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2.
Clin Transl Oncol ; 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38578537

ABSTRACT

BACKGROUND: Retrospective data suggest an association between bevacizumab efficacy and the incidence of arterial hypertension (AHT). Additionally, epigenetic mechanisms have been related to AHT. METHODS: This prospective observational study conducted by GEICAM Spanish Breast Cancer Research Group included metastatic breast (MBC) or colorectal (mCRC) cancer patients treated with bevacizumab-containing chemotherapy as first-line treatment. Blood pressure (BP) levels were measured (conventional and 24-h Holter monitoring) at baseline and up to cycle 3. Primary endpoint assessed BP levels increase as predictive factor for progression-free survival (PFS). Germline DNA methylation profile was explored in pre-treatment blood samples; principal component analysis was used to define an epigenetic predictive score for increased BP levels. RESULTS: From Oct-2012 to Jul-2016, 143 (78 MBC and 65 mCRC) patients were included. The incidence of AHT according to guidelines was neither predictive of PFS nor of best overall tumor response (BOR). No statistically significant association was observed with systolic BP nor diastolic BP increment for PFS or BOR. Grade 3 and 4 adverse events were observed in 37 and 5% of patients, respectively. We identified 27 sites which baseline methylation status was significantly associated to BP levels increase secondary to bevacizumab-containing chemotherapy. CONCLUSIONS: Neither the frequency of AHT nor the increase of BP levels were predictive of efficacy in MBC and mCRC patients treated with bevacizumab-containing chemotherapy. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov Identifier: NCT01733628.

3.
J Endocr Soc ; 8(3): bvae015, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38370444

ABSTRACT

Growth hormone (GH) modifies liver gene transcription in a sexually dimorphic manner to meet liver metabolic demands related to sex; thus, GH dysregulation leads to sex-biased hepatic disease. We dissected the steps of the GH regulatory cascade modifying GH-dependent genes involved in metabolism, focusing on the male-predominant genes Lcn13, Asns, and Cyp7b1, and the female-predominant genes Hao2, Pgc1a, Hamp2, Cyp2a4, and Cyp2b9. We explored mRNA expression in 2 settings: (i) intact liver GH receptor (GHR) but altered GH and insulin-like growth factor 1 (IGF1) levels (NeuroDrd2KO, HiGH, aHepIGF1kd, and STAT5bCA mouse lines); and (ii) liver loss of GHR, with or without STAT5b reconstitution (aHepGHRkd, and aHepGHRkd + STAT5bCA). Lcn13 was downregulated in males in most models, while Asns and Cyp7b1 were decreased in males by low GH levels or action, or constant GH levels, but unexpectedly upregulated in both sexes by the loss of liver Igf1 or constitutive Stat5b expression. Hao, Cyp2a4, and Cyp2b9 were generally decreased in female mice with low GH levels or action (NeuroDrd2KO and/or aHepGHRkd mice) and increased in HiGH females, while in contrast, Pgc1a was increased in female NeuroDrd2KO but decreased in STAT5bCA and aHepIGF1kd females. Bioinformatic analysis of RNAseq from aHepGHRkd livers stressed the greater impact of GHR loss on wide gene expression in males and highlighted that GH modifies almost completely different gene signatures in each sex. Concordantly, we show that altering different steps of the GH cascade in the liver modified liver expression of Lcn13, Asns, Cyp7b1, Hao2, Hamp2, Pgc1a, Cyp2a4, and Cyp2b9 in a sex- and gene-specific manner.

4.
Jpn J Infect Dis ; 2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38296539

ABSTRACT

Stenotrophomonas maltophilia is a non-fermenting Gram-negative drug-resistant pathogen causing healthcare-associated infections. Clinical isolates from Mexico were assessed for biofilm production by crystal violet staining. Antimicrobial susceptibility was evaluated using the broth microdilution method in planktonic and biofilm cells. The effect of antibiotics on the biofilm was visualized by fluorescence microscopy. Fifty isolates were included in the study, of which 28.0% were biofilm producers (64.2% from blood and 35.7% from respiratory samples). Resistance to levofloxacin (8.0%) and trimethoprim-sulfamethoxazole (44.0%) in planktonic cells increased to 100% in biofilm cells. Bacterial biofilm treated with several concentrations of both antibiotics was completely disrupted. In conclusion, S. maltophilia isolated from blood had higher biofilm production than those from respiratory samples. Resistance to antibiotics increased due to biofilm production. Antibiotic monotherapy might not be the best course of action for the treatment of S. maltophilia infections in Mexico, as they might also be causing biofilm production.

5.
Metabolism ; 151: 155740, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37995805

ABSTRACT

BACKGROUND & AIMS: Dysbiosis contributes to alcohol-associated liver disease (ALD); however, the precise mechanisms remain elusive. Given the critical role of the gut microbiota in ammonia production, we herein aim to investigate whether and how gut-derived ammonia contributes to ALD. METHODS: Blood samples were collected from human subjects with/without alcohol drinking. Mice were exposed to the Lieber-DeCarli isocaloric control or ethanol-containing diets with and without rifaximin (a nonabsorbable antibiotic clinically used for lowering gut ammonia production) supplementation for five weeks. Both in vitro (NH4Cl exposure of AML12 hepatocytes) and in vivo (urease administration for 5 days in mice) hyperammonemia models were employed. RNA sequencing and fecal amplicon sequencing were performed. Ammonia and triglyceride concentrations were measured. The gene and protein expression of enzymes involved in multiple pathways were measured. RESULTS: Chronic alcohol consumption causes hyperammonemia in both mice and human subjects. In healthy livers and hepatocytes, ammonia exposure upregulates the expression of urea cycle genes, elevates hepatic de novo lipogenesis (DNL), and increases fat accumulation. Intriguingly, ammonia promotes ethanol catabolism and acetyl-CoA formation, which, together with ammonia, synergistically facilitates intracellular fat accumulation in hepatocytes. Mechanistic investigations uncovered that ATF4 activation, as a result of ER stress induction and general control nonderepressible 2 activation, plays a central role in ammonia-provoked DNL elevation. Rifaximin ameliorates ALD pathologies in mice, concomitant with blunted hepatic ER stress induction, ATF4 activation, and DNL activation. CONCLUSIONS: An overproduction of ammonia by gut microbiota, synergistically interacting with ethanol, is a significant contributor to ALD pathologies.


Subject(s)
Ammonia , Fatty Liver , Hyperammonemia , Liver Diseases, Alcoholic , Animals , Humans , Mice , Activating Transcription Factor 4/genetics , Activating Transcription Factor 4/metabolism , Ammonia/adverse effects , Ammonia/metabolism , Ethanol/adverse effects , Ethanol/metabolism , Fatty Liver/chemically induced , Fatty Liver/metabolism , Hyperammonemia/complications , Hyperammonemia/metabolism , Hyperammonemia/pathology , Lipogenesis , Liver/metabolism , Liver Diseases, Alcoholic/metabolism , Mice, Inbred C57BL , Rifaximin/pharmacology
6.
Hum Cell ; 37(1): 101-120, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37874534

ABSTRACT

Circulating tumor cells (CTCs) are cancer cells that detach from the primary tumor, enter the bloodstream or body fluids, and spread to other body parts, leading to metastasis. Their presence and characteristics have been linked to cancer progression and poor prognosis in different types of cancer. Analyzing CTCs can offer valuable information about tumors' genetic and molecular diversity, which is crucial for personalized therapy. Epithelial-mesenchymal transition (EMT) and the reverse process, mesenchymal-epithelial transition (MET), play a significant role in generating and disseminating CTCs. Certain proteins, such as EpCAM, vimentin, CD44, and TGM2, are vital in regulating EMT and MET and could be potential targets for therapies to prevent metastasis and serve as detection markers. Several devices, methods, and protocols have been developed for detecting CTCs with various applications. CTCs interact with different components of the tumor microenvironment. The interactions between CTCs and tumor-associated macrophages promote local inflammation and allow the cancer cells to evade the immune system, facilitating their attachment and invasion of distant metastatic sites. Consequently, targeting and eliminating CTCs hold promise in preventing metastasis and improving patient outcomes. Various approaches are being explored to reduce the volume of CTCs. By investigating and discussing targeted therapies, new insights can be gained into their potential effectiveness in inhibiting the spread of CTCs and thereby reducing metastasis. The development of such treatments offers great potential for enhancing patient outcomes and halting disease progression.


Subject(s)
Neoplastic Cells, Circulating , Humans , Neoplastic Cells, Circulating/pathology , Biomarkers, Tumor/metabolism , Epithelial-Mesenchymal Transition/genetics , Tumor Microenvironment
7.
J Endocrinol ; 260(2)2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38032704

ABSTRACT

Short-chain fatty acids (SCFAs) are key nutrients that play a diverse set of roles in physiological function, including regulating metabolic homeostasis. Generated through the fermentation of dietary fibers in the distal colon by the gut microbiome, SCFAs and their effects are partially mediated by their cognate receptors, including free fatty acid receptor 2 (FFA2). FFA2 is highly expressed in the intestinal epithelial cells, where its putative functions are controversial, with numerous in vivo studies relying on global knockout mouse models to characterize intestine-specific roles of the receptor. Here, we used the Villin-Cre mouse line to generate a novel, intestine-specific knockout mouse model for FFA2 (Vil-FFA2) to investigate receptor function within the intestine. Because dietary changes are known to affect the composition of the gut microbiome, and can thereby alter SCFA production, we performed an obesogenic challenge on male Vil-FFA2 mice and their littermate controls (FFA2-floxed, FFA2fl/fl) to identify physiological changes on a high-fat, high-sugar 'Western diet' (WD) compared to a low-fat control diet (CD). We found that the WD-fed Vil-FFA2 mice were transiently protected from the obesogenic effects of the WD and had lower fat mass and improved glucose homeostasis compared to the WD-fed FFA2fl/fl control group during the first half of the study. Additionally, major differences in respiratory exchange ratio and energy expenditure were observed in the WD-fed Vil-FFA2 mice, and food intake was found to be significantly reduced at multiple points in the study. Taken together, this study uncovers a novel role of intestinal FFA2 in mediating the development of obesity.


Subject(s)
Diet, Western , Obesity , Receptors, G-Protein-Coupled , Animals , Male , Mice , Diet, Western/adverse effects , Eating , Fatty Acids, Volatile/metabolism , Intestines/metabolism , Mice, Inbred C57BL , Mice, Knockout , Obesity/genetics , Obesity/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism
8.
Clin Nutr ESPEN ; 57: 519-526, 2023 10.
Article in English | MEDLINE | ID: mdl-37739701

ABSTRACT

BACKGROUND: Sarcopenia is a condition associated with aging and multiple medical conditions such as CKD and hypovitaminosis D. METHODS: An observational cross-sectional study was carried out, based on patients registered in a database of specialized nephrology consultation in the city of Manizales, Colombia. 101 patients over 18 years of age who had stage 3 or 4 CKD were included. RESULTS: The frequency of sarcopenia was 10.9%. No relationship was found between sarcopenia alone and serum vitamin D levels. However, when sarcopenia was categorized as severe there was a direct relationship with hypovitaminosis D. There was also a direct relationship between dynapenia and hypovitaminosis D. In addition, patients who had serum vitamin D levels above 40 ng/ml had better muscle performance, and, consequently, probably a lower risk of frailty. CONCLUSION: When patients, within their treatment, received vitamin D supplementation, no effect on muscle performance was observed.


Subject(s)
Renal Insufficiency, Chronic , Sarcopenia , Vitamin D Deficiency , Humans , Adolescent , Adult , Colombia/epidemiology , Sarcopenia/epidemiology , Cross-Sectional Studies , Vitamin D Deficiency/complications , Vitamin D Deficiency/epidemiology , Vitamin D , Renal Insufficiency, Chronic/complications
9.
Elife ; 122023 09 11.
Article in English | MEDLINE | ID: mdl-37695317

ABSTRACT

Development of the dorsal aorta is a key step in the establishment of the adult blood-forming system, since hematopoietic stem and progenitor cells (HSPCs) arise from ventral aortic endothelium in all vertebrate animals studied. Work in zebrafish has demonstrated that arterial and venous endothelial precursors arise from distinct subsets of lateral plate mesoderm. Here, we profile the transcriptome of the earliest detectable endothelial cells (ECs) during zebrafish embryogenesis to demonstrate that tissue-specific EC programs initiate much earlier than previously appreciated, by the end of gastrulation. Classic studies in the chick embryo showed that paraxial mesoderm generates a subset of somite-derived endothelial cells (SDECs) that incorporate into the dorsal aorta to replace HSPCs as they exit the aorta and enter circulation. We describe a conserved program in the zebrafish, where a rare population of endothelial precursors delaminates from the dermomyotome to incorporate exclusively into the developing dorsal aorta. Although SDECs lack hematopoietic potential, they act as a local niche to support the emergence of HSPCs from neighboring hemogenic endothelium. Thus, at least three subsets of ECs contribute to the developing dorsal aorta: vascular ECs, hemogenic ECs, and SDECs. Taken together, our findings indicate that the distinct spatial origins of endothelial precursors dictate different cellular potentials within the developing dorsal aorta.


Subject(s)
Hemangioblasts , Zebrafish , Chick Embryo , Animals , Arteries , Hematopoietic Stem Cells , Aorta
10.
ACS Appl Nano Mater ; 6(11): 9315-9321, 2023 Jun 09.
Article in English | MEDLINE | ID: mdl-37325013

ABSTRACT

This research seeks to support reconnaissance efforts against homemade explosives (HMEs) and improvised explosive devices (IEDs), which are leading causes of combat casualties in recent conflicts. The successful deployment of a passive sensor to be developed for first responders and military must take expense, training requirements, and physical burden all into consideration. By harnessing the size-dependent luminescence of quantum dots (QDs) being electrospun into polymer fibers, the authors of this work hope to progress toward the development of lightweight, multivariable, inexpensive, easy to use and interpret, field-applicable sensors capable of detecting explosive vapors. The data demonstrate that poly(methyl methacrylate) (PMMA), polystyrene (PS), and polyvinyl chloride (PVC) fibers doped with Fort Orange cadmium selenide (CdSe) QDs, Birch Yellow CdSe QDs, or carbon (C) QDs will quench in the presence of explosive vapors (DNT, TNT, TATP, and RDX). In all cases, the fluorescent signal of the doped fiber continuously quenched upon sustained exposure to the headspace vapors. The simple method for the integration of QDs into the fibers' structure combined with their straightforward visual response, reusability, and durability all present characteristics desired for a field-operable and multimodal sensor with the ability to detect explosive threats.

11.
Breast Cancer Res Treat ; 201(2): 151-159, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37338729

ABSTRACT

PURPOSE: The monarchE trial showed that the addition of abemaciclib improves efficacy in patients with high-risk early breast cancer (EBC). We analyzed the long-term outcomes of a population similar to the monarchE trial to put into context the potential benefit of abemaciclib. METHODS: HR-positive/HER2-negative EBC patients eligible for the monarchE study were selected from 3 adjuvant clinical trials and a breast cancer registry. Patients with ≥ 4 positive axillary lymph nodes (N +) or 1-3 N + with tumor size ≥ 5 cm and/or histologic grade 3 and/or Ki67 ≥ 20%, who had undergone surgery with curative intent and had received anthracyclines ± taxanes and endocrine therapy in the neoadjuvant and /or adjuvant setting were included. We performed analysis of Invasive Disease-Free Survival (iDFS), Distant Disease-Free Survival (dDFS) and Overall Survival (OS) at 5 and 10 years, as well as yearly (up to 10) of Invasive Relapse Rate (IRR), Distant Relapse Rate (DRR) and Death Rate (DR). RESULTS: A total of 1,617 patients were analyzed from the GEICAM-9906 (312), GEICAM-2003-10 (210), and GEICAM-2006-10 (160) trials plus 935 from El Álamo IV. With a median follow-up of 10.1 years, the 5 and 10 years iDFS rates were 75.2% and 57.0%, respectively. The dDFS and OS rates at 5 years were 77.4% and 88.8% and the respective figures at 10 years were 59.7% and 70.9%. CONCLUSIONS: This data points out the need for new therapies for those patients. A longer follow-up of the monarchE study to see the real final benefit with abemaciclib is warranted. TRIAL REGISTRATION: ClinTrials.gov: GEICAM/9906: NCT00129922; GEICAM/ 2003-10: NCT00129935 and GEICAM/ 2006-10: NCT00543127.


Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Chemotherapy, Adjuvant , Neoplasm Recurrence, Local/drug therapy , Aminopyridines/therapeutic use , Disease-Free Survival , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Receptor, ErbB-2/genetics
12.
Metabolism ; 144: 155589, 2023 07.
Article in English | MEDLINE | ID: mdl-37182789

ABSTRACT

BACKGROUND: Evidence is accumulating that growth hormone (GH) protects against the development of steatosis and progression of non-alcoholic fatty liver disease (NAFLD). GH may control steatosis indirectly by altering systemic insulin sensitivity and substrate delivery to the liver and/or by the direct actions of GH on hepatocyte function. APPROACH: To better define the hepatocyte-specific role of GH receptor (GHR) signaling on regulating steatosis, we used a mouse model with adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd). To prevent the reduction in circulating insulin-like growth factor 1 (IGF1) and the subsequent increase in GH observed after aHepGHRkd, subsets of aHepGHRkd mice were treated with adeno-associated viral vectors (AAV) driving hepatocyte-specific expression of IGF1 or a constitutively active form of STAT5b (STAT5bCA). The impact of hepatocyte-specific modulation of GHR, IGF1 and STAT5b on carbohydrate and lipid metabolism was studied across multiple nutritional states and in the context of hyperinsulinemic:euglycemic clamps. RESULTS: Chow-fed male aHepGHRkd mice developed steatosis associated with an increase in hepatic glucokinase (GCK) and ketohexokinase (KHK) expression and de novo lipogenesis (DNL) rate, in the post-absorptive state and in response to refeeding after an overnight fast. The aHepGHRkd-associated increase in hepatic KHK, but not GCK and steatosis, was dependent on hepatocyte expression of carbohydrate response element binding protein (ChREBP), in re-fed mice. Interestingly, under clamp conditions, aHepGHRkd also increased the rate of DNL and expression of GCK and KHK, but impaired insulin-mediated suppression of hepatic glucose production, without altering plasma NEFA levels. These effects were normalized with AAV-mediated hepatocyte expression of IGF1 or STAT5bCA. Comparison of the impact of AAV-mediated hepatocyte IGF1 versus STAT5bCA in aHepGHRkd mice across multiple nutritional states, indicated the restorative actions of IGF1 are indirect, by improving systemic insulin sensitivity, independent of changes in the liver transcriptome. In contrast, the actions of STAT5b are due to the combined effects of raising IGF1 and direct alterations in the hepatocyte gene program that may involve suppression of BCL6 and FOXO1 activity. However, the direct and IGF1-dependent actions of STAT5b cannot fully account for enhanced GCK activity and lipogenic gene expression observed after aHepGHRkd, suggesting other GHR-mediated signals are involved. CONCLUSION: These studies demonstrate hepatocyte GHR-signaling controls hepatic glycolysis, DNL, steatosis and hepatic insulin sensitivity indirectly (via IGF1) and directly (via STAT5b). The relative contribution of these indirect and direct actions of GH on hepatocytes is modified by insulin and nutrient availability. These results improve our understanding of the physiologic actions of GH on regulating adult metabolism to protect against NAFLD progression.


Subject(s)
Human Growth Hormone , Insulin Resistance , Non-alcoholic Fatty Liver Disease , Male , Mice , Animals , Lipogenesis/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Receptors, Somatotropin/genetics , Receptors, Somatotropin/metabolism , Insulin Resistance/physiology , Liver/metabolism , Growth Hormone/metabolism , Insulin/metabolism , Glycolysis , Glucose/metabolism , Human Growth Hormone/metabolism
13.
Sci Rep ; 13(1): 8034, 2023 05 17.
Article in English | MEDLINE | ID: mdl-37198225

ABSTRACT

A primary role of the liver is to regulate whole body glucose homeostasis. Glucokinase (GCK) is the main hexokinase (HK) expressed in hepatocytes and functions to phosphorylate the glucose that enters via GLUT transporters to become glucose-6-phosphate (G6P), which subsequently commits glucose to enter downstream anabolic and catabolic pathways. In the recent years, hexokinase domain-containing-1 (HKDC1), a novel 5th HK, has been characterized by our group and others. Its expression profile varies but has been identified to have low basal expression in normal liver but increases during states of stress including pregnancy, nonalcoholic fatty liver disease (NAFLD), and liver cancer. Here, we have developed a stable overexpression model of hepatic HKDC1 in mice to examine its effect on metabolic regulation. We found that HKDC1 overexpression, over time, causes impaired glucose homeostasis in male mice and shifts glucose metabolism towards anabolic pathways with an increase in nucleotide synthesis. Furthermore, we observed these mice to have larger liver sizes due to greater hepatocyte proliferative potential and cell size, which in part, is mediated via yes-associated protein (YAP) signaling.


Subject(s)
Hexokinase , Non-alcoholic Fatty Liver Disease , Animals , Male , Mice , Glucokinase/metabolism , Glucose/metabolism , Hepatocytes/metabolism , Hexokinase/genetics , Hexokinase/metabolism , Liver/metabolism , Non-alcoholic Fatty Liver Disease/metabolism
14.
Am J Physiol Cell Physiol ; 325(1): C29-C41, 2023 07 01.
Article in English | MEDLINE | ID: mdl-37212549

ABSTRACT

Peroxisome proliferator-activated receptor γ (PPARγ) plays a pivotal role in regulating lipid metabolism and hepatic PPARγ transactivation contributes to fatty liver development. Fatty acids (FAs) are well-known endogenous ligands for PPARγ. Palmitate, a 16-C saturated FA (SFA) and the most abundant SFA in human circulation, is a strong inducer of hepatic lipotoxicity, a central pathogenic factor for various fatty liver diseases. In this study, using both alpha mouse liver 12 (AML12) and primary mouse hepatocytes, we investigated the effects of palmitate on hepatic PPARγ transactivation and underlying mechanisms, as well as the role of PPARγ transactivation in palmitate-induced hepatic lipotoxicity, all of which remain ambiguous currently. Our data revealed that palmitate exposure was concomitant with both PPARγ transactivation and upregulation of nicotinamide N-methyltransferase (NNMT), a methyltransferase catalyzing the degradation of nicotinamide, the predominant precursor for cellular NAD+ biosynthesis. Importantly, we discovered that PPARγ transactivation by palmitate was blunted by NNMT inhibition, suggesting that NNMT upregulation plays a mechanistic role in PPARγ transactivation. Further investigations uncovered that palmitate exposure is associated with intracellular NAD+ decline and NAD+ replenishment with NAD+-enhancing agents, nicotinamide and nicotinamide riboside, obstructed palmitate-induced PPARγ transactivation, implying that cellular NAD+ decline resulted from NNMT upregulation represents a potential mechanism behind palmitate-elicited PPARγ transactivation. At last, our data showed that the PPARγ transactivation marginally ameliorated palmitate-induced intracellular triacylglycerol accumulation and cell death. Collectively, our data provided the first-line evidence supporting that NNMT upregulation plays a mechanistic role in palmitate-elicited PPARγ transactivation, potentially through reducing cellular NAD+ contents.NEW & NOTEWORTHY Hepatic PPARγ transactivation contributes to fatty liver development. Saturated fatty acids (SFAs) induce hepatic lipotoxicity. Here, we investigated whether and how palmitate, the most abundant SFA in the human blood, affects PPARγ transactivation in hepatocytes. We reported for the first time that upregulation of nicotinamide N-methyltransferase (NNMT), a methyltransferase catalyzing the degradation of nicotinamide, the predominant precursor for cellular NAD+ biosynthesis, plays a mechanistic role in regulating palmitate-elicited PPARγ transactivation through reducing intracellular NAD+ contents.


Subject(s)
Fatty Liver , Palmitates , Mice , Animals , Humans , Palmitates/toxicity , Nicotinamide N-Methyltransferase/genetics , Nicotinamide N-Methyltransferase/metabolism , Up-Regulation , NAD/metabolism , Transcriptional Activation , PPAR gamma/genetics , PPAR gamma/metabolism , Hepatocytes/metabolism , Niacinamide/metabolism , Niacinamide/pharmacology , Fatty Acids/metabolism
15.
Am J Physiol Gastrointest Liver Physiol ; 324(5): G341-G353, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36852918

ABSTRACT

Hepatic lipotoxicity plays a central role in the pathogenesis of nonalcoholic fatty liver disease; however, the underlying mechanisms remain elusive. Here, using both cultured hepatocytes (AML-12 cells and primary mouse hepatocytes) and the liver-specific gene knockout mice, we investigated the mechanisms underlying palmitate-elicited upregulation of CD36, a class B scavenger receptor mediating long-chain fatty acids uptake, and its role in palmitate-induced hepatolipotoxicity. We found that palmitate upregulates hepatic CD36 expression. Despite being a well-established target gene of PPARγ transactivation, our data demonstrated that the palmitate-induced CD36 upregulation in hepatocytes is in fact PPARγ-independent. We previously reported that the activation of ATF4, one of three canonical pathways activated upon endoplasmic reticulum (ER) stress induction, contributes to palmitate-triggered lipotoxicity in hepatocytes. In this study, our data revealed for the first time that ATF4 plays a critical role in mediating hepatic CD36 expression. Genetic inhibition of ATF4 attenuated CD36 upregulation induced by either palmitate or ER stress inducer tunicamycin in hepatocytes. In mice, tunicamycin upregulates liver CD36 expression, whereas hepatocyte-specific ATF4 knockout mice manifest lower hepatic CD36 expression when compared with control animals. Furthermore, we demonstrated that CD36 upregulation upon palmitate exposure represents a feedforward mechanism in that siRNA knockdown of CD36 in hepatocytes blunted ATF4 activation induced by both palmitate and tunicamycin. Finally, we confirmed that the ATF4-CD36 pathway activation contributes to palmitate-induced hepatolipotoxicity as genetic inhibition of either ATF4 or CD36 alleviated cell death and intracellular triacylglycerol accumulation. Collectively, our data demonstrate that CD36 upregulation by ATF4 activation contributes to palmitate-induced hepatic lipotoxicity.NEW & NOTEWORTHY We provided the initial evidence that ATF4 is a principal transcription factor mediating hepatic CD36 expression in that both palmitate- and ER stress-elicited CD36 upregulation was blunted by ATF4 gene knockdown in hepatocytes, and hepatocyte-specific ATF4 knockout mice manifested lower hepatic CD36 expression. We further confirmed that the ATF4-CD36 pathway activation contributes to palmitate-induced hepatolipotoxicity as genetic inhibition of either ATF4 or CD36 alleviated cell death and intracellular triacylglycerol accumulation in response to exogenous palmitate exposure.


Subject(s)
PPAR gamma , Palmitates , Animals , Mice , Palmitates/toxicity , Palmitates/metabolism , Up-Regulation , Transcriptional Activation , PPAR gamma/metabolism , Tunicamycin/metabolism , Hepatocytes/metabolism , Endoplasmic Reticulum Stress , Mice, Knockout , Triglycerides/metabolism
16.
Cell Mol Life Sci ; 80(2): 39, 2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36629912

ABSTRACT

Non-alcoholic steatohepatitis (NASH) is associated with obesity and increased expression of hepatic peroxisome proliferator-activated receptor γ (PPARγ). However, the relevance of hepatocyte PPARγ in NASH associated with obesity is still poorly understood. In this study, hepatocyte PPARγ was knocked out (PpargΔHep) in male and female mice after the development of high-fat diet-induced obesity. The diet-induced obese mice were then maintained on their original diet or switched to a high fat, cholesterol, and fructose (HFCF) diet to induce NASH. Hepatic PPARγ expression was mostly derived from hepatocytes and increased by high fat diets. PpargΔHep reduced HFCF-induced NASH progression without altering steatosis, reduced the expression of key genes involved in hepatic fibrosis in HFCF-fed male and female mice, and decreased the area of collagen-stained fibrosis in the liver of HFCF-fed male mice. Moreover, transcriptomic and metabolomic data suggested that HFCF-diet regulated hepatic amino acid metabolism in a hepatocyte PPARγ-dependent manner. PpargΔHep increased betaine-homocysteine s-methyltransferase expression and reduced homocysteine levels in HFCF-fed male mice. In addition, in a cohort of 102 obese patients undergoing bariatric surgery with liver biopsies, 16 cases were scored with NASH and were associated with increased insulin resistance and hepatic PPARγ expression. Our study shows that hepatocyte PPARγ expression is associated with NASH in mice and humans. In male mice, hepatocyte PPARγ negatively regulates methionine metabolism and contributes to the progression of fibrosis.


Subject(s)
Non-alcoholic Fatty Liver Disease , Humans , Male , Female , Animals , Mice , Non-alcoholic Fatty Liver Disease/metabolism , PPAR gamma/genetics , PPAR gamma/metabolism , Mice, Obese , Hepatocytes/metabolism , Liver/metabolism , Liver Cirrhosis/metabolism , Obesity/metabolism , Diet, High-Fat/adverse effects , Mice, Inbred C57BL , Disease Models, Animal
17.
J Endocrinol ; 257(1)2023 04 01.
Article in English | MEDLINE | ID: mdl-36688873

ABSTRACT

Peroxisome proliferator-activated receptor γ (PPARγ) belongs to a family of nuclear receptors that could serve as lipid sensors. PPARγ is the target of a group of insulin sensitizers called thiazolidinediones (TZDs) which regulate the expression of genes involved in glucose and lipid metabolism as well as adipokines that regulate metabolic function in other tissues. Non-alcoholic fatty liver disease (NAFLD) has a high prevalence worldwide and is even higher in patients with obesity and insulin resistance. TZD-mediated activation of PPARγ could serve as a good treatment for NAFLD because TZDs have shown anti-fibrogenic and anti-inflammatory effectsin vitro and increase insulin sensitivity in peripheral tissues which improves liver pathology. However, mechanistic studies in mouse models suggest that the activation of PPARγ in hepatocytes might reduce or limit the therapeutic potential of TZD against NAFLD. In this review, we briefly describe the short history of PPAR isoforms, the relevance of their expression in different tissues, as well as the pathogenesis and potential therapeutics for NAFLD. We also discuss some evidence derived from mouse models that could be useful for endocrinologists to assess tissue-specific roles of PPARs, complement reverse endocrinology approaches, and understand the direct role that PPARγ has in hepatocytes and non-parenchymal cells.


Subject(s)
Insulin Resistance , Non-alcoholic Fatty Liver Disease , Thiazolidinediones , Animals , Mice , Hepatocytes/metabolism , Insulin Resistance/physiology , Non-alcoholic Fatty Liver Disease/metabolism , PPAR gamma/metabolism , Thiazolidinediones/metabolism , Thiazolidinediones/therapeutic use
18.
Nat Commun ; 13(1): 7323, 2022 11 28.
Article in English | MEDLINE | ID: mdl-36443308

ABSTRACT

Secreted isoform of endoplasmic reticulum membrane complex subunit 10 (scEMC10) is a poorly characterized secreted protein of largely unknown physiological function. Here we demonstrate that scEMC10 is upregulated in people with obesity and is positively associated with insulin resistance. Consistent with a causal role for scEMC10 in obesity, Emc10-/- mice are resistant to diet-induced obesity due to an increase in energy expenditure, while scEMC10 overexpression decreases energy expenditure, thus promoting obesity in mouse. Furthermore, neutralization of circulating scEMC10 using a monoclonal antibody reduces body weight and enhances insulin sensitivity in obese mice. Mechanistically, we provide evidence that scEMC10 can be transported into cells where it binds to the catalytic subunit of PKA and inhibits its stimulatory action on CREB while ablation of EMC10 promotes thermogenesis in adipocytes via activation of the PKA signalling pathway and its downstream targets. Taken together, our data identify scEMC10 as a circulating inhibitor of thermogenesis and a potential therapeutic target for obesity and its cardiometabolic complications.


Subject(s)
Antibodies, Neutralizing , Insulin Resistance , Humans , Mice , Animals , Diet , Obesity/genetics , Obesity/prevention & control , Biological Transport , Mice, Obese , Membrane Proteins
19.
Cancers (Basel) ; 14(19)2022 Sep 27.
Article in English | MEDLINE | ID: mdl-36230628

ABSTRACT

Breast cancer (BC) survivors are advised to follow the WCRF/AICR cancer prevention recommendations, given their high risk of developing a second tumour. We aimed to explore compliance with these recommendations in BC survivors and to identify potentially associated clinical and sociodemographic factors. A total of 420 BC survivors, aged 31-80, was recruited from 16 Spanish hospitals. Epidemiological, dietary and physical activity information was collected through questionnaires. A 7-item score to measure compliance with the recommendations was built according to the 2018 WCRF/AICR scoring criteria. Standardized prevalences and standardized prevalence ratios of moderate and high compliance across participant characteristics were estimated using multinomial and binary logistic regression models. The mean score was 3.9 (SD: 1.0) out of 7 points. Recommendations with the worst adherence were those of limiting consumption of red/processed meats (12% of compliance, 95% CI: 8.2-15.0) and high fibre intake (22% of compliance, 95% CI: 17.6-27.0), while the best compliance was observed for the consumption of fruits and vegetables (73% of compliance, 95% CI: 69.2-77.7). Overall, adherence was worse in women with university education and in those with first-degree relatives with BC. This information may be of interest to design and implement personalized preventive measures adapted to the characteristics of these patients.

20.
Farm Hosp ; 46(4): 215-223, 2022 07 17.
Article in English | MEDLINE | ID: mdl-36183219

ABSTRACT

OBJECTIVE: To analyse a patient journey based on the experience reported by  breast and lung cancer patients at Spanish hospital. Method: A mixed design was used, with interviews with 16 health  professionals and 25 patients (qualitative method) and a Net Promoter Score questionnaire to 127 patients (quantitative method). INCLUSION CRITERIA: oncology patients > 18 years treated in hospital between February-  May 2019. EXCLUSION CRITERIA: paediatric patients, in palliative care or who were  hospitalised at the time of the study. RESULTS: Six phases were identified from the data obtained in the qualitative method: my life before diagnosis; discovery; initiation; treatment;  followup; and my current life. In the my life before diagnosis phase, a  functional level of experience was established, as patients' lives met their  expectations. In the discovery phase, patients' expectations were observed to  be met, although several satellite experiences were found. In the initiation  phase, the experience tended to be negative due to long waiting times and  emotional and physical stress. The treatment phase was defined as a basic- poor experience, due to waiting times and lack of institutional support. The  experience in the follow-up phase was positive in terms of tests and visits, but  critical points were observed in waiting times. In the current phase, the effort  made by health professionals to ensure the best possible treatment and care  was mentioned. In terms of quantitative analysis, a positive score (46%) was obtained for the Net Promoter Score indicator, as 60% of patients were promoters, i.e. they were satisfied with the service offered by the hospital. CONCLUSIONS: This study provides insight into the experience of cancer patients in the six main stages of the disease. The most positive phases were "my life before diagnosis" and "follow-up" while the phases with a negative trend were "initiation" and "treatment" due to the waiting times  and the emotional burden on the patient.


OBJETIVO: Analizar la experiencia aportada por los pacientes con cáncer de  mama y pulmón utilizando la metodología del recorrido del paciente en un  hospital español. Método: Se empleó un diseño mixto, con entrevistas a 16 profesionales sanitarios y 25 pacientes (método cualitativo), y un cuestionario  basado en el indicador Net Promoter Score a 127 pacientes (método  cuantitativo). Criterios de inclusión: pacientes oncológicos > 18 años tratados  en el hospital entre febrero y mayo de 2019. Criterios de exclusión: pacientes pediátricos, en cuidados paliativos o que estaban hospitalizados en el  momento del estudio. RESULTADOS: Se identificaron seis fases a partir de los datos obtenidos en  el  método cualitativo: mi vida antes del diagnóstico, descubrir, comenzar, tratamiento, seguimiento y mi vida hoy. En la fase mi vida antes del  diagnóstico se estableció un nivel de experiencia funcional, ya que la vida  cumplía las expectativas de los pacientes. En la fase de descubrir se observó  que las expectativas de los pacientes se cumplían, aunque se  encontraron varias experiencias satélite. En la fase comenzar, la experiencia  tendió a ser negativa debido a los largos tiempos de espera y al estrés  emocional y físico. La fase de tratamiento se consideró como una experiencia  de nivel básico-deficiente, debido a los tiempos de espera y a la falta de apoyo  institucional. La experiencia en la fase de seguimiento fue positiva respecto   las pruebas y las visitas, pero se observaron puntos críticos en los tiempos de espera. en la fase mi vida hoy se mencionó el esfuerzo realizado  por  los profesionales sanitarios para garantizar el mejor tratamiento y  atención posibles. En cuanto al análisis cuantitativo, se obtuvo una puntuación positiva (46%) para el indicador Net Promoter Score, ya que el 60% de los  pacientes pertenecían a la categoría de promotores, es decir, estaban satisfechos con el servicio ofrecido por el hospital. CONCLUSIONES: Este estudio permite conocer la experiencia de los pacientes  oncológicos en las seis etapas principales de la enfermedad. Las fases más  positivas fueron "mi vida antes del diagnóstico" y "seguimiento", mientras que  las fases con tendencia negativa fueron "inicio" y "tratamiento" debido a los  tiempos de espera y la carga emocional que suponen para el paciente.


Subject(s)
Breast Neoplasms , Breast Neoplasms/therapy , Child , Female , Humans , Lung , Palliative Care , Patient Reported Outcome Measures , Qualitative Research
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