We established a pancreatic ß-cell oxidative stress damage model using Min6 cell lines cultured in vitro with tert-buty1 hydroperoxide and hydrogen peroxide. We then added Exendin-4 to observe changes in the rate of cell apoptosis (Annexin-V-FITC-PI staining flow cytometry and DNA ladder). We detected the activity of the caspase 3 and 8 apoptotic factors, measured the mitochondrial membrane potential losses and reactive oxygen species production levels, and detected the expression of cytochrome c and Smac/DLAMO in the cytosol and mitochondria, mitochondrial Ca2-independent phospholipase A2 and Ca(2+)-independent phospholipase A2 mRNA. RESULTS: The time-concentration curve showed that different percentages of apoptosis occurred at different time-concentrations in tert-buty1 hydroperoxide- and hydrogen peroxide-induced Min6 cells. Incubation with 100 µmol/l of Exendin-4 for 48 hours reduced the Min6 cell apoptosis rate (p<0.05). The mitochondrial membrane potential loss and total reactive oxygen species levels decreased (p<0.05), and the release of cytochrome c and Smac/DLAMO from the mitochondria was reduced. The study also showed that Ca(2+)-independent phospholipase A2 activity was positively related to Exendin-4 activity. CONCLUSION: Exendin-4 reduces Min6 cell oxidative damage and the cell apoptosis rate, which may be related to Ca(2)-independent phospholipase A2.


Assuntos
Apoptose/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Células Secretoras de Insulina/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Peptídeos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Peçonhas/farmacologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Caspase 3/metabolismo , Linhagem Celular , Fragmentação do DNA/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Exenatida , Ácidos Graxos/metabolismo , Regulação da Expressão Gênica , Fosfolipases A2 do Grupo VI/genética , Fosfolipases A2 do Grupo VI/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Estresse Oxidativo , Fosfolipases A2 Citosólicas/genética , Fosfolipases A2 Citosólicas/metabolismo , Fatores de Tempo , Transcrição Gênica
17.
J Immunol ; 188(10): 4747-58, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22490442

RESUMO

B cells play a critical role in the pathogenesis of autoimmune diabetes. To investigate the mechanisms by which B cell depletion therapy attenuates islet ß cell loss and particularly to examine the effect of B cells on both diabetogenic and regulatory Ag-specific T cells, we generated a transgenic BDC2.5NOD mouse expressing human CD20 on B cells. This allowed us to deplete B cells for defined time periods and investigate the effect of B cell depletion on Ag-specific BDC2.5 T cells. We depleted B cells with anti-human CD20 Ab using a multiple injection protocol. We studied two time points, before and after B cell regeneration, to examine the effect on BDC2.5 T cell phenotype and functions that included antigenic response, cytokine profile, diabetogenicity, and suppressive function of regulatory T (T(reg)) cells. We found unexpectedly that B cell depletion induced transient aggressive behavior in BDC2.5 diabetogenic T cells and reduction in T(reg) cell number and function during the depletion period. However, after B cell reconstitution, we found that more regenerated B cells, particularly in the CD1d(-) fraction, expressed immune regulatory function. Our results suggest that the regenerated B cells are likely to be responsible for the therapeutic effect after B cell depletion. Our preclinical study also provides direct evidence that B cells regulate both pathogenic and T(reg) cell function, and this knowledge could explain the increased T cell responses to islet Ag after rituximab therapy in diabetic patients in a recent report and will be useful in design of future clinical protocols.


Assuntos
Antígenos CD20/biossíntese , Subpopulações de Linfócitos B/imunologia , Complicações do Diabetes/imunologia , Epitopos de Linfócito T/imunologia , Linfopenia/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Antígenos CD20/genética , Antígenos CD20/imunologia , Subpopulações de Linfócitos B/metabolismo , Subpopulações de Linfócitos B/patologia , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Humanos , Contagem de Linfócitos , Linfopenia/metabolismo , Linfopenia/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Fenótipo , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia
18.
Nanotechnology ; 22(45): 455102, 2011 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-22019849

RESUMO

A targeted anticancer prodrug system was fabricated with 180 nm mesoporous silica nanoparticles (MSNs) as carriers. The anticancer drug doxorubicin (DOX) was conjugated to the particles through an acid-sensitive carboxylic hydrazone linker which is cleavable under acidic conditions. Moreover, folic acid (FA) was covalently conjugated to the particle surface as the targeting ligand for folate receptors (FRs) overexpressed in some cancer cells. The in vitro release profiles of DOX from the MSN-based prodrug systems showed a strong dependence on the environmental pH values. The fluorescent dye FITC was incorporated in the MSNs so as to trace the cellular uptake on a fluorescence microscope. Cellular uptakes by HeLa, A549 and L929 cell lines were tested for FA-conjugated MSNs and plain MSNs respectively, and a much more efficient uptake by FR-positive cancer cells (HeLa) can be achieved by conjugation of folic acid onto the particles because of the folate-receptor-mediated endocytosis. The cytotoxicities for the FA-conjugated MSN prodrug, the plain MSN prodrug and free DOX against three cell lines were determined, and the result indicates that the FA-conjugated MSN prodrug exhibits higher cytotoxicity to FR-positive cells, and reduced cytotoxicity to FR-negative cells. Thus, with 180 nm MSNs as the carriers for the prodrug system, good drug loading, selective targeting and sustained release of drug molecules within targeted cancer cells can be realized. This study may provide useful insights for designing and improving the applicability of MSNs in targeted anticancer prodrug systems.


Assuntos
Antineoplásicos/farmacocinética , Doxorrubicina/farmacocinética , Nanopartículas/química , Pró-Fármacos/farmacocinética , Dióxido de Silício/química , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Fluoresceína-5-Isotiocianato , Ácido Fólico/química , Ácido Fólico/metabolismo , Ácido Fólico/farmacologia , Transportadores de Ácido Fólico/metabolismo , Humanos , Hidrazonas , Concentração de Íons de Hidrogênio , Camundongos , Microscopia Eletrônica de Transmissão , Pró-Fármacos/administração & dosagem , Pró-Fármacos/química , Espectrometria de Fluorescência
19.
Diabetes Care ; 34(7): 1639-41, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21617097

RESUMO

OBJECTIVE: To determine the relationship between selected cytokines and diabetes in Chinese subjects. RESEARCH DESIGN AND METHODS: Adult patients with recent-onset type 1 diabetes (n=53), latent autoimmune diabetes in adults (LADA) (n=250), and type 2 diabetes (n=285) from multiple centers were compared with normal subjects (n=196). We centrally tested serum GAD antibodies (GADAs), interleukin-6 (IL-6), lipocalin 2 (LCN2), high-sensitivity C-reactive protein (hs-CRP), and adiponectin. RESULTS: After adjustment for age, sex, and BMI, all diabetes types had increased IL-6 and LCN2 (P<0.01), and all four cytokines were increased in LADA (P<0.01). In type 1 diabetes, adiponectin but not hs-CRP was increased (P<0.01), whereas in type 2 diabetes, hs-CRP but not adiponectin was increased (P<0.01). Adiponectin was correlated positively with GADA titer and negatively with hs-CRP (P<0.01 for both). CONCLUSIONS: In China, inflammatory markers are increased in all three major types of diabetes, but probably for different reasons, even in autoimmune diabetes.


Assuntos
Citocinas/sangue , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Proteínas de Fase Aguda , Adiponectina/sangue , Adulto , Povo Asiático , Proteína C-Reativa/análise , China , Feminino , Glutamato Descarboxilase/imunologia , Humanos , Interleucina-6/sangue , Lipocalina-2 , Lipocalinas/sangue , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas/sangue
20.
Ann Vasc Surg ; 22(5): 643-8, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18562162

RESUMO

The optimal dosing strategy for perioperative beta-blockers to safely achieve recommended target heart rates (HRs) by current guidelines is not well defined. An HR-titrated perioperative beta-blocker dosing regimen versus a fixed-dose regimen was assessed by clinical outcomes, postoperative heart rate, and beta-blocker-related complications. Patients (n = 64) scheduled to undergo moderate- to high-risk vascular surgery and without contraindications to beta-blockade were randomized to either a fixed-dose or HR-titrated beta-blocker dosing schedule. Clinical outcomes and HRs were followed immediately preoperatively to 24 hr postoperatively. A difference in mean HR between the two dosing arms was significant immediately postoperatively (70.1 vs. 58.2 bpm for fixed dose and HR-titrated arms, respectively; p = 0.012) but at no other time points. However, the HR-titrated strategy led to a significant reduction in the percentage of HR measurements >80 bpm (34.5% vs. 16.1%, p < 0.001) and to a significant reduction in absolute HR change (17.5 vs. 22.5 bpm, p = 0.034). There were no significant differences in the occurrence of asymptomatic hypotension between the two study arms, and no beta-blocker-related adverse events occurred in either study arm. An aggressive, HR-titrated perioperative beta-blocker dosing strategy was associated with more consistent maintenance of postoperative HRs within the range recommended by current guidelines and did not result in increased drug-related adverse events. The question of what is the best perioperative beta-blocker dosing regimen warrants further evaluation in a large-scale clinical trial.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Fármacos Cardiovasculares/administração & dosagem , Doenças Cardiovasculares/prevenção & controle , Frequência Cardíaca/efeitos dos fármacos , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Antagonistas Adrenérgicos beta/efeitos adversos , Idoso , Fármacos Cardiovasculares/efeitos adversos , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Esquema de Medicação , Feminino , Humanos , Masculino , Assistência Perioperatória , Guias de Prática Clínica como Assunto , Fatores de Tempo , Resultado do Tratamento
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