Limits...
GDNF protects enteric glia from apoptosis: evidence for an autocrine loop.

Steinkamp M, Gundel H, Schulte N, Spaniol U, Pflueger C, Zizer E, von Boyen GB - BMC Gastroenterol (2012)

Bottom Line: Increased GDNF expression and Caspase 3/7 activities were detected in in specimen of CD patients but not in healthy controls.Moreover, inactivation of GDNF sensitized in EGC cell to IFN-γ/TNF-α induced apoptosis.Alterations in this novel EGC self-protecting mechanism could lead to a higher susceptibility towards apoptosis and thus contribute to disruption of the mucosal integrity and severity of inflammation in CD.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Gastroenterology, Endocrinology and Metabolism, University of Giessen und Marburg GmbH, Site Marburg, Baldingerstrasse, 35037 Marburg, Germany.

ABSTRACT

Background: Enteric glia cells (EGC) play an important role in the maintenance of intestinal mucosa integrity. During the course of acute Crohn's disease (CD), mucosal EGC progressively undergo apoptosis, though the mechanisms are largely unknown. We investigated the role of Glial-derived neurotrophic factor (GDNF) in the regulation of EGC apoptosis.

Methods: GDNF expression and EGC apoptosis were determined by immunofluorescence using specimen from CD patients. In primary rat EGC cultures, GDNF receptors were assessed by western blot and indirect immunofluorescence microscopy. Apoptosis in cultured EGC was induced by TNF-α and IFN-γ, and the influence of GDNF on apoptosis was measured upon addition of GDNF or neutralizing anti-GDNF antibody.

Results: Increased GDNF expression and Caspase 3/7 activities were detected in in specimen of CD patients but not in healthy controls. Moreover, inactivation of GDNF sensitized in EGC cell to IFN-γ/TNF-α induced apoptosis.

Conclusions: This study proposes the existence of an autocrine anti-apoptotic loop in EGC cells which is operative in Crohn's disease and dependent of GDNF. Alterations in this novel EGC self-protecting mechanism could lead to a higher susceptibility towards apoptosis and thus contribute to disruption of the mucosal integrity and severity of inflammation in CD.

Show MeSH

Related in: MedlinePlus

Detection of the receptors GFR-α 1-3 and Ret receptor by Western Blot. The molecular weight (kDa) of the protein are shown on the right of the western blot figures. These blots are representative of 3 independent experiments (N = 3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3298702&req=5

Figure 2: Detection of the receptors GFR-α 1-3 and Ret receptor by Western Blot. The molecular weight (kDa) of the protein are shown on the right of the western blot figures. These blots are representative of 3 independent experiments (N = 3).

Mentions: The expression of the GDNF receptors GFR-α1, GFR-α2, GFR-α3 and the coreceptor Ret was determined from lysates of EGC cultures using western blot. We were able to detect specific bands for all GDNF receptors (Figure 2). Furthermore, we performed an indirect immunofluorescence staining of EG cells cultures to prove these results in a second method (Figure 3). We confirmed our results, as all receptors were specifically detectable in this second method. The blots are presented to confirm the presence of the receptors, but not the quantity or different expression levels. Therefore, a GAPDH control is omitted.


GDNF protects enteric glia from apoptosis: evidence for an autocrine loop.

Steinkamp M, Gundel H, Schulte N, Spaniol U, Pflueger C, Zizer E, von Boyen GB - BMC Gastroenterol (2012)

Detection of the receptors GFR-α 1-3 and Ret receptor by Western Blot. The molecular weight (kDa) of the protein are shown on the right of the western blot figures. These blots are representative of 3 independent experiments (N = 3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3298702&req=5

Figure 2: Detection of the receptors GFR-α 1-3 and Ret receptor by Western Blot. The molecular weight (kDa) of the protein are shown on the right of the western blot figures. These blots are representative of 3 independent experiments (N = 3).
Mentions: The expression of the GDNF receptors GFR-α1, GFR-α2, GFR-α3 and the coreceptor Ret was determined from lysates of EGC cultures using western blot. We were able to detect specific bands for all GDNF receptors (Figure 2). Furthermore, we performed an indirect immunofluorescence staining of EG cells cultures to prove these results in a second method (Figure 3). We confirmed our results, as all receptors were specifically detectable in this second method. The blots are presented to confirm the presence of the receptors, but not the quantity or different expression levels. Therefore, a GAPDH control is omitted.

Bottom Line: Increased GDNF expression and Caspase 3/7 activities were detected in in specimen of CD patients but not in healthy controls.Moreover, inactivation of GDNF sensitized in EGC cell to IFN-γ/TNF-α induced apoptosis.Alterations in this novel EGC self-protecting mechanism could lead to a higher susceptibility towards apoptosis and thus contribute to disruption of the mucosal integrity and severity of inflammation in CD.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Gastroenterology, Endocrinology and Metabolism, University of Giessen und Marburg GmbH, Site Marburg, Baldingerstrasse, 35037 Marburg, Germany.

ABSTRACT

Background: Enteric glia cells (EGC) play an important role in the maintenance of intestinal mucosa integrity. During the course of acute Crohn's disease (CD), mucosal EGC progressively undergo apoptosis, though the mechanisms are largely unknown. We investigated the role of Glial-derived neurotrophic factor (GDNF) in the regulation of EGC apoptosis.

Methods: GDNF expression and EGC apoptosis were determined by immunofluorescence using specimen from CD patients. In primary rat EGC cultures, GDNF receptors were assessed by western blot and indirect immunofluorescence microscopy. Apoptosis in cultured EGC was induced by TNF-α and IFN-γ, and the influence of GDNF on apoptosis was measured upon addition of GDNF or neutralizing anti-GDNF antibody.

Results: Increased GDNF expression and Caspase 3/7 activities were detected in in specimen of CD patients but not in healthy controls. Moreover, inactivation of GDNF sensitized in EGC cell to IFN-γ/TNF-α induced apoptosis.

Conclusions: This study proposes the existence of an autocrine anti-apoptotic loop in EGC cells which is operative in Crohn's disease and dependent of GDNF. Alterations in this novel EGC self-protecting mechanism could lead to a higher susceptibility towards apoptosis and thus contribute to disruption of the mucosal integrity and severity of inflammation in CD.

Show MeSH
Related in: MedlinePlus