Effects of GABA and Leptin Receptor-Expressing Neurons in the Lateral Hypothalamus on Feeding, Locomotion, and Thermogenesis
OBESITY
Authors: de Vrind, Veronne A. J.; Rozeboom, Annemieke; Wolterink-Donselaar, Inge G.; Luijendijk-Berg, Mieneke C. M.; Adan, Roger A. H.
Abstract
Objective The lateral hypothalamus (LH) is known for its role in feeding, and it also regulates other aspects of energy homeostasis. How genetically defined LH neuronal subpopulations mediate LH effects on energy homeostasis remains poorly understood. The behavioral effects of chemogenetically activating LH gamma-aminobutyric acid (GABA) and the more selective population of LH GABA neurons that coexpress the leptin receptor (LepR) were compared. Methods LepR-cre and VGAT-cre mice were injected with AAV5-hSyn-DIO-hM3DGq-mCherry in the LH. The behavioral effects of LH GABA or LH LepR neuronal activation on feeding, locomotion, thermogenesis, and body weight were assessed. Results The activation of LH GABA neurons increased body temperature (P <= 0.008) and decreased body weight (P <= 0.01) despite decreased locomotor activity (P = 0.03) and transiently increased chow intake (P <= 0.009). Also, similar to other studies, this study found that activation of LH GABA neurons induced gnawing on both food and nonfood (P = 0.001) items. Activation of LH LepR neurons decreased body weight (P <= 0.01) and chow intake when presented on the cage floor (P <= 0.04) but not when presented in the cage top and increased locomotor activity (P = 0.002) and body temperature (P = 0.03). Conclusions LH LepR neurons are a subset of LH GABA neurons, and LH LepR activation more specifically regulates energy homeostasis to promote a negative energy balance.
Gene modification by fast-track recombineering for cellular localization and isolation of components of plant protein complexes
PLANT JOURNAL
Authors: Hu, Zhoubo; Ghosh, Ajit; Stolze, Sara C.; Horvath, Mihaly; Bai, Bing; Schaefer, Sabine; Zuendorf, Simone; Liu, Shanda; Harzen, Anne; Hajheidari, Mohsen; Sarnowski, Tomasz J.; Nakagami, Hirofumi; Koncz, Zsuzsa; Koncz, Csaba
Abstract
To accelerate the isolation of plant protein complexes and study cellular localization and interaction of their components, an improved recombineering protocol is described for simple and fast site-directed modification of plant genes in bacterial artificial chromosomes (BACs). Coding sequences of fluorescent and affinity tags were inserted into genes and transferred together with flanking genomic sequences of desired size by recombination into Agrobacterium plant transformation vectors using three steps of E. coli transformation with PCR-amplified DNA fragments. Application of fast-track recombineering is illustrated by the simultaneous labelling of CYCLIN-DEPENDENT KINASE D (CDKD) and CYCLIN H (CYCH) subunits of kinase module of TFIIH general transcription factor and the CDKD-activating CDKF;1 kinase with green fluorescent protein (GFP) and mCherry (green and red fluorescent protein) tags, and a PIPL (His(18)-StrepII-HA) epitope. Functionality of modified CDKF;1 gene constructs is verified by complementation of corresponding T-DNA insertion mutation. Interaction of CYCH with all three known CDKD homologues is confirmed by their co-localization and co-immunoprecipitation. Affinity purification and mass spectrometry analyses of CDKD;2, CYCH, and DNA-replication-coupled HISTONE H3.1 validate their association with conserved TFIIH subunits and components of CHROMATIN ASSEMBLY FACTOR 1, respectively. The results document that simple modification of plant gene products with suitable tags by fast-track recombineering is well suited to promote a wide range of protein interaction and proteomics studies.