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1.
J Biol Chem ; 293(31): 11971-11983, 2018 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-29871925

RESUMEN

Degenerative diseases of organs lead to their impaired function. The cellular and molecular mechanisms underlying organ degeneration are therefore of great research and clinical interest but are currently incompletely characterized. Here, using a forward-genetic screen for genes regulating liver development and function in zebrafish, we identified a cq5 mutant that exhibited a liver-degeneration phenotype at 5 days postfertilization, the developmental stage at which a functional liver develops. Positional cloning revealed that the liver degeneration was caused by a single point mutation in the gene zc3h8 (zinc finger CCCH-type containing 8), changing a highly conserved histidine to glutamine at position 353 of the Zc3h8 protein. The zc3h8 mutation-induced liver degeneration in the mutant was accompanied by reduced proliferation, increased apoptosis, and macrophage phagocytosis of hepatocytes. Transcriptional profile analyses revealed up-regulation and activation of both proinflammatory cytokines and the NF-κB signaling pathway in the zc3h8 mutant. Suppression of NF-κB signaling activity efficiently rescued the proinflammatory cytokine response, as well as the inflammation-mediated liver degeneration phenotype of the mutant. Of note, the zc3h8 mutation-induced degeneration of several other organs, including the gut and exocrine pancreas, indicating that Zc3h8 is a general repressor of inflammation in zebrafish. Collectively, our findings demonstrate that Zc3h8 maintains organ homeostasis by inhibiting the NF-κB-mediated inflammatory response in zebrafish and that Zc3h8 dysfunction causes degeneration of multiple organs, including the liver, gut, and pancreas.


Asunto(s)
Hepatocitos/metabolismo , Hígado/metabolismo , FN-kappa B/genética , Páncreas Exocrino/metabolismo , Factores de Transcripción/genética , Proteínas de Pez Cebra/genética , Pez Cebra/genética , Secuencia de Aminoácidos , Animales , Apoptosis , Proliferación Celular , Citocinas/genética , Citocinas/metabolismo , Embrión no Mamífero , Regulación del Desarrollo de la Expresión Génica , Glutamina/metabolismo , Hepatocitos/patología , Histidina/metabolismo , Inflamación , Intestinos/anomalías , Intestinos/crecimiento & desarrollo , Hígado/anomalías , Hígado/crecimiento & desarrollo , Macrófagos/metabolismo , Macrófagos/patología , Mutación , FN-kappa B/metabolismo , Páncreas Exocrino/anomalías , Páncreas Exocrino/crecimiento & desarrollo , Fagocitosis , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de Señal , Factores de Transcripción/metabolismo , Pez Cebra/crecimiento & desarrollo , Pez Cebra/metabolismo , Proteínas de Pez Cebra/metabolismo , Dedos de Zinc
2.
Gastroenterology ; 146(3): 789-800.e8, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24315993

RESUMEN

BACKGROUND & AIMS: The liver has high regenerative capacity, but it is not clear whether most biliary cells (particularly larger cholangiocytes) transdifferentiate into hepatocytes in regenerating liver. We investigated how this process might contribute to liver regeneration in zebrafish. METHODS: Zebrafish transgenic lines were generated using the standard I-SceI meganuclease transgenesis technique. Hepatocytes of the Tg(lfabp:mCherry-NTR)(cq2) animals were ablated by the administration of metronidazole. We investigated transdifferentiation of biliary cells to hepatocytes and expression of markers using whole mount antibody staining, fluorescent in situ hybridization, and Cre/loxP-based genetic lineage tracing analyses. The role of biliary cells in hepatocyte regeneration was explored using zebrafish larvae with defects in biliary cell development. RESULTS: After extreme loss of hepatocytes, nearly all the biliary cells steadily lost their tubular morphology, proliferated, and expressed hepatocyte-specific markers. Cre/loxP-based inducible lineage tracing showed that new hepatocytes mainly arose from transdifferentiation of biliary cells; this process required Notch signaling and, in turn, activation of Sox9b in cholangiocytes. Activation of early endoderm and hepatoblast markers in most of the cholangiocytes indicated that biliary transdifferentiation includes a step of dedifferentiation into a bipotential intermediate. Defects in development of biliary cells impaired hepatocyte regeneration. CONCLUSIONS: Using our zebrafish liver regeneration model, we found that biliary cells can transdifferentiate into hepatocytes and are the major contributors to hepatocyte regeneration after extreme hepatocyte loss.


Asunto(s)
Sistema Biliar/citología , Transdiferenciación Celular/fisiología , Hepatocitos/citología , Regeneración Hepática/fisiología , Hígado/citología , Pez Cebra/fisiología , Técnicas de Ablación , Animales , Muerte Celular/efectos de los fármacos , Linaje de la Célula , Proliferación Celular , Hepatocitos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/fisiología , Metronidazol/farmacología , Modelos Animales
3.
Free Radic Biol Med ; 224: 521-539, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39278575

RESUMEN

Mitochondrial dysfunction and oxidative stress are involved in the development of contrast-induced acute kidney injury (CI-AKI). The present study aimed to reveal the role of transient receptor potential ankyrin 1 (TRPA1), an oxidative sensor, in CI-AKI. Trpa1PT-/- mice with Trpa1 conditionally knocked out in renal proximal tubular (PT) cells, Trpa1 overexpression mice (Trpa1-OE), and TRPA1 agonists and antagonists were used to study its function in a mouse model of iohexol-induced CI-AKI. We found that TRPA1 was functionally expressed in PT cells. Activation of TRPA1 with cinnamaldehyde or overexpression of Trpa1 remarkably ameliorated renal tubular injury and dysfunction in a mouse model of CI-AKI, while CI-AKI was significantly exacerbated in Trpa1PT-/- mice. Proteomics demonstrated that mouse kidneys with CI-AKI had downregulated proteins involved in mitochondrial dynamics and upregulated mitophagy-associated proteins. The beneficial effects of TRPA1 activation/overexpression on CI-AKI were associated with improved mitochondrial function, decreased mitochondrial fission and oxidative stress, enhanced mitophagy, and less apoptosis of renal tubular cells. TRPA1-induced decreases in mitochondrial fission were linked to upregulated fusion-related proteins (mitofusin 1, mitofusin 2 and optic atrophy 1) and downregulated fission mediator, phosphorylated dynamin-related protein 1 (Drp1). Importantly, inhibition of Drp1 with mitochondrial division inhibitor 1 improved CI-AKI. In addition, the decreased mitochondrial fission was also mediated by inactivation of AMP-activated protein kinase which mediates mitochondrial biogenesis. The findings suggest that TRPA1 plays a protective role in CI-AKI through regulating mitochondrial fission/fusion, biogenesis, and dysfunction. Activating TRPA1 may become novel therapeutic strategies for the prevention of CI-AKI.

4.
Zebrafish ; 20(3): 95-102, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37229597

RESUMEN

The liver plays a very important role in physiological processes of the human body. Liver regeneration has developed into an important area of study in liver disease. The Mtz (metronidazole)/NTR (nitroreductase)-mediated cell ablation system has been widely used to study the processes and mechanisms of liver injury and regeneration. However, high concentrations and toxic side effects of Mtz severely limit the application of the Mtz/NTR system. Therefore, screening new analogs to replace Mtz has become an important means to optimize the NTR ablation system. In this study, we screened five Mtz analogs including furazolidone, ronidazole, ornidazole, nitromide, and tinidazole. We compared their toxicity on the transgenic fish line Tg(fabp10a: mCherry-NTR) and their specific ablation ability on liver cells. The results showed that Ronidazole at a lower concentration (2 mM) had the same ability to ablate liver cells comparable with that of Mtz (10 mM), almost without toxic side effects on juvenile fish. Further study found that zebrafish hepatocyte injury caused by the Ronidazole/NTR system achieved the same liver regenerative effect as the Mtz/NTR system. The above results show that Ronidazole can replace Mtz with NTR to achieve superior damage and ablation effects in zebrafish liver.


Asunto(s)
Profármacos , Pez Cebra , Animales , Humanos , Pez Cebra/fisiología , Metronidazol/toxicidad , Profármacos/metabolismo , Ronidazol , Larva/metabolismo , Animales Modificados Genéticamente , Hepatocitos/metabolismo , Nitrorreductasas/metabolismo
5.
Cancer Rep (Hoboken) ; 6(4): e1782, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36746394

RESUMEN

BACKGROUND: Colorectal cancer (CRC) is a deadly and commonly diagnosed cancer. Cell-free circulating tumor DNAs (ctDNA) have been used in the diagnosis and treatment of CRC, but there are open questions about the relationship between ctDNAs and CRC. Although mutations of genes detected by ctDNA in CRC have been studied, the quantitative relationship between ctDNA mutations and ctDNA concentration has not been addressed. AIMS: We hypothesized that there was an association between mutations of genes identified in ctDNAs and ctDNA concentration. His study examined this association in a population of CRC patients. METHODS: In 85 CRC patients, we sampled 282 mutations in 36 genes and conducted an association study based on a Random forest model between mutations and ctDNA concentrations in all patients. RESULTS: This association study showed that mutations on five genes, ALK, PMS2, KDR, MAP2K1, and MSH2, were associated with the ctDNA concentrations in CRC patients' blood samples. Because ctDNA mutations correlate with ctDNA level, we can infer the tumor burden or tumor size from ctDNA mutations, as well as the survival time for prognosis. CONCLUSION: Our findings shed light on the associations between mutations of genes identified in ctDNAs and ctDNA concentration in the blood of CRC patients. This discovery provides information regarding the tumor burden or tumor size based on ctDNA mutations.


Asunto(s)
ADN Tumoral Circulante , Neoplasias Colorrectales , Humanos , Neoplasias Colorrectales/diagnóstico , Mutación , Pronóstico
6.
Oxid Med Cell Longev ; 2022: 1763922, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35615576

RESUMEN

Capsaicin, a transient receptor potential vanilloid 1 channel agonist, possesses antioxidative properties through activating nuclear factor-erythroid 2-related factor 2 (Nrf2). As oxidative stress is a major contributor to the development of contrast-associated acute kidney injury (CA-AKI), we investigated the protective effect of capsaicin against CA-AKI via Nrf2. C57BL/6J mice were treated with dehydration and iodixanol to establish the model of CA-AKI. For pretreatment, capsaicin (0.3 mg/kg) was given via intraperitoneal injection one hour before iodixanol injection. Nrf2-specific siRNA was given through the tail vein to knock down Nrf2. The CA-AKI mouse model had remarkable mitochondrial fragmentation and dysfunction and apoptosis of tubular cells, overproduction of superoxide in renal tubules, increased renal malondialdehyde, tubular epithelial cell injury, and renal dysfunction. Importantly, pretreatment with capsaicin significantly ameliorated tubular cell injury and renal dysfunction with decreased superoxide, renal malondialdehyde, and apoptotic tubular cells and improved mitochondrial morphology and function in the CA-AKI mouse model. The expression of Nrf2 was increased in the kidney from the CA-AKI mouse model and was further enhanced by capsaicin. Administration of siRNA through the tail vein successfully decreased Nrf2 expression in the kidney, and knockdown of Nrf2 by siRNA abolished the beneficial effects of capsaicin on CA-AKI. The present study demonstrated a protective effect of capsaicin pretreatment against CA-AKI via Nrf2.


Asunto(s)
Lesión Renal Aguda , Capsaicina , Factor 2 Relacionado con NF-E2 , Animales , Ratones , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/prevención & control , Capsaicina/farmacología , Modelos Animales de Enfermedad , Riñón/metabolismo , Malondialdehído/metabolismo , Ratones Endogámicos C57BL , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , ARN Interferente Pequeño/metabolismo , Superóxidos/metabolismo , Medios de Contraste/efectos adversos
7.
Front Cell Dev Biol ; 9: 634900, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33718370

RESUMEN

Diabetic cardiomyopathy (DCM), a common complication of diabetes mellitus, may eventually leads to irreversible heart failure. Metformin is the cornerstone of diabetes therapy, especially for type 2 diabetes. Statins are widely used to reduce the risk of cardiovascular diseases. In this study, we aimed to investigate whether the combined administration of metformin and atorvastatin could achieve superior protective effects on DCM and to elucidate its molecular mechanism. Here, db/db mice (9-10 weeks old) were randomly divided into four groups, including sterile water group (DM), metformin group (MET, 200 mg/kg/day), atorvastatin group (AVS, 10 mg/kg/day), and combination therapy group (MET + AVS). Mice were treated with different drugs via gavage once per day for 3 months. After 3 months of treatment, the pathological changes (inflammation, fibrosis, hypertrophy, and oxidative stress makers) were detected by histopathological techniques, as well as Western blotting. The H9C2 cardiomyocytes were treated with palmitate (PAL) to mimic diabetic condition. The cells were divided into control group, PAL treatment group, MET + PAL treatment group, AVS + PAL treatment group, and MET + AVS + PAL treatment group. The effects of MET and AVS on the cell viability and inflammation of H9C2 cells subjected to PAL condition were evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, immunofluorescence staining, and Western blotting. Both MET and AVS prevented diabetes-induced fibrosis, hypertrophy, and inflammation. The combination therapy showed superior effects in protecting myocardial tissue against diabetes-induced injury. Mechanistically, the combination therapy significantly inhibited oxidative stress and the expression levels of inflammation-related proteins, e.g., NLRP3, caspase-1, interleukin-1ß (IL-1ß), Toll-like receptor 4 (TLR4), and P-p65/p65, in both cardiac tissues and H9C2 cells. TUNEL assay showed that the combination therapy significantly attenuated the apoptosis of cardiomyocytes; decreased the expression level of pro-apoptotic-related proteins, such as cleaved caspase-3 and BAX; and enhanced the expression level of anti-apoptotic protein (Bcl-2). Furthermore, the combination therapy remarkably upregulated the expression levels of 5'-AMP-activated protein kinase (AMPK) and SIRT1. Our findings indicated that the anti-inflammation and anti-apoptosis effects of the combination therapy may be related to activation of AMPK/SIRT1 signaling pathway.

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