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The prevalence of autism spectrum disorders (ASD) has been steadily increasing, and growing evidence suggests a link between high-fat diet (HFD), obesity, and ASD; however, the mechanism underlying this association remains elusive. Herein, BTBR T + tf/J (BTBR) inbred mice (a mouse ASD model) and C57Bl/6J (C57) mice were fed an HFD and normal diet (ND) for 8 weeks (groups: C57 + ND, C57 + HFD, BTBR + ND, and BTBR + HFD). Subsequently, mice underwent behavioral assessments, followed by intestinal tissues harvesting to detect expression of intestinal barrier proteins and inflammatory factors and immune cell numbers, and a correlation analysis. HFD-fed BTBR mice developed obesity, elevated blood sugar, significantly aggravated anxiety-like behaviors, impaired intestinal barrier function, intestinal inflammation with elevated CD4+IL17+ T (Th17) cells and reduced CD4+Foxp3+ T (Treg) cells, exhibiting reduced expression of proteins related to AMPK regulatory pathway (AMPK, p-AMPK, SIRT1). Correlation analysis revealed that the degree of behavioral anxiety, the degree of intestinal barrier damage, the severity of intestinal inflammation, and the degree of immune cell imbalance positively correlated with each other. Accordingly, HFD-induced obesity may cause intestinal Th17/Treg imbalance via the AMPK-SIRT1 pathway, leading to an inflammatory environment in the intestine, impairing intestinal barrier function, and ultimately aggravating anxiety-like behaviors in mice.
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Sirtuína 1 , Linfócitos T Reguladores , Camundongos , Animais , Dieta Hiperlipídica/efeitos adversos , Proteínas Quinases Ativadas por AMP , Intestinos , Obesidade , Camundongos Endogâmicos , Camundongos Endogâmicos C57BL , Inflamação , Ansiedade/etiologia , Modelos Animais de DoençasRESUMO
OBJECTIVE: We examined the characteristics and heritability of Autism Spectrum Disorder (ASD) and ADHD through a twin study. METHOD: Our sample included 44 twins, with at least one twin diagnosed with ASD. Among the participants, 30 had ASD, and 18 of them also had coexisting ADHD. RESULTS: We observed higher concordance rates for ASD in monozygotic twins compared to dizygotic twins (67% vs. 25%), indicating a genetic influence on ASD. Inattentive symptoms of ADHD were more prevalent in monozygotic twins. The ASD + ADHD group exhibited significantly higher Social Responsiveness Scale scores, indicating greater social difficulties compared to the ASD and typical development groups. Twin analyses revealed that shared genetic factors accounted for 72.25% of the variance in both ASD and ADHD symptoms. CONCLUSIONS: Our findings suggest that the comorbidity of ASD and ADHD may indicate increased severity and can be explained by shared genetic factors underlying both conditions.
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Transtorno do Deficit de Atenção com Hiperatividade , Transtorno do Espectro Autista , Humanos , Criança , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/genética , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Transtorno do Deficit de Atenção com Hiperatividade/genética , Gêmeos Monozigóticos/genética , Gêmeos Dizigóticos/genética , ComorbidadeRESUMO
Clostridium difficile infection (CDI) is caused by a prevalent nosocomial enteric pathogen, leading to high morbidity and mortality. CDI recurrence after antibiotic treatment is high; therefore, it is necessary to develop novel therapeutics against this enteric pathogen. Butyrate is used to treat many diseases because it provides energy, has anti-inflammatory properties, and maintains intestinal barrier function. An anti-CDI effect for butyrate has been reported; however, the specific mechanism remains elusive. This study aimed to explore the potential role and mechanism of butyrate in the treatment of CDI. Using a CDI mouse model, we found that butyrate significantly inhibited CDI development by regulating bile acid metabolism. Dysregulation of fecal bile acid was significantly higher, and levels of short-chain fatty acids were significantly lower in patients with CDI than those in controls. In CDI mice, butyrate exhibited a protective role by enhancing barrier protection, exerting anti-inflammatory effects, and regulating bile acid metabolism. Butyrate treatment also regulated the production of bile salt hydrolase (BSH) flora and activated farnesoid X receptor (FXR), and its therapeutic effects were reduced in CDI mice treated with BSH or FXR inhibitors. Thus, butyrate treatment may serve as a novel therapeutic approach for patients with CDI. IMPORTANCE Here, we show that levels of fecal short-chain fatty acids (SCFAs), particularly butyrate, are reduced, and normal colon structure is damaged in patients with CDI compared with those in healthy individuals. Bile acid (BA) metabolic disorder in patients with CDI is characterized by increased primary BA levels and decreased secondary BAs. In mice, butyrate alters BA metabolism in CDI and may play a vital role in CDI treatment by promoting secondary BA metabolism. Lastly, butyrate-mediated therapeutic effects in CDI require FXR. Our findings demonstrate that butyrate treatment significantly decreases the severity of CDI-induced colitis in mice and affects BA metabolism and FXR activation, which provides a potential alternative treatment for CDI.
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Infecções por Clostridium , Enterocolite Pseudomembranosa , Camundongos , Animais , Butiratos/uso terapêutico , Recidiva Local de Neoplasia , Infecções por Clostridium/tratamento farmacológico , Ácidos Graxos Voláteis/metabolismo , Ácidos e Sais BiliaresRESUMO
Increased intestinal barrier permeability, leaky gut, has been reported in patients with autism. However, its contribution to the development of autism has not been determined. We selected dextran sulfate sodium (DSS) to disrupt and metformin to repair the intestinal barrier in BTBR T+tf/J autistic mice to test this hypothesis. DSS treatment resulted in a decreased affinity for social proximity; however, autistic behaviors in mice were improved after the administration of metformin. We found an increased affinity for social proximity/social memory and decreased repetitive and anxiety-related behaviors. The concentration of lipopolysaccharides in blood decreased after the administration of metformin. The expression levels of the key molecules in the toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-nuclear factor kappa B (NF-κB) pathway and their downstream inflammatory cytokines in the cerebral cortex were both repressed. Thus, "leaky gut" could be a trigger for the development of autism via activation of the lipopolysaccharide-mediated TLR4-MyD88-NF-κB pathway.
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Transtorno Autístico , NF-kappa B , Camundongos , Animais , Fator 88 de Diferenciação Mieloide/metabolismo , Lipopolissacarídeos/farmacologia , Receptor 4 Toll-Like/metabolismo , Transtorno Autístico/induzido quimicamente , Transtorno Autístico/metabolismo , Transdução de Sinais/fisiologiaRESUMO
Inflammatory bowel disease (IBD) patients are particularly vulnerable to infection with Clostridium difficile infection (CDI).Available treatments of IBD with CDI have not effective. Butyrate, the metabolites of microbiota, plays a vital role in maintaining immune homeostasis and potential drugs for treatment of IBD with CDI. The aim of this study was to investigate the effect of butyrate on IBD with CDI. Mice were given dextran sulfate sodium (DSS) and were infected with C. difficile (CD). Butyrate was treated during the study period. Butyrate protected from DSS+CD induced colitis by improving weight loss, survival, colon shorten, activity index score, and suppressing the expression of proinflammatory cytokines including IL-6, IL-17, TNF-α, IL-1ß as well as regulating Th17/Treg balance through activation of SIRT1/mTOR. Besides, SR1001, an inhitor of the orphan nuclear receptors retinoic acid-related receptor γt, which is a transcription factor specific to the formation of Th17 cells can suppress the Th17 development and alleviate the DSS+CD induced colitis in mice. Notably, the therapeutic effect of butyrate was revered when disease mice treated with butyrate and Ex-527, a SIRT1 inhibitor. Taken together, we demonstrate that butyrate alleviates dextran sulfate sodium and clostridium difficile induced colitis by preventing Th17 through activation of SIRT1/mTOR.
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Clostridioides difficile , Colite , Doenças Inflamatórias Intestinais , Camundongos , Animais , Células Th17 , Sulfato de Dextrana/toxicidade , Sirtuína 1/metabolismo , Butiratos/metabolismo , Modelos Animais de Doenças , Colite/induzido quimicamente , Colite/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Colo/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Children with autism spectrum disorder (ASD) experience gastrointestinal (GI) issues more frequently and severely than children who are typically developing (TD). The connections between gastrointestinal problems, microbiota, and short-chain fatty acids (SCFAs) in ASD are still being debated. We enrolled 90 children, 45 of whom were diagnosed with ASD, and examined the impact of GI disorders on ASD. The six-item GI Severity Index questionnaire was used to evaluate gastrointestinal symptoms, while the Social Responsiveness Scale was used to evaluate autism symptoms. Further, the Children's Sleep Habits Questionnaire and the Children's Eating Behavior Questionnaire are used to assess sleep and eating disorders in children. We assessed fecal microbiota by 16S rRNA gene sequencing, and SCFA concentrations by gas chromatography/mass spectrometry. The results revealed that children with ASD exhibited a high rate of gastrointestinal issues (78%), as well as higher rates of social impairment and poor sleeping habits, compared to TD children. However, GI disturbances have a minor impact on autism. In addition, the levels of propionic acid, butyric acid, and valeric acid were significantly higher in the ASD group. Besides, the ASD, TD, and GI subgroups possessed distinct microbiome profiles. These findings suggest that gastrointestinal disturbances have no discernible effect on the core symptoms of autism. Although autism may not cause an increase in GI symptoms directly, alterations in metabolites, such as SCFAs, may cause GI symptoms.
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Background: In recent years, parent-mediated intervention for children with autism spectrum disorder (ASD) has increased. Therefore, implementing effective parent training programs for parents of children with autism is of paramount importance, particularly in low- and middle-income countries. However, little is known about the status of and gaps in parents' knowledge on ASD, which may hinder the development of valid parental training programs. Herein, we aimed at exploring the status of Chinese parents' knowledge, attitude and behavior toward ASD, and potential factors affecting the acquisition of correct knowledge. Methods: This study used a self-designed parental knowledge questionnaire of autism (PKQA) comprising 20 questions alongside another questionnaire comprising additional 17 questions covering the aspects of family demographics, attitudes, and behaviors of parents. In total, we included 394 parents who visited the outpatient department of the Child's Development and Behavior Center of the Third Affiliated Hospital of Sun Yat-Sen University between December 2018 and May 2019, with their children meeting the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for ASD. Results: The median knowledge score in the PKQA was 15 [interquartile range (IQR), 13-17]. Advanced paternal age and longer time interval from diagnosis to enrolling into the parent training program were associated with a lower total knowledge score (all P<0.001). Higher maternal education attainment, higher family income, child being currently under intervention, and family members sharing a common perception of the diagnosis were associated with a higher total knowledge score (all P<0.01). Reading autism-related books (P<0.001) or attending professional lectures (P=0.019) were also associated with a higher total knowledge score. Conclusions: Taken together, this study revealed that family demographics and parents' attitudes and behaviors toward ASD may significantly influence their knowledge about autism, suggesting the need for promoting more targeted parental skills training programs.
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The biological mechanisms linking diet-related obesity and autism-related behaviors remain unclear. We aimed to characterize these interactions, focusing on gut microbiota, 5-hydroxytryptamine (5-HT) levels, and autistic behaviors in an animal model for autism; a high-fat diet (HFD) BTBR T + Itpr3tf/J (BTBR) mouse. In this model, we also examined the medication effects of metformin (Met) which is known to ameliorate several symptoms of autism spectrum disorder (ASD). Therefore, we hypothesized that HFD exacerbates BTBR autistic symptoms, which can be alleviated by Met, and the effects are associated with serotonin and the microbiota. As expected, compared with mice fed a normal diet, ten-week HFD-fed mice showed increased body weight, adiposity, and glucose levels. HFD consumption markedly aggravated repetitive behaviors in the self-grooming test. Met reduced HFD-induced hyperactivity. Notably, HFD intervention rescued sociability in the three-chamber sociability test. Furthermore, HFD stimulated tryptophan production, which was inhibited by Met. In contrast, 5-HT levels were lower in the gut and higher in the cortex in the HFD group. Moreover, Met suppressed inflammation in the hippocampus of HFD-fed mice by significantly downregulating the expression of pro-inflammatory cytokines (NF-κB, IL-17A, and IL-6). HFD increased the Firmicutes/Bacteroidetes ratio, and Met supplementation decreased richness while increasing bacterial diversity. We found that the abundance of gut microbiota (Lachnoclostridium, Anaerotruncus, Mucispirillum, and Lactococcus) was correlated with behavior scores and 5-HT levels. Overall, HFD consumption improved sociality in BTBR mice, which was related to the modulation of 5-HT levels and the composition of the microbiota. Met did not show any significant positive effects on the autism phenotype associated with HFD.
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Transtorno do Espectro Autista , Transtorno Autístico , Metformina , Animais , Transtorno do Espectro Autista/tratamento farmacológico , Transtorno Autístico/tratamento farmacológico , Transtorno Autístico/metabolismo , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Metformina/farmacologia , Metformina/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BLRESUMO
The biological mechanisms linking diet-related obesity and autistic behaviors remain unclear. Metformin has proven to be beneficial in the treatment of many syndromes, including autism spectrum disorder. Therefore, the aim of this study was to assess whether metformin treatment could ameliorate metabolic and behavioral alterations in C57BL/6 mice kept on a high-fat diet (HFD), and whether these changes were related to modifications in the gut microbiota and 5-HT levels. As expected, ten weeks of HFD ingestion increased body weight, adiposity, and glucose levels. HFD-fed mice showed a marked aggravation of repetitive behaviors (marble burying and self-grooming), and this was prevented by metformin administration. In addition, HFD-fed mice increased the total distance travelled in the open field test. This hyperactivity was counteracted by metformin cotreatment. In the elevated plus maze test, HFD-fed mice showed a reduced number of entries into the open arms. Interestingly, both HFD and metformin cotreatment increased social interactions in the three-chamber test. HFD increased the levels of intestinal tryptophan and 5-hydroxyindoleacetic acid. Metformin stimulated gut tryptophan and promoted the synthesis of 5-HT in the HFD group. Lactococcus, Trichococcus, Romboutsia, and Faecalibaculum were enriched in HFD-fed mice, whereas the HFD group cotreated with metformin was enriched in Intestinimonas and L. reuteri. Faecalibacterium was positively correlated with sociability and 5-HT pathway components in mice that received metformin. In summary, HFD consumption elicited a complex phenotype comprising higher levels of anxiety-like and repetitive behaviors but also increased sociability. Metformin could potentially improve HFD-induced disorders in the autistic spectrum through a mechanism involving positive modulation of 5-HT levels in the gut and its microbiota composition.
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Transtorno do Espectro Autista , Transtorno Autístico , Microbioma Gastrointestinal , Metformina , Animais , Transtorno do Espectro Autista/tratamento farmacológico , Dieta Hiperlipídica/efeitos adversos , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , SerotoninaRESUMO
The present study aimed to determine if metformin exerts anti-inflammatory and mucus-protective effects via the gut microbiota. Metformin has extensive benefits including anti-inflammatory effects. Previous studies showed that metformin changed the gut microbiota composition and increases the number of goblet cells. Intestinal dysbiosis and goblet cell depletion are important features of ulcerative colitis (UC). The underlying mechanism and whether metformin can improve the mucus barrier in UC remain unclear. Metformin (400 mg/kg/day) was administered to mice with dextran sulfate sodium (DSS)-induced UC for 2 wk to investigate the effects of metformin on the intestinal mucus barrier. The gut microbiota was depleted, using antibiotics, to explore its role in the mucus-protecting effects of metformin. Akkermansia muciniphila (A. muciniphila), which was enriched in metformin-treated mice, was administered to mice to investigate the effects of the bacteria on UC and the mucus barrier. Metformin attenuated DSS-induced UC in mice, as evidenced by the alleviation of diarrhea, hematochezia, and the decrease in body weight. The expression of mucin2, a prominent mucus barrier protein, was increased in the metformin-treated group compared to the DSS-treated group. Furthermore, fecal 16S rRNA analysis showed that metformin treatment changed the gut microbiota composition by increasing the relative abundance of Lactobacillus and Akkermansia species while decreasing Erysipelatoclostridium at the genus level. Antibiotic treatment partly abolished the anti-inflammatory and mucus-protecting effects of metformin. Administration of A. muciniphila alleviated the colonic inflammation and mucus barrier disruption. Metformin alleviated DSS-induced UC in mice and protected against cell damage via affecting the gut microbiota, thereby providing a new mechanism for the therapeutic effect of metformin in patients with UC. This study also provides evidence that A. muciniphila as a probiotic has potential benefits for UC.
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Clostridioides difficile infection (CDI) is a common infection of the gastrointestinal tract. Typically, 20%-30% of CDI patients experience recurrent C.difficile infection (RCDI). Although the role of Th17 in infectious and inflammatory diseases including CDI has gained attention, reports on the correlation between Th17 and RCDI are scarce. In this study, CDI and RCDI mice models were challenged with C. difficile. Serum lactic acid dehydrogenase, inflammatory factor levels, reverse transcriptase-polymerase chain reaction, western blot analysis, hematoxylin and eosin staining, immunohistochemistry, flow cytometry analysis, and enzyme-linked immunosorbent assay were performed on the CDI, RCDI, and control group mice. The results showed more serious clinical manifestations in the RCDI group compared with those in the CDI group. More severe gut barrier disruption and higher degree of microbiota translocation were observed in the RCDI group compared with those in the CDI group. Moreover, extremely severe apoptosis was observed in HCT-116 cells incubated with the serum from RCDI mice model. In addition, higher levels of Th17 and IL-17 were detected in the blood or serum from the RCDI mouse model. Treatment with RORγt small molecule inhibitor SR1001 increased the expression of occludin, decreased the apoptotic rate of HCT-116 cells, and decreased the concentrations of Th17 and IL-17. Concisely, Th17 and IL-17 are potential indicators of RCDI and may serve as therapeutic targets for RCDI treatment. This study lays the foundation for future research on RCDI diagnosis and treatment.
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Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/imunologia , Células Th17/metabolismo , Animais , Apoptose , Linhagem Celular Tumoral , Infecções por Clostridium/metabolismo , Infecções por Clostridium/patologia , Colo/efeitos dos fármacos , Colo/patologia , Modelos Animais de Doenças , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Janus Quinase 2/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/antagonistas & inibidores , Recidiva , Fator de Transcrição STAT3/metabolismo , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Células Th17/imunologia , Tiazóis/farmacologia , Tiazóis/uso terapêuticoRESUMO
The clearance of myelin debris is a critical step in the functional recovery following spinal cord injury (SCI). As phagocytes do, microvascular endothelial cells (MECs) participate in myelin debris clearance at the injury site within one week. Our group has verified that G protein-coupled receptor kinase 2 interacting protein-1 (GIT1) is essential in autophagy and angiogenesis, both of which are tightly related to the uptake and degradation of myelin debris by MECs. Here, we analyzed the performance and mechanism of GIT1 in myelin debris clearance after SCI. The SCI contusion model was established and in vitro MECs were treated with myelin debris. Better recovery from traumatic SCI was observed in the GIT1 WT mice than in the GIT1 KO mice. More importantly, we found that GIT1 prompted MECs to clear myelin debris and further enhanced MECs angiogenesis in vivo and in vitro. Mechanistically, GIT1-mediated autophagy contributed to the clearance of myelin debris by MECs. In this study, we demonstrated that GIT1 may prompt MECs to clear myelin debris via autophagy and further stimulate MECs angiogenesis via upregulating VEGF. Our results indicate that GITI may serve as a promising target for accelerating myelin debris clearance and improving SCI recovery.
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Autofagia , Proteínas de Ciclo Celular/fisiologia , Células Endoteliais/fisiologia , Proteínas Ativadoras de GTPase/fisiologia , Bainha de Mielina/fisiologia , Traumatismos da Medula Espinal/patologia , Animais , Células Cultivadas , Camundongos Knockout , Microvasos/patologia , Neovascularização Fisiológica , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
OBJECTIVE: To report on clinical characteristics and genetic findings in 15 Chinese patients with methylmalonic acidemia (MMA). METHODS: For the 15 MMA patients detected by tandem mass spectrometry, genetic analysis was carried out in twelve pedigrees. Clinical characteristics, genetic finding, treatment and outcomes were retrospectively analyzed. RESULTS: The main features of the patients included poor feeding, recurrent vomiting, lethargy, seizure and development retardation. Blood propionylcarnitine (except for 3 patients), its ratio with acetylcarnitine, and urine methylmalonic acid were increased in all patients. Twelve patients were diagnosed genetically, which included 7 with MUT variants, 4 with MMACHC variants, and 1 with MMAB variant. Nine MUT variants were detected, among which c.1159A>C, 753+1delGinsTGGTTATTA and c.504del were novel. Six known pathogenic MMACHC variants and two novel MMAB variants (c.289_290delGG, c.566G>A) were also detected. Seven patients died of metabolic crises within a year, others had improved effectively following the treatment, but had mild to severe growth delay and/or developmental retardation. CONCLUSION: The clinical manifestation of MMA are complex. Most patients have variants of the MUT and MMACHC genes. High mortality may occur before one year of age.
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Erros Inatos do Metabolismo dos Aminoácidos/genética , Alquil e Aril Transferases/genética , China , Humanos , Metilmalonil-CoA Mutase/genética , Oxirredutases/genética , Linhagem , Estudos RetrospectivosRESUMO
Autism spectrum disorders (ASD) comprise a heterogeneous group of neurodevelopmental disorders that have strong heritability. To better understand the heritable factors in twins with clinically diagnosed ASD and to discuss the relationship between social impairments and genetic and environmental factors. In last 13 years, over 12,000 cases of ASD were diagnosed in the children's development and behavior center, the authors review 37 pairs of these twins, in each pair, and at least 1 twin had been diagnosed with an ASD, and found that the concordance rate was 80% [95% confidence interval (CI) 51.9-95.7%] for monozygotic twins and 13.6% (95% CI: 2.9-34.9%) for dizygotic twins. The heritability of social impairments for ASD was 60.9% (95% CI: 47.3-74.5%). In addition, the rate of nonshared environmental factors was 39.1% (95% CI: 25.5-52.7%), and there were no shared environmental effects. Genetics and special environmental effect play an important role on ASD social impairments.
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Transtorno do Espectro Autista/genética , Criança , Pré-Escolar , Feminino , Interação Gene-Ambiente , Humanos , Masculino , Modelos Genéticos , Caracteres Sexuais , Gêmeos Dizigóticos , Gêmeos MonozigóticosRESUMO
We have previously demonstrated that the small molecule octadecenyl thiophosphate (OTP), a synthetic mimic of the growth factor-like mediator lysophosphatidic acid (LPA), showed radioprotective activity in a mouse model of total-body irradiation (TBI) when given orally or intraperitoneally 30 min before exposure to 9 Gy γ radiation. In the current study, we evaluated the effects of OTP, delivered subcutaneously, for radioprotection or radiomitigation from -24 h before to up to +72 h postirradiation using a mouse TBI model with therapeutic doses at around 1 mg/kg. OTP was injected at 10 mg/kg without observable toxic side effects in mice, providing a comfortable safety margin. Treatment of C57BL/6 mice with a single dose of OTP over the time period from -12 h before to +26 h after a lethal dose of TBI reduced mortality by 50%. When administered at +48 h to +72 h postirradiation (LD50/30 to LD100/30), OTP reduced mortality by ≥34%. OTP administered at +24 h postirradiation significantly elevated peripheral white blood cell and platelet counts, increased crypt survival in the jejunum, enhanced intestinal glucose absorption and reduced endotoxin seepage into the blood. In the 6.4-8.6 Gy TBI range using LD50/10 as the end point, OTP yielded a dose modification factor of 1.2. The current data indicate that OTP is a potent radioprotector and radiomitigator ameliorating the mortality and tissue injury of acute hematopoietic as well as acute gastrointestinal radiation syndrome.
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Síndrome Aguda da Radiação/prevenção & controle , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/efeitos da radiação , Hematopoese/efeitos dos fármacos , Hematopoese/efeitos da radiação , Lisofosfolipídeos/metabolismo , Compostos Organofosforados/farmacologia , ATPases Associadas a Diversas Atividades Celulares , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antígenos CD34/metabolismo , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/efeitos da radiação , Materiais Biomiméticos/efeitos adversos , Materiais Biomiméticos/farmacocinética , Materiais Biomiméticos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Clonais/citologia , Células Clonais/efeitos dos fármacos , Células Clonais/efeitos da radiação , Relação Dose-Resposta a Droga , Feminino , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Glucose/metabolismo , Células HEK293 , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos da radiação , Humanos , Proteínas com Domínio LIM/metabolismo , Contagem de Leucócitos , Camundongos , Camundongos Endogâmicos C57BL , Compostos Organofosforados/efeitos adversos , Compostos Organofosforados/farmacocinética , Fosfoproteínas/metabolismo , Contagem de Plaquetas , Complexo de Endopeptidases do Proteassoma , Protetores contra Radiação/efeitos adversos , Protetores contra Radiação/farmacocinética , Protetores contra Radiação/farmacologia , Trocadores de Sódio-Hidrogênio/metabolismo , Fatores de Transcrição/metabolismo , Irradiação Corporal Total/efeitos adversosRESUMO
OBJECTIVE: To investigate the correlation between four serum fibrosis markers and liver function in patients with infantile hepatitis syndrome (IHS), and to explore the clinical significance of these markers in the diagnosis of IHS and the assessment of disease severity. METHODS: A retrospective study was performed on 60 patients with IHS who were divided into hepatic fibrosis and normal groups based on ultrasound diagnosis. Levels of four liver fibrosis markers, i.e., hyaluronic acid (HA), type III procollagen (PC-III), type IV collagen (IV.C), and laminin (LN), were compared between the two groups, and the correlation between these markers and liver function was analyzed. RESULTS: Levels of liver function markers (alanine aminotransferase (ALT), glutamyl transpeptidase (GGT), total bilirubin (TBil), direct bilirubin (DBil), indirect bilirubin (IBil), and total bile acid (TBA)) in the hepatic fibrosis group were significantly higher than those in the normal group (P<0.05). Levels of HA and IV.C in the hepatic fibrosis group were significantly higher compared with those in the normal group (P<0.05). Furthermore, HA, IV.C, and PC-III levels were positively correlated with those of ALT, TBil, GGT, DBil, IBil, and TBA (r=0.25-0.49), and the strongest correlation existed between HA/IV.C and ALT/jaundice markers. CONCLUSIONS: Assay measuring serum fibrosis markers (HA, IV.C, and PC-III) in combination with liver function tests and ultrasound examination has an important clinical value in the early diagnosis of IHS and evaluation of disease severity.
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Biomarcadores/sangue , Hepatite/diagnóstico , Cirrose Hepática/diagnóstico , Colágeno Tipo III/sangue , Colágeno Tipo IV/sangue , Feminino , Hepatite/sangue , Hepatite/fisiopatologia , Humanos , Ácido Hialurônico/sangue , Lactente , Laminina/sangue , Fígado/fisiopatologia , Cirrose Hepática/sangue , Masculino , Estudos Retrospectivos , SíndromeRESUMO
BACKGROUND & AIMS: We recently identified lysophosphatidic acid (LPA) as a potent antiapoptotic agent for the intestinal epithelium. The objective of the present study was to evaluate the effect of octadecenyl thiophosphate (OTP), a novel rationally designed, metabolically stabilized LPA mimic, on radiation-induced apoptosis of intestinal epithelial cells in vitro and in vivo. METHODS: The receptors and signaling pathways activated by OTP were examined in IEC-6 and RH7777 cell lines and wild-type and LPA(1) and LPA(2) knockout mice exposed to different apoptotic stimuli. RESULTS: OTP was more efficacious than LPA in reducing gamma irradiation-, camptothecin-, or tumor necrosis factor alpha/cycloheximide-induced apoptosis and caspase-3-8, and caspase-9 activity in the IEC-6 cell line. In RH7777 cells lacking LPA receptors, OTP selectively protected LPA(2) but not LPA(1) and LPA(3) transfectants. In C57BL/6 and LPA(1) knockout mice exposed to 15 Gy gamma irradiation, orally applied OTP reduced the number of apoptotic bodies and activated caspase-3-positive cells but was ineffective in LPA(2) knockout mice. OTP, with higher efficacy than LPA, enhanced intestinal crypt survival in C57BL/6 mice but was without any effect in LPA(2) knockout mice. Intraperitoneally administered OTP reduced death caused by lethal dose (LD)(100/30) radiation by 50%. CONCLUSIONS: Our data indicate that OTP is a highly effective antiapoptotic agent that engages similar prosurvival pathways to LPA through the LPA(2) receptor subtype.
Assuntos
Apoptose/efeitos da radiação , Mucosa Intestinal/efeitos da radiação , Compostos Organofosforados/farmacologia , Lesões Experimentais por Radiação/prevenção & controle , Receptores de Ácidos Lisofosfatídicos/fisiologia , Administração Oral , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Linhagem Celular , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Proteínas de Ligação ao GTP/fisiologia , Raios gama/efeitos adversos , Regulação da Expressão Gênica , Injeções Intraperitoneais , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Proteínas do Tecido Nervoso/farmacologia , Compostos Organofosforados/administração & dosagem , Fosfatidilinositol 3-Quinases/fisiologia , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Receptores de Ácidos Lisofosfatídicos/genética , Transdução de Sinais/fisiologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Our group has previously shown that polyamine depletion delays apoptosis in rat intestinal epithelial (IEC-6) cells (Ray RM, Viar MJ, Yuan Q, and Johnson LR, Am J Physiol Cell Physiol 278: C480-C489, 2000). Here, we demonstrate that polyamine depletion inhibits gamma-irradiation-induced apoptosis in vitro and in vivo. Pretreatment of IEC-6 cells with 5 mM alpha-difluoromethylornithine (DFMO) for 4 days significantly reduced radiation-induced caspase-3 activity and DNA fragmentation. This protective effect was prevented by the addition of 10 muM exogenous putrescine. Radiation exposure to mice resulted in a high frequency of apoptosis over cells positioned fourth to seventh in crypt-villus units. Pretreatment of mice with 2% DFMO in drinking water significantly reduced apoptotic cells from approximately 2.75 to 1.61 per crypt-villus unit, accompanied by significant decreases in caspase-3 levels. Further examination showed that DFMO pretreatment inhibited the radiation-induced increase in the proapoptotic protein Bax. Moreover, DFMO pretreatment significantly enhanced the intestinal crypt survival rate by 2.1-fold subsequent to radiation and ameliorated mucosal structural damage. We conclude that polyamine depletion by DFMO inhibits gamma-irradiation-induced apoptosis of intestinal epithelial cells both in vitro and in vivo through inhibition of Bax and caspase-3 activity, which leads to attenuation of radiation-inflicted intestinal injury. These data indicate that DFMO may be therapeutically useful to counteract the gastrointestinal toxicity caused by chemoradiotherapy. This is the first demonstration that polyamines are required for apoptosis in vivo.
Assuntos
Apoptose , Inibidores Enzimáticos/farmacologia , Raios gama/efeitos adversos , Mucosa Intestinal/citologia , Mucosa Intestinal/patologia , Poliaminas/metabolismo , Animais , Eflornitina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Lesões por Radiação/fisiopatologia , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/farmacologiaRESUMO
Lysophosphatidic acid (LPA)-elicited transphosphorylation of receptor tyrosine kinases has been implicated in mediating extracellular signal-regulated kinase (ERK) 1/2 activation, which is necessary for LPA-induced cell proliferation, migration, and survival. B82L cells lack epidermal growth factor receptor (EGFR) but express LPA(1-3), platelet-derived growth factor (PDGF), ErbB2, and insulin-like growth factor receptor transcripts, yet LPA caused no detectable transphosphorylation of these receptor tyrosine kinases. LPA equally protected B82L cells, or transfectants expressing EGFR, the kinase dead EGFR(K721A), EGFR(Y5F) receptor mutant, which lacks five autophosphorylation sites, or EGFR(Y845F), which lacks the Src phosphorylation site from tumor necrosis factor-alpha-induced apoptosis. In contrast, LPA-elicited DNA synthesis and migration were augmented in cells expressing EGFR, EGFR(K721A), or EGFR(Y845F), but not EGFR(Y5F), although the PDGF responses were indistinguishable. LPA-induced transphosphorylation of the EGFR, ErbB2, or PDGF receptor was not required for its antiapoptotic effect. EGFR with or without intrinsic kinase activity or without the Src-phosphorylation site augmented, but was not required for, LPA-elicited cell proliferation or migration. In B82L cells, augmentation of these two LPA responses required intact autophosphorylation sites because among the four EGFR mutants, only cells expressing the EGFR(Y5F) mutant showed no enhancement. In EGFR(Y5F)-expressing cells, LPA failed to elicit tyrosine phosphorylation of Src homologous and collagen protein (SHC) and caused only a modest increase in ERK1/2 phosphorylation similar to that in wild-type B82L cells. The present data pinpoint the lack of importance of the intrinsic kinase activity in contrast to the importance of autophosphorylation sites of the EGFR for SHC phosphorylation in the enhancement of select ERK1/2-dependent LPA responses.
Assuntos
Movimento Celular/fisiologia , Sobrevivência Celular/fisiologia , DNA/metabolismo , Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Lisofosfolipídeos/metabolismo , Animais , Apoptose/fisiologia , Linhagem Celular , DNA/biossíntese , Fragmentação do DNA , Ativação Enzimática , Inibidores Enzimáticos/metabolismo , Receptores ErbB/genética , Flavonoides/metabolismo , Humanos , Camundongos , Toxina Pertussis/metabolismo , Fosforilação , Receptores Proteína Tirosina Quinases/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
A more complete understanding of the physiological and pathological role of lysophosphatidic acid (LPA) requires receptor subtype-specific agonists and antagonists. Here, we report the synthesis and pharmacological characterization of fatty alcohol phosphates (FAP) containing saturated hydrocarbon chains from 4 to 22 carbons in length. Selection of FAP as the lead structure was based on computational modeling as a minimal structure that satisfies the two-point pharmacophore developed earlier for the interaction of LPA with its receptors. Decyl and dodecyl FAPs (FAP-10 and FAP-12) were specific agonists of LPA(2) (EC(50) = 3.7 +/- 0.2 microM and 700 +/- 22 nM, respectively), yet selective antagonists of LPA(3) (K(i) = 90 nM for FAP-12) and FAP-12 was a weak antagonist of LPA(1). Neither LPA(1) nor LPA(3) receptors were activated by FAPs; in contrast, LPA(2) was activated by FAPs with carbon chains between 10 and 14. Computational modeling was used to evaluate the interaction between individual FAPs (8 to 18) with LPA(2) by docking each compound in the LPA binding site. FAP-12 displayed the lowest docked energy, consistent with its lower observed EC(50). The inhibitory effect of FAP showed a strong hydrocarbon chain length dependence with C12 being optimum in the Xenopus laevis oocytes and in LPA(3)-expressing RH7777 cells. FAP-12 did not activate or interfere with several other G-protein-coupled receptors, including S1P-induced responses through S1P(1,2,3,5) receptors. These data suggest that FAPs are ligands of LPA receptors and that FAP-10 and FAP-12 are the first receptor subtype-specific agonists for LPA(2).