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1.
Immunity ; 55(2): 237-253.e8, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35081371

RESUMO

The Th17 cell-lineage-defining cytokine IL-17A contributes to host defense and inflammatory disease by coordinating multicellular immune responses. The IL-17 receptor (IL-17RA) is expressed by diverse intestinal cell types, and therapies targeting IL-17A induce adverse intestinal events, suggesting additional tissue-specific functions. Here, we used multiple conditional deletion models to identify a role for IL-17A in secretory epithelial cell differentiation in the gut. Paneth, tuft, goblet, and enteroendocrine cell numbers were dependent on IL-17A-mediated induction of the transcription factor ATOH1 in Lgr5+ intestinal epithelial stem cells. Although dispensable at steady state, IL-17RA signaling in ATOH1+ cells was required to regenerate secretory cells following injury. Finally, IL-17A stimulation of human-derived intestinal organoids that were locked into a cystic immature state induced ATOH1 expression and rescued secretory cell differentiation. Our data suggest that the cross talk between immune cells and stem cells regulates secretory cell lineage commitment and the integrity of the mucosa.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Mucosa Intestinal/citologia , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Interleucina-17/metabolismo , Células-Tronco/metabolismo , Animais , Comunicação Celular , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Sulfato de Dextrana/efeitos adversos , Humanos , Interleucina-17/metabolismo , Interleucina-17/farmacologia , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/metabolismo , Intestinos/patologia , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , Receptores de Interleucina-17/deficiência , Fatores de Transcrição SOX9/metabolismo , Transdução de Sinais , Células-Tronco/citologia
2.
Circ Res ; 128(3): 335-357, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33539225

RESUMO

RATIONALE: Diabetic cardiomyopathy (DbCM) is a major complication in type-1 diabetes, accompanied by altered cardiac energetics, impaired mitochondrial function, and oxidative stress. Previous studies indicate that type-1 diabetes is associated with increased cardiac expression of KLF5 (Krüppel-like factor-5) and PPARα (peroxisome proliferator-activated receptor) that regulate cardiac lipid metabolism. OBJECTIVE: In this study, we investigated the involvement of KLF5 in DbCM and its transcriptional regulation. METHODS AND RESULTS: KLF5 mRNA levels were assessed in isolated cardiomyocytes from cardiovascular patients with diabetes and were higher compared with nondiabetic individuals. Analyses in human cells and diabetic mice with cardiomyocyte-specific FOXO1 (Forkhead box protein O1) deletion showed that FOXO1 bound directly on the KLF5 promoter and increased KLF5 expression. Diabetic mice with cardiomyocyte-specific FOXO1 deletion had lower cardiac KLF5 expression and were protected from DbCM. Genetic, pharmacological gain and loss of KLF5 function approaches and AAV (adeno-associated virus)-mediated Klf5 delivery in mice showed that KLF5 induces DbCM. Accordingly, the protective effect of cardiomyocyte FOXO1 ablation in DbCM was abolished when KLF5 expression was rescued. Similarly, constitutive cardiomyocyte-specific KLF5 overexpression caused cardiac dysfunction. KLF5 caused oxidative stress via direct binding on NADPH oxidase (NOX)4 promoter and induction of NOX4 (NADPH oxidase 4) expression. This was accompanied by accumulation of cardiac ceramides. Pharmacological or genetic KLF5 inhibition alleviated superoxide formation, prevented ceramide accumulation, and improved cardiac function in diabetic mice. CONCLUSIONS: Diabetes-mediated activation of cardiomyocyte FOXO1 increases KLF5 expression, which stimulates NOX4 expression, ceramide accumulation, and causes DbCM.


Assuntos
Cardiomiopatias Diabéticas/metabolismo , Proteína Forkhead Box O1/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Miócitos Cardíacos/metabolismo , Estresse Oxidativo , PPAR alfa/metabolismo , Idoso , Animais , Linhagem Celular , Cardiomiopatias Diabéticas/genética , Cardiomiopatias Diabéticas/patologia , Modelos Animais de Doenças , Feminino , Proteína Forkhead Box O1/genética , Regulação da Expressão Gênica , Humanos , Fatores de Transcrição Kruppel-Like/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Miócitos Cardíacos/patologia , PPAR alfa/genética , Transcrição Gênica
3.
Int J Mol Sci ; 24(10)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37239940

RESUMO

Krüppel-like factors (KLFs) belong to the family of transcription factors with three highly conserved zinc finger domains in the C-terminus. They regulate homeostasis, development, and disease progression in many tissues. It has been shown that KLFs play an essential role in the endocrine and exocrine compartments of the pancreas. They are necessary to maintain glucose homeostasis and have been implicated in the development of diabetes. Furthermore, they can be a vital tool in enabling pancreas regeneration and disease modeling. Finally, the KLF family contains proteins that act as tumor suppressors and oncogenes. A subset of members has a biphasic function, being upregulated in the early stages of oncogenesis and stimulating its progression and downregulated in the late stages to allow for tumor dissemination. Here, we describe KLFs' function in pancreatic physiology and pathophysiology.


Assuntos
Fatores de Transcrição Kruppel-Like , Neoplasias , Humanos , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição , Dedos de Zinco
4.
Int J Mol Sci ; 24(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36674571

RESUMO

Pancreatitis (acute and chronic) is an inflammatory disease associated with significant morbidity, including a high rate of hospitalization and mortality. MicroRNAs (miRs) are essential post-transcriptional modulators of gene expression. They are crucial in many diseases' development and progression. Recent studies have demonstrated aberrant miRs expression patterns in pancreatic tissues obtained from patients experiencing acute and chronic pancreatitis compared to tissues from unaffected individuals. Increasing evidence showed that miRs regulate multiple aspects of pancreatic acinar biology, such as autophagy, mitophagy, and migration, impact local and systemic inflammation and, thus, are involved in the disease development and progression. Notably, multiple miRs act on pancreatic acinar cells and regulate the transduction of signals between pancreatic acinar cells, pancreatic stellate cells, and immune cells, and provide a complex interaction network between these cells. Importantly, recent studies from various animal models and patients' data combined with advanced detection techniques support their importance in diagnosing and treating pancreatitis. In this review, we plan to provide an up-to-date summary of the role of miRs in the development and progression of pancreatitis.


Assuntos
MicroRNAs , Pâncreas Exócrino , Pancreatite , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Pancreatite/genética , Pancreatite/metabolismo , Pâncreas/metabolismo , Pâncreas Exócrino/metabolismo , Células Acinares/metabolismo
5.
Int J Mol Sci ; 24(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36835366

RESUMO

Chronic pancreatitis is characterized by chronic inflammation and fibrosis, processes heightened by activated pancreatic stellate cells (PSCs). Recent publications have demonstrated that miR-15a, which targets YAP1 and BCL-2, is significantly downregulated in patients with chronic pancreatitis compared to healthy controls. We have utilized a miRNA modification strategy to enhance the therapeutic efficacy of miR-15a by replacing uracil with 5-fluorouracil (5-FU). We demonstrated increased levels of YAP1 and BCL-2 (both targets of miR-15a) in pancreatic tissues obtained from Ptf1aCreERTM and Ptf1aCreERTM;LSL-KrasG12D mice after chronic pancreatitis induction as compared to controls. In vitro studies showed that delivery of 5-FU-miR-15a significantly decreased viability, proliferation, and migration of PSCs over six days compared to 5-FU, TGFß1, control miR, and miR-15a. In addition, treatment of PSCs with 5-FU-miR-15a in the context of TGFß1 treatment exerted a more substantial effect than TGFß1 alone or when combined with other miRs. Conditioned medium obtained from PSC cells treated with 5-FU-miR-15a significantly inhibits the invasion of pancreatic cancer cells compared to controls. Importantly, we demonstrated that treatment with 5-FU-miR-15a reduced the levels of YAP1 and BCL-2 observed in PSCs. Our results strongly suggest that ectopic delivery of miR mimetics is a promising therapeutic approach for pancreatic fibrosis and that 5-FU-miR-15a shows specific promise.


Assuntos
Fluoruracila , MicroRNAs , Células Estreladas do Pâncreas , Pancreatite Crônica , Animais , Camundongos , Proliferação de Células/genética , Fibrose , Fluoruracila/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , Células Estreladas do Pâncreas/efeitos dos fármacos , Células Estreladas do Pâncreas/patologia , Pancreatite Crônica/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas de Sinalização YAP/metabolismo
6.
Circulation ; 143(11): 1139-1156, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33430631

RESUMO

BACKGROUND: We previously showed that cardiomyocyte Krϋppel-like factor (KLF) 5 regulates cardiac fatty acid oxidation. As heart failure has been associated with altered fatty acid oxidation, we investigated the role of cardiomyocyte KLF5 in lipid metabolism and pathophysiology of ischemic heart failure. METHODS: Using real-time polymerase chain reaction and Western blot, we investigated the KLF5 expression changes in a myocardial infarction (MI) mouse model and heart tissue from patients with ischemic heart failure. Using 2D echocardiography, we evaluated the effect of KLF5 inhibition after MI using pharmacological KLF5 inhibitor ML264 and mice with cardiomyocyte-specific KLF5 deletion (αMHC [α-myosin heavy chain]-KLF5-/-). We identified the involvement of KLF5 in regulating lipid metabolism and ceramide accumulation after MI using liquid chromatography-tandem mass spectrometry, and Western blot and real-time polymerase chain reaction analysis of ceramide metabolism-related genes. We lastly evaluated the effect of cardiomyocyte-specific KLF5 overexpression (αMHC-rtTA [reverse tetracycline-controlled transactivator]-KLF5) on cardiac function and ceramide metabolism, and rescued the phenotype using myriocin to inhibit ceramide biosynthesis. RESULTS: KLF5 mRNA and protein levels were higher in human ischemic heart failure samples and in rodent models at 24 hours, 2 weeks, and 4 weeks post-permanent left coronary artery ligation. αMHC-KLF5-/- mice and mice treated with ML264 had higher ejection fraction and lower ventricular volume and heart weight after MI. Lipidomic analysis showed that αMHC-KLF5-/- mice with MI had lower myocardial ceramide levels compared with littermate control mice with MI, although basal ceramide content of αMHC-KLF5-/- mice was not different in control mice. KLF5 ablation suppressed the expression of SPTLC1 and SPTLC2 (serine palmitoyltransferase [SPT] long-chain base subunit ()1 2, respectively), which regulate de novo ceramide biosynthesis. We confirmed our previous findings that myocardial SPTLC1 and SPTLC2 levels are increased in heart failure patients. Consistently, αMHC-rtTA-KLF5 mice showed increased SPTLC1 and SPTLC2 expression, higher myocardial ceramide levels, and systolic dysfunction beginning 2 weeks after KLF5 induction. Treatment of αMHC-rtTA-KLF5 mice with myriocin that inhibits SPT, suppressed myocardial ceramide levels and alleviated systolic dysfunction. CONCLUSIONS: KLF5 is induced during the development of ischemic heart failure in humans and mice and stimulates ceramide biosynthesis. Genetic or pharmacological inhibition of KLF5 in mice with MI prevents ceramide accumulation, alleviates eccentric remodeling, and increases ejection fraction. Thus, KLF5 emerges as a novel therapeutic target for the treatment of ischemic heart failure.


Assuntos
Cardiomiopatias/fisiopatologia , Ceramidas/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Miócitos Cardíacos/metabolismo , Remodelação Ventricular/fisiologia , Animais , Modelos Animais de Doenças , Humanos , Masculino , Camundongos
7.
Int J Mol Sci ; 23(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36077352

RESUMO

Tumor development and progression depend on reprogramming of signaling pathways that regulate cell metabolism. Alterations to various metabolic pathways such as glycolysis, oxidative phosphorylation, lipid metabolism, and hexosamine biosynthesis pathway are crucial to sustain increased redox, bioenergetic, and biosynthesis demands of a tumor cell. Transcription factors (oncogenes and tumor suppressors) play crucial roles in modulating these alterations, and their functions are tethered to major metabolic pathways under homeostatic conditions and disease initiation and advancement. Specificity proteins (SPs) and Krüppel-like factors (KLFs) are closely related transcription factors characterized by three highly conserved zinc fingers domains that interact with DNA. Studies have demonstrated that SP and KLF transcription factors are expressed in various tissues and regulate diverse processes such as proliferation, differentiation, apoptosis, inflammation, and tumorigenesis. This review highlights the role of SP and KLF transcription factors in the metabolism of various cancers and their impact on tumorigenesis. A better understanding of the role and underlying mechanisms governing the metabolic changes during tumorigenesis could provide new therapeutic opportunities for cancer treatment.


Assuntos
Fatores de Transcrição Kruppel-Like/metabolismo , Neoplasias/metabolismo , Fatores de Transcrição Sp/metabolismo , Transformação Celular Neoplásica , Humanos , Dedos de Zinco
8.
Gastroenterology ; 157(5): 1413-1428.e11, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31352001

RESUMO

BACKGROUND & AIMS: Obesity is a risk factor for pancreatic cancer. In mice, a high-fat diet (HFD) and expression of oncogenic KRAS lead to development of invasive pancreatic ductal adenocarcinoma (PDAC) by unknown mechanisms. We investigated how oncogenic KRAS regulates the expression of fibroblast growth factor 21, FGF21, a metabolic regulator that prevents obesity, and the effects of recombinant human FGF21 (rhFGF21) on pancreatic tumorigenesis. METHODS: We performed immunohistochemical analyses of FGF21 levels in human pancreatic tissue arrays, comprising 59 PDAC specimens and 45 nontumor tissues. We also studied mice with tamoxifen-inducible expression of oncogenic KRAS in acinar cells (KrasG12D/+ mice) and fElasCreERT mice (controls). KrasG12D/+ mice were placed on an HFD or regular chow diet (control) and given injections of rhFGF21 or vehicle; pancreata were collected and analyzed by histology, immunoblots, quantitative polymerase chain reaction, and immunohistochemistry. We measured markers of inflammation in the pancreas, liver, and adipose tissue. Activity of RAS was measured based on the amount of bound guanosine triphosphate. RESULTS: Pancreatic tissues of mice expressed high levels of FGF21 compared with liver tissues. FGF21 and its receptor proteins were expressed by acinar cells. Acinar cells that expressed KrasG12D/+ had significantly lower expression of Fgf21 messenger RNA compared with acinar cells from control mice, partly due to down-regulation of PPARG expression-a transcription factor that activates Fgf21 transcription. Pancreata from KrasG12D/+ mice on a control diet and given injections of rhFGF21 had reduced pancreatic inflammation, infiltration by immune cells, and acinar-to-ductal metaplasia compared with mice given injections of vehicle. HFD-fed KrasG12D/+ mice given injections of vehicle accumulated abdominal fat, developed extensive inflammation, pancreatic cysts, and high-grade pancreatic intraepithelial neoplasias (PanINs); half the mice developed PDAC with liver metastases. HFD-fed KrasG12D/+ mice given injections of rhFGF21 had reduced accumulation of abdominal fat and pancreatic triglycerides, fewer pancreatic cysts, reduced systemic and pancreatic markers of inflammation, fewer PanINs, and longer survival-only approximately 12% of the mice developed PDACs, and none of the mice had metastases. Pancreata from HFD-fed KrasG12D/+ mice given injections of rhFGF21 had lower levels of active RAS than from mice given vehicle. CONCLUSIONS: Normal acinar cells from mice and humans express high levels of FGF21. In mice, acinar expression of oncogenic KRAS significantly reduces FGF21 expression. When these mice are placed on an HFD, they develop extensive inflammation, pancreatic cysts, PanINs, and PDACs, which are reduced by injection of FGF21. FGF21 also reduces the guanosine triphosphate binding capacity of RAS. FGF21 might be used in the prevention or treatment of pancreatic cancer.


Assuntos
Células Acinares/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Transformação Celular Neoplásica/metabolismo , Dieta Hiperlipídica , Fatores de Crescimento de Fibroblastos/metabolismo , Neoplasias Intraductais Pancreáticas/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Células Acinares/patologia , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/prevenção & controle , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Regulação para Baixo , Fatores de Crescimento de Fibroblastos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Klotho , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Transgênicos , Mutação , PPAR gama/genética , PPAR gama/metabolismo , Cisto Pancreático/genética , Cisto Pancreático/metabolismo , Cisto Pancreático/patologia , Neoplasias Intraductais Pancreáticas/genética , Neoplasias Intraductais Pancreáticas/patologia , Neoplasias Intraductais Pancreáticas/prevenção & controle , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/prevenção & controle , Pancreatite/genética , Pancreatite/metabolismo , Pancreatite/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
9.
Development ; 144(5): 737-754, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28246209

RESUMO

Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors that are found in many species. Recent studies have shown that KLFs play a fundamental role in regulating diverse biological processes such as cell proliferation, differentiation, development and regeneration. Of note, several KLFs are also crucial for maintaining pluripotency and, hence, have been linked to reprogramming and regenerative medicine approaches. Here, we review the crucial functions of KLFs in mammalian embryogenesis, stem cell biology and regeneration, as revealed by studies of animal models. We also highlight how KLFs have been implicated in human diseases and outline potential avenues for future research.


Assuntos
Desenvolvimento Embrionário , Fatores de Transcrição Kruppel-Like/metabolismo , Pulmão/embriologia , Células-Tronco/citologia , Animais , Diferenciação Celular , Linhagem da Célula , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Filogenia , Regeneração , Fatores de Transcrição/metabolismo , Dedos de Zinco
10.
Gastroenterology ; 154(5): 1494-1508.e13, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29248441

RESUMO

BACKGROUND & AIMS: Activating mutations in KRAS are detected in most pancreatic ductal adenocarcinomas (PDACs). Expression of an activated form of KRAS (KrasG12D) in pancreata of mice is sufficient to induce formation of pancreatic intraepithelial neoplasia (PanINs)-a precursor of PDAC. Pancreatitis increases formation of PanINs in mice that express KrasG12D by promoting acinar-to-ductal metaplasia (ADM). We investigated the role of the transcription factor Krüppel-like factor 5 (KLF5) in ADM and KRAS-mediated formation of PanINs. METHODS: We performed studies in adult mice with conditional disruption of Klf5 (Klf5fl/fl) and/or expression of KrasG12D (LSL-KrasG12D) via CreERTM recombinase regulated by an acinar cell-specific promoter (Ptf1a). Activation of KrasG12D and loss of KLF5 was achieved by administration of tamoxifen. Pancreatitis was induced in mice by administration of cerulein; pancreatic tissues were collected, analyzed by histology and immunohistochemistry, and transcriptomes were compared between mice that did or did not express KLF5. We performed immunohistochemical analyses of human tissue microarrays, comparing levels of KLF5 among 96 human samples of PDAC. UN-KC-6141 cells (pancreatic cancer cells derived from Pdx1-Cre;LSL-KrasG12D mice) were incubated with inhibitors of different kinases and analyzed in proliferation assays and by immunoblots. Expression of KLF5 was knocked down with small hairpin RNAs or CRISPR/Cas9 strategies; cells were analyzed in proliferation and gene expression assays, and compared with cells expressing control vectors. Cells were subcutaneously injected into flanks of syngeneic mice and tumor growth was assessed. RESULTS: Of the 96 PDAC samples analyzed, 73% were positive for KLF5 (defined as nuclear staining in more than 5% of tumor cells). Pancreata from Ptf1a-CreERTM;LSL-KrasG12D mice contained ADM and PanIN lesions, which contained high levels of nuclear KLF5 within these structures. In contrast, Ptf1a-CreERTM;LSL-KrasG12D;Klf5fl/fl mice formed fewer PanINs. After cerulein administration, Ptf1a-CreERTM;LSL-KrasG12D mice formed more extensive ADM than Ptf1a-CreERTM;LSL-KrasG12D;Klf5fl/fl mice. Pancreata from Ptf1a-CreERTM;LSL-KrasG12D;Klf5fl/fl mice had increased expression of the tumor suppressor NDRG2 and reduced phosphorylation (activation) of STAT3, compared with Ptf1a-CreERTM;LSL-KrasG12D mice. In UN-KC-6141 cells, PI3K and MEK signaling increased expression of KLF5; a high level of KLF5 increased proliferation. Cells with knockdown of Klf5 had reduced proliferation, compared with control cells, had reduced expression of ductal markers, and formed smaller tumors (71.61 ± 30.79 mm3 vs 121.44 ± 34.90 mm3 from control cells) in flanks of mice. CONCLUSION: Levels of KLF5 are increased in human PDAC samples and in PanINs of Ptf1a-CreERTM;LSL-KrasG12D mice, compared with controls. KLF5 disruption increases expression of NDRG2 and reduces activation of STAT3 and reduces ADM and PanINs formation in mice. Strategies to reduce KLF5 activity might reduce progression of acinar cells from ADM to PanIN and pancreatic tumorigenesis.


Assuntos
Carcinoma in Situ/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Carcinoma in Situ/genética , Carcinoma in Situ/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Ceruletídeo , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Genes ras , Humanos , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Metaplasia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Pancreatite/induzido quimicamente , Pancreatite/genética , Pancreatite/metabolismo , Pancreatite/patologia , Interferência de RNA , Transdução de Sinais , Fatores de Tempo , Transfecção , Carga Tumoral
11.
Gastroenterology ; 152(8): 1845-1875, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28366734

RESUMO

Specificity proteins (SPs) and Krüppel-like factors (KLFs) belong to the family of transcription factors that contain conserved zinc finger domains involved in binding to target DNA sequences. Many of these proteins are expressed in different tissues and have distinct tissue-specific activities and functions. Studies have shown that SPs and KLFs regulate not only physiological processes such as growth, development, differentiation, proliferation, and embryogenesis, but pathogenesis of many diseases, including cancer and inflammatory disorders. Consistently, these proteins have been shown to regulate normal functions and pathobiology in the digestive system. We review recent findings on the tissue- and organ-specific functions of SPs and KLFs in the digestive system including the oral cavity, esophagus, stomach, small and large intestines, pancreas, and liver. We provide a list of agents under development to target these proteins.


Assuntos
Doenças do Sistema Digestório/metabolismo , Sistema Digestório/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição Sp/metabolismo , Animais , Sistema Digestório/patologia , Sistema Digestório/fisiopatologia , Doenças do Sistema Digestório/genética , Doenças do Sistema Digestório/patologia , Doenças do Sistema Digestório/fisiopatologia , Regulação da Expressão Gênica , Humanos , Fatores de Transcrição Kruppel-Like/genética , Transdução de Sinais , Fatores de Transcrição Sp/genética
12.
J Am Soc Nephrol ; 28(1): 166-184, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27288011

RESUMO

Podocyte injury is the inciting event in primary glomerulopathies, such as minimal change disease and primary FSGS, and glucocorticoids remain the initial and often, the primary treatment of choice for these glomerulopathies. Because inflammation is not readily apparent in these diseases, understanding the direct effects of glucocorticoids on the podocyte, independent of the immunomodulatory effects, may lead to the identification of targets downstream of glucocorticoids that minimize toxicity without compromising efficacy. Several studies showed that treatment with glucocorticoids restores podocyte differentiation markers and normal ultrastructure and improves cell survival in murine podocytes. We previously determined that Krüppel-like factor 15 (KLF15), a kidney-enriched zinc finger transcription factor, is required for restoring podocyte differentiation markers in mice and human podocytes under cell stress. Here, we show that in vitro treatment with dexamethasone induced a rapid increase of KLF15 expression in human and murine podocytes and enhanced the affinity of glucocorticoid receptor binding to the promoter region of KLF15 In three independent proteinuric murine models, podocyte-specific loss of Klf15 abrogated dexamethasone-induced podocyte recovery. Furthermore, knockdown of KLF15 reduced cell survival and destabilized the actin cytoskeleton in differentiated human podocytes. Conversely, overexpression of KLF15 stabilized the actin cytoskeleton under cell stress in human podocytes. Finally, the level of KLF15 expression in the podocytes and glomeruli from human biopsy specimens correlated with glucocorticoid responsiveness in 35 patients with minimal change disease or primary FSGS. Thus, these studies identify the critical role of KLF15 in mediating the salutary effects of glucocorticoids in the podocyte.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/fisiologia , Glucocorticoides/farmacologia , Podócitos/citologia , Podócitos/efeitos dos fármacos , Fatores de Transcrição/fisiologia , Adolescente , Adulto , Animais , Antígenos de Diferenciação/efeitos dos fármacos , Criança , Dexametasona/farmacologia , Feminino , Glomerulosclerose Segmentar e Focal/imunologia , Humanos , Fatores de Transcrição Kruppel-Like , Masculino , Camundongos , Pessoa de Meia-Idade , Nefrose Lipoide/imunologia , Adulto Jovem
13.
Kidney Int ; 92(5): 1178-1193, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28651950

RESUMO

Large epidemiological studies clearly demonstrate that multiple episodes of acute kidney injury contribute to the development and progression of kidney fibrosis. Although our understanding of kidney fibrosis has improved in the past two decades, we have limited therapeutic strategies to halt its progression. Myofibroblast differentiation and proliferation remain critical to the progression of kidney fibrosis. Although canonical Wnt signaling can trigger the activation of myofibroblasts in the kidney, mediators of Wnt inhibition in the resident progenitor cells are unclear. Recent studies demonstrate that the loss of a Krüppel-like factor 15 (KLF15), a kidney-enriched zinc-finger transcription factor, exacerbates kidney fibrosis in murine models. Here, we tested whether Klf15 mRNA and protein expression are reduced in late stages of fibrosis in mice that underwent unilateral ureteric obstruction, a model of progressive renal fibrosis. Knockdown of Klf15 in Foxd1-expressing cells (Foxd1-Cre Klf15fl/fl) increased extracellular matrix deposition and myofibroblast proliferation as compared to wildtype (Foxd1-Cre Klf15+/+) mice after three and seven days of ureteral obstruction. This was validated in mice receiving angiotensin II treatment for six weeks. In both these murine models, the increase in renal fibrosis was found in Foxd1-Cre Klf15fl/fl mice and accompanied by the activation of Wnt/ß-catenin signaling. Furthermore, knockdown of Klf15 in cultured mouse embryonic fibroblasts activated canonical Wnt/ß-catenin signaling, increased profibrotic transcripts, and increased proliferation after treatment with a Wnt1 ligand. Conversely, the overexpression of KLF15 inhibited phospho-ß-catenin (Ser552) expression in Wnt1-treated cells. Thus, KLF15 has a critical role in attenuating kidney fibrosis by inhibiting the canonical Wnt/ß-catenin pathway.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Nefropatias/patologia , Rim/patologia , Miofibroblastos/patologia , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt , Angiotensina II/toxicidade , Animais , Proliferação de Células , Células Cultivadas , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Progressão da Doença , Fibrose , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Rim/citologia , Nefropatias/etiologia , Fatores de Transcrição Kruppel-Like , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miofibroblastos/metabolismo , Fosforilação , RNA Mensageiro/metabolismo , Células Estromais/metabolismo , Células Estromais/patologia , Fatores de Transcrição/genética , Proteína Wnt1/metabolismo , beta Catenina/metabolismo
14.
Am J Physiol Gastrointest Liver Physiol ; 313(5): G478-G491, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28864500

RESUMO

Krüppel-like factor 5 (KLF5) is a member of the zinc finger family of transcription factors that regulates homeostasis of the intestinal epithelium. Previous studies suggested an indispensable role of KLF5 in maintaining intestinal barrier function. In the current study, we investigated the mechanisms by which KLF5 regulates colonic barrier function in vivo and in vitro. We used an inducible and a constitutive intestine-specific Klf5 knockout mouse models (Villin-CreERT2;Klf5fl/fl designated as Klf5ΔIND and Villin-Cre;Klf5fl/fl as Klf5ΔIS ) and studied an inducible KLF5 knockdown in Caco-2 BBe cells using a lentiviral Tet-on system (Caco-2 BBe KLF5ΔIND). Specific knockout of Klf5 in colonic tissues, either inducible or constitutive, resulted in increased intestinal permeability. The phenotype was accompanied by a significant reduction in Dsg2, which encodes desmoglein-2, a desmosomal cadherin, at both mRNA and protein levels. Transmission electron microscopy showed alterations of desmosomal morphology in both KLF5 knockdown Caco-2 BBe cells and Klf5 knockout mouse colonic tissues. Inducible knockdown of KLF5 in Caco-2BBe cells grown on Transwell plates led to impaired barrier function as evidenced by decreased transepithelial electrical resistance and increased paracellular permeability to fluorescein isothiocyanate-4 kDa dextran. Furthermore, DSG2 was significantly decreased in KLF5 knockdown cells, and DSG2 overexpression partially rescued the impaired barrier function caused by KLF5 knockdown. Electron microscopy studies demonstrated altered desmosomal morphology after KLF5 knockdown. In combination with chromatin immunoprecipitation analysis and promoter study, our data show that KLF5 regulates intestinal barrier function by mediating the transcription of DSG2, a gene encoding a major component of desmosome structures.NEW & NOTEWORTHY The study is original research on the direct function of a Krüppel-like factor on intestinal barrier function, which is commonly exerted by cell junctions, including tight junctions, adherens junctions, and desmosomes. Numerous previous studies were focused on tight junctions and adherens junctions. However, this study provided a new perspective on how the intestinal barrier function is regulated by KLF5 through DSG2, a component of desmosome complexes.


Assuntos
Colo/fisiologia , Fatores de Transcrição Kruppel-Like/fisiologia , Animais , Células CACO-2 , Desmocolinas , Desmogleína 2/biossíntese , Desmogleína 2/genética , Desmossomos/ultraestrutura , Impedância Elétrica , Regulação da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/ultraestrutura , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Permeabilidade , RNA Mensageiro/biossíntese , RNA Mensageiro/genética
15.
FASEB J ; 30(12): 4159-4171, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27609772

RESUMO

Alterations in sphingolipid metabolism, especially ceramide and sphingosine 1-phosphate, have been linked to colon cancer, suggesting that enzymes of sphingolipid metabolism may emerge as novel regulators and targets in colon cancer. Neutral ceramidase (nCDase), a key enzyme in sphingolipid metabolism that hydrolyzes ceramide into sphingosine, is highly expressed in the intestine; however, its role in colon cancer has not been defined. Here we show that molecular and pharmacological inhibition of nCDase in colon cancer cells increases ceramide, and this is accompanied by decreased cell survival and increased apoptosis and autophagy, with minimal effects on noncancerous cells. Inhibition of nCDase resulted in loss of ß-catenin and inhibition of ERK, components of pathways relevant for colon cancer development. Furthermore, inhibition of nCDase in a xenograft model delayed tumor growth and increased ceramide while decreasing proliferation. It is noteworthy that mice lacking nCDase treated with azoxymethane were protected from tumor formation. Taken together, these studies show that nCDase is pivotal for regulating initiation and development of colon cancer, and these data suggest that this enzyme is a suitable and novel target for colon cancer therapy.-García-Barros, M., Coant, N., Kawamori, T., Wada, M., Snider, A. J., Truman, J.-P., Wu, B. X., Furuya, H., Clarke, C. J., Bialkowska, A. B., Ghaleb, A., Yang, V. W., Obeid, L. M., Hannun, Y. A. Role of neutral ceramidase in colon cancer.


Assuntos
Ceramidas/metabolismo , Neoplasias do Colo/enzimologia , Metabolismo dos Lipídeos/fisiologia , Ceramidase Neutra/metabolismo , Animais , Colo/metabolismo , Humanos , Masculino , Camundongos Knockout , Esfingolipídeos/metabolismo , beta Catenina/metabolismo
16.
Artigo em Inglês | MEDLINE | ID: mdl-28377281

RESUMO

Sphingosine-1-phosphate (S1P) is a biologically active sphingolipid metabolite which has been implicated in many diseases including cancer and inflammatory diseases. Recently, sphingosine kinase 1 (SK1), one of the isozymes which generates S1P, has been implicated in the development and progression of inflammatory bowel disease (IBD). Based on our previous work, we set out to determine the efficacy of a novel SK1 selective inhibitor, LCL351, in a murine model of IBD. LCL351 selectively inhibits SK1 both in vitro and in cells. LCL351, which accumulates in relevant tissues such as colon, did not have any adverse side effects in vivo. In mice challenged with dextran sodium sulfate (DSS), a murine model for IBD, LCL351 treatment protected from blood loss and splenomegaly. Additionally, LCL351 treatment reduced the expression of pro-inflammatory markers, and reduced neutrophil infiltration in colon tissue. Our results suggest inflammation associated with IBD can be targeted pharmacologically through the inhibition and degradation of SK1. Furthermore, our data also identifies desirable properties of SK1 inhibitors.


Assuntos
Colite/tratamento farmacológico , Colite/imunologia , Sulfato de Dextrana/efeitos adversos , Guanidinas/farmacologia , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Esfingosina/farmacologia , Células A549 , Quimiocina CXCL1/genética , Quimiocina CXCL2/genética , Colite/induzido quimicamente , Colite/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Guanidinas/uso terapêutico , Humanos , Esfingosina/uso terapêutico , Fator de Necrose Tumoral alfa/genética
17.
Dev Biol ; 387(2): 191-202, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24440658

RESUMO

Krüppel-like factor 5 (KLF5) is a pro-proliferative transcriptional regulator primarily expressed in the intestinal crypt epithelial cells. Constitutive intestine-specific deletion of Klf5 is neonatal lethal suggesting a crucial role for KLF5 in intestinal development and homeostasis. We have previously shown Klf5 to play an active role regulating intestinal tumorigenesis. Here we examine the effect of inducible intestine-specific deletion of Klf5 in adult mice. Klf5 is lost from the intestine beginning at day 3 after the start of a 5-day treatment with the inducer tamoxifen. Although the mice have no significant weight loss or lethality, the colonic tissue shows signs of epithelial distress starting at day 3 following induction. Accompanying the morphological changes is a significant loss of proliferative crypt epithelial cells as revealed by BrdU or Ki67 staining at days 3 and 5 after start of tamoxifen. We also observed a loss of goblet cells from the colon and Paneth cells from the small intestine upon induced deletion of Klf5. In addition, loss of Klf5 from the colonic epithelium is accompanied by a regenerative response that coincides with an expansion in the zone of Sox9 expression along the crypt axis. At day 11, both proliferation and Sox9 expression return to baseline levels. Microarray and quantitative PCR analyses reveal an up-regulation of several regeneration-associated genes (Reg1A, Reg3G and Reg3B) and down-regulation of many Klf5 targets (Ki-67, cyclin B, Cdc2 and cyclin D1). Sox9 and Reg1A protein levels are also increased upon Klf5 loss. Lentiviral-mediated knockdown of KLF5 and exogenous expression of KLF5 in colorectal cancer cell lines confirm that Sox9 expression is negatively regulated by KLF5. Furthermore, ChIP assays reveal a direct association of KLF5 with both the Sox9 and Reg1A promoters. We have shown that disruption of epithelial homeostasis due to Klf5 loss from the adult colon is followed by a regenerative response led by Sox9 and the Reg family of proteins. Our study demonstrates that adult mouse colonic tissue undergoes acute physiological changes to accommodate the loss of Klf5 withstanding epithelial damage further signifying importance of Klf5 in colonic homeostasis.


Assuntos
Colo/fisiologia , Fatores de Transcrição Kruppel-Like/genética , Regeneração/genética , Animais , Antineoplásicos Hormonais/farmacologia , Proteína Quinase CDC2/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/metabolismo , Ciclina B/metabolismo , Ciclina D1/metabolismo , Regulação para Baixo , Células Caliciformes/efeitos dos fármacos , Células HCT116 , Células HEK293 , Humanos , Antígeno Ki-67/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Litostatina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas a Pancreatite , Celulas de Paneth/efeitos dos fármacos , Regiões Promotoras Genéticas , Proteínas/metabolismo , Interferência de RNA , RNA Interferente Pequeno , Fatores de Transcrição SOX9/metabolismo , Deleção de Sequência , Transdução de Sinais/genética , Tamoxifeno/farmacologia , Regulação para Cima
18.
J Biol Chem ; 289(9): 5997-6005, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24398687

RESUMO

Krüppel-like factor 5 (KLF5) is a zinc finger transcription factor that is highly expressed in the crypt epithelial cells of the intestine and plays a critical role in regulating proliferation of both normal intestinal epithelial cells and colorectal cancer cells. Stability of the KLF5 is mediated by proteasomal degradation via phosphorylation by glycogen synthase kinase 3ß (GSK3ß) and recognition by F-box and WD repeat domain-containing 7 (FBW7) of a phosphodegron sequence surrounding serine 303 in KLF5. A genomic analysis of colorectal cancer tissues identified a somatic mutation (P301S) in KLF5 within the phosphodegron sequence. We hypothesized that due to its close proximity to the phosphodegron sequence, the P301S mutation may affect signaling that is involved in proper KLF5 degradation. We demonstrated that the P301S KLF5 mutant has a longer half-life than wild type (WT) KLF5. Furthermore, P301S KLF5 has a higher transcriptional activity than WT KLF5 as demonstrated by luciferase assays using cyclin D1 and CDC2 promoter constructs. In contrast to WT KLF5, P301S KLF5 does not physically interact with FBW7α. Concomitantly, the P301S KLF5 mutant displays reduced levels of phosphorylation at serine 303 in comparison with WT KLF5. These results of our study indicate that amino acid residue 301 of KLF5 is critical for proper recognition of the phosphodegron sequence by FBW7α and that the P301S mutation inhibits this recognition, leading to a degradation-resistant protein with elevated levels and enhanced transcriptional activity. These findings raise a potentially oncogenic role for the P301S KLF5 mutant in colorectal cancer.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Neoplasias do Colo/metabolismo , Proteínas F-Box/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Mutação de Sentido Incorreto , Proteínas de Neoplasias/metabolismo , Proteólise , Ubiquitina-Proteína Ligases/metabolismo , Substituição de Aminoácidos , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Proteínas F-Box/genética , Proteína 7 com Repetições F-Box-WD , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta , Células HEK293 , Humanos , Fatores de Transcrição Kruppel-Like/genética , Proteínas de Neoplasias/genética , Fosforilação/genética , Ubiquitina-Proteína Ligases/genética
19.
Am J Physiol Gastrointest Liver Physiol ; 308(2): G121-38, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25414097

RESUMO

Gut radiation-induced injury is a concern during treatment of patients with cancer. Krüppel-like factor 4 (KLF4) is expressed in differentiated villous epithelial cells of the small intestine. We previously showed that KLF4 protects cells from apoptosis following γ-irradiation in vitro. We sought to determine whether KLF4 mediates the small intestinal response to γ-irradiation in vivo. Mice with intestinal epithelium-specific deletion of Klf4 (Klf4(ΔIS)) and control (Klf4(fl/fl)) mice were irradiated with total-body γ-radiation. Following irradiation, the Klf4(ΔIS) mice had significantly increased mortality compared with irradiated Klf4(fl/fl) mice. Immunohistochemistry and immunofluorescence staining were used to assess the morphological changes, levels of proliferation, and apoptosis in the intestinal epithelium. At 96 h following irradiation, there was a regenerative response manifested by an expansion of the proliferative zone in both mouse groups, with the control mice having a higher proliferative activity than the Klf4(ΔIS) group. In addition, there was a significant increase in the number of Klf4/Ki67-copositive cells in the irradiated control mice compared with unirradiated mice. Also, the irradiated Klf4(ΔIS) mice had a significantly higher number of crypt cells positive for apoptosis, p53, and p21 compared with irradiated Klf4(fl/fl) mice. Taken together, our data suggest that Klf4 may function as a radioprotective factor against gastrointestinal syndrome in mice following γ-irradiation by inhibiting apoptosis in the acute response to irradiation and contributing to crypt regeneration.


Assuntos
Mucosa Intestinal/lesões , Mucosa Intestinal/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Animais , Apoptose/fisiologia , Linhagem Celular Tumoral , Dano ao DNA/efeitos da radiação , Modelos Animais de Doenças , Raios gama , Intestinos/efeitos da radiação , Fator 4 Semelhante a Kruppel , Camundongos , Fatores de Transcrição/genética
20.
Sci Rep ; 14(1): 9382, 2024 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654064

RESUMO

Acute Pancreatitis (AP) is associated with high mortality and current treatment options are limited to supportive care. We found that blockade of activin A (activin) in mice improves outcomes in two murine models of AP. To test the hypothesis that activin is produced early in response to pancreatitis and is maintained throughout disease progression to stimulate immune cells, we first performed digital spatial profiling (DSP) of human chronic pancreatitis (CP) patient tissue. Then, transwell migration assays using RAW264.7 mouse macrophages and qPCR analysis of "neutrophil-like" HL-60 cells were used for functional correlation. Immunofluorescence and western blots on cerulein-induced pancreatitis samples from pancreatic acinar cell-specific Kras knock-in (Ptf1aCreER™; LSL-KrasG12D) and functional WT Ptf1aCreER™ mouse lines mimicking AP and CP to allow for in vivo confirmation. Our data suggest activin promotes neutrophil and macrophage activation both in situ and in vitro, while pancreatic activin production is increased as early as 1 h in response to pancreatitis and is maintained throughout CP in vivo. Taken together, activin is produced early in response to pancreatitis and is maintained throughout disease progression to promote neutrophil and macrophage activation.


Assuntos
Ativinas , Movimento Celular , Macrófagos , Ativação de Neutrófilo , Pancreatite , Transdução de Sinais , Animais , Ativinas/metabolismo , Camundongos , Humanos , Macrófagos/metabolismo , Macrófagos/imunologia , Pancreatite/metabolismo , Pancreatite/patologia , Neutrófilos/metabolismo , Neutrófilos/imunologia , Modelos Animais de Doenças , Células RAW 264.7 , Ativação de Macrófagos , Células HL-60 , Pancreatite Crônica/metabolismo , Pancreatite Crônica/patologia , Masculino
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