Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

RNA sequencing unravels novel L cell constituents and mechanisms of GLP-1 secretion in human gastric bypass-operated intestine

Miskelly, Michael G. LU ; Lindqvist, Andreas LU ; Piccinin, Elena ; Hamilton, Alexander LU ; Cowan, Elaine LU orcid ; Nergård, Bent Johnny ; Del Giudice, Rita LU ; Ngara, Mtakai LU orcid ; Cataldo, Luis R. LU orcid and Kryvokhyzha, Dmytro LU , et al. (2023) In Diabetologia
Abstract

Aims/hypothesis: Roux-en-Y gastric bypass surgery (RYGB) frequently results in remission of type 2 diabetes as well as exaggerated secretion of glucagon-like peptide-1 (GLP-1). Here, we assessed RYGB-induced transcriptomic alterations in the small intestine and investigated how they were related to the regulation of GLP-1 production and secretion in vitro and in vivo. Methods: Human jejunal samples taken perisurgically and 1 year post RYGB (n=13) were analysed by RNA-seq. Guided by bioinformatics analysis we targeted four genes involved in cholesterol biosynthesis, which we confirmed to be expressed in human L cells, for potential involvement in GLP-1 regulation using siRNAs in GLUTag and STC-1 cells. Gene expression analyses, GLP-1... (More)

Aims/hypothesis: Roux-en-Y gastric bypass surgery (RYGB) frequently results in remission of type 2 diabetes as well as exaggerated secretion of glucagon-like peptide-1 (GLP-1). Here, we assessed RYGB-induced transcriptomic alterations in the small intestine and investigated how they were related to the regulation of GLP-1 production and secretion in vitro and in vivo. Methods: Human jejunal samples taken perisurgically and 1 year post RYGB (n=13) were analysed by RNA-seq. Guided by bioinformatics analysis we targeted four genes involved in cholesterol biosynthesis, which we confirmed to be expressed in human L cells, for potential involvement in GLP-1 regulation using siRNAs in GLUTag and STC-1 cells. Gene expression analyses, GLP-1 secretion measurements, intracellular calcium imaging and RNA-seq were performed in vitro. OGTTs were performed in C57BL/6j and iScd1 −/− mice and immunohistochemistry and gene expression analyses were performed ex vivo. Results: Gene Ontology (GO) analysis identified cholesterol biosynthesis as being most affected by RYGB. Silencing or chemical inhibition of stearoyl-CoA desaturase 1 (SCD1), a key enzyme in the synthesis of monounsaturated fatty acids, was found to reduce Gcg expression and secretion of GLP-1 by GLUTag and STC-1 cells. Scd1 knockdown also reduced intracellular Ca2+ signalling and membrane depolarisation. Furthermore, Scd1 mRNA expression was found to be regulated by NEFAs but not glucose. RNA-seq of SCD1 inhibitor-treated GLUTag cells identified altered expression of genes implicated in ATP generation and glycolysis. Finally, gene expression and immunohistochemical analysis of the jejunum of the intestine-specific Scd1 knockout mouse model, iScd1 −/−, revealed a twofold higher L cell density and a twofold increase in Gcg mRNA expression. Conclusions/interpretation: RYGB caused robust alterations in the jejunal transcriptome, with genes involved in cholesterol biosynthesis being most affected. Our data highlight SCD as an RYGB-regulated L cell constituent that regulates the production and secretion of GLP-1. Graphical Abstract: [Figure not available: see fulltext.]

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
in press
subject
keywords
Gastric bypass surgery, GLP-1, Glucagon-like peptide-1, Intestine, Obesity, Remission, RNA sequencing, SCD, Stearoyl-CoA desaturase, Type 2 diabetes
in
Diabetologia
publisher
Springer
external identifiers
  • pmid:38032369
  • scopus:85178171702
ISSN
0012-186X
DOI
10.1007/s00125-023-06046-8
language
English
LU publication?
yes
id
deb26a67-f5d2-4e0a-9129-c70b1c112f5e
date added to LUP
2024-01-08 15:03:58
date last changed
2024-04-23 10:42:02
@article{deb26a67-f5d2-4e0a-9129-c70b1c112f5e,
  abstract     = {{<p>Aims/hypothesis: Roux-en-Y gastric bypass surgery (RYGB) frequently results in remission of type 2 diabetes as well as exaggerated secretion of glucagon-like peptide-1 (GLP-1). Here, we assessed RYGB-induced transcriptomic alterations in the small intestine and investigated how they were related to the regulation of GLP-1 production and secretion in vitro and in vivo. Methods: Human jejunal samples taken perisurgically and 1 year post RYGB (n=13) were analysed by RNA-seq. Guided by bioinformatics analysis we targeted four genes involved in cholesterol biosynthesis, which we confirmed to be expressed in human L cells, for potential involvement in GLP-1 regulation using siRNAs in GLUTag and STC-1 cells. Gene expression analyses, GLP-1 secretion measurements, intracellular calcium imaging and RNA-seq were performed in vitro. OGTTs were performed in C57BL/6j and iScd1 <sup>−/−</sup> mice and immunohistochemistry and gene expression analyses were performed ex vivo. Results: Gene Ontology (GO) analysis identified cholesterol biosynthesis as being most affected by RYGB. Silencing or chemical inhibition of stearoyl-CoA desaturase 1 (SCD1), a key enzyme in the synthesis of monounsaturated fatty acids, was found to reduce Gcg expression and secretion of GLP-1 by GLUTag and STC-1 cells. Scd1 knockdown also reduced intracellular Ca<sup>2+</sup> signalling and membrane depolarisation. Furthermore, Scd1 mRNA expression was found to be regulated by NEFAs but not glucose. RNA-seq of SCD1 inhibitor-treated GLUTag cells identified altered expression of genes implicated in ATP generation and glycolysis. Finally, gene expression and immunohistochemical analysis of the jejunum of the intestine-specific Scd1 knockout mouse model, iScd1 <sup>−/−</sup>, revealed a twofold higher L cell density and a twofold increase in Gcg mRNA expression. Conclusions/interpretation: RYGB caused robust alterations in the jejunal transcriptome, with genes involved in cholesterol biosynthesis being most affected. Our data highlight SCD as an RYGB-regulated L cell constituent that regulates the production and secretion of GLP-1. Graphical Abstract: [Figure not available: see fulltext.]</p>}},
  author       = {{Miskelly, Michael G. and Lindqvist, Andreas and Piccinin, Elena and Hamilton, Alexander and Cowan, Elaine and Nergård, Bent Johnny and Del Giudice, Rita and Ngara, Mtakai and Cataldo, Luis R. and Kryvokhyzha, Dmytro and Volkov, Petr and Engelking, Luke and Artner, Isabella and Lagerstedt, Jens O. and Eliasson, Lena and Ahlqvist, Emma and Moschetta, Antonio and Hedenbro, Jan and Wierup, Nils}},
  issn         = {{0012-186X}},
  keywords     = {{Gastric bypass surgery; GLP-1; Glucagon-like peptide-1; Intestine; Obesity; Remission; RNA sequencing; SCD; Stearoyl-CoA desaturase; Type 2 diabetes}},
  language     = {{eng}},
  publisher    = {{Springer}},
  series       = {{Diabetologia}},
  title        = {{RNA sequencing unravels novel L cell constituents and mechanisms of GLP-1 secretion in human gastric bypass-operated intestine}},
  url          = {{http://dx.doi.org/10.1007/s00125-023-06046-8}},
  doi          = {{10.1007/s00125-023-06046-8}},
  year         = {{2023}},
}