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1.
Handb Exp Pharmacol ; 271: 23-38, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34085120

RESUMO

Antibodies are important tools for protein and peptide research, including for the kappa opioid receptor (KOR) and dynorphins (Dyns). Well-characterized antibodies are essential for rigorous and reproducible research. However, lack of validation of antibody specificity has been thought to contribute significantly to the reproducibility crisis in biomedical research. Since 2003, many scientific journals have required documentation of validation of antibody specificity and use of knockout mouse tissues as a negative control is strongly recommended. Lack of specificity of antibodies against many G protein-coupled receptors (GPCRs) after extensive testing has been well-documented, but antibodies generated against partial sequences of the KOR have not been similarly investigated. For the dynorphins, differential processing has been described in distinct brain areas, resulting in controversial findings in immunohistochemistry (IHC) when different antibodies were used. In this chapter, we summarized accepted approaches for validation of antibody specificity. We discussed two KOR antibodies most commonly used in IHC and described generation and characterization of KOR antibodies and phospho-KOR specific antibodies in western blotting or immunoblotting (IB). In addition, applying antibodies targeting prodynorphin or mature dynorphin A illustrates the diversity of results obtained regarding the distribution of dynorphins in distinct brain areas.


Assuntos
Dinorfinas , Receptores Opioides kappa , Animais , Encéfalo/metabolismo , Camundongos , Camundongos Knockout , Reprodutibilidade dos Testes
2.
Ann Anat ; 239: 151726, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33798691

RESUMO

Insulin receptor substrate (Irs) belongs to a family of proteins that mediate the intracellular signaling of insulin and IGF-1. Insulin receptor substrate 2 (Irs2) is necessary for retinal function, since its failure in Irs2-deficient mice in hyperglycemic situation promotes photoreceptor degeneration and visual dysfunction, like in diabetic retinopathy. The expression of P450 aromatase, which catalyzes androgen aromatization to form 17ß-estradiol, increases in some neurodegenerative diseases thus promoting the local synthesis of neuroestrogens that exert relevant neuroprotective functions. Aromatase is also expressed in neurons and glial cells of the central nervous system (CNS), including the retina. To further understand the role of Irs2 at the retinal level, we performed an immunocytochemical study in adult normoglycemic Irs2-deficient mice. For this aim, the retinal immunoexpression of neuromodulators, such as aromatase, glutamine synthetase (GS), and tyrosine hydroxylase (TH) was analyzed, joint to a morphometric and planimetric study of the retinal layers. Comparing with wild-type (WT) control mice, the Irs2-knockout (Irs2-KO) animals showed a significant increase in the immunopositivity to aromatase in almost all of the retinal layers. Besides, Irs2-KO mice exhibited a decreased immunopositive reaction for GS and TH, in Müller and amacrine cells, respectively; morphological variations were also found in these retinal cell types. Furthermore, the retina of Irs2-KO mice displayed alterations in the structural organization, and a generalized decrease in the retinal thickness was observed in each of the layers, except for the inner nuclear layer. Our findings suggest that the absence of Irs2 induces retinal neurodegenerative changes in Müller and amacrine cells that are unrelated to hyperglycemia. Accordingly, in the Irs2-KO mice, the increased retinal immunocytochemical reactivity of aromatase could be associated with an attempt to repair such neural retina injuries by promoting local neuroprotective mediators.


Assuntos
Aromatase , Retina , Células Amácrinas/metabolismo , Animais , Aromatase/genética , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Retina/metabolismo
3.
Phytomedicine ; 93: 153812, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34753029

RESUMO

BACKGROUND: Atherosclerosis is a progressive chronic disease characterised by aberrant lipid metabolism and a maladaptive inflammatory response. As atherosclerosis-driven cardiovascular disease remains the major cause of morbidity and mortality worldwide, more effective clinical therapies are urgently needed. Traditional Chinese Medicine (TCM) has demonstrated efficacy against atherosclerosis, with Qing-Xue-Xiao-Zhi formula (QXXZF) having been approved for clinical treatment of patients with atherosclerosis. However, the mechanisms underlying the anti-atherosclerotic activity of QXXZF remain unknown. PURPOSE: To investigate the anti-atherosclerotic effect of QXXZF and reveal its mechanisms using preclinical models. METHODS: In vivo, apolipoprotein E-deficient (ApoE-/-) mice were fed a high-fat and high-choline diet (HHD) to induce atherosclerosis. Serum metabolomic profiling was used to identify the concentration of trimethylamine N-oxide (TMAO) in mice. In vitro, RAW264.7 macrophages and bone marrow-derived macrophages (BMDMs) from WT and TLR4-/- C57BL/6 mice were used to explore the effects of QXXZF on macrophages. After confirming the therapeutic effects of QXXZF, mass spectrometry and network pharmacology analyses were used to predict and investigate the main components and the anti-atherogenic mechanisms of QXXZF in the context of atherosclerosis. RESULTS: Our results showed QXXZF significantly suppressed the development of atherosclerosis, as evidenced by the decreased atherosclerotic plaques in the aorta and aortic root, reduced plasma lipid levels and decreased serum TMAO content in HHD-fed ApoE-/- mice. Meanwhile, QXXZF effectively reduced foam cell formation in oxidized low-density lipoprotein (ox-LDL) and TMAO-stimulated RAW264.7 macrophages and BMDMs. Moreover, QXXZF facilitated reverse cholesterol transport (RCT) in macrophages by upregulating the expression of cholesterol efflux-related genes PPARγ/LXRα/ABCA1/ABCG1. Mechanistic studies revealed that QXXZF influenced cholesterol metabolism by inhibiting the TLR4-mediated nuclear factor kappa B (NF-κB) axis. Importantly, TLR4 knockout abolished the influence of QXXZF on macrophages. CONCLUSION: QXXZF promotes lipid efflux and inhibits macrophage-mediated inflammation, producing a therapeutic effect against atherosclerosis. Our study provides new insight into the mechanism of QXXZF against atherosclerosis.


Assuntos
Aterosclerose , NF-kappa B , Transportador 1 de Cassete de Ligação de ATP , Animais , Apolipoproteínas E/genética , Aterosclerose/tratamento farmacológico , Humanos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo
4.
J Immunol ; 207(11): 2799-2812, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740957

RESUMO

Absent in melanoma-2 (AIM2) is an inflammasome-forming innate immune sensor for dsDNA but also exhibits inflammasome-independent functions such as restricting cellular proliferation. AIM2 is expressed in the kidney, but its localization and function are not fully characterized. In normal human glomeruli, AIM2 localized to podocytes. In patients with glomerulonephritis, AIM2 expression increased in CD44+-activated parietal epithelial cells within glomerular crescents. To explore AIM2 effects in glomerular disease, studies in Aim2 -/- mice were performed. Aim2-/- glomeruli showed reduced expression of Wilm tumor gene-1 (WT1), WT1-driven podocyte genes, and increased proliferation in outgrowth assays. In a nephrotoxic serum (NTS)-induced glomerulonephritis model, Aim2-/- (B6) mice exhibited more severe glomerular crescent formation, tubular injury, inflammation, and proteinuria compared with wild-type controls. Inflammasome activation markers were absent in both Aim2 -/- and wild-type kidneys, despite an increased inflammatory transcriptomic signature in Aim2 -/- mice. Aim2 -/- mice also demonstrated dysregulated cellular proliferation and an increase in CD44+ parietal epithelial cells during glomerulonephritis. The augmented inflammation and epithelial cell proliferation in Aim2 -/- (B6) mice was not due to genetic background, as Aim2 -/- (B6.129) mice demonstrated a similar phenotype during NTS glomerulonephritis. The AIM2-like receptor (ALR) locus was necessary for the inflammatory glomerulonephritis phenotype observed in Aim2 -/- mice, as NTS-treated ALR -/- mice displayed equal levels of injury as wild-type controls. Podocyte outgrowth from ALR -/- glomeruli was still increased, however, confirming that the ALR locus is dispensable for AIM2 effects on epithelial cell proliferation. These results identify a noncanonical role for AIM2 in suppressing inflammation and epithelial cell proliferation during glomerulonephritis.


Assuntos
Proteínas de Ligação a DNA/imunologia , Células Epiteliais/imunologia , Glomerulonefrite/imunologia , Inflamação/imunologia , Animais , Proliferação de Células , Proteínas de Ligação a DNA/deficiência , Feminino , Glomerulonefrite/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
5.
J Immunol ; 207(11): 2710-2719, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740959

RESUMO

The single-nucleotide polymorphism (SNP) rs3184504 is broadly associated with increased risk for multiple autoimmune and cardiovascular diseases. Although the allele is uniquely enriched in European descent, the mechanism for the widespread selective sweep is not clear. In this study, we find the rs3184504*T allele had a strong association with reduced mortality in a human sepsis cohort. The rs3184504*T allele associates with a loss-of-function amino acid change (p.R262W) in the adaptor protein SH2B3, a likely causal variant. To better understand the role of SH2B3 in sepsis, we used mouse modeling and challenged SH2B3-deficient mice with a polymicrobial cecal-ligation puncture (CLP) procedure. We found SH2B3 deficiency improved survival and morbidity with less organ damage and earlier bacterial clearance compared with control mice. The peritoneal infiltrating cells exhibited augmented phagocytosis in Sh2b3 -/- mice with enriched recruitment of Ly6Chi inflammatory monocytes despite equivalent or reduced chemokine expression. Rapid cycling of monocytes and progenitors occurred uniquely in the Sh2b3 -/- mice following CLP, suggesting augmented myelopoiesis. To model the hypomorphic autoimmune risk allele, we created a novel knockin mouse harboring a similar point mutation in the murine pleckstrin homology domain of SH2B3. At baseline, phenotypic changes suggested a hypomorphic allele. In the CLP model, homozygous knockin mice displayed improved mortality and morbidity compared with wild-type or heterozygous mice. Collectively, these data suggest that hypomorphic SH2B3 improves the sepsis response and that balancing selection likely contributed to the relative frequency of the autoimmune risk variant.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Sepse/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Polimorfismo de Nucleotídeo Único/genética , Sepse/genética
6.
J Immunol ; 207(11): 2785-2798, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740960

RESUMO

Bacterial infections are a common and deadly threat to vulnerable patients. Alternative strategies to fight infection are needed. ß-Glucan, an immunomodulator derived from the fungal cell wall, provokes resistance to infection by inducing trained immunity, a phenomenon that persists for weeks to months. Given the durability of trained immunity, it is unclear which leukocyte populations sustain this effect. Macrophages have a life span that surpasses the duration of trained immunity. Thus, we sought to define the contribution of differentiated macrophages to trained immunity. Our results show that ß-glucan protects mice from Pseudomonas aeruginosa infection by augmenting recruitment of innate leukocytes to the site of infection and facilitating local clearance of bacteria, an effect that persists for more than 7 d. Adoptive transfer of macrophages, trained using ß-glucan, into naive mice conferred a comparable level of protection. Trained mouse bone marrow-derived macrophages assumed an antimicrobial phenotype characterized by enhanced phagocytosis and reactive oxygen species production in parallel with sustained enhancements in glycolytic and oxidative metabolism, increased mitochondrial mass, and membrane potential. ß-Glucan induced broad transcriptomic changes in macrophages consistent with early activation of the inflammatory response, followed by sustained alterations in transcripts associated with metabolism, cellular differentiation, and antimicrobial function. Trained macrophages constitutively secreted CCL chemokines and robustly produced proinflammatory cytokines and chemokines in response to LPS challenge. Induction of the trained phenotype was independent of the classic ß-glucan receptors Dectin-1 and TLR-2. These findings provide evidence that ß-glucan induces enhanced protection from infection by driving trained immunity in macrophages.


Assuntos
Memória Imunológica/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Substâncias Protetoras/farmacologia , beta-Glucanas/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Feminino , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Memória Imunológica/imunologia , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
7.
J Immunol ; 207(11): 2720-2732, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740961

RESUMO

Double-positive CD4+CD8αß+ (DP) cells are thought to reside as T cell progenitors exclusively within the thymus. We recently discovered an unexpected CD4+ and CD8αß+ immune cell population in healthy and atherosclerotic mice by single-cell RNA sequencing. Transcriptomically, these cells resembled thymic DPs. Flow cytometry and three-dimensional whole-mount imaging confirmed DPs in thymus, mediastinal adipose tissue, and aortic adventitia, but nowhere else. Deep transcriptional profiling revealed differences between DP cells isolated from the three locations. All DPs were dependent on RAG2 expression and the presence of the thymus. Mediastinal adipose tissue DPs resided in close vicinity to invariant NKT cells, which they could activate in vitro. Thymus transplantation failed to reconstitute extrathymic DPs, and frequencies of extrathymic DPs were unaltered by pharmacologic inhibition of S1P1, suggesting that their migration may be locally confined. Our results define two new, transcriptionally distinct subsets of extrathymic DPs that may play a role in aortic vascular homeostasis.


Assuntos
Tecido Adiposo/imunologia , Aorta Torácica/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Timo/imunologia , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/imunologia
8.
J Immunol ; 207(11): 2649-2659, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34732466

RESUMO

Dendritic cells (DCs) are the most specialized APCs that play a critical role in driving Th2 differentiation, but the mechanism is not fully understood. Here we show that vacuolar protein sorting 33B (Vps33B) plays an important role in this process. Mice with Vps33b-specific deletion in DCs, but not in macrophages or T cells, were more susceptible to Th2-mediated allergic lung inflammation than wild-type mice. Deletion of Vps33B in DCs led to enhanced CD4+ T cell proliferation and Th2 differentiation. Moreover, Vps33B specifically restrained reactive oxygen species production in conventional DC1s to inhibit Th2 responses in vitro, whereas Vps33B in monocyte-derived DCs and conventional DC2s was dispensable for Th2 development in asthma pathogenesis. Taken together, our results identify Vps33B as an important molecule that mediates the cross-talk between DCs and CD4+ T cells to further regulate allergic asthma pathogenesis.


Assuntos
Células Dendríticas/imunologia , Hipersensibilidade/imunologia , Inflamação/imunologia , Pyroglyphidae/imunologia , Proteínas de Transporte Vesicular/imunologia , Animais , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos
9.
Int J Mol Sci ; 22(19)2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34639076

RESUMO

Skeletal muscle suffers atrophy and weakness with aging. Denervation, oxidative stress, and mitochondrial dysfunction are all proposed as contributors to age-associated muscle loss, but connections between these factors have not been established. We examined contractility, mitochondrial function, and intracellular calcium transients (ICTs) in muscles of mice throughout the life span to define their sequential relationships. We performed these same measures and analyzed neuromuscular junction (NMJ) morphology in mice with postnatal deletion of neuronal Sod1 (i-mn-Sod1-/- mice), previously shown to display accelerated age-associated muscle loss and exacerbation of denervation in old age, to test relationships between neuronal redox homeostasis, NMJ degeneration and mitochondrial function. In control mice, the amount and rate of the decrease in mitochondrial NADH during contraction was greater in middle than young age although force was not reduced, suggesting decreased efficiency of NADH utilization prior to the onset of weakness. Declines in both the peak of the ICT and force were observed in old age. Muscles of i-mn-Sod1-/- mice showed degeneration of mitochondrial and calcium handling functions in middle-age and a decline in force generation to a level not different from the old control mice, with maintenance of NMJ morphology. Together, the findings support the conclusion that muscle mitochondrial function decreases during aging and in response to altered neuronal redox status prior to NMJ deterioration or loss of mass and force suggesting mitochondrial defects contribute to sarcopenia independent of denervation.


Assuntos
Envelhecimento , Cálcio/metabolismo , Mitocôndrias Musculares/patologia , Neurônios/patologia , Estresse Oxidativo , Sarcopenia/patologia , Superóxido Dismutase-1/fisiologia , Animais , Denervação , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias Musculares/metabolismo , Contração Muscular , Neurônios/metabolismo , Oxirredução , Sarcopenia/etiologia
10.
Int J Mol Sci ; 22(19)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34639094

RESUMO

Insulin stimulates glucose uptake in adipose tissue and skeletal muscle by inducing plasma membrane translocation of the glucose transporter GLUT4. Although the small GTPase Rac1 is a key regulator downstream of phosphoinositide 3-kinase (PI3K) and the protein kinase Akt2 in skeletal muscle, it remains unclear whether Rac1 also regulates glucose uptake in white adipocytes. Herein, we investigated the physiological role of Rac1 in white adipocytes by employing adipocyte-specific rac1 knockout (adipo-rac1-KO) mice. Subcutaneous and epididymal white adipose tissues (WATs) in adipo-rac1-KO mice showed significant reductions in size and weight. Actually, white adipocytes lacking Rac1 were smaller than controls. Insulin-stimulated glucose uptake and GLUT4 translocation were abrogated in rac1-KO white adipocytes. On the other hand, GLUT4 translocation was augmented by constitutively activated PI3K or Akt2 in control, but not in rac1-KO, white adipocytes. Similarly, to skeletal muscle, the involvement of another small GTPase RalA downstream of Rac1 was demonstrated. In addition, mRNA levels of various lipogenic enzymes were down-regulated in rac1-KO white adipocytes. Collectively, these results suggest that Rac1 is implicated in insulin-dependent glucose uptake and lipogenesis in white adipocytes, and reduced insulin responsiveness due to the deficiency of Rac1 may be a likely explanation for atrophy of WATs.


Assuntos
Tecido Adiposo Branco/patologia , Transportador de Glucose Tipo 4/metabolismo , Glucose/metabolismo , Insulina/farmacologia , Neuropeptídeos/fisiologia , Proteínas rac1 de Ligação ao GTP/fisiologia , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Animais , Atrofia , Feminino , Transportador de Glucose Tipo 4/genética , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Edulcorantes/farmacologia
11.
Int J Mol Sci ; 22(19)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34639126

RESUMO

Liver-specific deficiency of B-cell receptor-associated protein 31 knockout mice (BAP31-LKO) and the littermates were injected with acetaminophen (APAP), markers of liver injury, and the potential molecular mechanisms were determined. In response to APAP overdose, serum aspartate aminotransferase and alanine aminotransferase levels were increased in BAP31-LKO mice than in wild-type controls, accompanied by enhanced liver necrosis. APAP-induced apoptosis and mortality were increased. Hepatic glutathione was decreased (1.60 ± 0.31 µmol/g tissue in WT mice vs. 0.85 ± 0.14 µmol/g tissue in BAP31-LKO mice at 6 h, p < 0.05), along with reduced glutathione reductase activity and superoxide dismutase; while malondialdehyde was significantly induced (0.41 ± 0.03 nmol/mg tissue in WT mice vs. 0.50 ± 0.05 nmol/mg tissue in BAP31-LKO mice for 6 h, p < 0.05). JNK signaling activation and APAP-induced hepatic inflammation were increased in BAP31-LKO mice. The mechanism research revealed that BAP31-deficiency decreased Nrf2 mRNA stability (half-life of Nrf2 mRNA decreased from ~1.3 h to ~40 min) and miR-223 expression, led to reduced nuclear factor erythroid 2-related factor 2 (Nrf2) signaling activation and antioxidant genes induction. BAP31-deficiency decreased mitochondrial membrane potentials, reduced mitochondria-related genes expression, and resulted in mitochondrial dysfunction in the liver. Conclusions: BAP31-deficiency reduced the antioxidant response and Nrf2 signaling activation via reducing Nrf2 mRNA stabilization, enhanced JNK signaling activation, hepatic inflammation, and apoptosis, amplified APAP-induced hepatotoxicity in mice.


Assuntos
Acetaminofen/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/patologia , Proteínas de Membrana/fisiologia , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Animais , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Glutationa/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
12.
Int J Mol Sci ; 22(19)2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34639136

RESUMO

BACKGROUND: α-cyclodextrin (α-CD) is one of the dietary fibers that may have a beneficial effect on cholesterol and/or glucose metabolism, but its efficacy and mode of action remain unclear. METHODS: In the present study, we examined the anti-hyperglycemic effect of α-CD after oral loading of glucose and liquid meal in mice. RESULTS: Administration of 2 g/kg α-CD suppressed hyperglycemia after glucose loading, which was associated with increased glucagon-like peptide 1 (GLP-1) secretion and enhanced hepatic glucose sequestration. By contrast, 1 g/kg α-CD similarly suppressed hyperglycemia, but without increasing secretions of GLP-1 and insulin. Furthermore, oral α-CD administration disrupts lipid micelle formation through its inclusion of lecithin in the gut luminal fluid. Importantly, prior inclusion of α-CD with lecithin in vitro nullified the anti-hyperglycemic effect of α-CD in vivo, which was associated with increased intestinal mRNA expressions of SREBP2-target genes (Ldlr, Hmgcr, Pcsk9, and Srebp2). CONCLUSIONS: α-CD elicits its anti-hyperglycemic effect after glucose loading by inducing lecithin inclusion in the gut lumen and activating SREBP2, which is known to induce cholecystokinin secretion to suppress hepatic glucose production via a gut/brain/liver axis.


Assuntos
Trato Gastrointestinal/metabolismo , Hiperglicemia/prevenção & controle , Lecitinas/metabolismo , Período Pós-Prandial , Canais de Potássio Corretores do Fluxo de Internalização/fisiologia , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , alfa-Ciclodextrinas/farmacologia , Animais , Trato Gastrointestinal/efeitos dos fármacos , Hiperglicemia/etiologia , Hiperglicemia/metabolismo , Hiperglicemia/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína de Ligação a Elemento Regulador de Esterol 2/genética
13.
Nat Commun ; 12(1): 5862, 2021 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615873

RESUMO

NLRP3 controls the secretion of inflammatory cytokines IL-1ß/18 and pyroptosis by assembling the inflammasome. Upon coordinated priming and activation stimuli, NLRP3 recruits NEK7 within hetero-oligomers that nucleate ASC and caspase-1 filaments, but the apical molecular mechanisms underlying inflammasome assembly remain elusive. Here we show that NEK7 recruitment to NLRP3 is controlled by the phosphorylation status of NLRP3 S803 located within the interaction surface, in which NLRP3 S803 is phosphorylated upon priming and later dephosphorylated upon activation. Phosphomimetic substitutions of S803 abolish NEK7 recruitment and inflammasome activity in macrophages in vitro and in vivo. In addition, NLRP3-NEK7 binding is also essential for NLRP3 deubiquitination by BRCC3 and subsequently inflammasome assembly, with NLRP3 phosphomimetic mutants showing enhanced ubiquitination and degradation than wildtype NLRP3. Finally, we identify CSNK1A1 as the kinase targeting NLRP3 S803. Our findings thus reveal NLRP3 S803 phosphorylation status as a druggable apical molecular mechanism controlling inflammasome assembly.


Assuntos
Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/química , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Caseína Quinase II , Caseína Quinase Ialfa , Caspase 1/metabolismo , Citocinas/metabolismo , Enzimas Desubiquitinantes , Células HEK293 , Humanos , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Quinases Relacionadas a NIMA/metabolismo , Fosforilação , Piroptose , Ubiquitinação
14.
Int J Mol Sci ; 22(19)2021 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-34638689

RESUMO

Gonadotropins are essential for regulating ovarian development, steroidogenesis, and gametogenesis. While follicle stimulating hormone (FSH) promotes the development of ovarian follicles, luteinizing hormone (LH) regulates preovulatory maturation of oocytes, ovulation, and formation of corpus luteum. Cognate receptors of FSH and LH are G-protein coupled receptors that predominantly signal through cAMP-dependent and cAMP-independent mechanisms that activate protein kinases. Subsequent vital steps in response to gonadotropins are mediated through activation or inhibition of transcription factors required for follicular gene expression. Estrogen receptors, classical ligand-activated transcriptional regulators, play crucial roles in regulating gonadotropin secretion from the hypothalamic-pituitary axis as well as gonadotropin function in the target organs. In this review, we discuss the role of estrogen receptor ß (ERß) regulating gonadotropin response during folliculogenesis. Ovarian follicles in Erß knockout (ErßKO) mutant female mice and rats cannot develop beyond the antral state, lack oocyte maturation, and fail to ovulate. Theca cells (TCs) in ovarian follicles express LH receptor, whereas granulosa cells (GCs) express both FSH receptor (FSHR) and LH receptor (LHCGR). As oocytes do not express the gonadotropin receptors, the somatic cells play a crucial role during gonadotropin induced oocyte maturation. Somatic cells also express high levels of estrogen receptors; while TCs express ERα and are involved in steroidogenesis, GCs express ERß and are involved in both steroidogenesis and folliculogenesis. GCs are the primary site of ERß-regulated gene expression. We observed that a subset of gonadotropin-induced genes in GCs, which are essential for ovarian follicle development, oocyte maturation and ovulation, are dependent on ERß. Thus, ERß plays a vital role in regulating the gonadotropin responses in ovary.


Assuntos
Gonadotropina Coriônica/metabolismo , Receptor beta de Estrogênio/metabolismo , Hormônio Foliculoestimulante/metabolismo , Células da Granulosa/metabolismo , Células Tecais/metabolismo , Animais , Gonadotropina Coriônica/genética , Receptor beta de Estrogênio/genética , Feminino , Hormônio Foliculoestimulante/genética , Humanos , Camundongos , Camundongos Knockout , Ratos
15.
J Neurodev Disord ; 13(1): 47, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34645383

RESUMO

BACKGROUND: Individuals with Fragile X syndrome (FXS) and autism spectrum disorder (ASD) exhibit an array of symptoms, including sociability deficits, increased anxiety, hyperactivity, and sensory hyperexcitability. It is unclear how endocannabinoid (eCB) modulation can be targeted to alleviate neurophysiological abnormalities in FXS as behavioral research reveals benefits to inhibiting cannabinoid (CB) receptor activation and increasing endocannabinoid ligand levels. Here, we hypothesize that enhancement of 2-arachidonoyl-sn-glycerol (2-AG) in Fragile X mental retardation 1 gene knock-out (Fmr1 KO) mice may reduce cortical hyperexcitability and behavioral abnormalities observed in FXS. METHODS: To test whether an increase in 2-AG levels normalized cortical responses in a mouse model of FXS, animals were subjected to electroencephalography (EEG) recording and behavioral assessment following treatment with JZL-184, an irreversible inhibitor of monoacylglycerol lipase (MAGL). Assessment of 2-AG was performed using lipidomic analysis in conjunction with various doses and time points post-administration of JZL-184. Baseline electrocortical activity and evoked responses to sound stimuli were measured using a 30-channel multielectrode array (MEA) in adult male mice before, 4 h, and 1 day post-intraperitoneal injection of JZL-184 or vehicle. Behavior assessment was done using the open field and elevated plus maze 4 h post-treatment. RESULTS: Lipidomic analysis showed that 8 mg/kg JZL-184 significantly increased the levels of 2-AG in the auditory cortex of both Fmr1 KO and WT mice 4 h post-treatment compared to vehicle controls. EEG recordings revealed a reduction in the abnormally enhanced baseline gamma-band power in Fmr1 KO mice and significantly improved evoked synchronization to auditory stimuli in the gamma-band range post-JZL-184 treatment. JZL-184 treatment also ameliorated anxiety-like and hyperactivity phenotypes in Fmr1 KO mice. CONCLUSIONS: Overall, these results indicate that increasing 2-AG levels may serve as a potential therapeutic approach to normalize cortical responses and improve behavioral outcomes in FXS and possibly other ASDs.


Assuntos
Transtorno do Espectro Autista , Proteína do X Frágil de Retardo Mental , Animais , Endocanabinoides , Proteína do X Frágil de Retardo Mental/genética , Glicerol , Masculino , Camundongos , Camundongos Knockout
16.
Int J Mol Sci ; 22(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34638755

RESUMO

Cholesterol and fatty acids are essential lipids that are critical for membrane biosynthesis and fetal organ development. Cholesteryl esters (CE) are degraded by hormone-sensitive lipase (HSL) in the cytosol and by lysosomal acid lipase (LAL) in the lysosome. Impaired LAL or HSL activity causes rare pathologies in humans, with HSL deficiency presenting less severe clinical manifestations. The infantile form of LAL deficiency, a lysosomal lipid storage disorder, leads to premature death. However, the importance of defective lysosomal CE degradation and its consequences during early life are incompletely understood. We therefore investigated how defective CE catabolism affects fetus and infant maturation using Lal and Hsl knockout (-/-) mouse models. This study demonstrates that defective lysosomal but not neutral lipolysis alters placental and fetal cholesterol homeostasis and exhibits an initial disease pathology already in utero as Lal-/- fetuses accumulate hepatic lysosomal lipids. Immediately after birth, LAL deficiency exacerbates with massive hepatic lysosomal lipid accumulation, which continues to worsen into young adulthood. Our data highlight the crucial role of LAL during early development, with the first weeks after birth being critical for aggravating LAL deficiency.


Assuntos
Lipólise , Fígado , Lisossomos , Esterol Esterase/deficiência , Doença de Wolman , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Humanos , Fígado/metabolismo , Fígado/patologia , Lisossomos/metabolismo , Lisossomos/patologia , Camundongos , Camundongos Knockout , Doença de Wolman/genética , Doença de Wolman/metabolismo , Doença de Wolman/patologia
17.
Braz J Med Biol Res ; 54(12): e11353, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34669782

RESUMO

Cisplatin is a widely used chemotherapeutic drug, but its side effects are a major limiting factor. Nephrotoxicity occurs in one third of patients undergoing cisplatin treatment. The acute tubular injury caused by cisplatin often leads to a defective repair process, which translates into chronic renal disorders. In this way, cisplatin affects tubular cells, and maladaptive tubules regeneration will ultimately result in tubulointerstitial fibrosis. Kinins are well known for being important peptides in the regulation of inflammatory stimuli, and kinin B1 receptor deficiency and antagonism have been shown to be beneficial against acute cisplatin nephrotoxicity. This study aimed to analyze the effects of kinin B1 receptor deletion and antagonism against repeated cisplatin-induced chronic renal dysfunction and fibrosis. Both the deletion and the antagonism of B1 receptor exacerbated cisplatin-induced chronic renal dysfunction. Moreover, the inhibition of B1 receptor increased tubular injury and tubulointerstitial fibrosis after repeated treatment with cisplatin. The balance between M1/M2 macrophage polarization plays an important role in renal fibrosis. Kinin B1 receptor antagonism had no impact on M1 markers when compared to cisplatin. However, YM1, an M2 marker and an important molecule for the wound healing process, was decreased in mice treated with kinin B1 receptor antagonist, compared to cisplatin alone. Endothelin-1 levels were also increased in mice with B1 receptor inhibition. This study showed that kinin B1 receptor inhibition exacerbated cisplatin-induced chronic renal dysfunction and fibrosis, associated with reduced YM1 M2 marker expression, thus possibly affecting the wound healing process.


Assuntos
Injúria Renal Aguda , Preparações Farmacêuticas , Injúria Renal Aguda/induzido quimicamente , Animais , Cisplatino/efeitos adversos , Fibrose , Humanos , Cininas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
18.
FASEB J ; 35(11): e21957, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34606641

RESUMO

The Wnt signaling antagonist, sclerostin, is a potent suppressor of bone acquisition that also mediates endocrine communication between bone and adipose. As a result, Sost-/- mice exhibit dramatic increases in bone formation but marked decreases in visceral and subcutaneous adipose that are secondary to alterations in lipid synthesis and utilization. While interrogating the mechanism by which sclerostin influences adipocyte metabolism, we observed paradoxical increases in the adipogenic potential and numbers of CD45- :Sca1+ :PDGFRα+ adipoprogenitors in the stromal vascular compartment of fat pads isolated from male Sost-/- mice. Lineage tracing studies indicated that sclerostin deficiency blocks the differentiation of PDGFRα+ adipoprogenitors to mature adipocytes in association with increased Wnt/ß-catenin signaling. Importantly, osteoblast/osteocyte-specific Sost gene deletion mirrors the accumulation of PDGFRα+ adipoprogenitors, reduction in fat mass, and improved glucose metabolism evident in Sost-/- mice. These data indicate that bone-derived sclerostin regulates multiple facets of adipocyte physiology ranging from progenitor cell commitment to anabolic metabolism.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adipócitos/metabolismo , Adipogenia/genética , Osso e Ossos/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Células-Tronco/metabolismo , Proteínas Wnt/metabolismo , Via de Sinalização Wnt/genética , beta Catenina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Tecido Adiposo/metabolismo , Animais , Glicemia/metabolismo , Células Cultivadas , Técnicas de Inativação de Genes/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoblastos/metabolismo , Osteócitos/metabolismo , Osteogênese/genética
19.
FASEB J ; 35(11): e21910, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34610176

RESUMO

C1q/TNF-related protein (CTRP) family comprises fifteen highly conserved secretory proteins with diverse central and peripheral functions. In zebrafish, mouse, and human, CTRP4 is most highly expressed in the brain. We previously showed that CTRP4 is a metabolically responsive regulator of food intake and energy balance, and mice lacking CTRP4 exhibit sexually dimorphic changes in ingestive behaviors and systemic metabolism. Recent single-cell RNA sequencing also revealed Ctrp4/C1qtnf4 expression in diverse neuronal cell types across distinct anatomical brain regions, hinting at additional roles in the central nervous system not previously characterized. To uncover additional central functions of CTRP4, we subjected Ctrp4 knockout (KO) mice to a battery of behavioral tests. Relative to wild-type (WT) littermates, loss of CTRP4 does not alter exploratory, anxiety-, or depressive-like behaviors, motor function and balance, sensorimotor gating, novel object recognition, and spatial memory. While pain-sensing mechanisms in response to thermal stress and mild shock are intact, both male and female Ctrp4 KO mice have increased sensitivity to pain induced by higher-level shock, suggesting altered nociceptive function. Importantly, CTRP4 deficiency impairs hippocampal-dependent associative learning and memory as assessed by trace fear conditioning paradigm. This deficit is sex-dependent, affects only female mice, and is associated with altered expression of learning and memory genes (Arc, c-fos, and Pde4d) in the hippocampus and cortex. Altogether, our behavioral and gene expression analyses have uncovered novel aspects of the CTRP4 function and provided a physiological context to further investigate its mechanism of action in the central and peripheral nervous system.


Assuntos
Adipocinas/genética , Expressão Gênica , Técnicas de Inativação de Genes/métodos , Aprendizagem em Labirinto , Memória Espacial , Adipocinas/metabolismo , Animais , Ansiedade/genética , Comportamento Animal , Córtex Cerebelar/metabolismo , Feminino , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Teste de Desempenho do Rota-Rod
20.
J Clin Invest ; 131(17)2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34623320

RESUMO

Genome-wide association studies revealed that loss-of-function mutations in protein tyrosine phosphatase non-receptor type 2 (PTPN2) increase the risk of developing chronic immune diseases, such as inflammatory bowel disease (IBD) and celiac disease. These conditions are associated with increased intestinal permeability as an early etiological event. The aim of this study was to examine the consequences of deficient activity of the PTPN2 gene product, T cell protein tyrosine phosphatase (TCPTP), on intestinal barrier function and tight junction organization in vivo and in vitro. Here, we demonstrate that TCPTP protected against intestinal barrier dysfunction induced by the inflammatory cytokine IFN-γ by 2 mechanisms: it maintained localization of zonula occludens 1 and occludin at apical tight junctions and restricted both expression and insertion of the cation pore-forming transmembrane protein, claudin-2, at tight junctions through upregulation of the inhibitory cysteine protease, matriptase. We also confirmed that the loss-of-function PTPN2 rs1893217 SNP was associated with increased intestinal claudin-2 expression in patients with IBD. Moreover, elevated claudin-2 levels and paracellular electrolyte flux in TCPTP-deficient intestinal epithelial cells were normalized by recombinant matriptase. Our findings uncover distinct and critical roles for epithelial TCPTP in preserving intestinal barrier integrity, thereby proposing a mechanism by which PTPN2 mutations contribute to IBD.


Assuntos
Mucosa Intestinal/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 2/metabolismo , Junções Íntimas/metabolismo , Adolescente , Adulto , Idoso , Animais , Claudinas/metabolismo , Modelos Animais de Doenças , Feminino , Estudo de Associação Genômica Ampla , Humanos , Técnicas In Vitro , Doenças Inflamatórias Intestinais/etiologia , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Permeabilidade , Polimorfismo de Nucleotídeo Único , Proteína Tirosina Fosfatase não Receptora Tipo 2/deficiência , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Junções Íntimas/patologia , Adulto Jovem
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