scholarly journals tTARGIT AAVs mediate the sensitive and flexible manipulation of intersectional neuronal populations in mice

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Paul V Sabatini ◽  
Jine Wang ◽  
Alan C Rupp ◽  
Alison H Affinati ◽  
Jonathan N Flak ◽  
...  
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Transgene Expression ◽  
Ventromedial Hypothalamus ◽  
Cell Populations ◽  
Tetracycline Transactivator ◽  
Neuronal Populations ◽  
Combined Use ◽  
Neural Populations ◽  
Dna Recombinase

While Cre-dependent viral systems permit the manipulation of many neuron types, some cell populations cannot be targeted by a single DNA recombinase. Although the combined use of Flp and Cre recombinases can overcome this limitation, insufficient recombinase activity can reduce the efficacy of existing Cre+Flp-dependent viral systems. We developed a sensitive dual recombinase-activated viral approach: tTA-driven Recombinase-Guided Intersectional Targeting (tTARGIT) adeno-associated viruses (AAVs). tTARGIT AAVs utilize a Flp-dependent tetracycline transactivator (tTA) ‘Driver’ AAV and a tetracycline response element-driven, Cre-dependent ‘Payload’ AAV to express the transgene of interest. We employed this system in Slc17a6FlpO;LeprCre mice to manipulate LepRb neurons of the ventromedial hypothalamus (VMH; LepRbVMH neurons) while omitting neighboring LepRb populations. We defined the circuitry of LepRbVMH neurons and roles for these cells in the control of food intake and energy expenditure. Thus, the tTARGIT system mediates robust recombinase-sensitive transgene expression, permitting the precise manipulation of previously intractable neural populations.

scholarly journals tTARGIT AAVs: A sensitive and flexible method to manipulate intersectional neuronal populations

2021 ◽  
Author(s):  
Paul V. Sabatini ◽  
Jine Wang ◽  
Alan C. Rupp ◽  
Alison H. Affinati ◽  
Jonathan N. Flak ◽  
...  
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Transgene Expression ◽  
Ventromedial Hypothalamus ◽  
Cell Populations ◽  
Tetracycline Transactivator ◽  
Neuronal Populations ◽  
Combined Use ◽  
Neural Populations ◽  
Dna Recombinase

SummaryWhile Cre-dependent viral systems permit the manipulation of many neuron types, some cell populations cannot be targeted by a single DNA recombinase. Although the combined use of Flp and Cre recombinases can overcome this limitation, insufficient recombinase activity can reduce the efficacy of existing Cre+Flp-dependent viral systems. We developed a sensitive dual recombinase-activated viral approach: tTA-driven Recombinase-Guided Intersectional Targeting (tTARGIT) AAVs. tTARGIT AAVs utilize a Flp-dependent tetracycline transactivator (tTA) “Driver” AAV and a tetracycline response element (TRE)-driven, Cre-dependent “Payload” AAV to express the transgene of interest. We employed this system in Slc17a6FlpO;LeprCre mice to manipulate LepRb neurons of the ventromedial hypothalamus (VMH; LepRbVMH neurons) while omitting neighboring LepRb populations. We defined the circuitry of LepRbVMH neurons and roles for these cells in the control of food intake and energy expenditure. Thus, the tTARGIT system mediates robust recombinase-sensitive transgene expression, permitting the precise manipulation of previously intractable neural populations.

scholarly journals Arcuate nucleus and lateral hypothalamic CART neurons in the mouse brain exert opposing effects on energy expenditure

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Aitak Farzi ◽  
Jackie Lau ◽  
Chi Kin Ip ◽  
Yue Qi ◽  
Yan-Chuan Shi ◽  
...  
Keyword(s):  
Physical Activity ◽  
Food Intake ◽  
Energy Expenditure ◽  
Lateral Hypothalamus ◽  
Energy Homeostasis ◽  
Arcuate Nucleus ◽  
Neuronal Populations ◽  
Neuron Activation ◽  
Important Regulator ◽  
Opposing Effects

Cocaine- and amphetamine-regulated transcript (CART) is widely expressed in the hypothalamus and an important regulator of energy homeostasis; however, the specific contributions of different CART neuronal populations to this process are not known. Here, we show that depolarization of mouse arcuate nucleus (Arc) CART neurons via DREADD technology decreases energy expenditure and physical activity, while it exerts the opposite effects in CART neurons in the lateral hypothalamus (LHA). Importantly, when stimulating these neuronal populations in the absence of CART, the effects were attenuated. In contrast, while activation of CART neurons in the LHA stimulated feeding in the presence of CART, endogenous CART inhibited food intake in response to Arc CART neuron activation. Taken together, these results demonstrate anorexigenic but anabolic effects of CART upon Arc neuron activation, and orexigenic but catabolic effects upon LHA-neuron activation, highlighting the complex and nuclei-specific functions of CART in controlling feeding and energy homeostasis.

Consuming sucrose solution promotes leptin resistance and site specifically modifies hypothalamic leptin signaling in rats

2020 ◽  
Author(s):  
Ruth B.S. Harris
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Sucrose Solution ◽  
Ventromedial Hypothalamus ◽  
Primary Response ◽  
Leptin Resistance ◽  
Sprague Dawley ◽  
Leptin Signaling ◽  
Transient Rise

Rats consuming 30% sucrose solution and a sucrose-free diet (LiqS) become leptin resistant whereas rats consuming sucrose from a formulated diet (HS) remain leptin responsive. This study tested whether leptin resistance in LiqS rats extended beyond a failure to inhibit food intake and examined leptin responsiveness in the hypothalamus and hindbrain of rats offered HS, LiqS or a sucrose free diet (NS). Female LiqS Sprague Dawley rats initially only partially compensated for the calories consumed as sucrose, but energy intake matched that of HS and NS rats when they were transferred to calorimetry cages. There was no effect of diet on energy expenditure, IBAT temperature or fat pad weight. A peripheral injection of 2 mg leptin/kg on Day 23 or 26 inhibited energy intake of HS and NS, but not LiqS rats. Inhibition occurred earlier in HS than NS rats and was associated with a smaller meal size. Leptin had no effect on energy expenditure, but caused a transient rise in IBAT temperature of HS rats. Leptin increased pSTAT3 in the hindbrain and ventromedial hypothalamus of all rats. There was a minimal effect of leptin in the arcuate nucleus and only the dorsomedial hypothalamus showed a correlation between pSTAT3 and leptin responsiveness. These data suggest that the primary response to leptin is inhibition of food intake and that the pattern of sucrose consumption, rather than calories consumed as sucrose causes leptin resistance associated with site specific differences in hypothalamic leptin signaling.

scholarly journals Single cell profiling of the VMH reveals a sexually dimorphic regulatory node of energy expenditure

2019 ◽  
Author(s):  
J. Edward van Veen ◽  
Laura G. Kammel ◽  
Patricia C. Bunda ◽  
Michael Shum ◽  
Michelle S. Reid ◽  
...  
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Single Cell ◽  
Estrogen Receptor Alpha ◽  
Ventromedial Hypothalamus ◽  
Gonadal Hormones ◽  
Estrogen Signaling ◽  
Neuronal Populations ◽  
Neuron Populations ◽  
Architectural Framework

AbstractEstrogen signaling in the central nervous system promotes weight loss by increasing thermogenesis and physical activity in the ventromedial hypothalamus (VMH), but the precise neuronal populations regulating these aspects of energy expenditure remain unclear. Here we define the molecular and functional heterogeneity of the VMH using single cell RNA sequencing, in situ hybridization, chemogenetic activation, and targeted gene knockdown. We describe six molecularly distinct neuron clusters in the VMH. In females, estrogen receptor alpha (ERα) is restricted to neurons expressing tachykinin-1 (Tac1) or reprimo (Rprm). Further, Tac1 and Rprm expression is enriched in females, a sex difference that is established by permanent effects of gonadal hormones early in life. Finally, while Tac1 ablation selectively impairs movement, here we show that silencing Rprm selectively dysregulates temperature without affecting physical activity. Together this work provides a novel architectural framework whereby distinct and sexually differentiated neuron populations within the VMH mediate sex-specific aspects of metabolic homeostasis.

Plasma leptin in transition dairy cows. Effects of body fatness, ambient temperature and dietary factors

2002 ◽  
Vol 2002 ◽  
pp. 92-92 ◽  
Author(s):  
T. Kokkonen ◽  
J. Taponen ◽  
S. Alasuutari ◽  
M. Nousiainen ◽  
T. Anttila ◽  
...  
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Dairy Cows ◽  
Dairy Cow ◽  
Dietary Factors ◽  
Body Fatness ◽  
Increase Energy Expenditure ◽  
Transition Dairy Cows ◽  
Cow Performance ◽  
Plasma Leptin

In ruminants plasma leptin is increased with increasing body fatness. Leptin acts on hypothalamus to decrease food intake and increase energy expenditure. It is possible that leptin has a key role in transition from pregnancy to lactation of dairy cows. The objective of the present work was to investigate the pattern of plasma leptin concentration, as well as its relationship with other hormones and metabolites and dairy cow performance.

scholarly journals Severe protein deficiency induces hepatic expression and systemic level of FGF21 but inhibits its hypothalamic expression in growing rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Moro ◽  
Catherine Chaumontet ◽  
Patrick C. Even ◽  
Anne Blais ◽  
Julien Piedcoq ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Dietary Protein ◽  
Protein Deficiency ◽  
Protein Diet ◽  
Growing Rats ◽  
Low Protein ◽  
Protein Diets

AbstractTo study, in young growing rats, the consequences of different levels of dietary protein deficiency on food intake, body weight, body composition, and energy balance and to assess the role of FGF21 in the adaptation to a low protein diet. Thirty-six weanling rats were fed diets containing 3%, 5%, 8%, 12%, 15% and 20% protein for three weeks. Body weight, food intake, energy expenditure and metabolic parameters were followed throughout this period. The very low-protein diets (3% and 5%) induced a large decrease in body weight gain and an increase in energy intake relative to body mass. No gain in fat mass was observed because energy expenditure increased in proportion to energy intake. As expected, Fgf21 expression in the liver and plasma FGF21 increased with low-protein diets, but Fgf21 expression in the hypothalamus decreased. Under low protein diets (3% and 5%), the increase in liver Fgf21 and the decrease of Fgf21 in the hypothalamus induced an increase in energy expenditure and the decrease in the satiety signal responsible for hyperphagia. Our results highlight that when dietary protein decreases below 8%, the liver detects the low protein diet and responds by activating synthesis and secretion of FGF21 in order to activate an endocrine signal that induces metabolic adaptation. The hypothalamus, in comparison, responds to protein deficiency when dietary protein decreases below 5%.

scholarly journals Role of Ventromedial Hypothalamus in Sucrose-Induced Obesity on Metabolic Parameters

2021 ◽  
pp. 097275312110057
Author(s):  
Archana Gaur ◽  
G.K. Pal ◽  
Pravati Pal
Keyword(s):  
Insulin Resistance ◽  
Weight Gain ◽  
Food Intake ◽  
Ventromedial Hypothalamus ◽  
Female Rats ◽  
Metabolic Parameters ◽  
Male Rats ◽  
Significant Weight Gain ◽  
The Metabolic Syndrome

Background: Obesity is because of excessive fat accumulation that affects health adversely in the form of various diseases such as diabetes, hypertension, cardiovascular diseases, and many other disorders. Our Indian diet is rich in carbohydrates, and hence the sucrose-induced obesity is an apt model to mimic this. Ventromedial hypothalamus (VMH) is linked to the regulation of food intake in animals as well as humans. Purpose: To understand the role of VMHin sucrose-induced obesity on metabolic parameters. Methods: A total of 24 adult rats were made obese by feeding them on a 32% sucrose solution for 10 weeks. The VMH nucleus was ablated in the experimental group and sham lesions were made in the control group. Food intake, body weight, and biochemical parameters were compared before and after the lesion. Results: Male rats had a significant weight gain along with hyperphagia, whereas female rats did not have a significant weight gain inspite of hyperphagia. Insulin resistance and dyslipidemia were seen in both the experimental and control groups. Conclusion: A sucrose diet produces obesity which is similar to the metabolic syndrome with insulin resistance and dyslipidemia, and a VMH lesion further exaggerates it. Males are more prone to this exaggeration.

scholarly journals Position Effects Are Influenced by the Orientation of a Transgene with Respect to Flanking Chromatin

2001 ◽  
Vol 21 (1) ◽  
pp. 298-309 ◽  
Author(s):  
Yong-Qing Feng ◽  
Matthew C. Lorincz ◽  
Steve Fiering ◽  
John M. Greally ◽  
Eric E. Bouhassira
Keyword(s):  
Mammalian Cells ◽  
Transgene Expression ◽  
Methylation Status ◽  
Regulatory Elements ◽  
Cell Populations ◽  
Methylation Analysis ◽  
Position Effects ◽  
Methylation State ◽  
Cassette Exchange

ABSTRACT We have inserted two expression cassettes at tagged reference chromosomal sites by using recombinase-mediated cassette exchange in mammalian cells. The three sites of integration displayed either stable or silencing position effects that were dominant over the different enhancers present in the cassettes. These position effects were strongly dependent on the orientation of the construct within the locus, with one orientation being permissive for expression and the other being nonpermissive. Orientation-specific silencing, which was observed at two of the three site tested, was associated with hypermethylation but not with changes in chromatin structure, as judged by DNase I hypersensitivity assays. Using CRE recombinase, we were able to switch in vivo the orientation of the transgenes from the permissive to the nonpermissive orientation and vice versa. Switching from the permissive to the nonpermissive orientation led to silencing, but switching from the nonpermissive to the permissive orientation did not lead to reactivation of the transgene. Instead, transgene expression occurred dynamically by transcriptional oscillations, with 10 to 20% of the cells expressing at any given time. This result suggested that the cassette had been imprinted (epigenetically tagged) while it was in the nonpermissive orientation. Methylation analysis revealed that the methylation state of the inverted cassettes resembled that of silenced cassettes except that the enhancer had selectively lost some of its methylation. Sorting of the expressing and nonexpressing cell populations provided evidence that the transcriptional oscillations of the epigenetically tagged cassette are associated with changes in the methylation status of regulatory elements in the transgene. This suggests that transgene methylation is more dynamic than was previously assumed.

Sign in / Sign up

Export Citation Format

Share Document