The beta-3 adrenergic agonist (CL-316,243) restores the expression of down-regulated fatty acid oxidation genes in type 2 diabetic mice

Association analysis between Acetyl-Coenzyme A Acyltransferase-1 gene polymorphism and growth traits in Xiangsu pigs

Introduction

Acetyl-Coenzyme A Acyltransferase-1 (ACAA1) is a peroxisomal acyltransferase involved in fatty acid metabolism. Current evidence does not precisely reveal the effect of the ACAA1 gene on pig growth performance.

Methods

The present study assessed the mRNA expression levels of the ACAA1 gene in the heart, liver, spleen, lung, kidney of 6-month-old Xiangsu pigs and in the longissimus dorsi muscle at different growth stages (newborn, 6 months and 12 months of age) using RT-qPCR. The relationship between single-nucleotide polymorphisms (SNPs) of ACAA1 gene and growth traits in 6-month-old and 12-month-old Xiangsu pigs was investigated on 184 healthy Xiangsu pigs using Sanger sequencing.

Results

The ACAA1 gene was expressed in heart, liver, spleen, lung, kidney, and longissimus dorsi muscle of 6-month-old pigs, with the highest level of expression in the liver. ACAA1 gene expression in the longissimus dorsi muscle decreased with age (p < 0.01). In addition, four SNPs were identified in the ACAA1 gene, including exon g.48810 A>G (rs343060194), intron g.51546 T>C (rs319197012), exon g.55035 T>C (rs333279910), and exon g.55088 C>T (rs322138947). Hardy-Weinberg equilibrium (p > 0.05) was found for the four SNPs, and linkage disequilibrium (LD) analysis revealed a strong LD between g.55035 T>C (rs333279910) and g.55088 C>T (rs322138947) (r 2 = 1.000). Association analysis showed that g.48810 A>G (rs343060194), g.51546 T>C (rs319197012), g.55035 T>C (rs333279910), and g.55088 C>T (rs322138947) varied in body weight, body length, body height, abdominal circumference, leg and hip circumference and living backfat thickness between 6-month-old and 12-month-old Xiangsu pigs.

Conclusion

These findings strongly demonstrate that the ACAA1 gene can be exploited for marker-assisted selection to improve growth-related phenotypes in Xiangsu pigs and present new candidate genes for molecular pig breeding.

Proteomic Analysis of Mouse Kidney Tissue Associates Peroxisomal Dysfunction with Early Diabetic Kidney Disease

Background: The absence of efficient inhibitors for diabetic kidney disease (DKD) progression reflects the gaps in our understanding of DKD molecular pathogenesis. Methods: A comprehensive proteomic analysis was performed on the glomeruli and kidney cortex of diabetic mice with the subsequent validation of findings in human biopsies and omics datasets, aiming to better understand the underlying molecular biology of early DKD development and progression. Results: LC–MS/MS was employed to analyze the kidney proteome of 2 DKD models: Ins2Akita (early and late DKD) and db/db mice (late DKD). The abundance of detected proteins was defined. Pathway analysis of differentially expressed proteins in the early and late DKD versus the respective controls predicted dysregulation in DKD hallmarks (peroxisomal lipid metabolism and β-oxidation), supporting the functional relevance of the findings. Comparing the observed protein changes in early and late DKD, the consistent upregulation of 21 and downregulation of 18 proteins was detected. Among these were downregulated peroxisomal and upregulated mitochondrial proteins. Tissue sections from 16 DKD patients were analyzed by IHC confirming our results. Conclusion: Our study shows an extensive differential expression of peroxisomal proteins in the early stages of DKD that persists regardless of the disease severity, providing new perspectives and potential markers of diabetic kidney dysfunction.

Repurposing beta-3 adrenergic receptor agonists for Alzheimer's disease: beneficial effects in a mouse model

Background

Old age, the most important risk factor for Alzheimer’s disease (AD), is associated with thermoregulatory deficits. Brown adipose tissue (BAT) is the main thermogenic driver in mammals and its stimulation, through β3 adrenergic receptor (β3AR) agonists or cold acclimation, counteracts metabolic deficits in rodents and humans. Studies in animal models show that AD neuropathology leads to thermoregulatory deficits, and cold-induced tau hyperphosphorylation is prevented by BAT stimulation through cold acclimation. Since metabolic disorders and AD share strong pathogenic links, we hypothesized that BAT stimulation through a β3AR agonist could exert benefits in AD as well.

Methods

CL-316,243, a specific β3AR agonist, was administered to the triple transgenic mouse model of AD (3xTg-AD) and non-transgenic controls from 15 to 16 months of age at a dose of 1 mg/kg/day i.p.

Results

Here, we show that β3AR agonist administration decreased body weight and improved peripheral glucose metabolism and BAT thermogenesis in both non-transgenic and 3xTg-AD mice. One-month treatment with a β3AR agonist increased recognition index by 19% in 16-month-old 3xTg-AD mice compared to pre-treatment (14-month-old). Locomotion, anxiety, and tau pathology were not modified. Finally, insoluble Aβ42/Aβ40 ratio was decreased by 27% in the hippocampus of CL-316,243-injected 3xTg-AD mice.

Conclusions

Overall, our results indicate that β3AR stimulation reverses memory deficits and shifts downward the insoluble Aβ42/Aβ40 ratio in 16-month-old 3xTg-AD mice. As β3AR agonists are being clinically developed for metabolic disorders, repurposing them in AD could be a valuable therapeutic strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13195-021-00842-3.

ACAA1 Is a Predictive Factor of Survival and Is Correlated With T Cell Infiltration in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the predominant subtype of lung cancers. KRAS mutation is the second most prevalent mutation in NSCLC. KRAS mutant cancer cells suppress the anti-tumor T cell response. However, the underlying mechanism is still unknown. Here, we analyzed the differential expression of acetyl-CoA acyltransferase 1 (ACAA1) in various types of cancers using the TIMER database and validated the results in the NSCLC cell line H1944. We silenced oncogenic KRAS by siRNA targeting KRASG13D, and employed an MAPK signaling pathway inhibitor to clarify the possible regulatory pathway. Moreover, we analyzed the correlation of ACAA1 expression level with B cells, CD4+ T cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells. Correlations between expression of ACAA1 and several biomarkers of mutation burden were also tested. Finally, we evaluated the prognostic value of ACAA1 in a wide range of cancers using the Kaplan-Meier Plotter Database. We found lower expression of ACAA1 in tumor tissue than in adjacent normal tissue in various cancers. This result was confirmed using a GEO dataset. Knock-down of mutant KRAS resulted in increased ACAA1 mRNA level in H1944 cells. ACAA1 mRNA level was significantly upregulated in H1944 after treatment with MAPK pathway inhibitor sorafenib, indicating that oncogenic KRAS may downregulate ACAA1 through MAPK signaling. ACAA1 was negatively correlated with biomarkers of tumor mutation burden, including BRCA1, ATM, ATR, CDK1, PMS2, MSH2, and MDH6. Conversely, ACAA1 expression was positively correlated with infiltrating CD4+ cells and with Th1, Th2, Treg cells in the lung tumor microenvironment. Finally, we showed that ACAA1 is a predictive factor for survival in several cancer types. In summary, decreased ACAA1 expression is correlated with poor prognosis and decreases immune infiltration of CD4+ T cells in LUAD and LUSC. ACAA1 also predicts T cell exhaustion in LUSC. The mechanism underlying KRAS/ACAA1 axis-mediated regulation of immune cell infiltration requires further investigation.

Role of cAMP and cGMP Signaling in Brown Fat

Cold-induced activation of brown adipose tissue (BAT) is mediated by norepinephrine and adenosine that are released during sympathetic nerve activation. Both signaling molecules induce an increase in intracellular levels of 3',5'-cyclic adenosine monophosphate (cAMP) in murine and human BAT. In brown adipocytes, cAMP plays a central role, because it activates lipolysis, glucose uptake, and thermogenesis. Another well-studied intracellular second messenger is 3',5'-cyclic guanosine monophosphate (cGMP), which closely resembles cAMP. Several studies have shown that intact cGMP signaling is essential for normal adipogenic differentiation and BAT-mediated thermogenesis in mice. This chapter highlights recent observations, demonstrating the physiological significance of cyclic nucleotide signaling in BAT as well as their potential to induce browning of white adipose tissue (WAT) in mice and humans.

Adult Hippocampal Neurogenesis Can Be Enhanced by Cold Challenge Independently From Beigeing Effects

In this study, we investigated the effects of cold challenge on adult hippocampal neurogenesis (AHN) and hippocampal gene expression and whether these are mediated by beigeing of peripheral fat tissues. Cold challenge (6 ± 2°C) for 1 and 4 weeks was found to induce beigeing effects in inguinal white adipose tissue based on hematoxylin and eosin staining as well as uncoupled protein-1 immunohistochemical staining. In the hippocampus, cold challenge for 1 or 4 weeks increased dentate gyrus neurogenesis and expression of genes related to AHN, including notch signaling, G protein-coupled receptor signaling, and adrenergic beta receptor-1. However, this enhancement of neurogenesis and gene expression by cold challenge was not shown by administration of CL 316,243, which induces peripheral beigeing similar to cold challenge but does not cross the blood-brain barrier. These results suggest that cold challenge promotes AHN and central expression of AHN-related, signaling, and β1-adrenergic receptors genes, and that peripheral beigeing by itself is not sufficient to mediate these effects. Considering the increase in AHN and gene expression changes, cold challenge may offer a novel approach to hippocampal modulation.

Effect of amino acids on transcription and translation of key genes in E. coli K and B grown at a steady state in minimal medium

Growing E. coli to high densities is a common strategy for biologicals production. The process is implemented by using complex or minimal media with different feeding strategies. To understand the effect of amino acids, E. coli B and K were grown at a steady state of 0.35 h^-1 in glucose minimal medium with and without amino acids, while their metabolism, protein abundance and gene expression were compared. The results showed that amino acids promoted higher acetate excretion, higher fatty acid biosynthesis (K strain), repressed glucose uptake rate, and decreased expression of proteins associated with the TCA cycle, glyoxylate shunt and amino acid biosynthesis. In presence of amino acids, E. coli K upregulated fatty acid biosynthesis and repressed more genes and proteins involved in amino acid biosynthesis than E. coli B. These findings are correlated with higher yield on glucose (Y_x/s) and high specific biomass production rate (q_x) in K strain in the presence of amino acids. In contrast, pre-formed precursor molecules such as amino acids did not affect fatty acid biosynthesis in E. coli B or Y_x/s and q_x, which were higher than those of E. coli K, suggesting that constitutive synthesis of energetically demanding precursors and higher fatty acid β-oxidation activity is key for high biomass-performer E. coli B. Both strains turned off unnecessary pathways and directed their metabolism to proteome efficient overflow metabolism likely to generate energy and provide protein to functions supporting higher growth rate.

Di (2-ethyl hexyl) phthalate (DEHP)-induced kidney injury in quail (Coturnix japonica) via inhibiting HSF1/HSF3-dependent heat shock response

Di (2-ethyl hexyl) phthalate (DEHP) as a plasticizer can leach away from the plastic and hence entrances into the animal food chain which caused serious hazard in organs of animals, but there are few studies on DEHP kidney toxicity. The heat-shock response (HSR) consisting of the HSPs and HSFs plays an important role in various toxicity stress conditions. To investigate the influence on kidney toxicity and the modulation of HSR during DEHP exposure, female quail were fed the diet with 0, 250, 500 and 750 mg/kg DEHP by gavage administration for 45 days. The shrinkages of glomeruli and dilation of kidney tubule epithelia cells were observed in the kidney of DEHP-exposed quail. DEHP treatment could significantly decrease the expressions of HSP25, HSP27, HSP47, HSP60, while the expressions of HSP10, HSP40, HSP70, HSP90, HSP110 were upregulated in the kidney. In addition, the expression levels of HSF1 and HSF3 were significantly increased under DEHP. This is the first study to demonstrate quail exposure to DEHP is in fact detrimental to bird kidney. Besides, DEHP could attack HSR by affecting the synthesis of HSFs to mediate the transcription of the HSPs resulting in kidney damage.

Precision toxicology shows that troxerutin alleviates ochratoxin A-induced renal lipotoxicity

Lipotoxicity is the most common cause of severe kidney disease, with few treatment options available today. Precision toxicology can improve detection of subtle intracellular changes in response to exogenous substrates; thus, it facilitates in-depth research on bioactive molecules that may interfere with the onset of certain diseases. In the current study, troxerutin significantly relieved nephrotoxicity, increased endurance, and improved systemic energy metabolism and renal inflammation in OTA-induced nephrotic mice. Lipidomics showed that troxerutin effectively reduced the levels of triglycerides, phosphatidylcholines, and phosphatidylethanolamines in nephropathy. The mechanism was partly attributable to troxerutin in alleviating the aberrantly up-regulated expression of sphingomyelinase, the cystic fibrosis transmembrane conductance regulator, and chloride channel 2. Renal tubular epithelial cells, the main site of toxin-induced accumulation of lipids in the kidney, were subjected to transcriptomic profiling, which uncovered several metabolic factors relevant to aberrant lipid and lipoprotein metabolism. Our work provides new insights into the molecular features of toxin-induced lipotoxicity in renal tubular epithelial cells in vivo and demonstrates the function of troxerutin in alleviating OTA-induced nephrosis and associated systemic energy metabolism disorders.-Yang, X., Xu, W., Huang, K., Zhang, B., Wang, H., Zhang, X., Gong, L., Luo, Y., He, X. Precision toxicology shows that troxerutin alleviates ochratoxin A-induced renal lipotoxicity.

Hexarelin, a Growth Hormone Secretagogue, Improves Lipid Metabolic Aberrations in Nonobese Insulin-Resistant Male MKR Mice

Despite the occurrence of dyslipidemia and its contribution to the development of insulin resistance in obese subjects, a growing number of studies have described abnormal lipid profiles among leaner persons. For example, individuals with an abnormal paucity or distribution of fat (lipodystrophy) develop severe insulin resistance, dyslipidemia, and hepatic steatosis. Deranged adipocyte metabolism and differentiation contribute to ectopic fat deposition and consequent development of insulin resistance. Growth hormone (GH) therapy has been shown to correct body composition abnormalities in some lipodystrophy patients. However, little is known about the effects of GH-releasing peptides in this regard. Hexarelin, a GH secretagogue, has recently been shown to have beneficial effects on fat metabolism via the CD36 receptor. In this study, the effects of twice daily intraperitoneal injections of hexarelin (200 μg/kg body weight) were examined in nonobese insulin-resistant MKR mice and corresponding wild-type FVB mice for 12 days. Hexarelin treatment significantly improved glucose and insulin intolerance and decreased plasma and liver triglycerides in MKR mice. These beneficial metabolic effects could be due to the improved lipid metabolism and enhanced adipocyte differentiation of white adipose tissue with hexarelin treatment. Interestingly, although food intake of hexarelin-treated MKR mice was significantly increased, this did not change total body weight. Moreover, hexarelin treatment corrected the abnormal body composition of MKR mice, as demonstrated by a decrease in fat mass and an increase in lean mass. Our results suggest a possible application of hexarelin in treatment of lipid disorders associated with the metabolic syndrome.

Polyol accumulation in muscle and liver in a mouse model of type 2 diabetes

AIMS

Type 2 diabetes (T2D) is a complex metabolic disease leading to complications in multiple organs. Diabetic myopathy and liver disease are common complications of T2D, but are incompletely understood. To gain insight into the pathogenesis of these conditions we performed metabolomic analysis of skeletal muscle and liver in a mouse model of T2D.

METHODS

Tissue metabolomics were performed by GC/MS and LC/MS of the skeletal muscle and liver in the MKR mouse model of T2D, compared with control mice. MKR mice were treated with the β-3 adrenergic receptor agonist, CL-316,243 to determine metabolite changes after correcting hyperglycemia.

RESULTS

Blood glucose was higher in MKR vs WT mice, and normalized with CL-316,243 treatment. Compared with WT mice, MKR mice had 2.5 fold higher concentrations of sorbitol and 1.7 fold lower concentrations of reduced glutathione in skeletal muscle. In liver, MKR mice had 2 fold higher concentrations of the pentitol ribitol. CL-316,243 treatment normalized sorbitol and ribitol concentrations in MKR skeletal muscle and liver, respectively to the levels of the WT mice.

CONCLUSIONS

These results demonstrate tissue-specific accumulation of polyols in a mouse model of T2D and provide novel insights into the pathogenesis of myopathy and liver disease in T2D.