OBJECTIVE: To improve the recognition of Familial glucocorticoid deficiency type 1 (FGD1) due to variants of melanocortin 2 receptor (MC2R) gene. METHODS: Two children with FGD1 diagnosed at the Henan Children's Hospital respectively in 2019 and 2021 were selected as the study subjects. Clinical data, treatment, follow-up and results of genetic testing were collected and retrospectively analyzed. RESULTS: Whole exome sequencing revealed that both children had harbored compound heterozygous variants of the MC2R gene, including c.433C>T (p.R145C) and c.710T>C (p.L237P) in child 1, and c.145delG (p.V49Cfs*35) and c.307G>A (p.D103N) in child 2, among which c.710T>C (p.L237P) and c.145delG (p.V49Cfs*35) were unreported previously. CONCLUSION FGD1 is clinically rare, and genetic sequencing is crucial for the definite diagnosis. Discovery of the and novel variants has enriched the mutational spectrum of the FGD1 gene.
Humans ; Child ; Glucocorticoids/therapeutic use* ; Receptor, Melanocortin, Type 2/genetics* ; Retrospective Studies ; Adrenal Insufficiency/genetics* ; Mutation

Obesity has become a severe public health problem across the world, and seriously affects the health and life quality of human beings. Here we generated lepr and mc4r mutant zebrafish via the CRISPR/Cas9 technique, and performed morphological and functional characterizations of those mutants. We observed that there was no significant phenotypic difference between homozygous mutants and wild-type controls before 2.5 months post-fertilization (mpf). However, the adult leprand mc4rindividuals displayed increased food intake, heavier weight, and higher body fat percentage, the characteristics of obesity phenotypes. Blood glucose test showed that overfeeding induced significantly impaired glucose tolerance in adult leprand mc4rzebrafish. Furthermore, we analyzed 76 energy metabolism-related transcripts in leprand mc4rzebrafish livers by using real-time RT-PCR, and compared the results with the published microarray data of Lepmouse livers, and found that the changes in the expression of insulin/IGF signaling (IIS) pathway genes in leprzebrafish and Lepmouse were positively correlated, suggesting that the IIS pathway maintains functional conservation between zebrafish and mammals during the evolution of the obesity-regulating molecule network.
Animals ; CRISPR-Cas Systems ; Gene Knockout Techniques ; Insulin ; metabolism ; Leptin ; Mutation ; Obesity ; genetics ; Receptor, Melanocortin, Type 4 ; genetics ; Receptors, Leptin ; genetics ; Signal Transduction ; Zebrafish ; Zebrafish Proteins ; genetics

BACKGROUND: The melanocortin 4 receptor (MC4R) is involved in the regulation of homeostatic energy balance by the hypothalamus. Recent reports showed that MC4R can also control the motivation for food in association with a brain reward system, such as dopamine. We investigated the expression levels of MC4R and the dopamine D2 receptor (D2R), which is known to be related to food rewards, in both the hypothalamus and brain regions involved in food rewards. METHODS: We examined the expression levels of D2R and MC4R by dual immunofluorescence histochemistry in hypothalamic regions and in the bed nucleus of the stria terminalis (BNST), the central amygdala, and the ventral tegmental area of transgenic mice expressing enhanced green fluorescent protein under the control of the D2R gene. RESULTS: In the hypothalamic area, significant coexpression of MC4R and D2R was observed in the arcuate nucleus. We observed a significant coexpression of D2R and MC4R in the BNST, which has been suggested to be an important site for food reward. CONCLUSION: We suggest that MC4R and D2R function in the hypothalamus for control of energy homeostasis and that within the brain regions related with rewards, such as the BNST, the melanocortin system works synergistically with dopamine for the integration of food motivation in the control of feeding behaviors.
Amygdala ; Animals ; Arcuate Nucleus ; Brain* ; Dopamine* ; Eating* ; Feeding Behavior ; Fluorescent Antibody Technique ; Homeostasis ; Hypothalamus ; Mice ; Mice, Transgenic ; Motivation ; Obesity ; Receptor, Melanocortin, Type 4* ; Receptors, Dopamine D2* ; Reward ; Ventral Tegmental Area

OBJECTIVETo screen the coding region of melanocortin-4 receptor gene (MC4R) for mutations in children, analyze the association of the identified variants with obesity-related phenotypes, and predict the potential functions of the identified variants.

METHODSA case-control study was conducted in 160 severely obese children and 100 normal-weight controls, all aged 7-18 years. Their anthropometric data were collected and blood tests were performed. The coding region of MC4R gene was screened by polymerase chain reaction (PCR), single strand conformation polymorphism and sequencing, and the potential functions of the identified variants were predicted by related online databases.

RESULTSThree heterozygous missense mutations were identified in obese children (Val95Ile, Val166Ile and Val179Ala), and one heterozygous missense mutation was found in controls (Met218Thr). Val103Ile variant was found to be carried by seven subjects in the obese group and six in the control group (P>0.05). Val179Ala was a newly identified heterozygous mutation. No significant differences in BMI, weight, waist circumstance, hip circumstance, serum lipid parameters, fasting glucose, and body fat percentage were found between Val95Ile, Val166Ile or Val179Ala mutation carriers and non-carriers in obese children. The function prediction of the variants showed that all the five identified variants influenced the protein function.

CONCLUSIONSFive variants were identified in the coding region of MC4R gene, among which Val179Ala was newly identified. All the five variants might influence the protein function as evidenced by online prediction.

Adolescent ; Child ; Female ; Humans ; Male ; Mutation ; Obesity ; genetics ; Receptor, Melanocortin, Type 4 ; genetics ; physiology

Substantial evidence has suggested that deep brain stimulation of the cuneiform nucleus has become a remarkable treatment option for intractable pain, but the possible mechanism is poorly understood. Using a melanocortin-4 receptor (MC4R)-green fluorescent protein (GFP) reporter knockin mouse, we showed that a large number of MC4R-GFP-positive neurons were expressed in the cuneiform nucleus. Immunofluorescence revealed that approximately 40%-50% of MC4R-GFP-positive neurons expressed mu opioid receptors, indicating that they were opioidergic signaling. Our findings support the hypothesis that MC4R expression in the cuneiform nucleus is involved in the modulation of opioidergic signaling.
Animals ; Gene Expression Regulation ; Gene Knock-In Techniques ; Genes, Reporter ; Green Fluorescent Proteins ; genetics ; metabolism ; Mice ; Mice, Transgenic ; Microtomy ; Midbrain Reticular Formation ; cytology ; metabolism ; Neurons ; cytology ; metabolism ; Receptor, Melanocortin, Type 4 ; genetics ; metabolism ; Receptors, Opioid, mu ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; Signal Transduction

BACKGROUND: Melanocortin-1 receptor (Mc1r), a key signaling receptor for melanogenesis, has been reported to mediate migration of B16F10 melanoma cells. Interestingly, this activity appears to be a part of the constitutive signaling of Mc1r. METHODS: We carried out small interfering RNA-mediated knock-down of Mc1r on murine melanoma B16F10 cells and performed microarray analysis to characterize changes in the gene expression profile. RESULTS: We isolated 22 and four genes whose expression decreased and increased, respectively, by 2.5-fold or higher as the result of Mc1r knock-down. Several down-regulated genes have been proposed to be involved in cell migration. Among these genes are several members of the chemokine gene family. CONCLUSION: We provide a gene set for further functional analyses of Mc1r. The Mc1r target genes we present may be particularly relevant for understanding the ligand-independent activity of Mc1r. Further examination of the mode of action may lead to novel strategies in regulating the migration and metastasis of melanoma cells.
Cell Movement ; Chemokines ; Gene Expression Regulation* ; Genes, vif ; Humans ; Melanoma ; Microarray Analysis ; Neoplasm Metastasis ; Receptor, Melanocortin, Type 1* ; Transcriptome

The rostral ventromedial medulla (RVM) is a prominent component of the descending modulatory system involved in the control of spinal nociceptive transmission. In the current study, we investigated melanocortin-4 receptor (MC4R) expression in the RVM, where the neurons involved in modulation of nociception reside. Using a line of mice expressing green fluorescent protein (GFP) under the control of the MC4R promoter, we found a large number of GFP-positive neurons in the RVM [nucleus raphe magnus (NRM) and nucleus gigantocellularis pars α (NGCα)]. Fluorescence immunohistochemistry revealed that approximately 10% of MC4R-GFP-positive neurons coexpressed tyrosine hydroxylase, indicating that they were catecholaminergic, whereas 50%-75% of those coexpressed tryptophan hydroxylase, indicating that they were serotonergic. Our findings support the hypothesis that MC4R signaling in RVM may modulate the activity of serotonergic sympathetic outflow sensitive to nociceptive signals, and that MC4R signaling in RVM may contribute to the descending modulation of nociceptive transmission.
Animals ; Female ; Male ; Medulla Oblongata ; cytology ; metabolism ; Mice ; Mice, Transgenic ; Neural Pathways ; cytology ; metabolism ; Neurons, Afferent ; cytology ; metabolism ; Nociception ; physiology ; Receptor, Melanocortin, Type 4 ; genetics ; metabolism ; Serotonergic Neurons ; metabolism ; Tyrosine 3-Monooxygenase ; metabolism

Adult ; Asian Continental Ancestry Group ; genetics ; Female ; Humans ; Male ; Mutation ; Obesity ; genetics ; Receptor, Melanocortin, Type 4 ; genetics ; Young Adult

OBJECTIVETo assess the association between single nucleotide polymorphisms (SNPs) of melanocortin-1 receptor gene (MC1R) and freckles in Chinese Han population from Chengdu.

METHODSTwenty randomly selected samples were used to select SNPs of the MC1R gene through DNA sequencing. Pyrosequencing in combination with DNA pooling technique was used to assess allelic frequencies of the selected SNPs in 111 individuals with freckles and 124 normal controls. Representative SNPs were selected based on their functional implications and minimum allele frequency (MAF> 0.05). Genotype of the SNPs were determined with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or pyrosequencing.

RESULTSBased on results of DNA sequencing and pyrosequencing, 4 SNPs (rs2228479, rs885479, rs33932559 and rs2228478) were selected to determine the genotype for each sample. Comparison of genotypic and allelic frequencies of the 4 SNPs with χ (2) test has found no significant difference between the two groups (P> 0.05). For rs33932559, the frequencies of T allele were respectively 90.09% and 91.94% for individuals with freckles and normal controls. For rs2228479 and rs2228478, the frequencies of G and A allele were both about 77%. For rs885479, the frequency of T allele was about 60%. None of the above 3 SNPs showed a significant difference between the two groups in terms of allelic or genotypic frequencies.

CONCLUSIONNo association between the selected SNPs of MC1R gene has been found with development of freckles for the selected Chinese Han population from Chengdu.

Adult ; Alleles ; Asian Continental Ancestry Group ; genetics ; Case-Control Studies ; China ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Humans ; Male ; Melanosis ; genetics ; Middle Aged ; Polymorphism, Single Nucleotide ; Receptor, Melanocortin, Type 1 ; genetics ; Young Adult

The current study was designed to examine the effects of intracerebroventricular injections of SHU9119 [a nonselective melanocortin receptor (McR) antagonist] and MCL0020 (a selective McR antagonist) on the serotonin-induced eating and drinking responses of broiler cockerels deprived of food for 24 h (FD24). For Experiment 1, the chickens were intracerebroventricularly injected with 2.5, 5, and 10 microg serotonin. In Experiment 2, the chickens received 2 nmol SHU9119 before being injected with 10 microg serotonin. For Experiment 3, the chickens were given 10 microg serotonin after receiving 2 nmol MCL0020, and the level of food and water intake was determined 3 h post-injection. Results of this study showed that serotonin decreased food intake but increased water intake among the FD24 broiler cockerels and that these effects occurred in a dose-dependent manner. The inhibitory effect of serotonin on food intake was significantly attenuated by pretreatment with SHU9119 and MCL0020. However, the stimulatory effect of serotonin on water intake was not altered by this pretreatment. These results suggest that serotonin hypophagia and hyperdipsia were mediated by different mechanisms in the central nervous system, and that serotonin required downstream activation of McRs to promote hypophagia but not hyperdipsia in the FD24 chickens.
Animals ; Chickens ; Dose-Response Relationship, Drug ; Drinking Behavior/*drug effects ; Feeding Behavior/*drug effects ; Food Deprivation ; Injections, Intraventricular/veterinary ; Male ; Melanocyte-Stimulating Hormones/*pharmacology ; Oligopeptides/*pharmacology ; Receptor, Melanocortin, Type 3/*antagonists & inhibitors ; Receptor, Melanocortin, Type 4/*antagonists & inhibitors ; Serotonin/pharmacology