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1.
Diabetologia ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38910151

RESUMO

Given the proven benefits of screening to reduce diabetic ketoacidosis (DKA) likelihood at the time of stage 3 type 1 diabetes diagnosis, and emerging availability of therapy to delay disease progression, type 1 diabetes screening programmes are being increasingly emphasised. Once broadly implemented, screening initiatives will identify significant numbers of islet autoantibody-positive (IAb+) children and adults who are at risk of (confirmed single IAb+) or living with (multiple IAb+) early-stage (stage 1 and stage 2) type 1 diabetes. These individuals will need monitoring for disease progression; much of this care will happen in non-specialised settings. To inform this monitoring, JDRF in conjunction with international experts and societies developed consensus guidance. Broad advice from this guidance includes the following: (1) partnerships should be fostered between endocrinologists and primary-care providers to care for people who are IAb+; (2) when people who are IAb+ are initially identified there is a need for confirmation using a second sample; (3) single IAb+ individuals are at lower risk of progression than multiple IAb+ individuals; (4) individuals with early-stage type 1 diabetes should have periodic medical monitoring, including regular assessments of glucose levels, regular education about symptoms of diabetes and DKA, and psychosocial support; (5) interested people with stage 2 type 1 diabetes should be offered trial participation or approved therapies; and (6) all health professionals involved in monitoring and care of individuals with type 1 diabetes have a responsibility to provide education. The guidance also emphasises significant unmet needs for further research on early-stage type 1 diabetes to increase the rigour of future recommendations and inform clinical care.

2.
Mol Cell Proteomics ; 21(12): 100419, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36182100

RESUMO

Understanding how connective tissue cells respond to mechanical stimulation is important to human health and disease processes in musculoskeletal diseases. Injury to articular cartilage is a key risk factor in predisposition to tissue damage and degenerative osteoarthritis. Recently, we have discovered that mechanical injury to connective tissues including murine and porcine articular cartilage causes a significant increase in lysine-63 polyubiquitination. Here, we identified the ubiquitin signature that is unique to injured articular cartilage tissue upon mechanical injury (the "mechano-ubiquitinome"). A total of 463 ubiquitinated peptides were identified, with an enrichment of ubiquitinated peptides of proteins involved in protein processing in the endoplasmic reticulum (ER), also known as the ER-associated degradation response, including YOD1, BRCC3, ATXN3, and USP5 as well as the ER stress regulators, RAD23B, VCP/p97, and Ubiquilin 1. Enrichment of these proteins suggested an injury-induced ER stress response and, for instance, ER stress markers DDIT3/CHOP and BIP/GRP78 were upregulated following cartilage injury on the protein and gene expression levels. Similar ER stress induction was also observed in response to tail fin injury in zebrafish larvae, suggesting a generic response to tissue injury. Furthermore, a rapid increase in global DUB activity following injury and significant activity in human osteoarthritic cartilage was observed using DUB-specific activity probes. Combined, these results implicate the involvement of ubiquitination events and activation of a set of DUBs and ER stress regulators in cellular responses to cartilage tissue injury and in osteoarthritic cartilage tissues. This link through the ER-associated degradation pathway makes this protein set attractive for further investigation in in vivo models of tissue injury and for targeting in osteoarthritis and related musculoskeletal diseases.


Assuntos
Cartilagem Articular , Doenças Musculoesqueléticas , Osteoartrite , Humanos , Animais , Camundongos , Suínos , Cartilagem Articular/metabolismo , Peixe-Zebra/metabolismo , Ubiquitinação , Estresse do Retículo Endoplasmático , Retículo Endoplasmático/metabolismo , Ubiquitina/metabolismo , Peptídeos/metabolismo , Doenças Musculoesqueléticas/metabolismo , Osteoartrite/metabolismo
3.
Int J Mol Sci ; 24(10)2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37240151

RESUMO

Ribosomal S6 kinases (S6Ks) are critical regulators of cell growth, homeostasis, and survival, with dysregulation of these kinases found to be associated with various malignancies. While S6K1 has been extensively studied, S6K2 has been neglected despite its clear involvement in cancer progression. Protein arginine methylation is a widespread post-translational modification regulating many biological processes in mammalian cells. Here, we report that p54-S6K2 is asymmetrically dimethylated at Arg-475 and Arg-477, two residues conserved amongst mammalian S6K2s and several AT-hook-containing proteins. We demonstrate that this methylation event results from the association of S6K2 with the methyltransferases PRMT1, PRMT3, and PRMT6 in vitro and in vivo and leads to nuclear the localisation of S6K2 that is essential to the pro-survival effects of this kinase to starvation-induced cell death. Taken together, our findings highlight a novel post-translational modification regulating the function of p54-S6K2 that may be particularly relevant to cancer progression where general Arg-methylation is often elevated.


Assuntos
Fenômenos Biológicos , Proteínas Quinases S6 Ribossômicas 90-kDa , Animais , Fosforilação , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Mamíferos/metabolismo
4.
Diabetes Obes Metab ; 24(3): 539-545, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34866294

RESUMO

AIM: To report fasting C-peptide values and variations across demographics in healthy non-diabetic adolescents included in the National Health and Nutrition Examination Surveys (NHANES) dataset. RESEARCH DESIGN AND METHODS: In this analysis, we used fasting C-peptide data from the 1999 to 2004 NHANES dataset for participants aged 12 to <18 years (n = 2063). RESULTS: The mean ± SE age of the participants was 14.99 ± 0.06 years. The participants included 992 girls and 1071 boys, and more than 80% of participants had a body mass index (BMI) percentile of <85%. Among boys, the most notable finding was the increase in geometric mean C-peptide level from 0.51 nmol/L at age 12, to 0.65 nmol/L at age 15 years. Among girls, levels fluctuated around a geometric mean of 0.67 nmol/L. Girls had significantly higher mean log-transformed C-peptide concentrations than boys (P < 0.0001) after adjusting for age, race and BMI percentile category. After adjusting for age and BMI percentile category, non-Hispanic Black boys and girls had significantly lower C-peptide levels than non-Hispanic White (P = 0.0026 and P = 0.0093) and Mexican American boys and girls (P < 0.0001 and P < 0.0001), respectively. Despite these findings, both insulin and homeostatic model assessment of insulin resistance were greater in non-Hispanic Black compared to non-Hispanic White participants. CONCLUSIONS: Here we describe fasting C-peptide levels in a non-diabetic adolescent population. These data provide crucial insight into evaluating racial differences in endogenous insulin release and clearance and will provide novel information which can be used in assessing residual ß-cell function and response to intervention therapy.


Assuntos
Jejum , População Branca , Adolescente , Índice de Massa Corporal , Peptídeo C , Criança , Feminino , Humanos , Masculino , Inquéritos Nutricionais
5.
Diabetes Spectr ; 35(4): 461-468, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36561657

RESUMO

Background: Little is known about the coronavirus disease 2019 (COVID-19) pandemic's psychological effects on caregivers of children with type 1 diabetes. Objective: This study aimed to investigate the experience of caregivers of youth with type 1 diabetes during the COVID-19 pandemic. Methods: A 49-item questionnaire using a 5-point Likert scale and open-response questions was distributed via e-mail and type 1 diabetes-related social media platforms from 4 May to 22 June 2020. Quantitative data were analyzed using SPSS v.25 statistical software. Descriptive statistics were used. Relationships were compared using Pearson correlation. Qualitative data were coded and categorized. Results: A total of 272 caregivers participated (mean ± SD respondent age 42.1 ± 7.8 years; 94.5% females; 81.3% with college degree or higher; 52.6% with annual income >$99,000; 80.1% with private insurance). The mean ± SD age of caregivers' children with type 1 diabetes was 11.0 ± 4.1 years, and their mean ± SD diabetes duration was 4.2 ± 3.5 years. Participants reported being diagnosed with or knowing someone with COVID-19 (24.6%), increased stress (71.9%), job loss (10.3%), and financial difficulty (26.8%) as a result of the pandemic. General self-efficacy scores were high (mean ± SD 16.2 ± 2.6, range 8-20) and significantly correlated with COVID-19-related self-efficacy (mean ± SD 12.6 ± 2.1; R = 0.394, P <0.001) and type 1 diabetes self-efficacy during COVID-19 (mean ± SD 17.1 ± 2.5; R = 0.421, P <0.001). Conclusion: Despite reporting high overall self-efficacy, caregivers of children with type 1 diabetes reported greater overall stress and challenges during the pandemic. Health care providers should be prepared to provide families with specific social and mental health support.

6.
Diabetes Obes Metab ; 22(6): 997-1000, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32003110

RESUMO

We examined whether the timing of the C-peptide response during an oral glucose tolerance test (OGTT) in relatives of patients with type 1 diabetes (T1D) is predictive of disease onset. We examined baseline 2-h OGTTs from 670 relatives participating in the Diabetes Prevention Trial-Type 1 (age: 13.8 ± 9.6 years; body mass index z-score: 0.3 ± 1.1; 56% male) using univariate regression models. T1D risk increased with lower early C-peptide responses (30-0 min) (χ2 = 28.8, P < 0.001), and higher late C-peptide responses (120-60 min) (χ2 = 23.3, P < 0.001). When both responses were included in a proportional hazards model, they remained independently and oppositely associated with T1D, with a stronger overall association for the combined model than either response alone (χ2 = 41.1; P < 0.001). Using receiver operating characteristic curve analysis, the combined early and late C-peptide response was more accurately predictive of T1D than area under the curve C-peptide (P = 0.005). Our findings demonstrate that lower early and higher late C-peptide responses serve as indicators of increased T1D risk.


Assuntos
Autoanticorpos , Peptídeo C , Diabetes Mellitus Tipo 1 , Teste de Tolerância a Glucose , Adolescente , Adulto , Glicemia , Peptídeo C/metabolismo , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/diagnóstico , Feminino , Humanos , Masculino , Curva ROC , Adulto Jovem
7.
Pediatr Diabetes ; 20(4): 408-413, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30891858

RESUMO

BACKGROUND: In new onset type 1 diabetes (T1D), overall C-peptide measures such as area under the curve (AUC) C-peptide and peak C-peptide are useful for estimating the extent of ß-cell dysfunction, and for assessing responses to intervention therapy. However, measures of the timing of C-peptide responsiveness could have additional value. OBJECTIVES: We assessed the contribution of the timing of C-peptide responsiveness during oral glucose tolerance tests (OGTTs) to hemoglobin A1c (HbA1c) variation at T1D diagnosis. METHODS: We analyzed data from 85 individuals <18 years with OGTTs and HbA1c measurements at diagnosis. Overall [AUC and peak C-peptide] and timing measures [30-0 minute C-peptide (early); 60 to 120 minute C-peptide sum-30 minutes (late); 120/30 C-peptide; time to peak C-peptide] were utilized. RESULTS: At diagnosis, the mean (±SD) age was 11.2 ± 3.3 years, body mass index (BMI)-z was 0.4 ± 1.1, 51.0% were male. The average HbA1c was 43.54 ± 8.46 mmol/mol (6.1 ± 0.8%). HbA1c correlated inversely with the AUC C-peptide (P < 0.001), peak C-peptide (P < 0.001), early and late C-peptide responses (P < 0.001 each), and 120/30 C-peptide (P < 0.001). Those with a peak C-peptide occurring at ≤60 minutes had higher HbA1c values than those with peaks later (P = 0.003). HbA1c variance was better explained with timing measures added to regression models (R2 = 11.6% with AUC C-peptide alone; R2 = 20.0% with 120/30 C-peptide added; R2 = 13.7% with peak C-peptide alone, R2 = 20.4% with timing of the peak added). Similar associations were seen between the 2-hour glucose and the C-peptide measures. CONCLUSIONS: These findings show that the addition of timing measures of C-peptide responsiveness better explains HbA1c variation at diagnosis than standard measures alone.


Assuntos
Peptídeo C/metabolismo , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/genética , Hemoglobinas Glicadas/metabolismo , Adolescente , Adulto , Glicemia/genética , Glicemia/metabolismo , Peptídeo C/análise , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/sangue , Feminino , Estudos de Associação Genética , Teste de Tolerância a Glucose , Hemoglobinas Glicadas/análise , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto Jovem
8.
Diabetologia ; 61(1): 84-92, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28956083

RESUMO

AIMS/HYPOTHESIS: We aimed to examine: (1) whether specific glucose-response curve shapes during OGTTs are predictive of type 1 diabetes development; and (2) the extent to which the glucose-response curve is influenced by insulin secretion. METHODS: Autoantibody-positive relatives of people with type 1 diabetes whose baseline OGTT met the definition of a monophasic or biphasic glucose-response curve were followed for the development of type 1 diabetes (n = 2627). A monophasic curve was defined as an increase in OGTT glucose between 30 and 90 min followed by a decline of ≥ 0.25 mmol/l between 90 and 120 min. A biphasic response curve was defined as a decrease in glucose after an initial increase, followed by a second increase of ≥ 0.25 mmol/l. Associations of type 1 diabetes risk with glucose curve shapes were examined using cumulative incidence curve comparisons and proportional hazards regression. C-peptide responses were compared with and without adjustments for potential confounders. RESULTS: The majority of participants had a monophasic curve at baseline (n = 1732 [66%] vs n = 895 [34%]). The biphasic group had a lower cumulative incidence of type 1 diabetes (p < 0.001), which persisted after adjustments for age, sex, BMI z score and number of autoantibodies (p < 0.001). Among the monophasic group, the risk of type 1 diabetes was greater for those with a glucose peak at 90 min than for those with a peak at 30 min; the difference persisted after adjustments (p < 0.001). Compared with the biphasic group, the monophasic group had a lower early C-peptide (30-0 min) response, a lower C-peptide index (30-0 min C-peptide/30-0 min glucose), as well as a greater 2 h C-peptide level (p < 0.001 for all). CONCLUSIONS/INTERPRETATION: Those with biphasic glucose curves have a lower risk of progression to type 1 diabetes than those with monophasic curves, and the risk among the monophasic group is increased when the glucose peak occurs at 90 min than at 30 min. Differences in glucose curve shapes between the monophasic and biphasic groups appear to be related to C-peptide responses.


Assuntos
Peptídeo C/metabolismo , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/metabolismo , Teste de Tolerância a Glucose/métodos , Adulto , Glicemia/metabolismo , Feminino , Humanos , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade
10.
Pediatr Diabetes ; 19(3): 403-409, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29171129

RESUMO

BACKGROUND/OBJECTIVE: The extent of influence of BMI and age on C-peptide at the diagnosis of type 1 diabetes (T1D) is unknown. We thus studied the impact of body mass index Z-scores (BMIZ) and age on C-peptide measures at and soon after the diagnosis of T1D. METHODS: Data from Diabetes Prevention Trial-Type 1 (DPT-1) participants <18.0 years at diagnosis was analyzed. Analyses examined associations of C-peptide measures with BMIZ and age in 2 cohorts: oral glucose tolerance tests (OGTTs) at diagnosis (n = 99) and mixed meal tolerance tests (MMTTs) <6 months after diagnosis (n = 80). Multivariable linear regression was utilized. RESULTS: Fasting and area under the curve (AUC) C-peptide from OGTTs (n = 99) at diagnosis and MMTTs (n = 80) after diagnosis were positively associated with BMIZ and age (P < .001 for all). Associations persisted when BMIZ and age were included as independent variables in regression models (P < .001 for all). BMIZ and age explained 31%-47% of the variance of C-peptide measures. In an example, 2 individuals with identical AUC C-peptide values had an approximate 5-fold difference in values after adjustments for BMIZ and age. The association between fasting glucose and C-peptide decreased markedly when fasting C-peptide values were adjusted (r = 0.30, P < .01 to r = 0.07, n.s.). CONCLUSIONS: C-peptide measures are strongly and independently related to BMIZ and age at and soon after the diagnosis of T1D. Adjustments for BMIZ and age cause substantial changes in C-peptide values, and impact the association between glycemia and C-peptide. Such adjustments can improve assessments of ß-cell impairment at diagnosis.


Assuntos
Peptídeo C/sangue , Diabetes Mellitus Tipo 1/sangue , Adolescente , Fatores Etários , Índice de Massa Corporal , Criança , Diabetes Mellitus Tipo 1/diagnóstico , Feminino , Humanos , Masculino
11.
Pediatr Diabetes ; 19(5): 985-992, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29573523

RESUMO

OBJECTIVE: This study examines temporal trends in treatment-related outcomes surrounding a diabetic ketoacidosis (DKA) performance improvement intervention consisting of mandated intensive care unit admission and implementation of a standardized management pathway, and identifies physical and biochemical characteristics associated with outcomes in this population. METHODS: A retrospective cohort of 1225 children with DKA were identified in the electronic health record by international classification of diseases codes and a minimum pH less than 7.3 during hospitalization at a quaternary children's hospital between April, 2009 and May, 2016. Multivariable regression examined predictors and trends of hypoglycemia, central venous line placement, severe hyperchloremia, head computed tomography (CT) utilization, treated cerebral edema and hospital length of stay (LOS). RESULTS: The incidence of severe hyperchloremia and head CT utilization decreased during the study period. Among patients with severe DKA (presenting pH < 7.1), the intervention was associated with decreasing LOS and less variability in LOS. Lower pH at presentation was independently associated with increased risk for all outcomes except hypoglycemia, which was associated with higher pH. Patients treated for cerebral edema had a lower presenting mean systolic blood pressure z score (0.58 [95% confidence interval (CI) -0.02-1.17] vs 1.23 [1.13-1.33]) and a higher maximum mean systolic blood pressure (SBP) z score during hospitalization (3.75 [3.19-4.31] vs 2.48 [2.38-2.58]) compared to patients not receiving cerebral edema treatment. Blood pressure and cerebral edema remained significantly associated after covariate adjustment. CONCLUSION: Treatment-related outcomes improved over the entire study period and following a performance improvement intervention. The association of SBP with cerebral edema warrants further study.


Assuntos
Cetoacidose Diabética/terapia , Adolescente , Pressão Sanguínea , Edema Encefálico/etiologia , Criança , Procedimentos Clínicos , Cetoacidose Diabética/complicações , Feminino , Humanos , Masculino , Estudos Retrospectivos , Resultado do Tratamento
13.
Pediatr Diabetes ; 16(2): 129-37, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23944770

RESUMO

AIMS: Intravenous glucose tolerance testing (IVGTT) is a common test of ß-cell function in which a glucose load is administered and insulin and/or C-peptide responses are monitored. Since the first IVGTT may be more stressful and stress may alter ß-cell secretion or hepatic insulin extraction, we asked whether there was a first test effect. METHODS: Insulin and C-peptide responses were compared from two sequential IVGTTs performed within 6 months during staging for the Diabetes Prevention Trial-Type 1 (DPT-1) in 368 people at high risk for type 1 diabetes. Insulin data (1+3 min) were used because the first phase insulin response (and peak insulin concentration) occurs within this time frame. Areas under the curve (AUC) calculations represent early insulin or C-peptide responses from 0 through 10 min post-glucose challenge. RESULTS: More than half of all subjects were found to have first test values lower than the second. This was true for all measures of both insulin and C-peptide but the frequency was significantly different only for insulin measures corrected for basal and for insulin AUC (p < 0.05). However, for subjects (n = 99) whose 1+3 min insulin response was <10th percentile on the first test, there was a significant increase on the second test (p < 0.05). The C-peptide: insulin ratio did not change significantly between tests, indicating that differences are due to changes in ß-cell secretion rather than hepatic insulin uptake. CONCLUSIONS: A statistically significant first test effect occurs during the IVGTT attributable to variations in insulin secretion rather than hepatic uptake.


Assuntos
Intolerância à Glucose/diagnóstico , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Estresse Psicológico/complicações , Adolescente , Adulto , Peptídeo C/sangue , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/epidemiologia , Saúde da Família , Glucose/administração & dosagem , Glucose/metabolismo , Intolerância à Glucose/sangue , Intolerância à Glucose/complicações , Intolerância à Glucose/metabolismo , Teste de Tolerância a Glucose , Humanos , Infusões Intravenosas , Insulina/sangue , Secreção de Insulina , Fígado/metabolismo , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Risco , Adulto Jovem
14.
J Cell Biochem ; 115(6): 1048-62, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23564320

RESUMO

The activity of S6 kinases (S6K) is highly induced in cancer cells highlighting an essential role in carcinogenesis. The S6K family has two members: S6K1 and S6K2 which bear common as well as distinct features. In an attempt to identify S6K2 unique sequence features compared to S6K1, we applied extensive bioinformatic analysis and motif search approaches. Interestingly, we identified 14 unique protein signatures which are present in proteins directly connected to chromatin and/or involved in transcription regulation. Using chromatin binding assay, we biochemically showed that S6K2 is bound to chromatin as well as nuclear matrix cellular fractions in HEK293 cells. The presence of S6K2 in chromatin fractions raised the possibility that it may be in close proximity to a number of chromatin substrates. For that, we then searched for S6K phosphorylation consensus sites RXRXXT/S in mammalian proteins using the SWISS-PROT database. Interestingly, we identified some potential phosphorylation sites in histone H3 (Thr45). Using in vitro kinase assays and siRNA-based knockdown strategy; we confirmed that S6K2 but not S6K1 or AKT is essential for histone H3-Thr45 phosphorylation in HEK293 cells. Furthermore, we show that the nuclear localisation sequence in the S6K2 C-terminus is essential for this modification. We have found that, H3-Thr45 phosphorylation correlates to S6K activation in response to mitogens and TPA-induced cell differentiation of leukaemic cell lines U937, HL60 and THP1. Overall, we demonstrate that S6K2 is a novel kinase that can phosphorylate histone H3 at position Thr45, which may play a role during cell proliferation and/or differentiation.


Assuntos
Cromatina/metabolismo , Histonas/metabolismo , Matriz Nuclear/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Treonina/metabolismo , Sequência de Aminoácidos , Animais , Western Blotting , Diferenciação Celular/efeitos dos fármacos , Fracionamento Celular , Linhagem Celular Tumoral , Cromatina/genética , Células HEK293 , Células HL-60 , Humanos , Camundongos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Células NIH 3T3 , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Acetato de Tetradecanoilforbol/farmacologia , Células U937
15.
Arthritis Rheum ; 65(2): 397-407, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23124605

RESUMO

OBJECTIVE: To investigate whether cartilage injury activates protein tyrosine kinases distinct from fibroblast growth factor (FGF)-related signaling, and whether they contribute to injury-induced gene responses. METHODS: Phosphokinases and protein tyrosine phosphorylation were assayed by Western blotting of cartilage lysates. Immunoprecipitation and Western blotting with 4G10 antibody and immunoprecipitation kinase assay were carried out. Tyrosine-phosphorylated proteins on silver-stained gels of injured cartilage lysates were identified by mass spectrometry. Messenger RNA induction in cartilage explants was assessed by quantitative reverse transcriptase-polymerase chain reaction. RESULTS: Protein tyrosine phosphorylation occurred within seconds of injury to the surface of intact articular cartilage, as did activation of MAPKs and IKK. Activation did not reoccur upon reinjury of cultured explants. The prominent tyrosine-phosphorylated proteins focal adhesion kinase, paxillin, and cortactin were identified as substrates of Src family kinases. The Src family kinase inhibitor PP2 blocked injury-induced tyrosine phosphorylation. It did not prevent activation of the MAPKs and IKK but differentially inhibited 8 of 10 inflammatory response genes that were induced by injury. In contrast, FGF signaling blockade with PD173074 reduced all MAPK and IKK activation by ∼50% and inhibited a different subset of genes but had no effect on Src-like signaling. CONCLUSION: Injury to the surface of intact articular cartilage activates Src-like kinases as well as MAPKs and IKK (implying NF-κB activation). FGF-2 contributes to MAPK/IKK activation but not to Src-like signaling, suggesting that the latter is a parallel pathway that also regulates the injury-induced inflammatory gene response.


Assuntos
Cartilagem Articular/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Expressão Gênica/fisiologia , Transdução de Sinais/fisiologia , Quinases da Família src/metabolismo , Animais , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/lesões , Inibidores Enzimáticos/farmacologia , Fator 2 de Crescimento de Fibroblastos/genética , Proteína-Tirosina Quinases de Adesão Focal/genética , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Expressão Gênica/efeitos dos fármacos , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Pirimidinas/farmacologia , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Suínos , Quinases da Família src/genética
16.
medRxiv ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38798462

RESUMO

Acetylated and butyrylated high amylose starch (HAMS-AB) is a prebiotic shown to be effective in type 1 diabetes (T1D) prevention in mouse models and is safe in adults with established T1D. HAMS-AB alters the gut microbiome profile with increased bacterial fermenters that produce short chain fatty acids (SCFAs) with anti-inflammatory and immune-modulatory effects. We performed a pilot study using a cross-over design to assess the safety and efficacy of 4 weeks of oral HAMS-AB consumption by recently diagnosed (< 2 years of diagnosis) youths with T1D. Seven individuals completed the study. The mean±SD age was 15.0±1.2 years, diabetes duration 19.5±6.3 months, 5/7 were female and 4/7 were White, all with a BMI of < 85th%. The prebiotic was safe. Following prebiotic intake, gut microbiome changes were seen, including a notable increase in the relative abundance of fermenters such as Bifidobacterium and Faecalibacterium. Treatment was also associated with changes in bacterial functional pathways associated with either improved energy metabolism (upregulation of tyrosine metabolism) or anti-inflammatory effects (reduced geraniol degradation). There were no differences in stool SCFA levels. Plasma metabolites associated with improved glycemia, such as hippurate, were significantly increased after treatment and there were positive and significant changes in the immune regulatory function of mucosal associated invariant T cells. There was a significant decrease in the area under the curve glucose but not C-peptide, as measured during a mixed meal tolerance testing, following the prebiotic consumption. In summary, the prebiotic HAMS-AB was safe in adolescents with T1D and showed promising effects on the gut microbiome composition, function and immune regulatory function.

17.
J Clin Endocrinol Metab ; 109(8): 2116-2123, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38267821

RESUMO

CONTEXT: Metabolic measures are frequently used to predict type 1 diabetes (T1D) and to understand effects of disease-modifying therapies. OBJECTIVE: Compare metabolic endpoints for their ability to detect preventive treatment effects and predict T1D. METHODS: Six-month changes in metabolic endpoints were assessed for (1) detecting treatment effects by comparing placebo and treatment arms from the randomized controlled teplizumab prevention trial, a multicenter clinical trial investigating 14-day intravenous teplizumab infusion and (2) predicting T1D in the TrialNet Pathway to Prevention natural history study. For each metabolic measure, t-Values from t tests for detecting a treatment effect were compared with chi-square values from proportional hazards regression for predicting T1D. Participants in the teplizumab prevention trial and participants in the Pathway to Prevention study selected with the same inclusion criteria used for the teplizumab trial were studied. RESULTS: Six-month changes in glucose-based endpoints predicted diabetes better than C-peptide-based endpoints, yet the latter were better at detecting a teplizumab effect. Combined measures of glucose and C-peptide were more balanced than measures of glucose alone or C-peptide alone for predicting diabetes and detecting a teplizumab effect. CONCLUSION: The capacity of a metabolic endpoint to detect a treatment effect does not necessarily correspond to its accuracy for predicting T1D. However, combined glucose and C-peptide endpoints appear to be effective for both predicting diabetes and detecting a response to immunotherapy. These findings suggest that combined glucose and C-peptide endpoints should be incorporated into the design of future T1D prevention trials.


Assuntos
Anticorpos Monoclonais Humanizados , Glicemia , Peptídeo C , Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/administração & dosagem , Masculino , Feminino , Peptídeo C/sangue , Glicemia/análise , Glicemia/metabolismo , Adulto , Resultado do Tratamento , Pessoa de Meia-Idade , Adulto Jovem , Prognóstico , Biomarcadores/análise
18.
Diabetes Care ; 47(6): 1048-1055, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38621411

RESUMO

OBJECTIVE: Mixed-meal tolerance test-stimulated area under the curve (AUC) C-peptide at 12-24 months represents the primary end point for nearly all intervention trials seeking to preserve ß-cell function in recent-onset type 1 diabetes. We hypothesized that participant benefit might be detected earlier and predict outcomes at 12 months posttherapy. Such findings would support shorter trials to establish initial efficacy. RESEARCH DESIGN AND METHODS: We examined data from six Type 1 Diabetes TrialNet immunotherapy randomized controlled trials in a post hoc analysis and included additional stimulated metabolic indices beyond C-peptide AUC. We partitioned the analysis into successful and unsuccessful trials and analyzed the data both in the aggregate as well as individually for each trial. RESULTS: Among trials meeting their primary end point, we identified a treatment effect at 3 and 6 months when using C-peptide AUC (P = 0.030 and P < 0.001, respectively) as a dynamic measure (i.e., change from baseline). Importantly, no such difference was seen in the unsuccessful trials. The use of C-peptide AUC as a 6-month dynamic measure not only detected treatment efficacy but also suggested long-term C-peptide preservation (R2 for 12-month C-peptide AUC adjusted for age and baseline value was 0.80, P < 0.001), and this finding supported the concept of smaller trial sizes down to 54 participants. CONCLUSIONS: Early dynamic measures can identify a treatment effect among successful immune therapies in type 1 diabetes trials with good long-term prediction and practical sample size over a 6-month period. While external validation of these findings is required, strong rationale and data exist in support of shortening early-phase clinical trials.


Assuntos
Peptídeo C , Diabetes Mellitus Tipo 1 , Imunoterapia , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/imunologia , Humanos , Peptídeo C/sangue , Peptídeo C/metabolismo , Imunoterapia/métodos , Feminino , Masculino , Adolescente , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto , Criança , Adulto , Área Sob a Curva
19.
Commun Med (Lond) ; 4(1): 66, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582818

RESUMO

BACKGROUND: Islet autoantibodies form the foundation for type 1 diabetes (T1D) diagnosis and staging, but heterogeneity exists in T1D development and presentation. We hypothesized that autoantibodies can identify heterogeneity before, at, and after T1D diagnosis, and in response to disease-modifying therapies. METHODS: We systematically reviewed PubMed and EMBASE databases (6/14/2022) assessing 10 years of original research examining relationships between autoantibodies and heterogeneity before, at, after diagnosis, and in response to disease-modifying therapies in individuals at-risk or within 1 year of T1D diagnosis. A critical appraisal checklist tool for cohort studies was modified and used for risk of bias assessment. RESULTS: Here we show that 152 studies that met extraction criteria most commonly characterized heterogeneity before diagnosis (91/152). Autoantibody type/target was most frequently examined, followed by autoantibody number. Recurring themes included correlations of autoantibody number, type, and titers with progression, differing phenotypes based on order of autoantibody seroconversion, and interactions with age and genetics. Only 44% specifically described autoantibody assay standardization program participation. CONCLUSIONS: Current evidence most strongly supports the application of autoantibody features to more precisely define T1D before diagnosis. Our findings support continued use of pre-clinical staging paradigms based on autoantibody number and suggest that additional autoantibody features, particularly in relation to age and genetic risk, could offer more precise stratification. To improve reproducibility and applicability of autoantibody-based precision medicine in T1D, we propose a methods checklist for islet autoantibody-based manuscripts which includes use of precision medicine MeSH terms and participation in autoantibody standardization workshops.


Islet autoantibodies are markers found in the blood when insulin-producing cells in the pancreas become damaged and can be used to predict future development of type 1 diabetes. We evaluated published literature to determine whether characteristics of islet antibodies (type, levels, numbers) could improve prediction and help understand differences in how individuals with type 1 diabetes respond to treatments. We found existing evidence shows that islet autoantibody type and number are most useful to predict disease progression before diagnosis. In addition, the age when islet autoantibodies first appear strongly influences rate of progression. These findings provide important information for patients and care providers on how islet autoantibodies can be used to understand future type 1 diabetes development and to identify individuals who have the potential to benefit from intervention or prevention therapy.

20.
Diabetes Care ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38912694

RESUMO

Given the proven benefits of screening to reduce diabetic ketoacidosis (DKA) likelihood at the time of stage 3 type 1 diabetes diagnosis, and emerging availability of therapy to delay disease progression, type 1 diabetes screening programs are being increasingly emphasized. Once broadly implemented, screening initiatives will identify significant numbers of islet autoantibody-positive (IAb+) children and adults who are at risk for (confirmed single IAb+) or living with (multiple IAb+) early-stage (stage 1 and stage 2) type 1 diabetes. These individuals will need monitoring for disease progression; much of this care will happen in nonspecialized settings. To inform this monitoring, JDRF, in conjunction with international experts and societies, developed consensus guidance. Broad advice from this guidance includes the following: 1) partnerships should be fostered between endocrinologists and primary care providers to care for people who are IAb+; 2) when people who are IAb+ are initially identified, there is a need for confirmation using a second sample; 3) single IAb+ individuals are at lower risk of progression than multiple IAb+ individuals; 4) individuals with early-stage type 1 diabetes should have periodic medical monitoring, including regular assessments of glucose levels, regular education about symptoms of diabetes and DKA, and psychosocial support; 5) interested people with stage 2 type 1 diabetes should be offered trial participation or approved therapies; and 6) all health professionals involved in monitoring and care of individuals with type 1 diabetes have a responsibility to provide education. The guidance also emphasizes significant unmet needs for further research on early-stage type 1 diabetes to increase the rigor of future recommendations and inform clinical care.

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