Obesity results from a combination of genetic and environmental factors. However, in diet-induced obesity, individuals with the same genetic background exhibit different sensitivity to obesity, termed diet-induced obesity (DIO) and diet-induced obesity resistance (DR). The hypothalamus is crucial in regulating energy homeostasis. This study conducted a comparative hypothalamic proteomic analysis in DIO and DR rats to identify differentially expressed proteins (DEPs) associated with changes in body weight. In the hypothalamus of DR rats compared to DIO rats, 31 proteins (FDR<1%) were identified as DEPs (14 upregulated and 17 downregulated). Gene ontology analysis of DEPs revealed an enrichment in ion-binding proteins (such as Fe2+, Zn2+, Ca2+, and Se) and those involved in neuronal activity and function, which may positively influence neuronal development and cognition in DR rats. The DEPs were further analyzed using the KEGG pathway, which principally involved in starch and sucrose metabolism, antigen processing and presentation, and inflammatory mediator regulation of TRP channels. The changes of TRPV4, CaMKV, RSBN1, and BASP1, as detected by western blotting, were consistent with those obtained from TMT proteomic. In conclusion, this study provides a comprehensive and functional analysis of the hypothalamic proteome in DIO and DR rats, offering novel insights into important proteins that may be targets for the prevention and treatment of obesity.

Obesity arises from a complex interplay of genetic and environmental factors. Even among individuals with the same genetic predisposition, diet-induced obesity (DIO) exhibits varying degrees of susceptibility, which are categorized as DIO and diet-induced obesity resistance (DR). The hypothalamus plays a pivotal role in regulating energy homeostasis. This study performed a comparative hypothalamic proteomic analysis in DIO and DR rats to identify differentially expressed proteins (DEPs) associated with alterations in body weight. Male Sprague Dawley rats were fed either a standard chow diet or a high-fat diet for 12 weeks. DIO rats exhibited the most rapid weight gain compared to both the control and DR rats. Despite consuming similar caloric intake, DR rats exhibited less weight gain relative to DIO rats. Proteomic analysis revealed 31 DEPs in the hypothalamus of DR rats compared to DIO rats (with a false discovery rate (FDR) < 1%). Notably, 14 proteins were upregulated and 17 proteins were downregulated in DR rats. Gene ontology analysis revealed an enrichment of ion-binding proteins, such as those binding to Fe²⁺, Zn²⁺, Ca²⁺, and Se, as well as proteins involved in neuronal activity and function, potentially enhancing neuronal development and cognition in DR rats. The DEPs pathway analysis via the Kyoto Encyclopedia of Genes and Genomes (KEGG) implicated starch and sucrose metabolism, antigen processing and presentation, and the regulation of inflammatory mediator affecting TRP channels. Western blotting confirmed the proteomic findings for TRPV4, CaMKV, RSBN1, and BASP1, which were consistent with those obtained from Tandem Mass tag (TMT) proteomic analysis. In conclusion, our study highlights the hypothalamic proteome as a critical determinant in the susceptibility to DIO and provides novel targets for obesity prevention and treatment.