Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 13, 28
eCollection

SerpinA3N Is a Novel Hypothalamic Gene Upregulated by a High-Fat Diet and Leptin in Mice

Affiliations

SerpinA3N Is a Novel Hypothalamic Gene Upregulated by a High-Fat Diet and Leptin in Mice

Domenico Sergi et al. Genes Nutr.

Abstract

Background: Energy homeostasis is regulated by the hypothalamus but fails when animals are fed a high-fat diet (HFD), and leptin insensitivity and obesity develops. To elucidate the possible mechanisms underlying these effects, a microarray-based transcriptomics approach was used to identify novel genes regulated by HFD and leptin in the mouse hypothalamus.

Results: Mouse global array data identified serpinA3N as a novel gene highly upregulated by both a HFD and leptin challenge. In situ hybridisation showed serpinA3N expression upregulation by HFD and leptin in all major hypothalamic nuclei in agreement with transcriptomic gene expression data. Immunohistochemistry and studies in the hypothalamic clonal neuronal cell line, mHypoE-N42 (N42), confirmed that alpha 1-antichymotrypsin (α1AC), the protein encoded by serpinA3, is localised to neurons and revealed that it is secreted into the media. SerpinA3N expression in N42 neurons is upregulated by palmitic acid and by leptin, together with IL-6 and TNFα, and all three genes are downregulated by the anti-inflammatory monounsaturated fat, oleic acid. Additionally, palmitate upregulation of serpinA3 in N42 neurons is blocked by the NFκB inhibitor, BAY11, and the upregulation of serpinA3N expression in the hypothalamus by HFD is blunted in IL-1 receptor 1 knockout (IL-1R1 -/- ) mice.

Conclusions: These data demonstrate that serpinA3 expression is implicated in nutritionally mediated hypothalamic inflammation.

Keywords: High-fat diet; Hypothalamus; Leptin; SerpinA3N.

Conflict of interest statement

The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Data derived from NuGO Affymetrics arrays from the hypothalamus of C57BL/6J mice maintained on a HFD or LFD for 1 and 4 weeks challenged with IP vehicle or leptin. The log of serpinA3N gene expression is represented by box and whisker plots. Three-way ANOVA showed a significant effect of diet, leptin challenge and time on the diet but no interaction between any of these factors (n = 10)
Fig. 2
Fig. 2
a Representative in situ autoradiograph of a C57BL/6J mouse brain section after 4 weeks of HFD showing serpinA3N expression in the arcuate nuclei (ARC), the ventromedial nuclei of the hypothalamus (VMH), the dorsomedial nuclei of the hypothalamus (DMH) and the lateral hypothalamus (LH). be Representative immunostaining of α1AC (brown) and b GFAP, c Iba1, d AgRP and e NPY (all blue) in the arcuate nuclei after 1 week of HFD. Bar = 20 μm
Fig. 3
Fig. 3
Representative in situ autoradiographs of C57BL/6J mouse brain sections showing serpinA3N expression in a LFD-fed mouse and b HFD-fed mouse. Levels of serpinA3N gene expression in LFD- and HFD-fed mice measured by semi-quantitative in situ hybridisation c in the arcuate nuclei (ARC), d the ventromedial nuclei of the hypothalamus (VMH) and e the dorsomedial nuclei of the hypothalamus (DMH). Two-way ANOVA showed a significant effect of diet P < 0.001 for the ARC, VMH and DMH and time P < 0.001 for the VMH and P < 0.05 for the ARC and DMH with an interaction between diet and time P < 0.05 for the VMH only. One-way ANOVA showed differences between HFD and LFD from 4 weeks onwards for the ARC and for all times tested for the VMH and DMH. *P < 0.05, **P < 0.01, ***P < 0.001 (n = 6)
Fig. 4
Fig. 4
Representative in situ autoradiographs of mouse brain sections showing serpinA3N expression in a ob/ob mouse on a C57BL/6J background and b lean C57BL/6J mouse. Levels of serpinA3N gene expression in the arcuate nuclei measured by semi-quantitative in situ hybridisation of c db/db on a C57BL/6J background and lean C57BL/6J mice, d ob/ob and lean mice, e ob/ob mice injected with IP vehicle (veh.) or leptin after either 1 or 4 h (h) and f lean mice injected with IP vehicle (veh.) or leptin after either 1 or 4 h (h). *** P < 0.001 (n = 6)
Fig. 5
Fig. 5
Levels of serpinA3N gene expression measured by semi-quantitative in situ hybridisation in the a arcuate nuclei (ARC) and b ventromedial nuclei of the hypothalamus (VMH) of ob/ob mice fed either a LFD, 10% energy (kCal) from fat, or HFD either 45% or 60% energy (kCal) from fat for 8 weeks. ***P < 0.001 (n = 6)
Fig. 6
Fig. 6
Levels of serpinA3N gene expression measure by semi-quantitative in situ autoradiography in the a arcuate nuclei (ARC) and b ventromedial nuclei of the hypothalamus (VMH) of C57Bl/6J mice either fed, fasted for 24 h or refed for 24 h. *P < 0.05, **P < 0.01 (n = 8)
Fig. 7
Fig. 7
Levels of serpinA3N gene expression measured by semi-quantitative in situ autoradiography in the a arcuate nuclei (ARC), b ventromedial nuclei of the hypothalamus (VMH) and c dorsomedial nuclei of the hypothalamus (DMH) in IL-1R1−/− mice on a C57BL/6J background fed either a LFD or HFD for 8 weeks (n = 9 for HFD and n = 5 for LFD)
Fig. 8
Fig. 8
af In mHypoE-N42 cells, a–c SerpinA3N, IL-6 and TNFα gene expression were all upregulated by leptin and palmitic acid challenge and downregulated by oleic acid. df The upregulation of SerpinA3N, IL-6 and TNFα gene expression by palmitic acid was blocked by the NKκB inhibitor BAY11. P < 0.05, ***P < 0.001, **P < 0.01. NS not significant
Fig. 9
Fig. 9
Representative SDS PAGE gel and immunoblot showing alpha-1-antichymotrypsin (α1AC), secreted into the media from N42 neuronal cells. No bands are visible with media alone. The blot shows two immunoreactive bands in the media from N42 neurons

Similar articles

See all similar articles

Cited by 5 articles

References

    1. World Health Organisation . Obesity and overweight. 2014.
    1. Brown WV, Fujioka K, Wilson PW, Woodworth KA. Obesity: why be concerned? Am J Med. 2009;122:S4–11. doi: 10.1016/j.amjmed.2009.01.002. - DOI - PubMed
    1. Luchsinger JA, Gustafson DR. Adiposity, type 2 diabetes, and Alzheimer’s disease. J Alzheimers Dis. 2009;16:693–704. doi: 10.3233/JAD-2009-1022. - DOI - PMC - PubMed
    1. Mann T, Tomiyama AJ, Westling E, Lew AM, Samuels B, Chatman J. Medicare’s search for effective obesity treatments: diets are not the answer. Am Psychol. 2007;62:220–233. doi: 10.1037/0003-066X.62.3.220. - DOI - PubMed
    1. Madsbad S, Dirksen C, Holst JJ. Mechanisms of changes in glucose metabolism and bodyweight after bariatric surgery. Lancet Diabetes Endocrinol. 2014;2:152–164. doi: 10.1016/S2213-8587(13)70218-3. - DOI - PubMed
Feedback