Abstract 440: Activation of Hepatic CREBH-Insig-2a Signaling in the Triglyceride-Lowering Mechanism of R-Alpha-Lipoic Acid

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Xuedong Tong ◽  
Regis Moreau ◽  
Qiaozhu Su
Keyword(s):  
Lipoic Acid ◽  
De Novo ◽  
Therapeutic Potential ◽  
Regulatory Element ◽  
Ldl Receptor ◽  
De Novo Lipogenesis ◽  
Alpha Lipoic Acid ◽  
Very Low Density Lipoproteins ◽  
Expression Of Genes

Activation of the sterol regulatory element-binding proteins (SREBPs), a step regulated by a cluster of ER-resident proteins, Insig-1, Insig-2 and SCAP, is rate limiting in hepatic de novo lipogenesis. We previously reported that feeding R-alpha-lipoic acid (LA) to ZDF (fa/fa) rats improves severe hypertriglyceridemia and lowers abdominal fat mass by inhibiting expression of genes involved in hepatic long-chain fatty acids and triacylglycerol syntheses. In this study, we characterized a novel mechanism of action of LA that explains its triacylglycerol lowering properties. Dietary LA activates liver specific transcription factor cAMP responsive element binding protein H (CREBH), which in turn enhances transcription and translation of Insig-1 and Insig-2. Chromatin immunoprecipitation (ChIP) assay demonstrated interaction between CREBH and the promoter of Insig-2 but not Insig-1. The increased abundance of Insig-1 and Insig-2 proteins contributes to sequester SREBP-1c and SREBP-2 in the ER and prevents their translocation to the Golgi apparatus where they would become activated. As a consequence, mRNA expression of genes involved in fatty acid and cholesterol synthesis, including FASN, ACC, SCD-1, HMGCR and LDL receptor, were significantly decreased in LA-fed animals versus pair-fed controls. Concomitantly, the assembly and secretion of very-low-density lipoproteins (VLDL) by primary hepatocytes were suppressed in the LA-fed ZDF rats as indicated by the decrease in VLDL-associated apolipoprotein B and apolipoprotein E. In vitro, treating a rat McA-RH7777 hepatoma cells with LA (200 micromole) activated CREBH, induced expression of Insig-1 and Insig-2, and hindered the palmitic acid-induced synthesis of triacylglycerol. This study provides new mechanistic insight into the triacylglycerol lowering properties of LA and supports the therapeutic potential of LA against hypertriglyceridemia.

Abstract 325: Response Gene to Complement 32 Deficiency Protects Against Hepatic Steatosis by Inhibiting Lipogenesis in Mice

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Xiaobing Cui ◽  
Junna Luan ◽  
Shiyou Chen
Keyword(s):  
Hepatic Steatosis ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Regulatory Element ◽  
In Vitro Study ◽  
De Novo Lipogenesis ◽  
Dependent Manner ◽  
Response Gene ◽  
Normal Chow

Hepatic steatosis is associated with obesity due to the increased lipogenesis. Previously, we have found that RGC-32 (response gene to complement 32) deficiency prevents the mice from high-fat diet (HFD)-induced obesity and insulin resistance. The present study was conducted to determine the role of RGC-32 in the control of hepatic steatosis. We observed that hepatic RGC-32 expression was dramatically induced by HFD challenge. RGC-32 knockout (RGC32-/-) mice were resistant to HFD-induced hepatic steatosis. More importantly, hepatic triglyceride contents of RGC32-/- mice were significantly decreased compared with wild-type (WT) controls on both normal chow and HFD. Mechanistically, RGC-32 deficiency decreased expression of lipogenesis-related genes, sterol regulatory element (SRE) binding protein (SREBP)-1c, fatty acid synthase (FAS) and stearoyl-CoA desaturase-1 (SCD1). Our in vitro study showed that RGC-32 knockdown decreased while RGC-32 overexpression increased SCD1 expression in hepatocytes. Deletion or mutation of SRE in the SCD1 promoter abolished the function of RGC-32. These data demonstrate that RGC-32 contributes to HFD-induced hepatic steatosis by facilitating de novo lipogenesis in a SREBP-1c dependent manner. Therefore, RGC-32 may be a novel drug target in the treatment of hepatic steatosis and its related diseases.

Patchouli Oil Attenuates High Fat Diet-induced Non-alcoholic Hepatic Steatosis

Planta Medica ◽  
2020 ◽  
Vol 86 (04) ◽  
pp. 255-266 ◽  
Author(s):  
Nan Xu ◽  
Xue Wu ◽  
Hui-Juan Luo ◽  
Fang-Fang Xu ◽  
Qiong-Hui Huang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
De Novo ◽  
Regulatory Element ◽  
Chinese Herb ◽  
De Novo Lipogenesis ◽  
High Fat ◽  
Very Low Density Lipoproteins ◽  
Alcoholic Fatty Liver

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. Nevertheless, no first-line therapy exists. Hepatic steatosis is the earliest stage of NAFLD, which is characterized by an accumulation of hepatic lipids. Patchouli oil (PO), which is isolated from the well-known Chinese herb named Pogostemon cablin (Blanco) Benth. (Lamiaceae), inhibits hepatic lipid accumulation effectively. However, its potential ability for the treatment of NAFLD had not been reported before. Thus, the objective of this study was to investigate the effectiveness of PO against hepatic steatosis and its underlying mechanisms. We used a high fat diet (HFD)-induced hepatic steatosis model of rats to estimate the effect of PO against NAFLD. Hematoxylin-eosin and oil red O staining were used to analyze the hepatic histopathological changes. ELISA, RT-qPCR, and Western blotting analysis were applied to evaluate the parameters for hepatic steatosis. Our results showed that PO significantly attenuated the lipid profiles and the serum enzymes, evidenced by quantitative and histopathological analyses. It also markedly down-regulated the expression of sterol regulatory element-binding protein 1 (SREPB-1c) with its downstream factors in de novo lipogenesis. And, likewise, in lipid export by very low-density lipoproteins (VLDL), related molecules were dramatically improved. Furthermore, PO observably normalized the aberrant peroxisome proliferator-activated receptor α (PPAR-α) signal in fatty acids oxidation. In conclusion, PO exerted a preventing effect against HFD-induced steatosis and might be due to decrease de novo lipogenesis, promote export of lipids, as well as owing to improve fatty acids oxidation.

scholarly journals Mitochondrial Dysfunction and Alpha-Lipoic Acid: Beneficial or Harmful in Alzheimer’s Disease?

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Sávio Monteiro dos Santos ◽  
Camila Fernanda Rodrigues Romeiro ◽  
Caroline Azulay Rodrigues ◽  
Alícia Renata Lima Cerqueira ◽  
Marta Chagas Monteiro
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Lipoic Acid ◽  
Neurodegenerative Disorder ◽  
Therapeutic Potential ◽  
Pharmacokinetic Profile ◽  
In Vivo Studies ◽  
Alpha Lipoic Acid ◽  
Amyloid A

Alzheimer’s disease (AD) is a neurodegenerative disorder characterised by impairments in the cognitive domains associated with orientation, recording, and memory. This pathology results from an abnormal deposition of the β-amyloid (Aβ) peptide and the intracellular accumulation of neurofibrillary tangles. Mitochondrial dysfunctions play an important role in the pathogenesis of AD, due to disturbances in the bioenergetic properties of cells. To date, the usual therapeutic drugs are limited because of the diversity of cellular routes in AD and the toxic potential of these agents. In this context, alpha-lipoic acid (α-LA) is a well-known fatty acid used as a supplement in several health conditions and diseases, such as periphery neuropathies and neurodegenerative disorders. It is produced in several cell types, eukaryotes, and prokaryotes, showing antioxidant and anti-inflammatory properties. α-LA acts as an enzymatic cofactor able to regulate metabolism, energy production, and mitochondrial biogenesis. In addition, the antioxidant capacity of α-LA is associated with two thiol groups that can be oxidised or reduced, prevent excess free radical formation, and act on improvement of mitochondrial performance. Moreover, α-LA has mechanisms of epigenetic regulation in genes related to the expression of various inflammatory mediators, such PGE2, COX-2, iNOS, TNF-α, IL-1β, and IL-6. Regarding the pharmacokinetic profile, α-LA has rapid uptake and low bioavailability and the metabolism is primarily hepatic. However, α-LA has low risk in prolonged use, although its therapeutic potential, interactions with other substances, and adverse reactions have not been well established in clinical trials with populations at higher risk for diseases of aging. Thus, this review aimed to describe the pharmacokinetic profile, bioavailability, therapeutic efficacy, safety, and effects of combined use with centrally acting drugs, as well as report in vitro and in vivo studies that demonstrate the mitochondrial mechanisms of α-LA involved in AD protection.

scholarly journals Chemopreventive Effects of Alpha Lipoic Acid on Obesity-Related Cancers

2016 ◽  
Vol 68 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Hyun-Seuk Moon
Keyword(s):  
Risk Factor ◽  
Lipoic Acid ◽  
Octanoic Acid ◽  
Scattered Data ◽  
Alpha Lipoic Acid ◽  
Chemopreventive Agent ◽  
Anti Cancer ◽  
In Vivo Animal Models

Background: It has been generally accepted that being overweight or obese is a risk factor for several types of cancers, including breast, thyroid, colon, pancreatic and liver. In fact, people who are obese have more fat tissues that can produce hormones, such as insulin or estrogen, which may cause cancer cells to grow. Alpha lipoic acid (ALA) is anorganosulfur compound derived from octanoic acid, which is produced in animals normally, and is essential for aerobic metabolism. Summary: Studies in both in vitro cells and in vivo animal models have shown that ALA inhibits the initiation and promotion stages of carcinogenesis, suggesting that ALA has considerable attention as a chemopreventive agent. This brief review collects the scattered data available in the literature concerning ALA and highlights its anti-cancer properties, intermediary metabolism and exploratory implications. Key Messages: Based on scientific evidences so far, ALA might be useful agents in the management or chemoprevention of obesity-related cancers.

Effect of carbohydrate intake on de novo lipogenesis in human adipose tissue

1987 ◽  
Vol 253 (6) ◽  
pp. E664-E669 ◽  
Author(s):  
C. Chascione ◽  
D. H. Elwyn ◽  
M. Davila ◽  
K. M. Gil ◽  
J. Askanazi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
De Novo ◽  
Acid Synthesis ◽  
De Novo Lipogenesis ◽  
Whole Body ◽  
High Intake ◽  
Carbohydrate Diet ◽  
Triglyceride Synthesis ◽  
High Carbohydrate

Rates of synthesis, from [14C]glucose, of fatty acids (de novo lipogenesis) and glycerol (triglyceride synthesis) were measured in biopsies of adipose tissue from nutritionally depleted patients given low- or high-carbohydrate intravenous nutrition. Simultaneously, energy expenditure and whole-body lipogenesis were measured by indirect calorimetry. Rates of whole-body lipogenesis were zero on the low-carbohydrate diet and averaged 1.6 g.kg-1.day-1 on the high-carbohydrate diet. In vitro rates of triglyceride synthesis increased 3-fold going from the low to the high intake; rates of fatty acid synthesis increased approximately 80-fold. In vitro, lipogenesis accounted for less than 0.1% of triglyceride synthesis on the low intake and 4% on the high intake. On the high-carbohydrate intake, in vitro rates of triglyceride synthesis accounted for 61% of the rates of unidirectional triglyceride synthesis measured by indirect calorimetry. In vitro rates of lipogenesis accounted for 7% of whole-body lipogenesis. Discrepancies between in vitro rates of fatty acid synthesis from glucose, compared with acetate and citrate, as reported by others, suggest that in depleted patients on hypercaloric high-carbohydrate diets, adipose tissue may account for up to 40% of whole-body lipogenesis.

Regulation of the SREBP transcription factors by mTORC1

2011 ◽  
Vol 39 (2) ◽  
pp. 495-499 ◽  
Author(s):  
Caroline A. Lewis ◽  
Beatrice Griffiths ◽  
Claudio R. Santos ◽  
Mario Pende ◽  
Almut Schulze
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Target Genes ◽  
De Novo ◽  
Regulatory Element ◽  
Cholesterol Biosynthesis ◽  
Mammalian Target Of Rapamycin ◽  
Lipid Biosynthesis ◽  
De Novo Lipogenesis ◽  
Genes Encoding

In recent years several reports have linked mTORC1 (mammalian target of rapamycin complex 1) to lipogenesis via the SREBPs (sterol-regulatory-element-binding proteins). SREBPs regulate the expression of genes encoding enzymes required for fatty acid and cholesterol biosynthesis. Lipid metabolism is perturbed in some diseases and SREBP target genes, such as FASN (fatty acid synthase), have been shown to be up-regulated in some cancers. We have previously shown that mTORC1 plays a role in SREBP activation and Akt/PKB (protein kinase B)-dependent de novo lipogenesis. Our findings suggest that mTORC1 plays a crucial role in the activation of SREBP and that the activation of lipid biosynthesis through the induction of SREBP could be part of a regulatory pathway that co-ordinates protein and lipid biosynthesis during cell growth. In the present paper, we discuss the increasing amount of data supporting the potential mechanisms of mTORC1-dependent activation of SREBP as well as the implications of this signalling pathway in cancer.

scholarly journals Effect of In-Vitro Alpha Lipoic Acid Addition on Spermatozoa Motility in Sperm Preparation Process

2021 ◽  
Vol 55 (4) ◽  
pp. 246
Author(s):  
Gede Wira Buanayuda ◽  
Hamdani Lunardhi ◽  
Indra Gusti Mansur
Keyword(s):  
Lipoic Acid ◽  
Intrauterine Insemination ◽  
Control Group ◽  
Infertile Couple ◽  
Preparation Process ◽  
Alpha Lipoic Acid ◽  
Sperm Preparation ◽  
Progressive Motility ◽  
Child Hospital

Infertility is a problem for husband and wife, in the last 20 years the number of infertile couples has tended to increase by around 6.5 million pairs. The infertile couple can use the intrauterine insemination method to obtain offspring if a conventional method approach cannot be performed. Insemination requires a sperm preparation stage in which there are centrifugation and resuspension procedures that tend to produce excess reactive oxygen species (ROS). Excessive ROS will damage the motility of the spermatozoa. This study aims to prove the addition of alpha lipoic acid (ALA) as an antioxidant in the process of sperm preparation to improve and maintain better sperm motility. This research is a laboratory study with an experimental research design. The sample consisted of 10 infertile men who visited the Andrology section of the Sayyidah Jakarta Mother and Child Hospital (RSIA), where each ejaculate from the patient would be divided into 3 groups namely (k1) fresh semen as a control group, (k2) sperm preparation group without ALA, (k3) group of sperm preparation with the addition of ALA. The motility of spermatozoa was observed with the WHO 1999 method for 4 hours in units of percent. Progressive motility in k3 (47.95 ± 3.617) was higher than in k2 (38.05 ± 3.278) statistically significantly different after 3 hours of observation (p<0.0001). Progressive motility in k3 (78.8 ± 5.841) was higher than k1 (56.55 ± 7.511) from the initial observation (p <0.0001). The progressive motility of k2 (76.05 ± 6.768) was higher than k1 (56.55 ± 7.511) from the start of the observation (0.0001). It can be concluded that the addition of ALA in the sperm preparation process increases and maintains progressive motility that is better than sperm preparation without ALA addition after 3 hours of observation.

scholarly journals Targeting de novo lipogenesis and the Lands cycle induces ferroptosis in KRAS-mutant lung cancer

2021 ◽  
Author(s):  
Caterina Bartolacci ◽  
Cristina Andreani ◽  
Goncalo Dias do Vale ◽  
Stefano Berto ◽  
Margherita Melegari ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Fatty Acid ◽  
Metabolic Networks ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Genetically Engineered ◽  
De Novo Lipogenesis ◽  
Main Process

Mutant KRAS (KM) is the most common oncogene in lung cancer (LC). KM regulates several metabolic networks, but their role in tumorigenesis is still not sufficiently characterized to be exploited in cancer therapy. To identify metabolic networks specifically deregulated in KMLC, we characterized the lipidome of genetically engineered LC mice, cell lines, patient derived xenografts and primary human samples. We also determined that KMLC, but not EGFR-mutant (EGFR-MUT) LC, is enriched in triacylglycerides (TAG) and phosphatidylcholines (PC). We also found that KM upregulates fatty acid synthase (FASN), a rate-limiting enzyme in fatty acid (FA) synthesis promoting the synthesis of palmitate and PC. We determined that FASN is specifically required for the viability of KMLC, but not of LC harboring EGFR-MUT or wild type KRAS. Functional experiments revealed that FASN inhibition leads to ferroptosis, a reactive oxygen species (ROS)-and iron-dependent cell death. Consistently, lipidomic analysis demonstrated that FASN inhibition in KMLC leads to accumulation of PC with polyunsaturated FA (PUFA) chains, which are the substrate of ferroptosis. Integrating lipidomic, transcriptome and functional analyses, we demonstrated that FASN provides saturated (SFA) and monounsaturated FA (MUFA) that feed the Lands cycle, the main process remodeling oxidized phospholipids (PL), such as PC. Accordingly, either inhibition of FASN or suppression of the Lands cycle enzymes PLA2 and LPCAT3, promotes the intracellular accumulation of lipid peroxides and ferroptosis in KMLC both in vitro and in vivo. Our work supports a model whereby the high oxidative stress caused by KM dictates a dependency on newly synthesized FA to repair oxidated phospholipids, establishing a targetable vulnerability. These results connect KM oncogenic signaling, FASN induction and ferroptosis, indicating that FASN inhibitors already in clinical trial in KMLC patients (NCT03808558) may be rapidly deployed as therapy for KMLC.

Effect of alpha lipoic acid on in vitro development of bovine secondary preantral follicles

2017 ◽  
Vol 88 ◽  
pp. 124-130 ◽  
Author(s):  
Khairy M.A. Zoheir ◽  
Gamaleldin I. Harisa ◽  
Ahmed A. Allam ◽  
Liguo Yang ◽  
Xiang Li ◽  
...  
Keyword(s):  
Lipoic Acid ◽  
Alpha Lipoic Acid ◽  
In Vitro Development ◽  
Preantral Follicles ◽  
Vitro Development

scholarly journals Sub-Chronic Microcystin-LR Liver Toxicity in Preexisting Diet-Induced Nonalcoholic Steatohepatitis in Rats

Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 398 ◽  
Author(s):  
Tarana Arman ◽  
Katherine D. Lynch ◽  
Michelle L. Montonye ◽  
Michael Goedken ◽  
John D. Clarke
Keyword(s):  
Nonalcoholic Steatohepatitis ◽  
Liver Toxicity ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Sprague Dawley ◽  
Toxicant Exposure ◽  
Expression Of Genes ◽  
Sprague Dawley Rats ◽  
Progressive Liver Disease ◽  
Acid Esterification

Microcystin-LR (MCLR) is a hepatotoxic cyanotoxin reported to cause a phenotype similar to nonalcoholic steatohepatitis (NASH). NASH is a common progressive liver disease that advances in severity due to exogenous stressors such as poor diet and toxicant exposure. Our objective was to determine how sub-chronic MCLR toxicity affects preexisting diet-induced NASH. Sprague-Dawley rats were fed one of three diets for 10 weeks: control, methionine and choline deficient (MCD), or high fat/high cholesterol (HFHC). After six weeks of diet, animals received vehicle, 10 µg/kg, or 30 µg/kg MCLR via intraperitoneal injection every other day for the final 4 weeks. Incidence and severity scoring of histopathology endpoints suggested that MCLR toxicity drove NASH to a less fatty and more fibrotic state. In general, expression of genes involved in de novo lipogenesis and fatty acid esterification were altered in favor of decreased steatosis. The higher MCLR dose increased expression of genes involved in fibrosis and inflammation in the control and HFHC groups. These data suggest MCLR toxicity in the context of preexisting NASH may drive the liver to a more severe phenotype that resembles burnt-out NASH.

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