Study on the mechanism of glial maturation factor-β induced inflammatory response of retinal Müller cells in diabetes rats

doi:10.11958/20221106

Abstract

Abstract:

Objective To study the activation and its related mechanisms of glial maturation factor-β(GMFB) on retinal MüLler cells in diabetes rats. Methods Sixty SPF grade male SD rats were divided into the streptozotocin (STZ) group, the STZ+AAV-GMFB group and the STZ+AAV-GMFB+K252a (TrkB inhibitor) group with 15 rats in each group. Another 15 normal rats were taken as the CON group. Rats in the STZ+AAV-GMFB group and the STZ+AAV-GMFB+K252a group were injected with AAV-GMFB adenovirus vector 5 μL in vitreous cavity 8 weeks after modeling. The STZ+AAV-GMFB+K252a group received intraperitoneal injection of K252a (25 μg·kg^-1·d^-1). After 12 weeks, the expression of GMFB in Müller cells was detected by immunofluorescence, the expression of glial fibrillary acidic protein (GFAP) in retina was detected by immunohistochemistry, and the retinal inflammatory factor tumor necrosis factor- α (TNF-α), interleukin (IL)-1β and IL-6 were detected by ELISA. The relative expression levels of GMFB, brain derived neurotrophic factor (BDNF) and its tyrosine kinase receptor B (p-TrkB) were detected by Western blot assay. HE staining was used to detect the pathological changes of retina. Results GMFB was expressed in Müller cells. Compared with the CON group, the expression levels of GMFB, GFAP and TNF-α, IL-1β, IL-6 levels increased, the number of retinal ganglion cells (RGC) and the expression levels of BDNF, p-TrkB decreased in the STZ group. Compared with the STZ group, the expression levels of GMFB, GFAP and TNF-α, IL-1β and IL-6 levels decreased, the expression of BDNF, p-TrkB and the number of RGC were increased in the STZ+AAV-GMFB group. However, K252a can largely reverse the protective effect of AAV-GMFB. Conclusion The expression of GMFB in the retina of rats with diabetes is increased, which can induce the activation of Müller cells and aggravate the inflammatory response. This effect is related to the inhibition of BDNF/TrkB signal pathway.

Key words: diabetes mellitus, diabetic retinopathy, inflammation, glial maturation factor-β, Müller cells, BDNF/TrkB signaling pathway

CLC Number:

R587.1，R774.1

Figures/Tables 6

Fig.1 The expression of GMFB in Müller cells (Immunofluorescence staining, ×400)

Fig.2 The expression of GFAP in retina (immunohistochemical staining, ×400)

Tab.1 Comparison of expression levels of TNF-α, IL-1β and IL-6 in retina between the four groups

组别	TNF-α	IL-1β	IL-6
CON组	13.01±0.33	10.93±0.47	31.77±0.68
STZ组	23.81±1.05^a	19.68±1.01^a	64.20±0.96^a
STZ+AAV-GMFB组	16.31±0.92^b	14.72±0.73^b	46.92±1.06^b
STZ+AAV-GMFB+K252a组	20.40±1.15^c	17.72±1.12^c	58.69±1.09^c
F	132.331^**	95.411^**	1 118.879^**

Tab.2 Comparison of relative expression levels of GMFB, BDNF and p-TrkB proteins in retina between the four groups

组别	GMFB	BDNF		p-TrkB
CON组	0.30±0.02	0.66±0.02		1.42±0.04
STZ组	0.70±0.03^a	0.31±0.02^a		0.57±0.03^a
STZ+AAV-GMFB组	0.34±0.02^b	0.52±0.03^b		1.08±0.04^b
STZ+AAV-GMFB+K252a组	0.34±0.03	0.40±0.02^c		0.51±0.03^c
F	245.966^**		193.648^**		837.808^**

Fig.3 The relative expressions of GMFB, BDNF and p-TrkB proteins detected by Western blot assay

Fig.4 Pathological changes of retina (HE staining, ×400)

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