Embryonic Hyperglycemia Disrupts Myocardial Growth, Morphological Development, and Cellular Organization: An In Vivo Experimental Study.

Hyperglycemia during gestation can disrupt fetal heart development and increase postnatal cardiovascular disease risk. It is therefore imperative to identify early biomarkers of hyperglycemia during gestation-induced fetal heart damage and elucidate the underlying molecular pathomechanisms. Clinical investigations of diabetic adults with heart dysfunction and transgenic mouse studies have revealed that overexpression or increased expression of TNNI3K, a heart-specific kinase that binds troponin cardiac I, may contribute to abnormal cardiac remodeling, ventricular hypertrophy, and heart failure. Optimal heart function also depends on the precise organization of contractile and excitable tissues conferred by intercellular occlusive, adherent, and communicating junctions. The current study evaluated changes in embryonic heart development and the expression levels of sarcomeric proteins (troponin I, desmin, and TNNI3K), junctional proteins, glucose transporter-1, and Ki-67 under fetal hyperglycemia. Stage 22HH Gallus domesticus embryos were randomly divided into two groups: a hyperglycemia (HG) group, in which individual embryos were injected with 30 mmol/L glucose solution every 24 h for 10 days, and a no-treatment (NT) control group, in which individual embryos were injected with physiological saline every 24 h for 10 days (stage 36HH). Embryonic blood glucose, height, and weight, as well as heart size, were measured periodically during treatment, followed by histopathological analysis and estimation of sarcomeric and junctional protein expression by western blotting and immunostaining. Hyperglycemic embryos demonstrated delayed heart maturation, with histopathological analysis revealing reduced left and right ventricular wall thickness (-39% and -35% vs. NT). Immunoexpression levels of TNNI3K and troponin 1 increased (by 37% and 39%, respectively), and desmin immunofluorescence reduced (by 23%). Embryo-fetal hyperglycemia may trigger an increase in the expression levels of TNNI3K and troponin I, as well as dysfunction of occlusive and adherent junctions, ultimately inducing abnormal cardiac remodeling.

Hepatocyte growth factor reverses cholemic nephropathy associated with α-naphthylisothiocyanate-induced cholestasis in mice.

Hepatocyte growth factor (HGF) has been proved to protect the liver against α-naphthylisothiocyanate (ANIT)-induced cholestasis by acting as an antioxidant agent and redirecting toxic biliary solutes towards blood for urinary excretion. However, this may represent an additional potential risk for kidney integrity, which is already compromised by the cholestatic process itself (cholemic nephropathy). Therefore, in the present work, we studied the renal damage caused by ANIT-induced cholestasis and whether it is aggravated or, on the contrary, counteracted by HGF; if the latter holds, the involvement of its antioxidant properties will be ascertained. ANIT-induced cholestatic deleterious renal effects were corroborated by the presence of urine bile salts, impairment of renal function, and the alterations of renal damage markers, such as HSP72, creatinine clearance, and albuminuria. HGF fully reverted all these, and the cast formation in the tubules was significantly decreased. These findings were associated with the control of renal oxidative stress. In summary, despite HGF enhancing the overload of potentially harmful biliary constituents that the kidney should remove from the bloodstream as an alternative depuration organ in cholestasis, it simultaneously protects the kidney from this damage by counteracting the prooxidant effects resulting from this harmful exposure.

Low-Intensity Exercise Routine for a Long Period of Time Prevents Osteosarcopenic Obesity in Sedentary Old Female Rats, by Decreasing Inflammation and Oxidative Stress and Increasing GDF-11.

The loss of skeletal muscle mass and strength is known as sarcopenia; it is characterized as a progressive and generalized muscle disorder associated with aging. This deterioration can seriously compromise the elderly's health and reduce their quality of life. In addition to age, there are other factors that induce muscle mass loss, among which are sedentary lifestyle, chronic diseases, inflammation, and obesity. In recent years, a new clinical condition has been observed in older adults that affects their physical capacities and quality of life, which is known as osteosarcopenic obesity (OSO). Osteoporosis, sarcopenia, and obesity coexist in this condition. Physical exercise and nutritional management are the most widely used interventions for the treatment and prevention of sarcopenia. However, in older adults, physical exercise and protein intake do not have the same outcomes observed in younger people. Here, we used a low-intensity exercise routine for a long period of time (LIERLT) in order to delay the OSO appearance related to sedentarism and aging in female Wistar rats. The LIERLT routine consisted of walking at 15 m/min for 30 min, five days a week for 20 months. To evaluate the effects of the LIERLT routine, body composition was determined using DXA-scan, additionally, biochemical parameters, inflammatory profile, oxidative protein damage, redox state, and serum concentration of GDF-11 at different ages were evaluated (4, 8, 12, 18, 22, and 24 months). Our results show that the LIERLT routine delays OSO phenotype in old 24-month-old rats, in a mechanism involving the decrease in the inflammatory state and oxidative stress. GDF-11 was evaluated as a protein related to muscle repair and regeneration; interestingly, rats that perform the LIERLT increased their GDF-11 levels.

Mechanism of the Hypoglycemic Activity and Hepatoprotective Effect of the Aqueous Extract of Cecropia obtusifolia Bertol.

In Central and South American traditional medicine, people use Cecropia obtusifolia Bertol (Cecropiaceae) for the treatment of diabetes mellitus. However, its hypoglycemic action mechanism at pancreatic and liver level has been poorly explored. The present research aimed to establish the influence of the aqueous extract of C. obtusifolia, standardized in its content of chlorogenic acid, on insulin secretion in RINm5F cells and over the liver carbohydrates and lipids metabolism, and to determine concomitantly its hepatoprotective effect on mice with streptozotocin-induced diabetes. In RINm5F cells, concentrations 5, 50, 100, and 200 µg/mL of aqueous extract of C. obtusifolia were used to determine [Ca2+]i and insulin secretion. In an acute study, the extract was administered at doses of 500 mg/kg. In another test (subacute), the extract was daily administrated to diabetic mice (200 mg/kg/day) for 30 days. Blood glucose levels and other biochemical parameters were determined, and a liver histological analysis was performed. In RINm5F cells, C. obtusifolia increased [Ca2+]i and insulin secretion, whereas in diabetic mice exhibited acute and subacute hypoglycemic effects. Daily administration of C. obtusifolia to diabetic mice also increased liver glycogen storage and glycogen synthase levels, without apparent changes in gluconeogenesis. Besides, it increased peroxisome proliferator-activated receptor-α (PPAR-α) and long-chain-fatty-acid-CoA ligase 1 (ACSL-1) expression and reduced triglycerides, transaminases (alanine aminotransferase and aspartate aminotransferase), and collagen fibers, modifying anti-inflammatory (adiponectin and interleukin-10) and inflammatory (tumor necrosis factor-α) cytokines in serum. Therefore, the hypoglycemic effect of C. obtusifolia implicates a dual action, promoting insulin secretion, liver glycogen accumulation, and hepatoprotection by decreasing collagen fibers and inflammatory markers, whereas it improves lipid metabolism, due in part to PPAR-α.

Long-Term Moderate Exercise Combined with Metformin Treatment Induces an Hormetic Response That Prevents Strength and Muscle Mass Loss in Old Female Wistar Rats.

Sarcopenia is a syndrome characterized by a progressive and generalized skeletal muscle mass and strength loss, as well as a poor physical performance, which as strongly been associated with aging. Sedentary lifestyle in the elderly contributes to this condition; however, physical activity improves health, reducing morbidity and mortality. Recent studies have shown that metformin (MTF) can also prevent muscle damage promoting muscular performance. To date, there is great controversy if MTF treatment combined with exercise training improves or nullifies the benefits provided by physical activity. This study is aimed at evaluating the effect of long-term moderate exercise combined with MTF treatment on body composition, strength, redox state, and survival rate during the life of female Wistar rats. In this study, rats performed moderate exercise during 20 of their 24 months of life and were treated with MTF for one year or for 6 months, i.e., from 12 to 24 months old and 18 to 24 months old. The body composition (percentage of fat, bone, and lean mass) was determined using a dual-energy X-ray absorption scanner (DXA), and grip strength was determined using a dynamometer. Likewise, medial and tibial nerve somatosensory evoked potentials were evaluated and the redox state was measured by HPLC, calculating the GSH/GSSG ratio in the gastrocnemius muscle. Our results suggest- that the MTF administration, both in the sedentary and the exercise groups, might activate a mechanism that is directly related to the induction of the hormetic response through the redox state modulation. MTF treatment does not eliminate the beneficial effects of exercise throughout life, and although MTF does not increase muscle mass, it increases longevity.

GDF11 exhibits tumor suppressive properties in hepatocellular carcinoma cells by restricting clonal expansion and invasion.

Growth differentiation factor 11 (GDF11) has been characterized as a key regulator of differentiation in cells that retain stemness features, despite some controversies in age-related studies. GDF11 has been poorly investigated in cancer, particularly in those with stemness capacity, such as hepatocellular carcinoma (HCC), one of the most aggressive cancers worldwide. Here, we focused on investigating the effects of GDF11 in liver cancer cells. GDF11 treatment significantly reduced proliferation, colony and spheroid formation in HCC cell lines. Consistently, down-regulation of CDK6, cyclin D1, cyclin A, and concomitant upregulation of p27 was observed after 24 h of treatment. Interestingly, cell viability was unchanged, but cell functionality was compromised. These effects were potentially induced by the expression of E-cadherin and occludin, as well as Snail and N-cadherin repression, in a time-dependent manner. Furthermore, GDF11 treatment for 72 h induced that cells were incapable of sustaining colony and sphere capacity in the absent of GDF11, up to 5 days, indicating that the effect of GDF11 on self-renewal capacity is not transient. Finally, in vivo invasion studies revealed a significant decrease in cell migration of hepatocellular carcinoma cells treated with GDF11 associated to a decreased proliferation judged by Ki67 staining. Data show that exogenous GDF11 displays tumor suppressor properties in HCC cells.

Recombinant human hepatocyte growth factor provides protective effects in cerulein-induced acute pancreatitis in mice.

Acute pancreatitis is a multifactorial disease associated with profound changes of the pancreas induced by release of digestive enzymes that lead to increase in proinflammatory cytokine production, excessive tissue necrosis, edema, and bleeding. Elevated levels of hepatocyte growth factor (HGF) and its receptor c-Met have been observed in different chronic and acute pancreatic diseases including experimental models of acute pancreatitis. In the present study, we investigated the protective effects induced by the recombinant human HGF in a mouse model of cerulein-induced acute pancreatitis. Pancreatitis was induced by 8 hourly administrations of supramaximal cerulein injections (50 µg/kg, ip). HGF treatment (20 µg/kg, iv), significantly attenuated lipase content and amylase activity in serum as well as the degree inflammation and edema overall leading to less severe histologic changes such as necrosis, induced by cerulein. Protective effects of HGF were associated with activation of pro-survival pathways such as Akt, Erk1/2, and Nrf2 and increase in executor survival-related proteins and decrease in pro-apoptotic proteins. In addition, ROS content and lipid peroxidation were diminished, and glutathione synthesis increased in pancreas. Systemic protection was observed by lung histology. In conclusion, our data indicate that HGF exerts an Nrf2 and glutathione-mediated protective effect on acute pancreatitis reflected by a reduction in inflammation, edema, and oxidative stress.

Neuroprotective effect of WIN55,212-2 against 3-nitropropionic acid-induced toxicity in the rat brain: involvement of CB1 and NMDA receptors.

The endocannabinoid system (ECS), and agonists acting on cannabinoid receptors (CBr), are known to regulate several physiological events in the brain, including modulatory actions on excitatory events probably through N-methyl-D-aspartate receptor (NMDAr) activity. Actually, CBr agonists can be neuroprotective. The synthetic CBr agonist WIN55,212-2 acts mainly on CB1 receptor. In turn, the mitochondrial toxin 3-nitropropionic acid (3-NP) produces striatal alterations in rats similar to those observed in the brain of Huntington's disease patients. Herein, the effects of WIN55,212-2 were tested on different endpoints of the 3-NP-induced toxicity in rat brain synaptosomes and striatal tissue. Motor activity was also evaluated. The 3-NP (1 mM)-induced mitochondrial dysfunction and lipid peroxidation was attenuated by WIN55,212-2 (1 µM) in synaptosomal fractions. The intrastriatal bilateral injection of 3-NP (500 nmol/µL) to rats increased lipid peroxidation and locomotor activity, augmented the rate of cell damage, and decreased the striatal density of neuronal cells. These alterations were accompanied by transcriptional changes in the NMDA (NR1 subunit) content. The administration of WIN55212-2 (1 mg/kg, i.p.) to rats for six consecutive days, before the 3-NP injection, exerted preventive effects on all alterations elicited by the toxin. The prevention of the 3-NP-induced NR1 transcriptional alterations by the CBr agonist together with the increase of CB1 content suggest an early reduction of the excitotoxic process via CBr activation. Our results demonstrate a protective role of WIN55,212-2 on the 3-NP-induced striatal neurotoxicity that could be partially related to the ECS stimulation and induction of NMDAr hypofunction, representing an effective therapeutic strategy at the experimental level for further studies.

Membrane-initiated estradiol signaling of epithelial-mesenchymal transition-associated mechanisms through regulation of tight junctions in human breast cancer cells.

Tumor cells utilize inappropriate epithelial-mesenchymal transition (EMT) mechanisms during the invasive process. It is becoming increasingly clear that estradiol (E2) induces breast cancer cell progression and enhances EMT; however, the mechanisms associated with this are unclear. We investigated the role of E2 on the expression and intracellular localization of the tight junction (TJ)-associated proteins, zonula occluden 1 (ZO-1), ZO-1-associated nucleic acid binding (ZONAB), and occludin, on the activation of c-Src and human epidermal growth factor receptor 2 (HER2) expression and cellular migration in the estrogen receptor (ER)-positive breast cancer cell lines, MCF-7 and T47D. We demonstrated that 1 nM E2 elicits c-Src activation after 15 min. The p-Src/ZO-1 complex led to ZO-1 and ZONAB disruption at the TJ and increased expression of HER2 mRNAs. These changes correlate with decreased expression of the epithelial markers occludin and CRB3 and increased synthesis of N-cadherin. This led to increased MCF-7 cell migration induced by E2, even in the presence of a cell proliferation inhibitor. Incubation with ICI 182,780 (Fulvestrant), an ER antagonist, precluded the effects of E2 on c-Src phosphorylation, p-Src/ZO-1 complex formation, ZO-1/ZONAB nuclear translocation, and migration of MCF-7 cells. Our findings suggest that E2 promotes TJ disruption during tumor progression and increases cell motility. We propose a novel pathway where estrogens promote EMT-associated mechanisms that possibly lead to metastasis.