Metabolic consequences of interesterified palm oil and PCB-126 co-exposure in C57BL/6 mice.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is defined as morphofunctional changes in the liver. Studies have shown that Westernized eating patterns and environmental pollutants can directly induce the development of MASLD. This study evaluates the effect of co-exposure to interesterified palm oil (IPO) and 3,3',4,4',5-pentachlorobiphenyl (PCB-126) on the progression of MASLD in an animal model. C57BL/6 mice were fed IPO and co-exposed to PCB-126 for ten weeks. The co-exposure led to an imbalance in carbohydrate metabolism, increased systemic inflammation markers, and morphofunctional changes in the liver. These liver changes included the presence of inflammatory cells, fibrosis, alterations in aspartate transaminase (AST) and alanine transaminase (ALT) enzymes, and imbalance in gene expression related to fatty acid ß-oxidation, de novo lipogenesis, mitochondrial dynamics, and endoplasmic reticulum stress. Separate exposures to IPO and PCB-126 affected metabolism and MASLD progression. Nutritional and lifestyle factors may potentiate the onset and severity of MASLD.

Consumption of interesterified palm oil leads inflammation of white adipose tissue and triggers metabolic disturbances in mice on a high-fat diet.

Growing obesity is linked to shifts in dietary patterns, particularly the increased intake of ultra-processed high-fat foods. This study aimed to evaluate the effects of interesterified palm oil consumption on glucose homeostasis, adipose tissue remodeling, and hepatic lipogenesis in C57BL/6 mice fed a high-fat diet. Sixty C57BL/6 mice were divided into four groups (n = 15): the control group (C) fed a standard diet (4% soybean oil), the high-fat group (HF) (23.8% lard), the high palm oil fat group (HFP) (23.8% palm oil), and the high interesterified palm fat group (HFI) (23.8% interesterified palm oil) for 8 weeks (all groups received 50% energy from lipids). The HFI group exhibited higher body mass than the HF group (+ 11%, P < 0.05), which was attributed to an increased percentage of fat mass. Plasma concentrations of IL-6, insulin, and HOMA-IR were also elevated in the HFI group. Both the HFP and HFI groups showed hypertrophied adipocytes and pancreatic islets, increased alpha and beta cell masses, hepatic steatosis, low expression of genes related to beta-oxidation, and upregulated lipogenesis. In conclusion, the consumption of interesterified palm oil alters inflammatory and glucose profiles.

Treatment with semaglutide, a GLP-1 receptor agonist, improves extracellular matrix remodeling in the pancreatic islet of diet-induced obese mice.

AIMS: The extracellular matrix (ECM) is fundamental for the normal endocrine functions of pancreatic islet cells and plays key roles in the pathophysiology of type 2 diabetes. Here we investigated the turnover of islet ECM components, including islet amyloid polypeptide (IAPP), in an obese mouse model treated with semaglutide, a glucagon-like peptide type 1 receptor agonist. MAIN METHODS: Male one-month-old C57BL/6 mice were fed a control diet (C) or a high-fat diet (HF) for 16 weeks, then treated with semaglutide (subcutaneous 40 µg/kg every three days) for an additional four weeks (HFS). The islets were immunostained and gene expressions were assessed. KEY FINDINGS: Comparisons refer to HFS vs HF. Thus, IAPP immunolabeling and beta-cell-enriched beta-amyloid precursor protein cleaving enzyme (Bace2, -40 %) and heparanase immunolabeling and gene (Hpse, -40 %) were mitigated by semaglutide. In contrast, perlecan (Hspg2, +900 %) and vascular endothelial growth factor A (Vegfa, +420 %) were enhanced by semaglutide. Also, semaglutide lessened syndecan 4 (Sdc4, -65 %) and hyaluronan synthases (Has1, -45 %; Has2, -65 %) as well as chondroitin sulfate immunolabeling, and collagen type 1 (Col1a1, -60 %) and type 6 (Col6a3, -15 %), lysyl oxidase (Lox, -30 %) and metalloproteinases (Mmp2, -45 %; Mmp9, -60 %). SIGNIFICANCE: Semaglutide improved the turnover of islet heparan sulfate proteoglycans, hyaluronan, chondroitin sulfate proteoglycans, and collagens in the islet ECM. Such changes should contribute to restoring a healthy islet functional milieu and should reduce the formation of cell-damaging amyloid deposits. Our findings also provide additional evidence for the involvement of islet proteoglycans in the pathophysiology of type 2 diabetes.

Brown adipose tissue as an endocrine organ: updates on the emerging role of batokines.

Brown adipose tissue (BAT) remains active in adults, oxidizing fatty acids or glucose and releasing energy in the form of heat. Brown adipocytes and enhanced thermogenesis are targets for treating obesity and its comorbidities. BAT shows high synthesis activity and secretes several signaling molecules. The brown adipokines, or batokines, take action in an autocrine, paracrine, and endocrine manner. Batokines have a role in the homeostasis of the cardiovascular system, central nervous system, white adipose tissue, liver, and skeletal muscle and exert beneficial effects on BAT. The systemic function of batokines gives BAT an endocrine organ profile. Besides, the batokines Fibroblast Growth Factor-21, Vascular Endothelial Growth Factor A, Bone Morphogenetic Protein 8, Neuregulin 4, Myostatin, and Interleukin-6 emerge as targets to treat obesity and its comorbidities, deserving attention. This review outlines the role of six emerging batokines on BAT and their cross-talk with other organs, focusing on their physiological significance and diet-induced changes.

Peroxisome proliferator-activated receptor-alpha activation and dipeptidyl peptidase-4 inhibition target dysbiosis to treat fatty liver in obese mice.

BACKGROUND: Obesity and comorbidities onset encompass gut dysbiosis, altered intestinal permeability, and endotoxemia. Treatments that target gut dysbiosis can cope with obesity and nonalcoholic fatty liver disease (NAFLD) management. Peroxisome proliferator-activated receptor (PPAR)-alpha activation and dipeptidyl-peptidase-4 (DPP-4) inhibition alleviate NAFLD, but the mechanism may involve gut microbiota modulation and merits further investigation. AIM: To address the effects of PPAR-alpha activation and DPP-4 inhibition (isolated or combined) upon the gut-liver axis, emphasizing inflammatory pathways in NAFLD management in high-fat-fed C57BL/6J mice. METHODS: Male C57BL/6J mice were fed a control diet (C, 10% of energy as lipids) or a high-fat diet (HFD, 50% of energy as lipids) for 12 wk, when treatments started, forming the groups: C, HF, HFA (HFD + PPAR-alpha agonist WY14643, 2.5 mg/kg body mass), HFL (HFD + DPP-4 inhibitor linagliptin, 15 mg/kg body mass), and HFC (HFD + the combination of WY14643 and linagliptin). RESULTS: The HFD was obesogenic compared to the C diet. All treatments elicited significant body mass loss, and the HFC group showed similar body mass to the C group. All treatments tackled oral glucose intolerance and raised plasma glucagon-like peptide-1 concentrations. These metabolic benefits restored Bacteroidetes/Firmicutes ratio, resulting in increased goblet cells per area of the large intestine and reduced lipopolysaccharides concentrations in treated groups. At the gene level, treated groups showed higher intestinal Mucin 2, Occludin, and Zo-1 expression than the HFD group. The reduced endotoxemia suppressed inflammasome and macrophage gene expression in the liver of treated animals. These observations complied with the mitigation of liver steatosis and reduced hepatic triacylglycerol, reassuring the role of the proposed treatments on NAFLD mitigation. CONCLUSION: PPAR alpha activation and DPP-4 inhibition (isolated or combined) tackled NAFLD in diet-induced obese mice by restoration of gut-liver axis. The reestablishment of the intestinal barrier and the rescued phylogenetic gut bacteria distribution mitigated liver steatosis through anti-inflammatory signals. These results can cope with NAFLD management by providing pre-clinical evidence that drugs used to treat obesity comorbidities can help to alleviate this silent and harmful liver disease.

Consumption of phenolic-rich jabuticaba (Myrciaria jaboticaba) powder ameliorates obesity-related disorders in mice.

Accumulating evidence indicates that dietary phenolic compounds can prevent obesity-related disorders. We investigated whether the consumption of polyphenol-rich jabuticaba peel and seed powder (JPSP) could ameliorate the progression of diet-induced obesity in mice. Male mice were fed a control diet or a high-fat (HF) diet for 9 weeks. After this period, mice were fed control, HF or HF diets supplemented with 5 % (HF-J5), 10 % (HF-J10) or 15 % (HF-J15) of JPSP, for 4 additional weeks. Supplementation with JPSP not only attenuated HF-induced weight gain and fat accumulation but also ameliorated the pro-inflammatory response associated with obesity, as evidenced by the absence of mast cells in the visceral depot accompanied by lower IL-6 and TNF-α at the tissue and circulating levels. JPSP-supplemented mice also exhibited smaller-sized adipocytes, reduced levels of leptin and higher levels of adiponectin, concomitant with improved glucose metabolism and insulin sensitivity. The magnitude of the observed effects was dependent on JPSP concentration with HF-J10- and HF-J15-fed mice showing metabolic profiles similar to control. This study reveals that the consumption of JPSP protects against the dysfunction of the adipose tissue and metabolic disturbances in obese mice. Thus, these findings indicate the therapeutic potential of the phenolic-rich JPSP in preventing obesity-related disorders.

Pancreatic islet cells disarray, apoptosis, and proliferation in obese mice. The role of Semaglutide treatment.

There are significant injuries of pancreatic islets due to obesity and insulin resistance. Therefore, GLP-1 receptor agonists like Semaglutide might benefit the islet structural remodeling and its endocrine function in diet-induced obese mice. One-month-old male C57BL/6 mice were allotted into two dietary groups (n = 60/group) and fed for 16 weeks a control diet (C) or a high‒fat diet (HF). Then, for an additional four weeks, the main groups were resampled to include treatment (Semaglutide, S, 40 µg/kg), or paired feed with the treated group (PF), totaling six groups (n = 20/group): C, CS, CPF, HF, HFS, HFPF. Biochemistry, stereology, immunohistochemistry/immunofluorescence, confocal microscopy, and RT-qPCR were used in the study. The mouse model reproduced metabolism and bodily changes due to diet-induced obesity. Pancreatic islet hypertrophy was observed with alpha- and beta-cell remodeling, cell disarray, and apoptosis. Semaglutide increased islet cell proliferation and recovered islet size and alpha- and beta-cell masses. The changes include recovery of glucose and hormone levels, reduction of pro-inflammatory markers, improvement of pancreatic duodenal homeobox 1 (PDX-1), glucose transporter 2 (GLUT-2), v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MAF-A), and peroxisome proliferator-activated receptors (PPAR) -gamma. In conclusion, damage to the pancreatic islet caused by insulin resistance and the attempt to adapt the islet of obese mice involved different pathways, especially the pro-inflammatory pathway, PDX1, and PPAR-alpha and gamma. Semaglutide showed beneficial effects on these pathways, reducing the lesion on the islet. However, the weight loss influence of Semaglutide was of little relevance in the pancreatic islet.

Liver structural injury in leptin-deficient (ob/ob) mice: lipogenesis, fibrogenesis, inflammation, and apoptosis / Lesión estructural del hígado en ratones con deficiencia de leptina (ob/ob): lipogénesis, fibrogénesis, inflamación y apoptosis

SUMMARY: Nonalcoholic fatty liver disease (NAFLD) might progress the steatosis to nonalcoholic steatohepatitis (NASH), reaching a cirrhosis state and possibly hepatocellular carcinoma. The liver of three-month-old C57BL/6J mice (wild-type, WT group, n=10) and leptin- deficient obese mice (ob/ob group, n=10) were studied, focusing on the mechanisms associated with the activation of the hepatic stellate cells (HSCs) and pro-fibrogenesis. The obese ob/ob animals' liver showed steatosis, increased lipogenesis gene expressions, inflammation, increased pro-inflammatory gene expressions, inflammatory infiltrate, and potential apoptosis linked to a high Caspase 3 expression. In ob/ob mice, liver sections were labeled in the fibrotic zones by anti-alpha-smooth muscle actin (alpha-SMA) and anti-Reelin, but not in the WT mice. Moreover, the alpha-SMA gene expression was higher in the ob/ob group's liver than the WT group. The pro-fibrogenic gene expressions were parallel to anti- alpha-SMA and anti-Reelin immunofluorescence, suggesting HSCs activation. In the ob/ob animals, there were increased gene expressions involved with lipogenesis (Peroxisome proliferator-activated receptor-gamma, Cell death-inducing DFFA-like effector-c, Sterol regulatory element-binding protein-1c, and Fatty acid synthase), pro-fibrogenesis (Transforming growth factor beta1, Smad proteins- 3, Yes-associated protein-1, Protein platelet-derived growth factor receptor beta), pro-inflammation (Tumor necrosis factor-alpha, and Interleukin-6), and apoptosis (Caspase 3). In conclusion, the results in obese ob/ob animals provide a clue to the events in humans. In a translational view, controlling these targets can help mitigate the hepatic effects of human obesity and NAFLD progression to NASH.

RESUMEN: La enfermedad del hígado graso no alcohólico (HGNA) puede progresar de la esteatosis a esteatohepatitis no alcohólica (ENA), alcanzando un estado de cirrosis y posiblemente carcinoma hepatocelular. Se estudió el hígado de ratones C57BL / 6J de tres meses de edad (tipo salvaje, grupo WT, n = 10) y ratones obesos con deficiencia de leptina (grupo ob/ob, n = 10), centrándose en los mecanismos asociados con la activación de las células estrelladas hepáticas (HSC) y profibrogénesis. El hígado de los animales obesos ob/ob mostró esteatosis, aumento de la expresión génica de la lipogénesis, inflamación, aumento de la expresión génica proinflamatoria, infiltrado inflamatorio y posible apoptosis ligada a una alta expresión de Caspasa 3. En ratones ob/ob, las sec- ciones de hígado se marcaron en las zonas fibróticas con anti-alfa- actina de músculo liso (alfa-SMA) y anti-Reelin, pero no en los ratones WT. Además, la expresión del gen alfa-SMA fue mayor en el hígado del grupo ob/ob que en el grupo WT. Las expresiones génicas profibrogénicas fueron paralelas a la inmunofluorescencia anti-alfa-SMA y anti-Reelin, lo que sugiere la activación de las HSC. En los animales ob/ob, hubo un aumento de las expresiones génicas involucradas con la lipogénesis (receptor activado por proliferador de peroxisoma gamma, efector c similar a DFFA inductor de muerte celular, proteína de unión al elemento regulador de esterol-1c y sintasa de ácidos grasos), pro-fibrogénesis (factor de crecimiento transformante beta 1, proteínas Smad-3, proteína-1 asociada a Yes, receptor beta del factor de crecimiento derivado de plaquetas de proteínas), proinflamación (factor de necrosis tumoral alfa e interleucina-6) y apoptosis (caspasa 3). ). En conclusión, los resultados en animales obesos ob/ob proporcionan una pista de los eventos en humanos. Desde un punto de vista traslacional, el control de estos objetivos puede ayudar a mitigar los efectos hepáticos de la obesidad humana y la progresión de HGNA a ENA.

PPAR-α activation counters brown adipose tissue whitening: a comparative study between high-fat- and high-fructose-fed mice.

OBJECTIVES: To examine the effects of a selective peroxisome proliferator-activated receptor (PPAR-α) agonist treatment on interscapular brown adipose tissue (iBAT) whitening, focusing on thermogenic, lipolysis, and lipid oxidation markers in mice fed a high-fat or high-fructose diet. METHODS: Fifty animals were randomly assigned to receive a control diet (C, 10% lipids as energy), high-fat diet (HF, 50% lipids as energy), or high-fructose diet (HFRU, 50% fructose as energy) for 12 wk. Each group was redivided to begin the 5-wk treatment, totaling five experimental groups: C, HF, HF-a, HFRU, and HFRU-a. The drug was mixed with diet at the dose of 3.5 mg/kg body mass. RESULTS: HF group was the heaviest group, and the HF and HFRU groups had glucose intolerance. PPAR-α activation alleviated these metabolic constraints. HF and HFRU groups had negative vascular endothelial growth factor A (VEGF-A) immunostaining, but only the HF group had a pattern of lipid droplet accumulation that resembled the white adipose tissue, characterizing the whitening phenomenon. Whitening in the HF group was accompanied by decreased expression of genes related to thermogenesis, ß-oxidation, and antiinflammatory effects. All of them were augmented by the PPAR-α activation in HF-a and HFRU-a groups, countering the whitening in the HF-a group. Treated groups also had a lower respiratory exchange ratio than untreated groups, suggesting that lipids were used as fuel for the enhanced thermogenesis. CONCLUSIONS: The PPAR-α agonist countered iBAT whitening by inducing the thermogenic pathway and reducing the lipid droplet size, in addition to enhanced VEGF-A expression, adrenergic stimulus, and lipolysis in HF-fed mice.

Lean vs. obese mice: the ventral prostate revisited / Ratones magros vs. ratones obesos: revisión de la próstata ventral

Obese mice (C57BL/6J-ob/ob) do not express leptin and develops hyperphagia, decreased energy expenditure, obesity, hyperglycemia, hyperinsulinemia, hypothermia, and infertility. Obesity causes reproductive dysfunction with negative impacts on prostatic structure and fertility. We aimed to compare the structure and molecular aspects of the ventral prostate between of lean and obese (ob/ob) mice. Three months old male lean and obese mice had their prostates dissected and prepared for light microscopy and immunofluorescence. In comparison to the lean mouse, the obese mouse showed a substantial structural modification in the ventral prostate starting with an atrophy of the prostate ventral lobe. Histologically, the acini showed a reduction in size, and in the lumen, we found a mixed secretion PAS positive and negative. Epithelial changes consisted of a hypertrophied acinar epithelium with intraepithelial neoplasia focuses. Also, we observed a marked expression of PCNA and Caspase3 in the epithelium indicating even cellular proliferation as cell death. The stroma showed a high activity of the extracellular matrix remodeling with marked deposition of collagen fibers and smooth muscle cells. Around the ventral region, we observed an increase in the presence of adipose tissue. The expressions of interleukin 6 and tumor necrosis factor alpha were present in the ventral prostate of the obese mice indicating inflammation. In conclusion, obesity negatively modulates prostate in ob/ob mice, directly affecting cellular and structural mechanisms necessary for the maintenance of prostate and reproductive structure.

Los ratones obesos (C57BL / 6J-ob / ob) no expresan leptina y desarrollan hiperfagia, disminución del gasto energético, obesidad, hiperglucemia, hiperinsulinemia, hipotermia e infertilidad. La obesidad causa disfunción reproductiva con impacto negativo sobre la estructura prostática y la fertilidad. El objetivo de nuestro trabajo consistió en comparar la estructura y los aspectos moleculares de la próstata ventral en ratones magros y obesos (ob/ob). Se disecaron las próstatas de ratones machos obesos, de tres meses de edad, y fueron preparadas para visualizarlas por microscopía óptica e inmunofluorescencia. En comparación con el ratón magro, el ratón obeso mostró una sustancial modificación estructural en la próstata ventral comenzando con una atrofia del lóbulo ventral de la próstata. Histológicamente, los acinos mostraron una reducción de tamaño, y en el lumen, encontramos una secreción mixta PAS positiva y negativa. Los cambios epiteliales consistieron en un epitelio acinar hipertrofiado con focos de neoplasia intraepitelial. Además, se observó una marcada expresión de PCNA y Caspase3 en el epitelio, que indica tanto la proliferación celular como la muerte celular. El estroma mostró una alta remodelación de la matriz extracelular con marcada deposición de fibras de colágeno y células de músculo liso. Alrededor de la región ventral, se observó un aumento en la presencia de tejido adiposo. Las expresiones de interleuquina 6 y factor de necrosis tumoral alfa estaban presentes en la próstata ventral de los ratones obesos indicando inflamación. En conclusión, la obesidad modula negativamente la próstata en los ratones ob/ob, afectando directamente los mecanismos celulares y estructurales necesarios para el mantenimiento de la estructura de la próstata y la reproducción.

Impaired steroidogenesis in the testis of leptin-deficient mice (ob/ob -/-).

The obesity and its comorbidities, including resistance to leptin, impacts the reproductive function. Testes express leptin receptors in the germ cells and Leydig cells. Then, leptin-deficient animals are obese and infertile. We aimed to evaluate the structure and steroidogenic pathway of the testis of deficient leptin mice. Three months old male C57BL/6 mice (wild-type, WT) and deficient leptin (ob/ob) mice had their testes dissected and prepared for analyses. Compared to the WT group, the ob/ob group showed a greater body mass with smaller testes, and alterations in the germinative epithelium: fewer spermatogonia, spermatocytes, and spermatids. The Sertoli cells and the germ cells showed condensed nuclei and nuclear fragmentation indicating cell death, in agreement with a low expression of the proliferating cell nuclear antigen and a high expression of Caspase3. In the ob/ob group, the sperm was absent in the seminiferous tubules, and the steroidogenic pathway was compromised (low 3Beta hydroxysteroid dehydrogenase and steroidogenic acute regulatory protein). Further, all hormone receptors involved in the testicular function were down expressed (androgen, estrogen, follicle-stimulating, luteinizing, aromatase, and nicotinamide adenine dinucleotide phosphate). In conclusion, the findings indicate significant morphological, hormonal and enzymatic changes in the testis of the ob/ob mice. The shifts in the enzymatic steroidogenic pathway and the enzymes related to spermatic activity support the insights about the failures in the fertility of these animals. The study provides new evidence and contributes to the understanding of how the lack of leptin and obesity might negatively modulate the testicular function leading to infertility.

Thermogenesis, fatty acid synthesis with oxidation, and inflammation in the brown adipose tissue of ob/ob (-/-) mice.

Brown adipose tissue (BAT) is specialized in heat production, but its metabolism in ob/ob mice is still a matter of debate. We aimed to verify ob/ob mice BAT using C57Bl/6 male mice (as the wild-type, WT) and leptin-deficient ob/ob mice (on the C57Bl/6 background strain), at three months of age (n=10/group). At euthanasia, animals had their interscapular BAT weighed, and prepared for analysis (Western blot, and RT-qPCR). In comparison with the WT group, the ob/ob group showed reduced thermogenic signaling markers (gene expression of beta 3-adrenergic receptor, beta3-AR; PPARgamma coactivator 1 alpha, PGC1alpha, and uncoupling protein 1, UCP1). The ob/ob group also showed impaired gene expression for lipid utilization (perilipin was increased, while other markers were diminished: carnitine palmitoyltransferase-1b, CPT-1b; cluster of differentiation 36, CD36; fatty acid binding protein 4, FABP4; fatty acid synthase, FAS, and sterol regulatory element-binding protein 1c, SREBP1c), and altered protein expression of insulin signaling (diminished pAKT, TC10, and GLUT-4). Lastly, the ob/ob group showed increased gene expression of markers of inflammation (interleukin 1 beta, IL-1beta; IL-6, tumor necrosis factor alpha, TNFalpha; and monocyte chemotactic protein-1, MCP-1). In conclusion, the ob/ob mice have decreased thermogenic markers associated with reduced gene expression related to fatty acid synthesis, mobilization, and oxidation. There were also alterations in insulin signaling and protein and gene expressions of inflammation. The findings suggest that the lack of substrate for thermogenesis and the local inflammation negatively regulated thermogenic signaling in the ob/ob mice.