Senolytic treatment fails to improve ovarian reserve or fertility in female mice.

Senescent cell number increases with age in different tissues, leading to greater senescent cell load, proinflammatory stress, and tissue dysfunction. In the current study, we tested the efficacy of senolytic drugs to reduce ovarian senescence and improve fertility in reproductive age female mice. In the first experiment, 1-month-old C57BL/6 female mice were treated every other week with D + Q (n = 24) or placebo (n = 24). At 3 and 6 months of age, female mice were mated with untreated males to evaluate pregnancy rate and litter size. In the second experiment, 6-month-old C57BL/6 female mice were treated monthly with D + Q (n = 30), fisetin (n = 30), or placebo (n = 30). Females were treated once a month until 11 months of age, then they were mated with untreated males for 30 days to evaluate pregnancy rate and litter size. In the first experiment, D + Q treatment did not affect pregnancy rate (P = 0.68), litter size (P = 0.58), or ovarian reserve (P > 0.05). Lipofuscin staining was lower in females treated with D + Q (P = 0.04), but expression of senescence genes in ovaries was similar. In the second experiment, D + Q or fisetin treatment also did not affect pregnancy rate (P = 0.37), litter size (P = 0.20), or ovarian reserve (P > 0.05). Lipofuscin staining (P = 0.008) and macrophage infiltration (P = 0.002) was lower in fisetin treated females. Overall, treatment with D + Q or fisetin did not affect ovarian reserve or fertility but did decrease some senescence markers in the ovary.

Dasatinib and quercetin increase testosterone and sperm concentration in mice.

Cellular senescence is a defense mechanism to arrest proliferation of damaged cells. The number of senescent cells increases with age in different tissues and contributes to the development of age-related diseases. Old mice treated with senolytics drugs, dasatinib and quercetin (D+Q), have reduced senescent cells burden. The aim of this study was to evaluate the effects of D+Q on testicular function and fertility of male mice. Mice (n = 9/group) received D (5 mg kg-1) and Q (50 mg kg-1) via gavage every moth for three consecutive days from 3 to 8 months of age. At 8 months mice were breed with young non-treated females and euthanized. The treatment of male mice with D+Q increased serum testosterone levels and sperm concentration and decreased abnormal sperm morphology. Sperm motility, seminiferous tubule morphometry, testicular gene expression and fertility were not affected by treatment. There was no effect of D+Q treatment in ß-galactosidase activity and in lipofuscin staining in testes. D+Q treatment also did not affect body mass gain and testes mass. In conclusion, D+Q treatment increased serum testosterone levels and sperm concentration and decreased abnormal sperm morphology, however did not affect fertility. Further studies with older mice and different senolytics are necessary to elucidate the effects in the decline of sperm output (quality and quantity) associated with aging.

Kinin B1 receptor deficiency protects mice fed by cafeteria diet from abnormal glucose homeostasis.

The kallikrein-kinin system has been implicated in body weight and glucose homeostasis. Their major effectors act by binding to the kinin B2 and B1 receptors. It was assessed the role of the kinin B1 receptor in weight and glucose homeostasis in B1 receptor knockout mice (B1RKO) subjected to a cafeteria diet (CAF). Wild-type (WT) and B1RKO male mice (C57BL/6 background; 8 weeks old) were fed a standard diet (SD) or CAF for 14 weeks, ad libitum, and four groups were formed: WT-SD; B1RKO-SD; WT-CAF; B1RKO-CAF. Body weight and food intake were assessed weekly. It was performed glucose tolerance (GTT) and insulin tolerance tests (ITT), and HOMA-IR, HOMA-ß and HOMA-ß* 1/HOMA-IR were calculated. Islets from WT and B1RKO were isolated in order to measure the insulin secretion. Western blot was used to assess the hepatic AKT phosphorylation and qPCR to assess gene expression. CAF induced a higher body mass gain in B1RKO compared to WT mice. CAF diet increased epididymal fat depot mass, hepatic fat infiltration and hepatic AKT phosphorylation in both genotypes. However, B1RKO mice presented lower glycemic response during GTT when fed with CAF, and a lower glucose decrease in the ITT. This higher resistance was overcomed with higher insulin secretion when stimulated by high glucose, resulting in higher glucose uptake in the GTT when submitted to CAF, despite lower insulin sensitivity. Islets from B1RKO delivered 4 times more insulin in 3-month-old mice than islets from WT. The higher insulin disposition index and high insulin delivery of B1RKO can explain the decreased glucose excursion during GTT. In conclusion, CAF increased the ß-cell function in B1RKO mice, compensated by the diet-induced insulin resistance and resulting in a healthier glycemic response despite the higher weight gain.

Senolytic treatment reverses obesity-mediated senescent cell accumulation in the ovary.

Senescent cells are in a cell cycle arrest state and accumulate with aging and obesity, contributing to a chronic inflammatory state. Treatment with senolytic drugs dasatinib and quercetin (D + Q) can reduce senescent cell burden in several tissues, increasing lifespan. Despite this, there are few reports about senescent cells accumulating in female reproductive tissues. Therefore, the aim of the study was to characterize the ovarian reserve and its relationship with cellular senescence in genetically obese mice (ob/ob). In experiment 1, ob/ob (n = 5) and wild-type (WT) mice (n = 5) at 12 months of age were evaluated. In experiment 2, 2-month-old female ob/ob mice were treated with senolytics (D + Q, n = 6) or placebo (n = 6) during the 4 months. Obese mice had more senescent cells in ovaries, indicated by increased p21 and p16 and lipofuscin staining and macrophage infiltration. Treatment with D + Q significantly reduced senescent cell burden in ovaries of obese mice. Neither obesity nor treatment with D + Q affected the number of ovarian follicles. In conclusion, our data indicate that obesity due to leptin deficiency increases the load of senescent cells in the ovary, which is reduced by treatment by senolytics. However, neither obesity nor D + Q treatment affected the ovarian reserve.

Growth hormone increases DNA damage in ovarian follicles and macrophage infiltration in the ovaries.

Evidence points to an important role of the growth hormone (GH) in the aging process and longevity. GH-deficient mice are smaller, live longer than normal littermates, and females have an increased ovarian reserve. The aim of the study was to evaluate the role of GH in the ovarian reserve by evaluating DNA damage, macrophage infiltration, and granulosa cell number in primordial and primary follicles. Experiment 1 used GH-deficient Ames dwarf mice (df/df, n = 12) and their normal littermates (N/df, n = 12), receiving GH or saline injections. Experiment 2 included transgenic mice overexpressing bovine GH (bGH) (n = 6) and normal mice (N, n = 6). DNA damage (anti-γH2AX) and macrophage counting (anti-CD68) were evaluated by immunofluorescence. Female df/df mice had lower γH2AX foci intensity in both oocytes and granulosa cells of primordial and primary follicles (p < 0.05), indicating fewer DNA double-strand breaks (DSBs). GH treatment increased DSBs in both df/df and N/df mice. Inversely, bGH mice had a higher quantity of DSBs in both oocytes and granulosa cells of primordial and primary follicles (p < 0.05). Df/df mice showed ovarian tissue with less macrophage infiltration than N/df mice (p < 0.05) and GH treatment increased macrophage infiltration (p < 0.05). In contrast, bGH mice had ovarian tissue with more macrophage infiltration compared to normal mice (p < 0.05). The current study shows that GH increases DNA DSBs in oocytes and granulosa cells and raises macrophage infiltration in the ovaries, pointing to the role of the GH/IGF-I axis in maintenance of oocyte DNA integrity and ovarian macrophage infiltration in mice.

Endocytosis and the Participation of Glycosaminoglycans Are Important to the Mechanism of Cell Death Induced by ß-Hairpin Antimicrobial Peptides.

The cytotoxic mode of action of four antimicrobial peptides (AMPs) (gomesin, tachyplesin, protegrin, and polyphemusin) against a HeLa cell tumor model is discussed. A study of cell death by AMP stimulation revealed some similarities, including annexin-V externalization, reduction of mitochondrial potential, insensitivity against inhibitors of cell death, and membrane permeabilization. Evaluation of signaling proteins and gene expression that control cell death revealed wide variation in the responses to AMPs. However, the ability to cross cell membranes emerged as an important characteristic of AMP-dependent cell death, where endocytosis mediated by dynamin is a common mechanism. Furthermore, the affinity between AMPs and glycosaminoglycans (GAGs) and GAG participation in the cytotoxicity of AMPs were verified. The results show that, despite their primary and secondary structure homology, these peptides present different modes of action, but endocytosis and GAG participation are an important and common mechanism of cytotoxicity for ß-hairpin peptides.

Calorie restriction during gestation affects ovarian reserve in offspring in the mouse.

The aim of this study was to investigate the effect of calorie restriction (CR) during pregnancy in mice on metabolism and ovarian function in the offspring. Pregnant female mice were divided into two groups, a control group and a CR group (n=7 in each). Mice in the CR group were fed 50% of the amount consumed by control females from Day 10 of gestation until delivery. After weaning, the offspring received diet ad libitum until 3 months of age, when ovaries were collected. Ovaries were serially cut and every sixth section was used for follicle counting. Female offspring from CR dams tended to have increased bodyweight compared with offspring from control females (P=0.08). Interestingly, fewer primordial follicles (60% reduction; P=0.001), transitional follicles (P=0.0006) and total follicles (P=0.006) were observed in offspring from CR mothers. The number of primary, secondary and tertiary follicles did not differ between the groups (P>0.05). The CR offspring had fewer DNA double-strand breaks in primary follicle oocytes (P=0.03). In summary, CR during the second half of gestation decreased primordial ovarian follicle reserve in female offspring. These findings suggest that undernutrition during the second half of gestation may decrease the reproductive lifespan of female offspring.

Effect of caloric restriction and rapamycin on ovarian aging in mice.

Caloric restriction (CR) increases the preservation of the ovarian primordial follicular reserve, which can potentially delay menopause. Rapamycin also increases preservation on the ovarian reserve, with similar mechanism to CR. Therefore, the aim of our study was to evaluate the effects of rapamycin and CR on metabolism, ovarian reserve, and gene expression in mice. Thirty-six female mice were allocated into three groups: control, rapamycin-treated (4 mg/kg body weight every other day), and 30% CR. Caloric restricted females had lower body weight (P < 0.05) and increased insulin sensitivity (P = 0.003), while rapamycin injection did not change body weight (P > 0.05) and induced insulin resistance (P < 0.05). Both CR and rapamycin females displayed a higher number of primordial follicles (P = 0.02 and 0.04, respectively), fewer primary, secondary, and tertiary follicles (P < 0.05) and displayed increased ovarian Foxo3a gene expression (P < 0.05). Despite the divergent metabolic effects of the CR and rapamycin treatments, females from both groups displayed a similar increase in ovarian reserve, which was associated with higher expression of ovarian Foxo3a.

Chronic Overexpression of Bradykinin in Kidney Causes Polyuria and Cardiac Hypertrophy.

Acute intra-renal infusion of bradykinin increases diuresis and natriuresis via inhibition of vasopressin activity. However, the consequences of chronically increased bradykinin in the kidneys have not yet been studied. A new transgenic animal model producing an excess of bradykinin by proximal tubular cells (KapBK rats) was generated and submitted to different salt containing diets to analyze changes in blood pressure and other cardiovascular parameters, urine excretion, and composition, as well as levels and expression of renin-angiotensin system components. Despite that KapBK rats excrete more urine and sodium, they have similar blood pressure as controls with the exception of a small increase in systolic blood pressure (SBP). However, they present decreased renal artery blood flow, increased intrarenal expression of angiotensinogen, and decreased mRNA expression of vasopressin V1A receptor (AVPR1A), suggesting a mechanism for the previously described reduction of renal vasopressin sensitivity by bradykinin. Additionally, reduced heart rate variability (HRV), increased cardiac output and frequency, and the development of cardiac hypertrophy are the main chronic effects observed in the cardiovascular system. In conclusion: (1) the transgenic KapBK rat is a useful model for studying chronic effects of bradykinin in kidney; (2) increased renal bradykinin causes changes in renin angiotensin system regulation; (3) decreased renal vasopressin sensitivity in KapBK rats is related to decreased V1A receptor expression; (4) although increased renal levels of bradykinin causes no changes in mean arterial pressure (MAP), it causes reduction in HRV, augmentation in cardiac frequency and output and consequently cardiac hypertrophy in rats after 6 months of age.

Caloric Restriction Is More Efficient than Physical Exercise to Protect from Cisplatin Nephrotoxicity via PPAR-Alpha Activation.

The antineoplastic drug cisplatin promotes renal injury, which limits its use. Protocols that reduce renal cisplatin toxicity will allow higher doses to be used in cisplatin treatment. Here, we compare physical exercise and caloric restriction (CR) as protocols to reduce cisplatin renal injury in mice. Male C57BL/6 were divided into four groups: Control, cisplatin, exercise + cisplatin, and 30% CR + cisplatin. Animals were injected with a single dose of cisplatin (20 mg/kg i.p.) and sacrificed 96 h after injection. Quantitative real time PCR, histological analyses, immunohistochemistry, and biochemical measurements were performed to investigate renal injury, necrosis, apoptosis, and inflammatory mechanisms. Both protocols protected against cisplatin renal injury, but CR was more effective in reducing uraemia and renal necrosis. The CR + Cisplatin group exhibited reduced serum IL-1ß and TNF-α levels. No differences were noted in the renal mRNA expression of cytokines. Both interventions reduced apoptosis, but only the CR + Cisplatin group decreased TNFR2 protein expression. PPAR-α was activated in mice after CR. An antagonist of PPAR-α blocked the protective effect of CR. Both interventions attenuated the nephrotoxicity caused by cisplatin injection, but CR + Cisplatin showed a better response by modulating TNFR2. Moreover, part of the CR benefit depends on PPAR-α activation.

Ovarian aging and the activation of the primordial follicle reserve in the long-lived Ames dwarf and the short-lived bGH transgenic mice.

The aim of this study was to evaluate the effect of growth hormone (GH) in the maintenance of the ovarian primordial follicle reserve. Ovaries from 16 mo old GH-deficient Ames Dwarf (df/df) and Normal (N/df) mice were used. A subgroup of df/df and N mice received GH or saline injections for six weeks starting at 14 mo of age. In addition, ovaries from 12 mo old mice overexpressing bovine GH (bGH) and controls were used. df/df mice had higher number of primordial and total follicles than N/df mice (p < 0.05), while GH treatment decreased follicle counts in both genotypes (p < 0.05). In addition, bGH mice had lower number of primordial and total follicles than the controls (p < 0.05). pFoxO3a levels were higher in mice treated with GH and in bGH mice (p < 0.05) when comparing with age match controls. These results indicate that increased circulating GH is associated with a reduced ovarian primordial follicle reserve and increased pFoxO3a content in oocytes.

Association between paraoxonase 1 (PON1) enzyme activity, PON1 C(−107)T polymorphism, nutritional status, and lipid profile in children

BACKGROUND: Paraoxonase 1 (PON1) is an enzyme that possesses anti-atherogenic and anti-inflammatory properties with serum levels determined by genetic and exogenous factors. Lower serum PON1 arylesterase activity is associated to metabolic alterations related to childhood overweight and onset and/or development of diabetes and CVD later in life. However, data on the relationship between genetic PON1 polymorphisms and nutritional status as well as lipid profile in children are limited. To investigate the distribution of the C(−107)T PON1 gene polymorphism and its relation with serum PON1 enzyme activity, nutritional status and lipid profile in children. METHODS: A cross-sectional study was performed including 73 children aged 5 to 7 years who attended public pediatric clinics. PON1 C(−107)T, arylesterase activity, body mass index for the age, and serum lipid profile were evaluated. RESULTS: PON1 activity was higher in overweight children compared to the normal weight ones (p= 0.02). The genotypic frequency did not differ between the two groups (p> 0.05). Carriers of CC genotype had higher enzyme activity than T allele carriers, and this difference was greater among normal weight children. HDL levels were higher among normal weight children carrying CC genotype, compared to those carrying the T allele (p< 0.01).CONCLUSION: The PON1 C(−107)T polymorphism is associated with higher serum enzyme activity in children, as observed previously in adults. In addition, this polymorphism also shows association to higher high density lipoprotein (HDL) levels and serum PON1 arylesterase activity in the normal weight children studied.

The ACTN3 R577X polymorphism affects the lipid profile and the prognosis of nutritional intervention in HIV-positive patients.

The hypothesis of the present study is that the polymorphisms in the APOC3, CEPT, ACE, and ACTN3 genes can affect the outcome of nutritional intervention and the plasma lipid profile of HIV+ patients. To test the hypothesis, genetic material was collected from buccal cells, and serum was collected for biochemical analysis. Sixty-five patients were analyzed. The incorporation of protease inhibitor (PI) was more frequent in women (77% vs 33% in men). Nutritional intervention improved anthropometric parameters independent of the genotype. Patients with the RR genotype for the ACTN3 R577X polymorphism had lower glycemia (RR = 95.4 ± 6.5 mg/dL, RX = 102.6 ± 10.6 mg/dL, XX = 110.1 ± 16.3 mg/dL; P = .03) and a greater reduction in low-density lipoproteins (LDL) after intervention (LDL: RR = -23.7 ± 15.8 mg/dL, RX = 1.32 ± 5.13 mg/dL, XX = 30.21 ± 24.4 mg/dL; P = .01). Patients using PI had a negative response to dietary intervention regarding the levels of high-density lipoprotein (-2.4 ± 1.70 with PI, 2.56 ± 1.60 mg/dL without PI; P = .02), very low density lipoprotein (0.84 ± 2.73 with IP, -5.46 ± 3.37 mg/dL without PI; P = .03), and triglycerides (1.79 ± 13.22 with PI, -34.00 ± 17.67 mg/dL without PI; P = .052). This response was also independent of the genotype (P > 0.05) and suggested the need for oral lipid-lowering drugs in all HIV+ patients using PI. Our results indicate that the ACTN3 R577X polymorphism is a good predictor of both the lipid profile and the prognosis of nutritional intervention in reducing LDL in HIV+ patients.

The effect of the paraoxonase 1 (PON1) T(-107)C polymorphism on serum PON1 activity in women is dependent on fatty acid intake.

Paraoxonase 1 (PON1) is an enzyme that prevents the peroxidation of lipoprotein and cell membranes. Our hypothesis is that the effect of the PON1 T(-107)C polymorphism on serum PON1 activity in healthy adult women is dependent on their fatty acid intake profile. This study included women (n = 39) who completed a food frequency questionnaire. Fatty acid intake was estimated based on the interview and a nutrient reference table. Blood samples were collected for genotyping and to measure serum PON1 activity. Serum PON1 activity was different among genotypes and was higher for women of the CC genotype (P < .001). Women in the study were categorized in 2 groups according to the median nutrient intake. Overall, there was a difference (P < .05) in serum PON1 activity between the CC and TT genotypes in women ingesting either above or below the median total fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, omega 3 (n-3) and omega 6 (n-6; P < .05). However, genotype effects on serum PON1 activity were not observed in women ingesting below the median (15:1) ratio of n-6/n-3 (P > .05) but were observed in women ingesting above the ratio of n-6/n-3 (P < .05). This is partly because women of the CC genotype had decreased PON1 activity when ingesting a lower ratio of n-6/n-3 diet (P < .05), while women of the TT genotype had increased PON1 activity (P < .05). In conclusion, the overall presence of the C allele was associated with increased serum PON1 activity, although a diet with high saturated fatty acid or a low ratio of n-6/n-3 reduced PON1 activity in women with the CC genotype.

Characterization of single nucleotide polymorphisms in the promoter region of the bovine paraoxonase 1 (PON1) gene affecting serum enzyme activity in dairy cows.

The aim of the present study was to characterize single nucleotide polymorphisms (SNPs) in the promoter region of the bovine paraoxonase 1 (PON1) gene and determine their relationship with PON1 serum activity. Blood samples were collected from 47 Holstein cows during the periparturient period. Serum PON1 was measured and DNA extracted for PCR and sequencing of the promoter region of the PON1 gene. Seven novel SNPs were identified and of these, five SNPs, at positions -105, -221, -392, -611 and -674, upstream of the start of the published mRNA sequence (NM_001046269.2), were found to be associated with variability in serum PON1 activity (P < 0.05). The SNPs at positions -221 and -611 were located in regions predicted to bind to transcription factors linked to the acute phase response.

Nitric oxide-induced murine hematopoietic stem cell fate involves multiple signaling proteins, gene expression, and redox modulation.

There are a growing number of reports showing the influence of redox modulation in cellular signaling. Although the regulation of hematopoiesis by reactive oxygen species (ROS) and reactive nitrogen species (RNS) has been described, their direct participation in the differentiation of hematopoietic stem cells (HSCs) remains unclear. In this work, the direct role of nitric oxide (NO(•)), a RNS, in the modulation of hematopoiesis was investigated using two sources of NO(•) , one produced by endothelial cells stimulated with carbachol in vitro and another using the NO(•)-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP) in vivo. Two main NO(•) effects were observed: proliferation of HSCs-especially of the short-term HSCs-and its commitment and terminal differentiation to the myeloid lineage. NO(•)-induced proliferation was characterized by the increase in the number of cycling HSCs and hematopoietic progenitor cells positive to BrdU and Ki-67, upregulation of Notch-1, Cx43, PECAM-1, CaR, ERK1/2, Akt, p38, PKC, and c-Myc. NO(•)-induced HSCs differentiation was characterized by the increase in granulocytic-macrophage progenitors, granulocyte-macrophage colony forming units, mature myeloid cells, upregulation of PU.1, and C/EBPα genes concomitantly to the downregulation of GATA-3 and Ikz-3 genes, activation of Stat5 and downregulation of the other analyzed proteins mentioned above. Also, redox status modulation differed between proliferation and differentiation responses, which is likely associated with the transition of the proliferative to differentiation status. Our findings provide evidence of the role of NO(•) in inducing HSCs proliferation and myeloid differentiation involving multiple signaling.

Neurolysin knockout mice generation and initial phenotype characterization.

The oligopeptidase neurolysin (EC 3.4.24.16; Nln) was first identified in rat brain synaptic membranes and shown to ubiquitously participate in the catabolism of bioactive peptides such as neurotensin and bradykinin. Recently, it was suggested that Nln reduction could improve insulin sensitivity. Here, we have shown that Nln KO mice have increased glucose tolerance, insulin sensitivity, and gluconeogenesis. KO mice have increased liver mRNA for several genes related to gluconeogenesis. Isotopic label semiquantitative peptidomic analysis suggests an increase in specific intracellular peptides in gastrocnemius and epididymal adipose tissue, which likely is involved with the increased glucose tolerance and insulin sensitivity in the KO mice. These results suggest the exciting new possibility that Nln is a key enzyme for energy metabolism and could be a novel therapeutic target to improve glucose uptake and insulin sensitivity.

Kinin B1 receptor deficiency attenuates cisplatin-induced acute kidney injury by modulating immune cell migration.

UNLABELLED: Cisplatin is a chemotherapeutic agent that causes severe renal dysfunction. The kinin B1 receptor has been associated with the migration of immune cells to injured tissue as well as with renal inflammation. To examine the role of the kinin B1 receptor in cisplatin-induced acute kidney injury, we used kinin B1 receptor knockout mice and treatment with a receptor antagonist before and after cisplatin administration. Cisplatin injection caused exacerbation of renal macrophage and neutrophil migration, higher levels of serum creatinine and blood urea, upregulation of B1 receptor mRNA and an increase in pro-inflammatory cytokines expression. B1 receptor knockout mice exhibited a reduction in serum creatinine and blood urea levels, diminished apoptosis, and decreased cisplatin-induced upregulation of inflammatory components. Moreover, treatment with the B1 receptor antagonist prior to cisplatin administration normalized serum creatinine, blood urea levels, protected from acute tubular necrosis, apoptosis-related genes, and prevented upregulation of pro-inflammatory cytokines. Thus, we propose that kinins have an important role in cisplatin-induced acute kidney injury by impairing immune cells migration to renal tissue during cisplatin nephrotoxicity. KEY MESSAGE: Kinin B1 receptor is upregulated after cisplatin exposure. Kinin B1 receptor deficiency diminishes the nephrotoxicity caused by cisplatin. Kinin B1 receptor deficiency ameliorates the inflammatory response. Kinin B1 receptor deficiency diminishes apoptosis caused by cisplatin. Kinin B1 receptor antagonism ameliorates renal function after cisplatin injection.

Exercise and caloric restriction alter the immune system of mice submitted to a high-fat diet.

As the size of adipocytes increases during obesity, the establishment of resident immune cells in adipose tissue becomes an important source of proinflammatory mediators. Exercise and caloric restriction are two important, nonpharmacological tools against body mass increase. To date, their effects on the immune cells of adipose tissue in obese organisms, specifically when a high-fat diet is consumed, have been poorly investigated. Thus, after consuming a high-fat diet, mice were submitted to chronic swimming training or a 30% caloric restriction in order to investigate the effects of both interventions on resident immune cells in adipose tissue. These strategies were able to reduce body mass and resulted in changes in the number of resident immune cells in the adipose tissue and levels of cytokines/chemokines in serum. While exercise increased the number of NK cells in adipose tissue and serum levels of IL-6 and RANTES, caloric restriction increased the CD4+/CD8+ cell ratio and MCP-1 levels. Together, these data demonstrated that exercise and caloric restriction modulate resident immune cells in adipose tissues differently in spite of an equivalent body weight reduction. Additionally, the results also reinforce the idea that a combination of both strategies is better than either individually for combating obesity.

Altered glucose homeostasis and hepatic function in obese mice deficient for both kinin receptor genes.

The Kallikrein-Kinin System (KKS) has been implicated in several aspects of metabolism, including the regulation of glucose homeostasis and adiposity. Kinins and des-Arg-kinins are the major effectors of this system and promote their effects by binding to two different receptors, the kinin B2 and B1 receptors, respectively. To understand the influence of the KKS on the pathophysiology of obesity and type 2 diabetes (T2DM), we generated an animal model deficient for both kinin receptor genes and leptin (obB1B2KO). Six-month-old obB1B2KO mice showed increased blood glucose levels. Isolated islets of the transgenic animals were more responsive to glucose stimulation releasing greater amounts of insulin, mainly in 3-month-old mice, which was corroborated by elevated serum C-peptide concentrations. Furthermore, they presented hepatomegaly, pronounced steatosis, and increased levels of circulating transaminases. This mouse also demonstrated exacerbated gluconeogenesis during the pyruvate challenge test. The hepatic abnormalities were accompanied by changes in the gene expression of factors linked to glucose and lipid metabolisms in the liver. Thus, we conclude that kinin receptors are important for modulation of insulin secretion and for the preservation of normal glucose levels and hepatic functions in obese mice, suggesting a protective role of the KKS regarding complications associated with obesity and T2DM.