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1.
J Neurosci ; 44(14)2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38395612

ABSTRACT

ß-Catenin is a bifunctional molecule that is an effector of the wingless-related integration site (Wnt) signaling to control gene expression and contributes to the regulation of cytoskeleton and neurotransmitter vesicle trafficking. In its former role, ß-catenin binds transcription factor 7-like 2 (TCF7L2), which shows strong genetic associations with the pathogenesis of obesity and type-2 diabetes. Here, we sought to determine whether ß-catenin plays a role in the neuroendocrine regulation of body weight and glucose homeostasis. Bilateral injections of adeno-associated virus type-2 (AAV2)-mCherry-Cre were placed into the arcuate nucleus of adult male and female ß-catenin flox mice, to specifically delete ß-catenin expression in the mediobasal hypothalamus (MBH-ß-cat KO). Metabolic parameters were then monitored under conditions of low-fat (LFD) and high-fat diet (HFD). On LFD, MBH-ß-cat KO mice showed minimal metabolic disturbances, but on HFD, despite having only a small difference in weekly caloric intake, the MBH-ß-cat KO mice were significantly heavier than the control mice in both sexes (p < 0.05). This deficit seemed to be due to a failure to show an adaptive increase in energy expenditure seen in controls, which served to offset the increased calories by HFD. Both male and female MBH-ß-cat KO mice were highly glucose intolerant when on HFD and displayed a significant reduction in both leptin and insulin sensitivity compared with controls. This study highlights a critical role for ß-catenin in the hypothalamic circuits regulating body weight and glucose homeostasis and reveals potential mechanisms by which genetic variation in this pathway could impact on development of metabolic disease.


Subject(s)
Diabetes Mellitus, Type 2 , Diet, High-Fat , Animals , Female , Male , Mice , beta Catenin/genetics , beta Catenin/metabolism , Body Weight/genetics , Diabetes Mellitus, Type 2/pathology , Diet, High-Fat/adverse effects , Energy Metabolism/genetics , Glucose/metabolism , Hypothalamus/metabolism , Leptin/metabolism , Mice, Inbred C57BL , Mice, Knockout , Obesity/genetics , Obesity/metabolism
2.
J Neuroendocrinol ; 35(8): e13326, 2023 08.
Article in English | MEDLINE | ID: mdl-37534400

ABSTRACT

Gluten, which is found in cereals such as wheat, rye and barley, makes up a major dietary component in most western nations, and has been shown to promote body mass gain and peripheral inflammation in mice. In the current study, we investigated the impact of gluten on central inflammation that is typically associated with diet-induced obesity. While we found no effect of gluten when added to a low-fat diet (LFD), male mice fed high fat diet (HFD) enriched with gluten increased body mass and adiposity compared with mice fed HFD without gluten. We furthermore found that gluten, when added to the LFD, increases circulating C-reactive protein levels. Gluten regardless of whether it was added to LFD or HFD led to a profound increase in the number of microglia and astrocytes in the arcuate nucleus of the hypothalamus, as detected by immunohistochemistry for ionised calcium binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP), respectively. In mice fed LFD, gluten mimicked the immunogenic effects of HFD exposure and when added to HFD led to a further increase in the number of immunoreactive cells. Taken together, our results confirm a moderate obesogenic effect of gluten when fed to mice exposed to HFD and for the first-time report gluten-induced astro- and microgliosis suggesting the development of hypothalamic injury in rodents.


Subject(s)
Hypothalamus , Triticum , Mice , Male , Animals , Triticum/metabolism , Hypothalamus/metabolism , Obesity/metabolism , Diet, High-Fat/adverse effects , Inflammation/metabolism , Glutens/metabolism , Mice, Inbred C57BL
3.
Waste Manag Res ; 41(6): 1063-1080, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36644994

ABSTRACT

With the burning issue of air, land and water pollution, the premonition of looking forward towards a future devoid of any kind of oil and gas reserves has caused a paradigm shift towards recycling, recovery of any synthetic polymer and also to dispose them off environmentally. Among them are plastics such as polyethylene terephthalate and poly vinyl chloride. Polyurethane (PU) is also under the scanner to dispose of or recycle it environmentally and sustainably. PU is at present the sixth most utilized polymer all over the world with a production of nearly 18 million tonnes per annum, which roughly estimates a daily production of PU products of greater than a million of cubic metres. Its thermostable nature is one of the major reasons for its higher preference over other polymers. This review article discusses the current disposal and technologies available to recycle waste PU foams and also sheds some light on some additional work being done in the field to upgrade the existing technology. Interestingly, some methods mentioned here are probably undergoing scale-up trials runs by now. Currently, the most researched and studied ones are mechanical recycling and glycolysis. But microbial and enzymatic disposal methods can be turned into full-scale industrial recycling processes in the near future. Additionally, we can see an archetypal shift from traditional oil-based sources to the agrarian sources.


Subject(s)
Polyurethanes , Waste Management , Plastics , Polymers , Recycling/methods
4.
FASEB J ; 36(3): e22207, 2022 03.
Article in English | MEDLINE | ID: mdl-35188286

ABSTRACT

Leptin is best known for its role in adipostasis, but it also regulates blood glucose levels. The molecular mechanism by which leptin controls glucose homeostasis remains largely unknown. Here, we use a zebrafish model to show that Wnt signaling mediates the glucoregulatory effects of leptin. Under normal feeding conditions, leptin regulates glucose homeostasis but not adipostasis in zebrafish. In times of nutrient excess, however, we found that leptin also regulates body weight and size. Using a Wnt signaling reporter fish, we show that leptin activates the canonical Wnt pathway in vivo. Utilizing two paradigms for hyperglycemia, it is revealed that leptin regulates glucose homeostasis via the Wnt pathway, as pharmacological inhibition of this pathway impairs the glucoregulatory actions of leptin. Our results may shed new light on the evolution of the physiological function of leptin.


Subject(s)
Glucose/metabolism , Hyperglycemia/metabolism , Leptin/metabolism , Wnt Signaling Pathway , Animals , Homeostasis , Leptin/genetics , Receptors, Leptin/genetics , Receptors, Leptin/metabolism , Zebrafish , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolism
5.
J Neurosci ; 41(3): 474-488, 2021 01 20.
Article in English | MEDLINE | ID: mdl-33219002

ABSTRACT

RF-amide related peptide 3 (RFRP-3) is a neuropeptide thought to inhibit central regulation of fertility. We investigated whether alterations in RFRP neuronal activity led to changes in puberty onset, fertility, and stress responses, including stress and glucocorticoid-induced suppression of pulsatile luteinizing hormone secretion. We first validated a novel RFRP-Cre mouse line, which we then used in combination with Cre-dependent neuronal ablation and DREADD technology to selectively ablate, stimulate, and inhibit RFRP neurons to interrogate their physiological roles in the regulation of fertility and stress responses. Chronic RFRP neuronal activation delayed male puberty onset and female reproductive cycle progression, but RFRP-activated and ablated mice exhibited apparently normal fertility. When subjected to either restraint- or glucocorticoid-induced stress paradigms. However, we observed a critical sex-specific role for RFRP neurons in mediating acute and chronic stress-induced reproductive suppression. Female mice exhibiting RFRP neuron ablation or silencing did not exhibit the stress-induced suppression in pulsatile luteinizing hormone secretion observed in control mice. Furthermore, RFRP neuronal activation markedly stimulated glucocorticoid secretion, demonstrating a feedback loop whereby stressful stimuli activate RFRP neurons, which in turn further activate the stress axis. These data provide evidence for a neuronal link between the stress and reproductive axes.


Subject(s)
Neurons/physiology , Neuropeptides/physiology , Reproduction/physiology , Stress, Psychological/physiopathology , Animals , Female , Fertility/physiology , Gene Knock-In Techniques , Gene Silencing , Genotype , Glucocorticoids/metabolism , Luteinizing Hormone/metabolism , Male , Mice , Mice, Inbred C57BL , Neuropeptides/genetics , Restraint, Physical , Sex Characteristics , Sexual Maturation/physiology
6.
FASEB J ; 35(2): e21216, 2021 02.
Article in English | MEDLINE | ID: mdl-33230896

ABSTRACT

Obesity has emerged as a major risk factor for insulin resistance leading to the development of type 2 diabetes (T2D). The condition is characterized by high circulating levels of the adipose-derived hormone leptin and a state of chronic low-grade inflammation. Pro-inflammatory signaling in the hypothalamus is associated with a decrease of central leptin- and insulin action leading to impaired systemic glucose tolerance. Intriguingly, leptin not only regulates body weight and glucose homeostasis but also acts as a pro-inflammatory cytokine. Here we demonstrate that increasing leptin levels (62,5 µg/kg/d, PEGylated leptin) in mice fed a high-fat diet (HFD) exacerbated body weight gain and aggravated hypothalamic micro- as well as astrogliosis. In contrast, administration of a predetermined dose of a long-acting leptin antagonist (100 µg/kg/d, PESLAN) chosen to block excessive leptin signaling during diet-induced obesity (DIO) showed the opposite effect and significantly improved glucose tolerance as well as decreased the total number of microglia and astrocytes in the hypothalamus of mice fed HFD. These results suggest that high levels of leptin, such as in obesity, worsen HFD-induced micro-and astrogliosis, whereas the partial reduction of hyperleptinemia in DIO mice may have beneficial metabolic effects and improves hypothalamic gliosis.


Subject(s)
Glucose Intolerance/metabolism , Leptin/metabolism , Obesity/metabolism , Animals , Anti-Obesity Agents/pharmacology , Anti-Obesity Agents/therapeutic use , Diet, High-Fat/adverse effects , Gliosis/drug therapy , Gliosis/metabolism , Glucose Intolerance/drug therapy , Hypothalamus/metabolism , Hypothalamus/pathology , Leptin/analogs & derivatives , Leptin/antagonists & inhibitors , Male , Mice , Mice, Inbred C57BL , Obesity/drug therapy , Polyethylene Glycols/chemistry
7.
Br J Nutr ; 125(9): 972-982, 2021 05 14.
Article in English | MEDLINE | ID: mdl-32594917

ABSTRACT

To induce diet-induced obesity (DIO) in rodents, diets high in saturated fat and/or carbohydrates are commonly used. In the laboratory, standardised diets evolved over time without paying particular attention to the effect of fat composition on metabolic alterations. In the present study, customised high-fat diets (HFD) enriched with a combination of lard and different concentrations of New Zealand green-lipped mussel (Perna canaliculus) oil or MSC Hoki (Macruronus novaezelandiae, blue grenadier) liver oil, important sources of n-3 PUFA, in comparison with a solely lard-based diet, were fed to lean and DIO male C57BL/6 mice and their effects on metabolic parameters were monitored. Intriguingly, an isoenergetic HFD containing 63 % of total fat in the form of mussel oil and only 28 % in the form of lard attenuated HFD-induced body weight gain after 1 and 4 weeks, respectively. Consistently, changing a lard-enriched HFD to the mussel oil diet reduced body weight markedly even after mice had been exposed to the former diet for 10 months. The weight-reducing effect of the diet was not caused by altered energy intake or expenditure, but was associated with reduced visceral fat mass. Collectively, these data suggest a novel weight-reducing potential of green-lipped mussel oil.


Subject(s)
Bivalvia , Diet, High-Fat , Dietary Fats, Unsaturated/administration & dosage , Fatty Acids, Omega-3/administration & dosage , Metabolism , Weight Loss , Animals , Body Water/metabolism , Body Weight , Calorimetry, Indirect , Carbon Dioxide/metabolism , Dietary Fats , Eating , Energy Intake , Energy Metabolism , Homeostasis , Male , Mice , Mice, Inbred C57BL , Obesity , Oxygen Consumption
8.
FASEB J ; 33(11): 12175-12187, 2019 11.
Article in English | MEDLINE | ID: mdl-31366239

ABSTRACT

Synchronization between biologic clocks and metabolism is crucial for most species. Here, we examined the ability of leptin, important in the control of energy metabolism, to induce leptin signaling at the molecular as well as the behavioral level throughout the 24-h day in mice fed either a control or a high-fat diet (HFD). Furthermore, we investigated the effects of time-restricted feeding (TRF; a limitation of HFD access to 6 h each day) on energy metabolism during different periods throughout the 24-h day. In control mice, molecular leptin sensitivity was highest at zeitgeber time (ZT)0 (lights on), declining during the light phase, and increasing during the dark phase. Surprisingly, leptin resistance in HFD-fed mice was only present from the middle of the dark to the middle of the light period. Specifically, when TRF occurred from ZT21 to ZT3 (when leptin resistance in HFD-fed mice was most profound), it resulted in a disruption of the daily rhythms of locomotor activity and energy expenditure and in increased plasma insulin levels compared with other TRF periods. These data provide evidence that leptin sensitivity is controlled by the circadian rhythm and that TRF periods may be most efficient when aligned with the leptin-sensitive period.-Boucsein, A., Rizwan, M. Z., Tups, A. Hypothalamic leptin sensitivity and health benefits of time-restricted feeding are dependent on the time of day in male mice.


Subject(s)
Eating , Energy Metabolism , Hypothalamus/physiology , Leptin/physiology , Animals , Blood Glucose/analysis , Circadian Rhythm , Diet, High-Fat , Insulin/blood , Leptin/blood , Male , Mice , Mice, Inbred C57BL , Oxygen Consumption , STAT3 Transcription Factor/physiology , Time Factors
9.
Endocrinology ; 160(10): 2257-2270, 2019 10 01.
Article in English | MEDLINE | ID: mdl-31276158

ABSTRACT

Recent evidence suggests that the circadian timing system plays a role in energy and glucose homeostasis, and disruptions to this system are a risk factor for the development of metabolic disorders. We exposed animals to a constantly shifting lighting environment comprised of a 6-hour advance, occurring every 6 days, to chronically disrupt their circadian timing system. This treatment caused a gradual increase in body weight of 12 ± 2% after 12 phase shifts, compared with a 6 ± 1% increase in mice under control lighting conditions. Additionally, after the fifth phase shift, light cycle-disrupted (CD) animals showed a reversal in their diurnal pattern of energy homeostasis and locomotor activity, followed by a subsequent loss of this rhythm. To investigate potential molecular mechanisms mediating these metabolic alterations, we assessed central leptin and insulin sensitivity. We discovered that CD mice had a decrease in central leptin signaling, as indicated by a reduction in the number of phosphorylated signal transducer and activator of transcription 3 immunoreactive cells in the arcuate nucleus of the hypothalamus. Furthermore, CD animals exhibited a marked increase in fasting blood glucose (269.4 ± 21.1 mg/dL) compared with controls (108.8 ± 21.3 mg/dL). This dramatic increase in fasting glucose levels was not associated with an increase in insulin levels, suggesting impairments in pancreatic insulin release. Peripheral hyperglycemia was accompanied by central alterations in insulin signaling at the level of phospho Akt and insulin receptor substrate 1, suggesting that light cycle disruption alters central insulin signaling. These results provide mechanistic insights into the association between light cycle disruption and metabolic disease.


Subject(s)
Insulin/physiology , Leptin/physiology , Photoperiod , Signal Transduction/radiation effects , Animals , Biomarkers , Body Weight , Insulin/blood , Leptin/blood , Light , Male , Mice , Mice, Inbred C57BL
10.
J Comp Physiol B ; 189(3-4): 413-424, 2019 08.
Article in English | MEDLINE | ID: mdl-31123821

ABSTRACT

Saturated fatty acids are implicated in the development of metabolic diseases, including obesity and type 2 diabetes. There is evidence, however, that polyunsaturated fatty acids can counteract the pathogenic effects of saturated fatty acids. To gain insight into the early molecular mechanisms by which fatty acids influence hypothalamic inflammation and insulin signalling, we performed time-course experiments in a hypothalamic cell line, using different durations of treatment with the saturated fatty acid palmitate, and the omega-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA). Western blot analysis revealed that palmitate elevated the protein levels of phospho(p)AKT in a time-dependent manner. This effect is involved in the pathogenicity of palmitate, as temporary inhibition of the PI3K/AKT pathway by selective PI3K inhibitors prevented the palmitate-induced attenuation of insulin signalling. Similar to palmitate, DHA also increased levels of pAKT, but to a weaker extent. Co-administration of DHA with palmitate decreased pAKT close to the basal level after 8 h, and prevented the palmitate-induced reduction of insulin signalling after 12 h. The monounsaturated fatty acid oleate had a similar effect on the palmitate-induced attenuation of insulin signalling, the polyunsaturated fatty acid linoleate had no effect. Measurement of the inflammatory markers pJNK and pNFκB-p65 revealed tonic elevation of both markers in the presence of palmitate alone. DHA alone transiently induced elevation of pJNK, returning to basal levels by 12 h treatment. Co-administration of DHA with palmitate prevented palmitate-induced inflammation after 12 h, but not at earlier timepoints.


Subject(s)
Gene Expression Regulation/drug effects , Hypothalamus/cytology , Neurons/drug effects , Palmitic Acid/pharmacology , Animals , Cell Line , Cell Survival/drug effects , Docosahexaenoic Acids/pharmacology , Hydrazones/pharmacology , Insulin/metabolism , Mice , Morpholines/pharmacology , Oleic Acid/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors/pharmacology , Pyrimidinones/pharmacology , Signal Transduction/drug effects , Sulfonamides/pharmacology
12.
Cardiovasc Ther ; 35(3)2017 Jun.
Article in English | MEDLINE | ID: mdl-28296232

ABSTRACT

AIM: We designed a study to evaluate the cardioprotective effect of two soluble epoxide hydrolase (sEH) inhibitors, 1-(1-propanoylpiperidin-4-yl)-3-(4-trifluoromethoxy)phenyl)urea (TPPU) and trans-4-{4-[3-(4-trifluoromethoxyphenyl)-ureido]cyclohexyloxy}benzoic acid (t-TUCB), in ischemia-reperfusion (IR) model. METHODS: Cardioprotective effects of the sEH inhibitors were evaluated against IR-induced myocardial damage in hearts from normal, hypertensive, and diabetic rats using Langendorff's apparatus. In addition, the effect of sEH inhibitors on endothelial function was evaluated in vitro and ex vivo using isolated rat thoracic aorta. RESULTS: Ischemia-reperfusion (IR) increased the myocardial damage in hearts from normal rats. IR-induced myocardial damage was augmented in hearts isolated from hypertensive and diabetic rats. Myocardial damage as evident from increase in the activities of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) in heart perfusate was associated with significant decrease in the heart rate and developed tension, and increase in the resting tension in isolated heart. Both sEH inhibitors protected the heart in normal, hypertensive, and diabetic rats subjected to IR injury. The sEH inhibitor t-TUCB relaxed phenylephrine precontracted aorta from normal rats. Relaxant effect of acetylcholine (ACh) was reduced in aortas from diabetic and hypertensive rats compared to normal rats. Pretreatment of sEH inhibitors to diabetic and hypertensive rats increased relaxant effect of ACh on aortas isolated from these rats. CONCLUSIONS: Prophylactic treatment with sEH inhibitors decreased myocardial damage due to IR, hypertension and diabetes, and decreased endothelial dysfunction created by diabetes and hypertension. Therefore, inhibitors of sEH are useful probes to study cardiovascular pathology, and inhibition of the sEH is a potential approach in the management of IR-induced cardiac damage and endothelial dysfunction-related cardiovascular disorders.


Subject(s)
Benzoates/pharmacology , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 1/drug therapy , Enzyme Inhibitors/pharmacology , Epoxide Hydrolases/antagonists & inhibitors , Hypertension/drug therapy , Myocardial Reperfusion Injury/prevention & control , Myocardium/enzymology , Phenylurea Compounds/pharmacology , Piperidines/pharmacology , Animals , Aorta, Thoracic/drug effects , Aorta, Thoracic/enzymology , Aorta, Thoracic/pathology , Aorta, Thoracic/physiopathology , Diabetes Mellitus, Experimental/enzymology , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Experimental/physiopathology , Diabetes Mellitus, Type 1/enzymology , Diabetes Mellitus, Type 1/pathology , Diabetes Mellitus, Type 1/physiopathology , Dose-Response Relationship, Drug , Epoxide Hydrolases/metabolism , Heart Rate/drug effects , Hypertension/enzymology , Hypertension/pathology , Hypertension/physiopathology , Isolated Heart Preparation , Male , Myocardial Contraction/drug effects , Myocardial Infarction/enzymology , Myocardial Infarction/etiology , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Myocardial Reperfusion Injury/enzymology , Myocardial Reperfusion Injury/pathology , Myocardial Reperfusion Injury/physiopathology , Myocardium/pathology , Rats, Wistar , Vasodilation/drug effects
13.
Endocrinology ; 157(5): 1991-2001, 2016 05.
Article in English | MEDLINE | ID: mdl-26937712

ABSTRACT

Estradiol and leptin are critical hormones in the regulation of body weight. The aim of this study was to determine whether this cross talk between leptin receptor (LepRb) and estrogen receptor-α (ERα) signaling is critical for estradiol's anorexigenic effects. Leprb-Cre mice were crossed with Cre-dependent Tau-green fluorescent protein (GFP) reporter, Stat3-flox or Erα-flox mice to generate female mice with GFP expression, signal transducer and activator of transcription 3 (STAT3) knockout (KO), or ERα KO, specifically in LepRb-expressing cells. The proportion of Leprb-GFP cells colocalizing ERα was high (∼80%) in the preoptic area but low (∼10%) in the mediobasal hypothalamus, suggesting that intracellular cross talk between these receptors is minimal for metabolic regulation. To test whether estradiol enhanced arcuate leptin sensitivity, ovarectomized mice received varying levels of estradiol replacement. Increasing estrogenic states did not increase the degree of leptin-induced STAT3 phosphorylation. LepRb-specific STAT3 KO mice and controls were ovarectomized and given either chronic estradiol or vehicle treatment to test whether STAT3 is required for estrogen-induced body weight suppression. Both groups of estradiol-treated mice showed an equivalent reduction in body weight and fat content compared with vehicle controls. Finally, mice lacking ERα specifically in LepRb-expressing neurons also showed no increase in body weight or impairments in metabolic function compared with controls, indicating that estradiol acts independently of leptin-responsive cells to regulate body weight. However, fecundity was impaired in in Leprb-ERα KO females. Contrary to the current dogma, we report that estradiol has minimal direct actions on LepRb cells in the mediodasal hypothalamus and that its anorexigenic effects can occur entirely independently of LepRb-STAT3 signaling in female mice.


Subject(s)
Body Weight/genetics , Eating/genetics , Estradiol/pharmacology , Neurons/metabolism , Receptors, Leptin/genetics , Signal Transduction/physiology , Animals , Body Weight/drug effects , Eating/drug effects , Estrogen Receptor alpha/genetics , Estrogen Receptor alpha/metabolism , Female , Hypothalamus/drug effects , Hypothalamus/metabolism , Leptin/metabolism , Mice , Mice, Knockout , Neurons/drug effects , Phosphorylation/drug effects , Receptors, Leptin/metabolism , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , Signal Transduction/drug effects
14.
PLoS One ; 10(10): e0140245, 2015.
Article in English | MEDLINE | ID: mdl-26448186

ABSTRACT

Tuberculosis(TB) is a disease of global significance, which accounts for a death in every 15 seconds. Recent studies shows TB is rising in certain parts of the world, and Saudi Arabia is one of them. Several factor contribute in predisposing the subjects for infection including but not limited to addiction to various compounds which have immune modulation properties, such as amphetamines and Heroin etc. Khat a plant whose leaves are chewed for its euphoric effect in east Africa and Arabian Peninsula including Saudi Arabia, is considered as mildly addictive, and its principle compound, Cathinone shares structural and functional similarity with amphetamine a known immunomodulator. Tuberculosis being a disease of immune modulation has a varied spectrum of complex interplay of proinflammatory molecules, resistin is one of them. In the present study, we try to explore the trinity of khat addiction, serum resistin level and tuberculosis by correlating the serum resistin level in non khat addicted healthy subjects, khat addicted healthy subjects, and in patients, both khat addicted and non khat addicted, with active tuberculosis. We observed significantly higher resistin level among the apparently healthy khat addicted subjects as compared to non addicted healthy controls. Thereafter, when we compare the resistin levels between khat addicted and non khat addicted TB patients we did not found significant difference between the two groups. However bacillary load was observe to be significantly higher among the khat addicted TB patient as compare to non addicted one. Validation of above results in animal model revealed dose dependant increase in bacillary growth in the Wistar rats treated with khat. Taken together these results suggest the role of khat in immune modulation albeit in the limited frame of resistin level.


Subject(s)
Resistin/blood , Substance-Related Disorders/blood , Tuberculosis, Pulmonary/blood , Animals , Case-Control Studies , Catha/chemistry , Male , Mycobacterium smegmatis/drug effects , Mycobacterium smegmatis/growth & development , Plant Extracts/pharmacology , Rats, Wistar , Saudi Arabia , Tuberculosis, Pulmonary/microbiology
15.
Endocrinology ; 155(11): 4368-79, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25116708

ABSTRACT

Insulin signaling in the brain plays an important role in the central regulation of energy homeostasis and fertility, such that mice exhibiting brain-specific deletion of insulin receptors (InsRs) display a diet-sensitive obesogenic phenotype and hypothalamic hypogonadism. However, the specific neurons mediating insulin's central effects on fertility remain largely unidentified. The neurotransmitters γ-aminobutyric acid (GABA) and glutamate are important modulators of fertility and energy homeostasis and are widely distributed in the hypothalamus. We therefore investigated whether insulin signaling via GABAergic or glutamatergic neurons plays an important role in the metabolic regulation of fertility. We used the Cre-loxP system to generate mice with a selective inactivation of the Insr gene from GABAergic (Vgat(+)) or glutamatergic (Vglut2(+)) cells by crossing Insr-flox mice with Vgat-Cre or Vglut2-Cre mice, respectively. Multiple reproductive and metabolic parameters were then compared between male and female Insr-flox/Vgat-Cre(+) (VgatIRKO), Insr-flox/Vglut2-Cre(+) (VglutIRKO), and Insr-flox/Cre-negative control (CON) mice. Female VgatIRKO mice exhibited a significant increase in adult body weight, abdominal fat mass, and fasting plasma insulin and leptin concentrations, but normal fasting glucose concentration and glucose tolerance compared with CON mice. Surprisingly, VgatIRKO and VglutIRKO mice exhibited normal reproductive maturation and function compared with CONs. No differences in the age of puberty onset, estrous cyclicity, or fertility were observed between VgatIRKO, VglutIRKO, and CON mice. However, male VgatIRKO mice exhibited significantly augmented LH concentration and a trend toward reduced seminal vesicle weight compared with CON mice, which may be indicative of primary hypogonadism. Our results therefore demonstrate that insulin signaling via GABAergic and glutamatergic cells is not required for fertility in mice, but show that GABAergic neurons encompass circuitry through which insulin acts to modulate energy homeostasis.


Subject(s)
Energy Metabolism/drug effects , Fertility/drug effects , GABAergic Neurons/drug effects , Insulin/pharmacology , gamma-Aminobutyric Acid/metabolism , Animals , Body Weight/drug effects , Body Weight/genetics , Energy Metabolism/genetics , Female , Fertility/genetics , Homeostasis/drug effects , Homeostasis/genetics , Luteinizing Hormone/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, Leptin/genetics , Receptors, Leptin/metabolism , Seminal Vesicles/metabolism
16.
Saudi J Gastroenterol ; 20(4): 212-8, 2014.
Article in English | MEDLINE | ID: mdl-25038206

ABSTRACT

Helicobacter pylori is recognized as a major cause of gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoma. Infection with this gram-negative microaerophile has been treated using combination of antibiotics and proton pump inhibitors for different gastrointestinal diseases. The most commonly used treatment is triple therapy which consists of administration of a proton pump inhibitor, clarithromycin, and amoxicillin. Many factors contribute to treatment failure, but one of the main reasons is development of bacterial antibiotic resistance. The percent prevalence of antibiotic resistance varies among different countries; it appears to be partly determined by the geographic factors and its ability to undergo frequent homologous recombination. The aim of this paper is to review the prevalence of H. pylori infection, association of clinical outcomes with H. pylori genotypes, and current status of antibiotic resistance in H. pylori in Saudi Arabia. It also discusses the different alternative approaches for the treatment of H. pylori using antibiotics. In addition, association of antibiotic resistance with H. pylori virulent genotypes in Saudi population and its underlying resistance mechanism will also be discussed.


Subject(s)
Helicobacter Infections/drug therapy , Helicobacter pylori/drug effects , Drug Resistance, Bacterial , Genotype , Helicobacter Infections/epidemiology , Helicobacter pylori/genetics , Humans , Prevalence , Saudi Arabia/epidemiology
17.
Med Hypotheses ; 82(6): 667-9, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24661941

ABSTRACT

Drug abuse is a serious problem associated with different pathological outcomes including modulating the immune system. Drug abuse is rising in Saudi Arabia and so as TB, a disease of worldwide significance, caused by immunological modulation in the host system. Khat chewing is a common practice in Arabian Peninsula which is now gaining momentum in other parts of the world. It is considered as an addiction. It has been associated with different adverse outcomes such as periodontitis, oral leukoplakia and oral cancer and also has shown to promote apoptotic cell death through cysteine proteases. The active ingredient of khat, cathinone is shown to have immunomodulatory effect. In principle, this leads to enhanced susceptibility to various infections. The present study is designed to delineate the mechanism of immunomodulation produced by khat/cathinone in human/mouse macrophage. Further, this activity will be evaluated both in vivo and in vitro in response to infection with Mycobacterium smegmatis to get an insight if there exists a co relation between the Mycobacterium tuberculosis infection and khat chewing.


Subject(s)
Alkaloids/adverse effects , Catha/chemistry , Disease Susceptibility/metabolism , Immunomodulation/drug effects , Mycobacterium tuberculosis , Tuberculosis/etiology , Alkaloids/analysis , Humans , Mastication/physiology , Models, Biological , Mycobacterium smegmatis/metabolism , Saudi Arabia , Substance-Related Disorders
19.
Endocrinology ; 153(8): 3770-9, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22691552

ABSTRACT

RFamide-related peptide-3 (RFRP-3) is known to inhibit the activity of GnRH neurons. It is not yet clear whether its G protein-coupled receptors, GPR147 and GPR74, are present on GnRH neurons or on afferent inputs of the GnRH neuronal network or whether RFRP-3 can inhibit gonadotropin secretion independently of GnRH. We tested the following: 1) whether GnRH is essential for the effects of RFRP-3 on LH secretion; 2) whether RFRP-3 neurons project to GnRH and rostral periventricular kisspeptin neurons in mice, and 3) whether Gpr147 and Gpr74 are expressed by these neurons. Intravenous treatment with the GPR147 antagonist RF9 increased plasma LH concentration in castrated male rats but was unable to do so in the presence of the GnRH antagonist cetrorelix. Dual-label immunohistochemistry revealed that approximately 26% of GnRH neurons from male and diestrous female mice were apposed by RFRP-3 fibers, and 19% of kisspeptin neurons from proestrous female mice were apposed by RFRP-3 fibers. Using immunomagnetic purification of GnRH and kisspeptin cells, single-cell nested RT-PCR, and in situ hybridization, we showed that 33% of GnRH neurons and 9-16% of rostral periventricular kisspeptin neurons expressed Gpr147, whereas Gpr74 was not expressed in either population. These data reveal that RFRP-3 can act at two levels of the GnRH neuronal network (i.e. the GnRH neurons and the rostral periventricular kisspeptin neurons) to modulate reproduction but is unable to inhibit gonadotropin secretion independently of GnRH.


Subject(s)
Gonadotropin-Releasing Hormone/metabolism , Kisspeptins/metabolism , Neurons/metabolism , Neuropeptides/metabolism , Animals , Female , Immunohistochemistry , In Situ Hybridization , Male , Mice , Mice, Inbred C57BL , Rats , Rats, Sprague-Dawley , Receptors, Neuropeptide/genetics , Receptors, Neuropeptide/metabolism , Reverse Transcriptase Polymerase Chain Reaction
20.
PLoS One ; 6(7): e22530, 2011.
Article in English | MEDLINE | ID: mdl-21789261

ABSTRACT

Helicobacter pylori induces cytokine mediated changes in gastroduodenal pathophysiology, wherein, the activated macrophages at the sub-mucosal space play a central role in mounting innate immune response against the antigens. The bacterium gains niche through persistent inflammation and local immune-suppression causing peptic ulcer disease or chronic gastritis; the latter being a significant risk factor for the development of gastric adenocarcinoma. What favors persistence of H. pylori in the gastric niches is not clearly understood. We report detailed characterization of a functionally unknown gene (HP986), which was detected in patient isolates associated with peptic ulcer and gastric carcinoma. Expression and purification of recombinant HP986 (rHP986) revealed a novel, ∼29 kDa protein in biologically active form which associates with significant levels of humoral immune responses in diseased individuals (p<0.001). Also, it induced significant levels of TNF-α and Interleukin-8 in cultured human macrophages concurrent to the translocation of nuclear transcription factor-κB (NF-κB). Further, the rHP986 induced apoptosis of cultured macrophages through a Fas mediated pathway. Dissection of the underlying signaling mechanism revealed that rHP986 induces both TNFR1 and Fas expression to lead to apoptosis. We further demonstrated interaction of HP986 with TNFR1 through computational and experimental approaches. Independent proinflammatory and apoptotic responses triggered by rHP986 as shown in this study point to its role, possibly as a survival strategy to gain niche through inflammation and to counter the activated macrophages to avoid clearance.


Subject(s)
Apoptosis , Bacterial Proteins/metabolism , Helicobacter Infections/metabolism , Helicobacter pylori/metabolism , Inflammation Mediators/metabolism , Amino Acid Sequence , Bacterial Proteins/chemistry , Gastrointestinal Diseases/metabolism , Gastrointestinal Diseases/microbiology , Gastrointestinal Diseases/pathology , Genetic Loci/genetics , Helicobacter Infections/microbiology , Helicobacter Infections/pathology , Helicobacter pylori/isolation & purification , Humans , Immunity, Humoral , Interleukin-8/metabolism , Models, Biological , Molecular Sequence Data , NF-kappa B/metabolism , Protein Binding , Receptors, Tumor Necrosis Factor, Type I/metabolism , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Analysis, Protein , Time Factors , Tumor Necrosis Factor-alpha/metabolism , fas Receptor/metabolism
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