scholarly journals Codon-optimized FAM132b prevents diet-induced obesity by modulating adrenergic response and insulin action

2020 ◽  
Author(s):  
Zhengtang Qi ◽  
Jie Xia ◽  
Xiangli Xue ◽  
Wenbin Liu ◽  
Zhuochun Huang ◽  
...  

AbstractFAM132b, also known as myonectin, has been identified as a myokine produced by exercise. It is a secreted protein precursor that belongs to the adipolin/erythroferrone family, and has hormone activity in circulation to regulate cellular iron homeostasis and lipid metabolism via unknown receptors. Here, adeno-associated viral vectors (AAV9) were engineered to induce overexpression of FAM132b with 2 codon mutations (A136T and P159A). Treatment of mice under high-fat diet feeding with FAM132b gene transfer resulted in marked reductions in body weight, fat depot, adipocytes size, glucose intolerance and insulin resistance. Moreover, FAM132b overproduction reduced glycemic response to epinephrine (EPI) in whole body and increased lipolytic response to EPI in adipose tissues. This adrenergic response of adipose tissue led to the result that gene transfer reduced glycogen utilization and increased fat consumption in skeletal muscle during exercise. FAM132b knockdown by shRNA significantly increased glycemic response to EPI in vivo and reduced adipocytes response to EPI and adipose tissue browning. Structural analysis suggested that FAM132b mutants delivered by AAV9 may form a weak bond with ADRB2, and potentially bind to insulin against insulin receptor by blocking the receptor binding sites on insulin B-chain. Our study underscores the potential of FAM132b gene therapy with codon optimization to treat obesity by modulating adrenergic response and interfering insulin action.SignificanceWe show here that AAV9-mediated expression of FAM132b with A136T and P159A is a safe and effective therapeutic strategy for improving glucose homeostasis. This is the first demonstration of a therapeutic effect on metabolic disorders in mice with FAM132b codon optimization. These therapeutic effects indicate that FAM132b gene transfer with selective codon mutants in vivo might be a valid therapy for diabetes that can be extended to other metabolic disorders.

Nanoscale ◽  
2020 ◽  
Author(s):  
Naishun Liao ◽  
Da Zhang ◽  
Ming Wu ◽  
Huang-Hao Yang ◽  
Xiaolong Liu ◽  
...  

Adipose tissue derived mesenchymal stem cell (ADSC)-based therapy is attractive for liver diseases, but the long-term therapeutic outcome is still far from satisfaction due to low hepatic engraftment efficiency of...


2021 ◽  
Author(s):  
Ye Yin ◽  
Yangyang Wu ◽  
Xu Zhang ◽  
Yeting Zhu ◽  
Yue Sun ◽  
...  

<a>Downregulation of mitochondrial function in adipose tissue is considered as one important driver for the development of obesity-associated metabolic disorders. Inorganic Pyrophosphatase 1 (PPA1) is an enzyme catalyzes the hydrolysis of PPi to Pi, and is required for anabolism to take place in cells. Although alternation of PPA1 has been related to some diseases, the importance of PPA1 in metabolic syndromes has never been discussed before. In this study, we found that global PPA1 knockout mice (PPA1<sup>+/-</sup>) showed impaired glucose tolerance and severe insulin resistance under HFD feeding. In addition, impaired adipose tissue development and ectopic lipid accumulation were also observed. Conversely, overexpression of PPA1 in adipose tissue by AAV injection can partly reverse the metabolic disorders in PPA1<sup>+/-</sup> mice, suggesting that impaired adipose tissue function is responsible for the metabolic disorders observed in PPA1<sup>+/- </sup>mice. Mechanistic studies revealed that PPA1 acted as a PPARγ target gene to maintain mitochondrial function in adipocytes. Furthermore, specific knockdown of PPA1 in fat body of <i>Drosophila</i> led to impaired mitochondria morphology, decreased lipid storage, and made <i>Drosophila</i> more sensitive to starvation. In conclusion, for the first time, our findings demonstrated the importance of PPA1 in maintaining adipose tissue function and whole body metabolic homeostasis.</a>


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jain Jeong ◽  
Soyoung Jang ◽  
Song Park ◽  
Wookbong Kwon ◽  
Si-Yong Kim ◽  
...  

Abstract Background Juxtaposed with another zinc finger protein 1 (JAZF1) is associated with metabolic disorders, including type 2 diabetes mellitus (T2DM). Several studies showed that JAZF1 and body fat mass are closely related. We attempted to elucidate the JAZF1 functions on adipose development and related metabolism using in vitro and in vivo models. Results The JAZF1 expression was precisely regulated during adipocyte differentiation of 3T3-L1 preadipocyte and mouse embryonic fibroblasts (MEFs). Homozygous JAZF1 deletion (JAZF1-KO) resulted in impaired adipocyte differentiation in MEF. The JAZF1 role in adipocyte differentiation was demonstrated by the regulation of PPARγ—a key regulator of adipocyte differentiation. Heterozygous JAZF1 deletion (JAZF1-Het) mice fed a normal diet (ND) or a high-fat diet (HFD) had less adipose tissue mass and impaired glucose homeostasis than the control (JAZF1-Cont) mice. However, other metabolic organs, such as brown adipose tissue and liver, were negligible effect on JAZF1 deficiency. Conclusion Our findings emphasized the JAZF1 role in adipocyte differentiation and related metabolism through the heterozygous knockout mice. This study provides new insights into the JAZF1 function in adipose development and metabolism, informing strategies for treating obesity and related metabolic disorders.


2000 ◽  
Vol 279 (3) ◽  
pp. E554-E560 ◽  
Author(s):  
Bronwyn A. Ellis ◽  
Ann Poynten ◽  
Andrew J. Lowy ◽  
Stuart M. Furler ◽  
Donald J. Chisholm ◽  
...  

Long-chain acyl-CoAs (LCACoA) are an activated lipid species that are key metabolites in lipid metabolism; they also have a role in the regulation of other cellular processes. However, few studies have linked LCACoA content in rat and human muscle to changes in nutritional status and insulin action. Fasting rats for 18 h significantly elevated the three major LCACoA species in muscle ( P < 0.001), whereas high-fat feeding of rats with a safflower oil (18:2) diet produced insulin resistance and increased total LCACoA content ( P < 0.0001) by specifically increasing 18:2-CoA. The LCACoA content of red muscle from rats (4–8 nmol/g) was 4- to 10-fold higher than adipose tissue (0.4–0.9 nmol/g, P < 0.001), suggesting that any contamination of muscle samples with adipocytes would contribute little to the LCACoA content of muscle. In humans, the LCACoA content of muscle correlated significantly with a measure of whole body insulin action in 17 male subjects ( r 2 = 0.34, P = 0.01), supporting a link between muscle lipid metabolism and insulin action. These results demonstrate that the LCACoA pool reflects lipid metabolism and nutritional state in muscle. We conclude that the LCACoA content of muscle provides a direct index of intracellular lipid metabolism and its links to insulin action, which, unlike triglyceride content, is not subject to contamination by closely associated adipose tissue.


2006 ◽  
Vol 0 (0) ◽  
pp. 060815083008001
Author(s):  
Hiroaki Mizukami ◽  
Jun Mimuro ◽  
Tsuyoshi Ogura ◽  
Takashi Okada ◽  
Masashi Urabe ◽  
...  

2018 ◽  
Vol 98 (4) ◽  
pp. 2133-2223 ◽  
Author(s):  
Max C. Petersen ◽  
Gerald I. Shulman

The 1921 discovery of insulin was a Big Bang from which a vast and expanding universe of research into insulin action and resistance has issued. In the intervening century, some discoveries have matured, coalescing into solid and fertile ground for clinical application; others remain incompletely investigated and scientifically controversial. Here, we attempt to synthesize this work to guide further mechanistic investigation and to inform the development of novel therapies for type 2 diabetes (T2D). The rational development of such therapies necessitates detailed knowledge of one of the key pathophysiological processes involved in T2D: insulin resistance. Understanding insulin resistance, in turn, requires knowledge of normal insulin action. In this review, both the physiology of insulin action and the pathophysiology of insulin resistance are described, focusing on three key insulin target tissues: skeletal muscle, liver, and white adipose tissue. We aim to develop an integrated physiological perspective, placing the intricate signaling effectors that carry out the cell-autonomous response to insulin in the context of the tissue-specific functions that generate the coordinated organismal response. First, in section II, the effectors and effects of direct, cell-autonomous insulin action in muscle, liver, and white adipose tissue are reviewed, beginning at the insulin receptor and working downstream. Section III considers the critical and underappreciated role of tissue crosstalk in whole body insulin action, especially the essential interaction between adipose lipolysis and hepatic gluconeogenesis. The pathophysiology of insulin resistance is then described in section IV. Special attention is given to which signaling pathways and functions become insulin resistant in the setting of chronic overnutrition, and an alternative explanation for the phenomenon of ‟selective hepatic insulin resistanceˮ is presented. Sections V, VI, and VII critically examine the evidence for and against several putative mediators of insulin resistance. Section V reviews work linking the bioactive lipids diacylglycerol, ceramide, and acylcarnitine to insulin resistance; section VI considers the impact of nutrient stresses in the endoplasmic reticulum and mitochondria on insulin resistance; and section VII discusses non-cell autonomous factors proposed to induce insulin resistance, including inflammatory mediators, branched-chain amino acids, adipokines, and hepatokines. Finally, in section VIII, we propose an integrated model of insulin resistance that links these mediators to final common pathways of metabolite-driven gluconeogenesis and ectopic lipid accumulation.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Scott Fuller ◽  
Allison J. Richard ◽  
David M. Ribnicky ◽  
Robbie Beyl ◽  
Randall Mynatt ◽  
...  

In addition to serving as a storage site for reserve energy, adipocytes play a critical role in whole-body insulin sensitivity and glucose metabolism. St. John’s Wort (SJW) is a botanical supplement widely used as an over-the-counter treatment of depression and a variety of other conditions associated with anxiety and nerve pain. Previous studies in our laboratory demonstrated that SJW inhibits insulin-stimulated glucose uptake and adipocyte differentiation in cultured murine and mature human adipocytes. To investigate the effects of SJW on adipocyte functionin vivo, we utilized C57BL/6J mice. In our studies, mice were administered SJW extract (200 mg/kg) once daily by gavage for two weeks. In contrast to ourin vitrostudies, mice treated with SJW extract showed increased levels of adiponectin in white adipose tissue in a depot specific manner(P<0.01). SJW also exerted an insulin-sensitizing effect as indicated by a significant increase in insulin-stimulated Akt serine phosphorylation in epididymal white adipose tissue(P<0.01). Food intake, body weight, fasting blood glucose, and fasting insulin did not differ between the two groups. These results are important as they indicate that SJW does not promote metabolic dysfunction in adipose tissuein vivo.


2010 ◽  
Vol 299 (1) ◽  
pp. E117-E125 ◽  
Author(s):  
Kathleen R. Markan ◽  
Michael J. Jurczak ◽  
Margaret B. Allison ◽  
Honggang Ye ◽  
Maria M. Sutanto ◽  
...  

Adipose tissue is a primary site for lipid storage containing trace amounts of glycogen. However, refeeding after a prolonged partial fast produces a marked transient spike in adipose glycogen, which dissipates in coordination with the initiation of lipid resynthesis. To further study the potential interplay between glycogen and lipid metabolism in adipose tissue, the aP2-PTG transgenic mouse line was utilized since it contains a 100- to 400-fold elevation of adipocyte glycogen levels that are mobilized upon fasting. To determine the fate of the released glucose 1-phosphate, a series of metabolic measurements were made. Basal and isoproterenol-stimulated lactate production in vitro was significantly increased in adipose tissue from transgenic animals. In parallel, basal and isoproterenol-induced release of nonesterified fatty acids (NEFAs) was significantly reduced in transgenic adipose tissue vs. control. Interestingly, glycerol release was unchanged between the genotypes, suggesting that enhanced triglyceride resynthesis was occurring in the transgenic tissue. Qualitatively similar results for NEFA and glycerol levels between wild-type and transgenic animals were obtained in vivo during fasting. Additionally, the physiological upregulation of the phospho enolpyruvate carboxykinase cytosolic isoform (PEPCK-C) expression in adipose upon fasting was significantly blunted in transgenic mice. No changes in whole body metabolism were detected through indirect calorimetry. Yet weight loss following a weight gain/loss protocol was significantly impeded in the transgenic animals, indicating a further impairment in triglyceride mobilization. Cumulatively, these results support the notion that the adipocyte possesses a set point for glycogen, which is altered in response to nutritional cues, enabling the coordination of adipose glycogen turnover with lipid metabolism.


Cell Medicine ◽  
2017 ◽  
Vol 9 (1-2) ◽  
pp. 21-33 ◽  
Author(s):  
Yasuma Yoshizumi ◽  
Hiroshi Yukawa ◽  
Ryoji Iwaki ◽  
Sanae Fujinaka ◽  
Ayano Kanou ◽  
...  

Cell therapy with adipose tissue-derived stem cells (ASCs) is expected to be a candidate for the treatment of fulminant hepatic failure (FHF), which is caused by excessive immune responses. In order to evaluate the therapeutic effects of ASCs on FHF, the in vitro and in vivo immunomodulatory effects of ASCs were examined in detail in the mouse model. The in vitro effects of ASCs were examined by assessing their influence on the proliferation of lymphomononuclear cells (LMCs) stimulated with three kinds of mitogens: phorbol 12-myristate 13-acetate (PMA) plus ionomycin, concanavalin A (ConA), and lipopolysaccharide (LPS). The proliferation of LMCs was efficiently suppressed in a dose-dependent manner by ASCs in the cases of PMA plus ionomycin stimulation and ConA stimulation, but not in the case of LPS stimulation. The in vivo effects of transplanted ASCs were examined in the murine FHF model induced by ConA administration. The ALT levels and histological inflammatory changes in the ConA-administered mice were apparently relieved by the transplantation of ASCs. The analysis of mRNA expression patterns in the livers indicated that the expressions of the cytokines such as Il-6, Il-10, Ifn-γ, and Tnf-α, and the cell surface markers such as Cd3γ, Cd4, Cd8α, Cd11b, and Cd11c were downregulated in the ASC-transplanted mice. The immunomodulatory and therapeutic effects of ASCs were confirmed in the mouse model both in vitro and in vivo. These suggest that the cell therapy with ASCs is beneficial for the treatment of FHF.


1986 ◽  
Vol 251 (5) ◽  
pp. E576-E583 ◽  
Author(s):  
L. H. Storlien ◽  
D. E. James ◽  
K. M. Burleigh ◽  
D. J. Chisholm ◽  
E. W. Kraegen

High levels of dietary fat may contribute to both insulin resistance and obesity in humans but evidence is limited. The euglycemic clamp technique combined with tracer administration was used to study insulin action in vivo in liver and individual peripheral tissues after fat feeding. Basal and nutrient-stimulated metabolic rate was assessed by open-circuit respirometry. Adult male rats were pair-fed isocaloric diets high in either carbohydrate (69% of calories; HiCHO) or fat (59% of calories; HiFAT) for 24 +/- 1 days. Feeding of the HiFAT diet resulted in a greater than 50% reduction in net whole-body glucose utilization at midphysiological insulin levels (90-100 mU/l) due to both reduced glucose disposal and, to a lesser extent, failure to suppress liver glucose output. Major suppressive effects of the HiFAT diet on glucose uptake were found in oxidative skeletal muscles (29-61%) and in brown adipose tissue (BAT; 78-90%), the latter accounting for over 20% of the whole-body effect. There was no difference in basal metabolic rate but thermogenesis in response to glucose ingestion was higher in the HiCHO group. In contrast to their reduced BAT weight, the HiFAT group accumulated more white adipose tissue, consistent with reduced energy expenditure. HiFAT feeding also resulted in major decreases in basal and insulin-stimulated conversion of glucose to lipid in liver (26-60%) and brown adipose tissue (88-90%) with relatively less effect in white adipose (0-43%). We conclude that high-fat feeding results in insulin resistance due mainly to effects in oxidative skeletal muscle and BAT.(ABSTRACT TRUNCATED AT 250 WORDS)


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