Leptin Receptor mRNA Expression Research Articles

Abstract C046: Aryl hydrocarbon receptor activity may lead to the downstream transcription of several genes relevant to prostate cancer progression, apoptosis and lipid metabolism

Abstract The aryl hydrocarbon receptor (AhR) is a nuclear transcription factor and xenobiotic sensor reported to mediate diet-induced obesity and is both upregulated and constitutively active in high-grade prostate cancer. AhR activity has also been reported to contribute to proliferation and potentially disease progression in C4-2 cells (Powell et al. 2015). To determine if the aryl hydrocarbon receptor mediates transcription of genes pertinent to cancer progression, we performed an RNA-seq analysis in C4-2 AhR knockdown cells and the vehicle control. When a fold-change cutoff of ±1.5 and an adjusted p-value (p-adj) <0.05 were used, data analyses revealed several differentially expressed genes (DEGS), i.e. LEPROT, CHAC1/2, GDF11/15, CDKN2, FAS, FASTKD, ATF1/3, CCNL2, and CCNG2 with known functions involving the cell cycle, apoptosis, epigenetic modifications, tumor aggressiveness, and interestingly – lipid metabolism. Recent evidence demonstrates significant changes in the expression profile of many of these genes in response to treatment with chemotherapeutics, specifically bromocriptine (Wu et al 2023). In murine models AhR has been shown to promote diet-induced obesity coupled with metabolic dysregulation leading to obesity, which has been reported to cause malignant behaviors in prostate cancer. Leptin, a pleiotropic obesity-associated adipokine, is significantly overexpressed in mCRPC tissues. Our lab previously reported an integrative bioinformatics analysis using TCGA data (n=498) to explore the role of AHR and leptin receptor (LEPR) in prostate cancer, which revealed AHR and LEPR mRNA expression positively correlate in a subset of prostate cancer patients (P<0.05, Pearson: 0.68, R^2=0.46). We also confirmed AhR inhibits bortezomib and docetaxel -mediated apoptosis of C4-2 cells (data not shown). Further understanding of the potential interactions between metabolism and drug treatment should lead to a better understanding of the complex network of factors influencing prostate cancer progression and lead to more effective therapeutics for patients. Citation Format: Kofi K. Khamit-Kush, Joann B. Powell, Jeffrey A. Handy, Nathan J. Bowen, Daqing Wu, Valerie Odero-Marah. Aryl hydrocarbon receptor activity may lead to the downstream transcription of several genes relevant to prostate cancer progression, apoptosis and lipid metabolism [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C046.

Adipose lipolysis is important for ethanol to induce fatty liver in the National Institute on Alcohol Abuse and Alcoholism murine model of chronic and binge ethanol feeding.

Alcohol-associated liver disease (ALD) pathologies include steatosis, inflammation, and injury, which may progress to fibrosis, cirrhosis, and cancer. The liver receives ~60% of fatty acids from adipose tissue triglyceride hydrolysis, but the role of this lipolytic pathway in ALD development has not been directly examined in any genetic animal models with selective inactivation of adipose lipolysis. Using adipose-specific comparative gene identification-58 (CGI-58) knockout (FAT-KO) mice, a model of impaired adipose lipolysis, we show that mice deficient in adipose lipolysis are almost completely protected against ethanol-induced hepatic steatosis and lipid peroxidation when subjected to the National Institute on Alcohol Abuse and Alcoholism chronic and binge ethanol feeding model. This is unlikely due to reduced lipid synthesis because this regimen of ethanol feeding down-regulated hepatic expression of lipogenic genes similarly in both genotypes. In the pair-fed group, FAT-KO relative to control mice displayed increased hepatocyte injury, neutrophil infiltration, and activation of the transcription factor signal transducer and activator of transcription 3 (STAT3) in the liver; and none of these were exacerbated by ethanol feeding. Activation of STAT3 is associated with a marked increase in hepatic leptin receptor mRNA expression and adipose inflammatory cell infiltration. Our findings establish a critical role of adipose lipolysis in driving hepatic steatosis and oxidative stress during ALD development.

Seed-derived peptide lunasin suppressed breast cancer cell growth by regulating inflammatory mediators, aromatase, and estrogen receptors.

Breast cancer is one of the most prevalent cancers in women. Its pathology comprises tumor cells and nearby stromal cells, accompanied by cytokines and stimulated molecules, resulting in a favorable microenvironment for tumor progression. Lunasin is a seed peptide with multiple bioactivities derived from seeds. However, the chemopreventive effect of lunasin on different characteristics of breast cancer has not been fully explored. This study aims to explore the chemopreventive mechanisms of lunasin through inflammatory mediators and estrogen-related molecules in breast cancer cells. Estrogen-dependent MCF-7 and independent MDA-MB-231 breast cancer cells were used. The β-estradiol was used to mimic physiological estrogen. The gene expression, mediator secretion, cell vitality, and apoptosis impacting breast malignancy were explored. Lunasin did not affect normal MCF-10A cell growth but inhibited breast cancer cell growth, increased interleukin (IL)-6 gene expression and protein production at 24 h, and decreased its secretion at 48 h. In both breast cancer cells, aromatase gene and activity and estrogen receptor (ER)α gene expression were decreased by lunasin treatment, while ERβ gene levels were significantly increased in MDA-MB-231 cells. Moreover, lunasin decreased vascular endothelial growth factor (VEGF) secretion and cell vitality and induced cell apoptosis in both breast cancer cell lines. However, lunasin only decreased leptin receptor (Ob-R) mRNA expression in MCF-7 cells. Additionally, β-estradiol increased MCF-7-cell proliferation but not the proliferation of other cells; in particular, lunasin still inhibited MCF-7-cell growth and cell vitality in the presence of β-estradiol. Seed peptide lunasin inhibited breast cancer cell growth by regulating inflammatory, angiogenic, and estrogen-related molecules, suggesting that lunasin is a promising chemopreventive agent.

Circadian rhythm in hypothalamic leptin receptor (Ob-Rb) mRNA expressions and cerebrospinal fluid and circulating glucose and leptin levels in lactating rats

In lactating animals, the food consumption increases several-fold for milk supply to the pups. The present study was conducted to clarify the relationship between the hyperphagia during lactation and hypothalamic leptin receptor (Ob-Rb) mRNA expression, cerebrospinal fluid (CSF) and circulating leptin and glucose levels. Food intakes significantly higher in lactation than in non-lactation at all time points (3 points: light phase, 4 points: dark phase) of the day. However, the expression of the hypothalamic Ob-Rb mRNA showed similar circadian rhythms in both the non-lactation and lactation, with only slight differences between the two groups. CSF leptin and glucose levels were constant throughout the day in both non-lactation and lactation, and there was almost no difference between the two groups at each time point. Circulating leptin and glucose levels showed circadian rhythms only in the non-lactating period, and were lower in lactation than in non-lactation, especially in the dark phase. In conclusion, the present study provides evidence that Ob-Rb mRNA expression fluctuates in the lactation period as well as in the non-lactation period, suggesting that the expression profile of whole hypothalamic Ob-Rb may not contribute to the difference in food consumption between lactation and non-lactation, and that chronic decrease in blood glucose levels may be associated with the increase in food consumption during lactation.

Leptin Modulates the mRNA Expression of Follicle Development Markers in Post-hatch Chicks in an Age-Dependent Manner.

Leptin is involved in regulating reproductive function in chickens, and the development of the leptin system is initiated during the early embryonic stage; however, whether leptin has a specific role in regulating the ovarian development in early post-hatch days is still not fully understood. This study investigated the expression of ovarian functional markers in growing juvenile chickens, along with the effects of leptin on gene expression in the hypothalamus–pituitary–gonadal (HPG) axis on specific ovarian-remodeling days. Leptin receptor (LEPR), follicle-stimulating hormone receptor (FSHR), and the mRNA expression of aromatase (CYP19A1) tended to increase with age in the ovaries of growing chicks. In the ovaries of 7-day-old chicks, intraperitoneally injected leptin significantly increased the mRNA expressions of LEPR, FSHR, and CYP19A1, and this resulted in the increased serum estradiol levels. However, leptin had no effect on hypothalamic LEPR, gonadotropin-releasing hormone 1 (GnRH1), or gonadotropin-inhibitory hormone (GnIH) mRNAs; however, in the pituitary gland, leptin significantly increased the mRNA expression of luteinizing hormone beta subunit (LHB) but had no effect on the mRNA expression of follicle-stimulating hormone beta subunit (FSHB). In 28-day-old chicks, hypothalamic and pituitary mRNAs were unaffected by leptin administration, except hypothalamic LEPR mRNA that was upregulated by a high dose of leptin. In the ovary, leptin dose-dependently decreased the mRNA expression of LEPR; low doses of leptin significantly increased the mRNA expression of FSHR, whereas high doses significantly decreased this expression; leptin did not affect the mRNA expression of CYP19A1; and high leptin doses significantly reduced the serum estradiol levels. Collectively, the results of this study show that leptin modulates ovarian development and folliculogenesis marker genes by primarily acting on ovaries on the specific ovarian-remodeling days in post-hatch chicks, which may alter folliculogenesis and ovarian development toward puberty in chicken.

Leptin Supplementation Stimulates Synergism with Growth Factors and Hormones to Express Its Receptor in Cultured Preantral Follicles of Sheep

Background: Leptin receptor is a transmembrane receptor that regulates reproduction at molecular level.Since for action of any hormone on target cell and to have local action on any tissue, expression of its own receptor is necessary and also it is not known whether such improvement in ovarian follicular development by Leptin is mediated through presence of its homologous receptors in the sheep ovaries. Therefore this study aimed on expression of Leptin receptor mRNA in cultured ovarian follicles of sheep by RT PCR.Methods: Leptin receptor mRNA expression in sheep was studied using qRT-PCR from: (i) In vivo grown preantral, early antral, antral, large antral follicles and cumulus oocyte complexes obtained from large antral follicles subjected to 24h of in vitro maturation and (ii) PFs’ exposed to three different culture media for 3min, two, four or six days and subsequently matured in vitro for 24h. Result: Leptin receptor was observed at all stages ovarian follicles in both cumulus cells and oocytes. Leptin supplementation along with other growth factors and hormones stimulated the expression of its receptor mRNA which is parallel to in vivo stages which could suggest synergistic action of growth factors and hormones with Leptin.

Assessment of expression levels of leptin and leptin receptor as potential biomarkers for risk of prostate cancer development and aggressiveness.

BackgroundProstate cancer (PCa) is one of the most frequently diagnosed cancers worldwide. Despite the growing evidence associating obesity and adipokines, particularly leptin and its receptors, with cancer development and progression, it is still a debatable matter in PCa.ObjectivesWe aimed to assess the role of leptin and its receptors as potential biomarkers for the risk of PCa development and aggressiveness.MethodsIn this study, 176 men were included and categorized according to an established histopathological diagnosis into three age‐ and BMI‐matched groups. The PCa group included 56 patients while the BPH group and the control group comprised 60 men each. Serum levels of total PSA (tPSA) were assessed by ELISA and mRNA expression levels of leptin and leptin receptors were assessed by RT‐PCR.ResultsLeptin and leptin receptor mRNA expression levels were significantly higher in PCa patients relative to BPH and to healthy control men. Both were overexpressed in PCa patients with aggressive and distantly metastasizing tumors compared to patients with confined tumors. Leptin receptor mRNA was an independent predictor of high Gleason score ≥ 7, distant metastasis, LN, and seminal vesicles invasion.ConclusionLeptin and its receptors are suggested to be potential biomarkers for PCa; leptin receptor mRNA might predict risk and aggressiveness of PCa.

Ghrelin antagonist regulates metabolic hormone receptorsin the hypothalamus of ewes

Abstract This study evaluates the effects of ghrelin antagonist on mRNA abundance for metabolic hormone receptors in feed-restricted ewes. Ewes were randomly assigned to one of three treatments; Control (CO): feed above maintenance energy intake requirements and daily subcutaneous saline infusion; Feed restriction (FR): feed restricted and daily subcutaneous saline infusion; Ghrelin antagonist (GA): feed restricted and daily subcutaneous of 7.5 μg/kg of d -Lys3-GHRP-6. Blood was sampled on days 1, 4, 9, and 13, relative to the start of the experiment, to quantify plasma glucose, NEFA and ghrelin concentrations. At day 13, the hypothalamus was collected to evaluate relative mRNA expression. The CO ewes had lesser plasma NEFA concentration compared with FR and GA ewes. There was a treatment by time interaction for plasma glucose concentration, all treatment started with similar plasma glucose concentration, but at day 13 CO ewes had a greater plasma concentration than FR and GA. Relative mRNA expression for glucagon receptor in GA ewes tended to be lesser compared with CO and FR treated ewes. There were no differences in insulin receptor mRNA relative expression between the groups. Ghrelin receptor mRNA relative expression tended to be greater in the GA compared with the CO treated ewes. There was no effect of GA on leptin receptors. However, there was a tendency toward greater relative expression of leptin receptor mRNA in the FR compared with the CO ewes. Relative expression of adiponectin receptor mRNA was lesser in the GA compared with CO and FR ewes. Cortisol receptor relative mRNA expression was greater in the FR compared with the CO ewes. Restricting dietary intake of ewes change mRNA relative expression of cortisol and leptin receptors in the hypothalamus of ewes. These variations are countered with ghrelin antagonist. Ghrelin antagonist modifies the mRNA relative expression of ghrelin, glucagon and adiponectin receptors. These results suggest that ghrelin could regulates metabolic hormone activity by modifying the relative expression of their receptors mRNA.

Delayed access to feed alters gene expression associated with hormonal signaling, cellular differentiation, and protein metabolism in muscle of newly hatch chicks

Birds rely solely on utilization of the yolk sac as a means of nutritional support throughout embryogenesis and early post-hatch, before first feeding occurs. Newly hatched broiler (meat-type) chickens are frequently not given immediate access to feed, and this can result in numerous alterations to developmental processes, including those that occur in muscle. The objective of this study was to characterize the gene expression profile of newly hatched chicks’ breast muscle with regards to hormonal regulation of growth and metabolism and development and differentiation of muscle tissue, and determine impacts of delayed access to feed on these profiles. Within 3 h of hatch, birds were placed in battery pens and given immediate access to feed (Fed) or delayed access to feed for 48 h (Delayed Fed). Breast muscle collected from male birds at hatch, or 4 h, 1 day (D), 2D, 4D, and 8D after hatch was used for analysis of mRNA expression by reverse transcription-quantitative PCR. Under fully fed conditions, insulin-like growth factor receptor and leptin receptor mRNA expression decreased as birds aged; however, delayed access to feed resulted in prolonged upregulation of these genes so their mRNA levels were higher in Delayed Fed birds at 2D. These expression profiles suggest that delayed feed access alters sensitivity to hormones that may regulate muscle development. Myogenin, a muscle differentiation factor, showed increasing mRNA expression in Fed birds through 2D, after which expression decreased. A similar expression pattern in Delayed Fed birds was deferred until 4D. Levels of myostatin, a negative regulator of muscle growth, increased in Fed birds starting at 2D, while levels in Delayed Fed birds began to increase at 4D. In Fed birds, levels of transcripts for two genes associated with protein catabolism, F-box protein 32 and forkhead box O3, were lower at 2D, while Delayed Fed mRNA levels did not decrease until 4D. Mechanistic target of rapamycin mRNA levels decreased from 1D through 8D in both treatments, except for a transient increase in the Delayed Fed birds between 1D and 2D. These data suggest that within breast muscle, delayed feeding alters hormonal signaling, interrupts tissue differentiation, postpones onset of growth, and may lead to increased protein catabolism. Together, these processes could ultimately contribute to a reduction in proper growth and development of birds not given feed immediately after hatch, and ultimately hinder the long-term potential of muscle accretion in meat type birds.

The role of leptin in nutritional status and reproductive function

Infertility associated with suboptimal nutrition is a major concern among livestock producers. Undernourished prepubertal animals will not enter puberty until they are well fed; similarly, adult, normally cyclic females will stop cycling when faced with extreme undernutrition. Work in our laboratory has focused on how body fat (or adiposity) of an animal can communicate to the brain and regulate reproductive competence. In 1994, the discovery in rodents of the obese (ob) gene product leptin, secreted as a hormone from adipocytes, provided a unique opportunity to understand and hence regulate whole body compositional changes. There is now evidence that similar mechanisms are functioning in livestock species in which food intake, body composition, and reproductive performance are of considerable economic importance. Leptin has been reported to be a potent regulator of food intake and reproduction in rodents. There is evidence indicating that at least some of the effects of leptin occur through receptor-mediated regulation of the hypothalamic protein neuropeptide Y (NPY). NPY is a potent stimulator of food intake, is present at high concentrations in feed-restricted cattle and ewes, and is an inhibitor of LH secretion in these livestock species. In our investigations in sheep, we have cloned a partial cDNA corresponding to the ovine long-form leptin receptor, presumably the only fully active form, and have localized the long-form leptin receptor in the ventromedial and arcuate nuclei of the hypothalamus. Leptin receptor mRNA expression was colocalized with NPY mRNA-containing cell bodies in those regions. We have also determined that hypothalamic leptin receptor expression is greater in feed-restricted ewes than in well-fed ewes. These observations provide a foundation for future investigations into the nutritional modulators of reproduction in livestock.

Novel variant in the leptin receptor (LEPR) gene and its association with fat quality, odour and flavour in sheep

The aim of this study was to investigate the association and expression of LEPR with fat quality, flavour and odour in sheep. A total of 47 rams were used in this study. Fatty acids composition, BCFA (Branch Chanin Fatty Acids; MNA, MP, MOA, and EOA) and skatole (MI) representing fat quality, flavour and odour in sheep were measured at ages of 10-12 months old. Identification of novel variant and expression analysis of LEPR gene with different fat quality, odour and flavour were performed by PCR RFLP and qRT-PCR, respectively. A SNP in genomic region g.40854778 A>C of the LEPR gene was associated (P<0.05) with fat quality of saturated fatty acids (SFA) including [tricosanoic acid (C23:0) and tetracosanoic acid (C24:0)] and poly unsaturated fatty acid (PUFA) [docosahexaenoic acid (C22:6n3)]. However, the novel variant of LEPR was not significantly associated (P<0.05) with fat content, odour and flavour (MNA, MP, MOA, EOA, and MI). The mRNA expression analysis showed that LEPR mRNA expression was higher (P<0.01) in sheep found at the AA genotype. It could be concluded that variant SNP in the LEPR may contribute to fatty acid composition without influencing odour and flavour traits in sheep.

Abstract P2-01-14: Adipocytes and cancer cell interactions promote leptin receptor expression and drive β-catenin-mediated progression in triple negative breast cancer

Abstract Background Triple negative breast cancer (TNBC) patients suffer from poor prognosis due to short-term recurrence and/or metastasis. Obesity is reported to predict poor prognosis of TNBC. However, the mechanisms connecting obesity to progression of TNBC remain unclarified. Methods We co-cultured TNBC model cells with adipocytes differentiated from human adipose-derived mesenchymal stem cells (hMSC-ad) and TNBC patients derived primary adipocytes to examine migration, invasion and metastasis abilities using Transwell assays and tail vein injection xenograft mouse model, respectively. Expression levels of leptin receptor (LEPR) , epithelial-mesenchymal transition (EMT) markers and β-catenin signaling pathway related molecules in the control and co-cultured TNBC model were analyzed by real time quantitative polymerase chain reaction (RT-qPCR) and western blot assays. Downregulation of LEPR by LEPR specific short hairpin RNA (shRNA) and upregulation of the downstream pathway with continuous activated β-catenin were applied to access their roles in adipocytes and cancer cell interactions. Degree of adipocytes infiltration in tumor tissue was evaluated by histopathology. LEPR mRNA expression level in breast cancer and corresponding patients' information was retrieved from The Cancer Genome Atlas (TCGA) database. Results Here we first reported that both hMSC-ad- and patients-derived adipocytes promoted migration and invasion of TNBC model cells in vitro and lung metastasis in vivo. Adipocytes were then confirmed to induce upregulation of LEPR in each TNBC model cell compared to the control groups (p<0.0001), resulting in higher expression of EMT markers and molecules related to β-catenin signaling pathway.Afterwards, LEPR knockdown led to decreased migration, invasion and metastasis capacities, as well as reduced expression of EMT markers and molecules related to ?-catenin signaling pathway, while activation of ?-catenin could restore robust EMT and metastatic abilities of TNBC model cells. Last, clinical specimen analyses showed that infiltration of adipocytes to tumor tissue was significantly associated with shorter DFS of TNBC patients (p<0.05) and upregulated LEPR in breast cancer tissue indicated poor prognosis (median OS of 7.43 vs 10.81 years of the LEPR-low group, p < 0.05). Conclusions To our knowledge, adipocytes are first shown to promote progression of TNBC via previously uncharacterized LEPR-β-catenin signaling pathway. Citation Format: Feng Z, Tao Z, Hu X. Adipocytes and cancer cell interactions promote leptin receptor expression and drive β-catenin-mediated progression in triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-01-14.

Lack of Suppression of Aldosterone Production Leads to Salt-Sensitive Hypertension in Female but Not Male Balb/C Mice.

Clinical studies indicate that salt-sensitive hypertension is more prevalent in women than in men. However, animal models of salt sensitivity have primarily focused on the mechanisms of salt sensitivity in male animals; therefore, elucidation of these mechanisms in female animal models is needed. We have previously shown that female Balb/C mice have higher aldosterone synthase expression and aldosterone production than males. We hypothesized that female Balb/C mice develop salt-sensitive increases in blood pressure. Seven-day feeding of a 4% NaCl high-salt (HS) diet increased blood pressure in female mice without altering blood pressure in males. Females on an HS diet displayed no apparent increases in sodium retention as assessed by 24-hour urine collection, sodium balance measure, and saline loading excretion analysis. Females on an HS diet exhibited lower renin-angiotensin system activity (plasma Ang II [angiotensin II], plasma renin activity, and ACE [angiotensin-converting enzyme] activity) compared with males but developed a salt-induced elevation in adrenal aldosterone synthase expression and retained higher aldosterone levels than males on HS. This resulted in a higher aldosterone/plasma renin activity ratio in females compared with males on HS feeding. Adrenal mRNA expression of angiotensinogen and leptin receptor was increased in female mice on an HS diet. HS impaired endothelium-dependent relaxation in female mice only. MR (mineralocorticoid receptor) inhibition (eplerenone) restored blood pressure and endothelial function in females on an HS diet. Collectively, these data indicate that Balb/C mice develop sex-discrepant salt-sensitive hypertension likely via aldosterone-MR-mediated mechanisms involving impaired endothelium-dependent relaxation in females only. This study presents the first model of spontaneous sex-specific salt sensitivity, which mimics the human pathology.

Effects of Resistance Exercise Training on Leptin Receptor (Ob-R), GLUT2 mRNA of the Hypothalamus and GLUT4 mRNA Expression of the Skeletal Muscle in OLETF Rats

PURPOSE The hypothalamus plays a central role in integrating hormonal and nutritional signals from the periphery and modulating food intake, energy balance. However, obesity and type 2 diabetes cause dysfunction of hypothalamus. This study was to investigate the effects of 8 weeks resistance exercise training on leptin receptor, GLUT2 mRNA of the hypothalamus and skeletal muscle GLUT4 mRNA expression in OLETF rats. METHODS Thirty male OLETF rats were randomly divided into three groups: LETO (CON, n=10), OLETF (OLETF+CON, n=10), OLETF+resistance exercise (OLETF+EXE, n=10). Exercise group conducted gradual ladder climbing exercise 3 days per week for 8 weeks. RESULTS The results of this study was following; In the hypothalamus, leptin receptor (Ob-R) and GLUT2 mRNA expression were significantly increased in OLETF+EXE group compared with OLETF group (p<.05). Activation of AMPK was significantly decreased in OLETF+EXE group compared to OLETF group (p<.05). GLUT4 mRNA expression of skeletal muscle was significantly increased in OLETF+EXE group compared with OLETF group (p<.05), and HOMA-IR index also was significantly lower in OLETF+EXE group than OLETF group (p<.05). CONCLUSIONS These results showed that 8 weeks resistance exercise training can improve leptin receptor mRNA expression and glucose sensing in hypothalamic. Also, these effects may contribute to energy homeostasis in peripheral such as skeletal muscle. 색인어: ì €í•­ì„± 운동, 시상하부, ì œ2형 당뇨병, ë ™í‹´ìˆ˜ìš©ì²´, GLUTs Keywords: Resistance exercise, Hypothalamus, Type 2 diabetes mellitus, Leptin receptor (Ob-R), GLUTs

Induction of uterine hyperplasia after cafeteria diet exposure.

Our aim was to evaluate whether chronic administration of CAF affects the uterus and induces the morphological and molecular changes associated with endometrial hyperplasia. Female Wistar rats exposed to CAF from weaning for 20 weeks displayed increased energy intake, body weight and fat depots, but did not develop metabolic syndrome. The adult uteri showed an increase in glandular volume fraction and stromal area. The epithelial proliferation rate and protein expression of oestrogen receptor alpha (ERα) were also increased. The CAF diet enhanced leptin serum levels and the long form of leptin receptor (Ob-Rb) mRNA expression in the uterus. No changes were detected in either insulin serum levels or those of insulin growth factor I (IGF-I) mRNA expression. However the levels of IGF-I receptor (IGF-IR) mRNA were lower in CAF-fed animals. Overall, the results indicate that our rat model of the CAF diet produces morphological and molecular changes associated with uterine hyperplasia and could predispose to endometrial carcinogenesis.

Optimal dietary lipid level promoted ovary development of Chinese sturgeon (Acipenser sinensis) broodstocks

A one-year feeding trial was conducted to determine the effects of dietary lipid level on gonad development and steroidogenesis-related gene expressions of Chinese sturgeon (Acipenser sinensis). Three isonitrogenous experimental diets (L10, L14 and L18) were compounded with different lipid levels. Results of the feeding trial showed that 2 female Chinese sturgeons in L18 group had developed the ovary to stage III. Chi-square independence test indicated that ovary development was significantly affected by dietary lipid level (P < .05). Po and d values of ovary also increased with dietary lipid level. Serum estradiol (E2) and testosterone (T) of L14 group was significantly higher than those in the other two groups (P < .05). Blood urea nitrogen (BUN) content decreased as dietary lipid level increased, while triglyceride (TG) and glucose (GLU) contents increased with dietary lipid level (P < .05). Vitellogenin receptor (vtgr) mRNA expression increased with dietary lipid level (P < .05); Gene expressions of androgen receptor (ar), cytochrome p450 17A1 (cyp17a1), steroidogenic acute regulatory protein (star), follicle stimulating hormone receptor (fshr), luteinizing hormone receptor (lhr) and cytochrome p450 aromatase (cyp19a1) were significantly higher in L14 group than in other groups (P < .05), whereas mRNA expression of leptin receptor (lepr) and DNA-binding protein inhibitor ID-1 (dbi) in L14 group were significantly lower (P < .05). Based on the gonad development, higher dietary lipid level (16.31%) would promote ovary development of Chinese sturgeon broodstocks through the elevation of vtgr expression to increase the assimilation of vitellogenin in ovary.

Pregnancy Promotes Inflammation and Pro‐contractile Effects in Uterine Perivascular Adipose Tissue

BackgroundPerivascular adipose tissue (PVAT) regulates function and remodeling of its adjacent arteries via paracrine actions of adipocyte‐derived factors. The vasoactive effects of PVAT are vascular bed specific and the morphology and function of perivascular adipocytes differs from adipocytes of other adipose depots. In normal pregnancy, there is an increase in circulating adipokines, expansion and inflammation of non‐perivascular adipose tissue; however, the metabolic and inflammatory profiles of PVAT have not been defined. In addition, in normal pregnancy, extensive uterine artery remodeling and increased vasodilatory responses contribute to increased uterine blood flow. Whether uterine PVAT plays a role in these adaptations is currently unknown. Thus, our goals are to define the metabolic and inflammatory profiles of uterine PVAT, and examine its vasoactive effects during pregnancy.HypothesisIn normal pregnancy, uterine PVAT would have increased inflammation and modulate uterine artery reactivity.MethodsUterine PVAT, mesenteric and uterine arteries from pregnant (gestational day 16, term=22–23) and aged‐matched non‐pregnant rats were used. To determine gene and protein expression of adipokines in uterine PVAT, we used reverse transcription polymerase chain reaction (RT‐PCR) and a proteome adipokine profiler, respectively. Circulating leptin and adiponectin concentrations were determined using ELISA. To evaluate the vasoactive effects of uterine PVAT on uterine artery function, we measured uterine and mesenteric artery reactivity in the presence and absence of uterine PVAT using wire myography.ResultsGene expression of interleukin (IL)‐11, and monocyte chemoattractant protein‐1 (MCP‐1) were upregulated in uterine PVAT from pregnant rats by 4.8‐ and 2.8‐fold, respectively, as compared to non‐pregnant rats. Protein expression of these adipocytokines as well as expression of IL‐6 and IL‐10 were also greater in uterine PVAT from pregnant compared to non‐pregnant rats. While mRNA expression of leptin receptor, OB‐Rb, did not change with pregnancy, leptin gene expression was downregulated by 1.7‐fold. Pregnancy did not affect mRNA expression of adiponectin and its receptor, Adipo‐R1, in uterine PVAT. Leptin (112.6 ± 10.7 pg/ml vs. 251.0 ± 25.8 pg/ml) and adiponectin (17561 ± 1460 ng/ml vs. 25564 ± 2950 ng/ml) concentrations were greater in sera from pregnant compared to non‐pregnant rats (p≤0.02). Uterine arteries from pregnant rats incubated with PVAT had increased contractile responses to potassium chloride [KCl (30 mM), PVAT(−): 4.0 ± 0.8 mN vs. PVAT(+): 14.7 ± 1.7 mN, p&lt;0.05]. To establish whether the vasoactive effects of uterine PVAT are vascular bed specific, mesenteric arteries from pregnant rats were incubated with uterine PVAT. Arteries incubated with uterine PVAT had increased contractile responses to KCl [area under the curve, PVAT(−): 366 ± 46 vs. PVAT(+): 529 ± 53, p=0.02].ConclusionPregnancy upregulates inflammation, alters expression of adipokines and their receptors, and promotes a pro‐contractile profile in uterine PVAT.Support or Funding InformationUNT Health Science Center Pilot Grant.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Gene expression profiling in embryonic chicken ovary during asymmetric development.

The reproductive system in female birds arises as bilateral asymmetrical anlagen, excluding the birds of prey. Earlier, histological and messenger RNA (mRNA) expression profile studies of several genes related to gonadal sex differentiation in chicken embryos tried to elucidate the query of this asymmetry in a scattered manner. To understand the matter precisely, we have focused on mRNA expression of a cohort of genes (FSHR, CYP19A1, caspase 3, caspase 8) in second half of the embryonic days (E10-E18). The established role of leptin in development of the embryo and its expression in the embryonic ovary also drove us to check leptin receptor (LEPR) expression in the ovary. Increased expression of FSHR and CYP19A1 in the left ovary compared with that in the right ovary was identified (P<0.05), promoting preferential left ovarian development and functionality. Significant high expression (P<0.05) of the apoptotic genes in the right ovary were also involved here. Leptin probably has no direct influence on ovarian asymmetry as no significant variation in gonadal mRNA expression of LEPR was observed within the same experimental days. We propose that asymmetric expression of this cohort of genes (FSHR, CYP19A1, caspase 3, caspase 8) leads to the development of dimorphic gonads during embryogenesis.

Abstract A09: Role of adipocytokines in obesity associated Triple Negative Breast Cancer

Abstract Background: Triple-negative breast cancer (TNBC), accounts for a large percentage of breast cancer cases in India including Northeast India. TNBC has an unclear molecular aetiology and hence limited targeted therapies. Human breast is comprised of glandular, ductal, connective, and adipose tissues. Adipose tissue is composed of adipocytes. The adipocytes apart from being energy storage depots are also active sources of adipocytokines and/or adipokines. The role of adipokines in breast cancer including TNBC has been sporadically documented. Two adipokines in particular, leptin and adiponectin, have come to be recognized for their influence on breast cancer risk and tumor biology. Therefore, the aim of this study was to understand the association of differential expression of critical adipokines and associated cellular mechanism in the susceptibility and severity of TNBC in northeast Indian population. Materials and Methods: We collected 68 TNBC and 63 controls cases and examined for serum leptin and adiponectin levels using enzyme linked immunosorbent assay (ELISA). Leptin Receptor (Ob-R) mRNA expression was determined by real-time polymerase chain reaction (RT-PCR) assay. Differential Ob-R mRNA expression and correlation with cancer stem cell (CSC) markers oct4 and nanog was evaluated, and correlated with severity. Results: The serum leptin levels were significantly associated with TNBC severity, while the adiponectin levels were comparative. The serum leptin levels correlated inversely with the adiponetin levels. Serum leptin levels were unaffected with difference in parity. The difference in leptin levels in pre and post menopausal cases were found to be statistically non-significant. Higher leptin levels were also found to be associated obesity, mortality and recurrence. Obesity was found to be a factor for TNBC pathogenesis and severity. Increased Ob-R mRNA expression was associated with TNBC, significantly with TNBC severity, and was significantly higher in obese patients with higher grade TNBC cases. The Ob-R gene mRNA expression was significantly higher in the obese TNBC cases showing recurrence or mortality. The higher Ob-R gene mRNA expression correlated significantly with higher serum leptin levels and lower serum adiponectin levels in TNBC cases. The Ob-R mRNA expression with associated with modulation of CSC. Conclusions: In conclusion, the present study is first of its kind on TNBC from northeast India, indicates that adipocytokines does play a role in TNBC pathogenesis. Thus, the understanding of molecular mechanisms of both leptin and adiponectin and their interplay in TNBC offer the prospects for new therapeutic approaches targeting similar signaling pathways. Note: This abstract was not presented at the conference. Citation Format: Rizwana Sultana, Amal Ch Kataki, Bibhuti Bhusan Barthakur, Sujoy Bose. Role of adipocytokines in obesity associated Triple Negative Breast Cancer [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr A09.

Imbalance in leptin-adiponectin levels and leptin receptor expression as chief contributors to triple negative breast cancer progression in Northeast India

BackgroundTriple-Negative breast cancer (TNBC), accounts for a large percentage of breast cancer cases in India including Northeast India. TNBC has an unclear molecular aetiology and hence limited targeted therapies. Human breast is comprised of glandular, ductal, connective, and adipose tissues. Adipose tissue is composed of adipocytes. The adipocytes apart from being energy storage depots, are also active sources of adipocytokines and/or adipokines. The role of adipokines in breast cancer including TNBC has been sporadically documented. Two adipokines in particular, leptin and adiponectin, have come to be recognized for their influence on breast cancer risk and tumour biology. Therefore, the aim of this study was to understand the association of differential expression of critical adipokines and associated cellular mechanism in the susceptibility and severity of TNBC in northeast Indian population. Materials and methodsWe collected 68 TNBC and 63 controls cases and examined for serum leptin and adiponectin levels using enzyme linked immunosorbent assay (ELISA). Leptin Receptor (Ob-R) mRNA expression was determined by real-time polymerase chain reaction (RT-PCR) assay. Differential Ob-R mRNA expression and correlation with cancer stem cell (CSC) markers was evaluated, and correlated with severity. ResultsThe serum leptin levels were significantly associated with TNBC severity, while the adiponectin levels were comparative. The serum leptin levels correlated inversely with the adiponetin levels. Serum leptin levels were unaffected with difference in parity. The difference in leptin levels in pre and post menopausal cases were found to be statistically non-significant. Higher leptin levels were also found to be associated obesity, mortality and recurrence. Obesity was found to be a factor for TNBC pathogenesis and severity. Increased Ob-R mRNA expression was associated with TNBC, significantly with TNBC severity, and was significantly higher in obese patients with higher grade TNBC cases. The Ob-R gene mRNA expression was significantly higher in the obese TNBC cases showing recurrence or mortality. The higher Ob-R gene mRNA expression correlated significantly with higher serum leptin levels and lower serum adiponectin levels in TNBC cases. The Ob-R mRNA expression with associated with modulation of CSC oct4 and nanog. ConclusionsIn conclusion, the present study is first of its kind on TNBC from northeast India, indicates that adipocytokines does play a role in TNBC pathogenesis. Thus, the understanding of molecular mechanisms of both leptin and adiponectin and their interplay in TNBC offer the prospects for new therapeutic approaches targeting similar signalling pathways.