UEGJournal Abstracts 2021 - 83

Tuesday, October 5, 2021
Monday, October 4, 2021
Sunday, October 3, 2021
proliferation/apoptosis, and transepithelial transport and barrier function.
Downregulation of the nuclear bile acid receptor, farnesoid X receptor
(FXR), in intestinal epithelium occurs in inflammatory bowel disease
and colorectal cancer, whereas FXR activation prevents disease progression
in pre-clinical models. Thus, strategies to upregulate epithelial FXR
expression have been proposed to treat such conditions. Previous studies
suggest that some plant-derived phytochemicals have the capacity to
modulate FXR activity. Plant sources have been reported to contain these
phytochemicals, such as KFS1, which are proposed to have FXR modulatory
activity.
Aims & Methods: The aim of the current study was to investigate the potential
for developing plant extracts, rich in FXR-modulating phytochemicals,
as a novel nutraceutical-based approach to treat and prevent intestinal
diseases.
T84
human colonic epithelial cells and primary cultures of murine colonic
epithelial enteroids were employed to examine the effects of a commondietary
phytochemical, denoted here as KFS1, and a KFS1-rich plant extract
on FXR expression and FXR signaling in vitro. Ex vivo studies were carried
out on human colonic tissue obtained during endoscopy with ethical
approval from Beaumont Hospital. In vivo studies in C57BL/6 mice were
carried out and proximal colonic tissue were examined with ethical approval
from the HPRA. Expression of FXR and FGF19/15, an established
marker of FXR activation, was assessed by qRT-PCR, ELISA and immunoblotting.
Data are expressed as mean ± SEM for a series of n experiments.
Results: KFS1 treatment (5 μM; 24hrs) increased FXR mRNA and protein
expression in T84
cells by 4.2 ± 0.4 (p<0.05; n = 4) and 1.7 ± 0.1 fold (p<0.05;
n = 7), respectively. KFS1 also enhanced FGF-19 protein expression, an established
marker of FXR activity, in response to the FXR agonist, GW4064
(5 μM), by 4.1 ± 0.5 fold (p<0.001; n = 7). Similarly, KFS1 significantly upregulated
FXR expression by 2.1 ± 0.4 fold in human biopsies (p<0.05; n
= 6). Oral KFS1 administration to mice had a tendency to upregulate colonic
epithelial FXR signalling in vivo and increased FXR expression and
GW4064-induced FGF15 mRNA by 2.3 ± 0.2 (p<0.01; n = 4) and 2.2 ± 0.1 fold
(p<0.01; n = 4) in murine epithelial colonic enteroids. Finally, a methanolic
KFS1-rich plant extract, denoted QE1, verified by LC/MS to contain KFS1,
increased FXR protein expression in T84
cells by 1.8 ± 0.2 fold (p<0.05; n =
5) and enhanced GW4064-induced FGF19 protein release by 1.9 ± 0.1 fold
(p<0.01; n = 9).
Conclusion: In conclusion, our data demonstrate that KFS1-containing
plant extracts modulate expression and activity of the nuclear bile acid
receptor, FXR, in the intestinal epithelium. Given the critical role of FXR
in maintenance of gut health, such extracts have significant therapeutic
and commercial potential to be developed as a novel first-in-class " FXRtargeted
nutraceutical " for treatment and prevention of common intestinal
disorders.
Disclosure: Nothing to disclose.
OP109
STUDY ON THE EFFECT AND MECHANISM OF DECREASED
ESTROGEN ON THE ABSORPTION OF GLUCOSE IN THE DUODENAL
MUCOSA IN MENOPAUSAL FEMALES
W. Shan1
, B. Tuo1
, X. Jingyu1
, R. Xie1
1Affiliated Hospital of Zunyi Medical University, Zunyi, China
Contact E-Mail Address: shanweixi1994@126.com
Introduction: Obesity is closely related to abnormal glucose metabolism
and absorption. Clinical studies have found that the obesity rate of middle
and old aged females, especially menopausal females, has increased significantly,
but the specific regulation mechanism is not clear. It is known
that menopausal women are accompanied by a significant decreased
Vol. 9 | October 2021
83
estrogen, but whether this change in estrogen level can regulate the metabolism
and absorption of glucose is rarely reported at home and abroad.
This study aims to elucidate the effect of estrogen on duodenal glucose
absorption and its possible regulatory mechanism through animal experiments
in vivo and cell experiments in vitro.
Aims & Methods: C57 mice were selected to establish an ovariectomized
surgery model, and the sham-operated group was used as a control to
dynamically compare the body weight, venous blood glucose levels and
observe the changes of fat distribution of the two groups of mice. Immunohistochemistry
was used to detect the expression of estrogen receptors
(ER-α, ER-β) and sugar transporters (SGLT1 and GLUT2) in the duodenum
of the two groups of mice. The Ussing chamber compares the short-circuit
current changes caused by glucose absorption in the duodenum of ovariectomized
mice. Western-blot detects the expression changes of the target
gene protein, agonists and inhibitors of PKC verify the important role
of the PKC signaling pathway, construct ER-α and ER-β shRNA lentiviruses
to transfect SCBN cells, and observe SGLT1 and GLUT2 expression.
Results:
1. Vivo animal experiments confirmed that the ovariectomized mice had
decreased serum estradiol levels andduodenal mucosal ER-α and ER-β
expressions, but increased body weight, fat, and blood sugar levels, compared
with the sham operation group.
2. The Ussing chamber found that compared with the sham operation
group, the ∆Isc change caused by the duodenal glucose absorption in the
ovariectomized group was significantly reduced, suggesting that the reduction
of estrogen inhibits the duodenal glucose absorption, rather than
promoting it
3. Immunohistochemistry found that SGLT1 and GLUT2 expression in the
duodenal epithelium of the ovariectomized group was decreased, but
SGLT1 and GLUT2 expression in the pancreatic tissue was significantly increased,
suggesting that the reduction of estrogen inhibits duodenal glucose
absorption ,this effect maybe due to the down-regulation of SGLT1
and GLUT2 expression.
4. Vitro cell experiments confirmed that SGLT1 and GLUT2 expression increased
after estrogen stimulated SCBN cells, and SGLT1 and GLUT2 expression
was reduced after ER-α expression in SCBN cells was knocked out
by shRNA, while interference with ER-β had no significant effect on SGLT1
and GLUT2 expression.
5. Mechanism studies found that the activation of PKC pathway was inhibited
after estrogen stimulated SCBN cells, while the PKC pathway was
significantly activated after ER-α was knocked out. After PKC agonist PMA
was given to stimulate SCBN cells, the SGLT1 and GLUT2 expression decreased,
while using PKC inhibitor GÖ6976 to stimulate SCBN cells, SGLT1
and GLUT2 expression increased, and GÖ6976 could also significantly reverse
the upregulation SGLT1 and GLUT2 induced by estrogen, suggesting
that the estrogen's downstream, PKC, has a negative regulatory effect on
SGLT1 and GLUT2 expression.
Conclusion: After the decline in the expression of estrogen and its
receptor ER-α in menopausal females, it promotes the activation of the
downstream PKC pathway, and then negatively down-regulates the
expression of SGLT1 and GLUT2, which ultimately leads to a decrease in
duodenal glucose absorption.
Disclosure: no conflict interest.
UEGJournal Abstracts 2021

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