Polymorphisms in HIF-1a gene are not associated with diabetic retinopathy in China

Association study of HIF-1α rs11549465 and VEGF rs3025039 genetic variants with diabetic retinopathy in Egyptian patients: crosslinks with angiogenic, inflammatory, and anti-inflammatory markers

Background

Genetic factors are implicated in the progression of DR—a global cause of blindness. Hence, the current work investigated the association of HIF-1α rs11549465 and VEGF rs3025039 genetic variants with the different stages of retinopathy among T2DM Egyptian patients. The crosslinks of these variants were explored with angiogenesis (VEGF), inflammation (AGEP and VCAM-1), and anti-inflammation (CTRP3) markers. Two hundred eighty-eight subjects were recruited in this study: 72 served as controls and 216 were having T2DM and were divided into diabetics without retinopathy (DWR), diabetics with non-proliferative retinopathy (NPDR), and diabetics with proliferative retinopathy (PDR). The genetic variants were analyzed using PCR-RFLP and their associations with NPDR and PDR were statistically tested. The circulating levels of AGEP, VCAM-1, HIF-1α, VEGF, and CTRP3 were assayed followed by analyzing their associations statistically with the studied variants.

Results

Only HIF-1α rs11549465 genetic variant (recessive model) was significantly associated with the development of NPDR among T2DM patients (p < 0.025) with a significant correlation with the circulating HIF-1α level (p < 0.0001). However, this variant was not associated with PDR progression. Neither HIF-1α rs11549465 nor VEGF rs3025039 genetic variants were associated with the PDR progression. The circulating AGEP, VCAM-1, HIF-1α, and VEGF were significantly elevated (p < 0.0001) while the CTRP3 was significantly decreased (p < 0.0001) in NPDR and PDR groups. The HIF-1α rs11549465 CT and/or TT genotype carriers were significantly associated with AGEP and VCAM-1 levels in the NPDR group, while it showed a significant association with the CTRP3 level in the PDR group. The VEGF rs3025039 TT genotype carriers showed only a significant association with the CTRP3 level in the PDR group.

Conclusion

The significant association of HIF-1α rs11549465 other than VEGF rs3025039 with the initiation of NPDR in T2DM Egyptian patients might protect them from progression to the proliferative stage via elevating circulating HIF-1α. However, this protective role was not enough to prevent the development of NPDR because of enhancing angiogenesis and inflammation together with suppressing anti-inflammation. The non-significant association of HIF-1α rs11549465 with PDR among T2DM patients could not make this variant a risk factor for PDR progression.

Transplantation of Roxadustat-preconditioned bone marrow stromal cells improves neurological function recovery through enhancing grafted cell survival in ischemic stroke rats

AIMS

The therapeutic effect of bone marrow stromal cell (BMSC) transplantation for ischemic stroke is limited by its low survival rate. The purpose of this study was to evaluate whether Roxadustat (FG-4592) pretreatment could promote the survival rate of grafted BMSCs and improve neurological function deficits in ischemia rats.

METHODS

Oxygen-glucose deprivation (OGD) and permanent middle cerebral artery occlusion (pMCAO) were constructed as stroke models in vitro and in vivo. Flow cytometry analysis and expression of Bax and Bcl-2 were detected to evaluate BMSCs apoptosis. Infarct volume and neurobehavioral score were applied to evaluate functional recovery. Inflammatory cytokine expression, neuronal apoptosis, and microglial M1 polarization were assessed to confirm the enhanced neurological recovery after FG-4592 pretreatment.

RESULTS

FG-4592 promoted autophagy level to inhibit OGD-induced apoptosis through HIF-1α/BNIP3 pathway. GFP and Ki67 double staining showed an improved survival rate of BMSCs in the FG-4592 group, whereas infarct volume and neurobehavioral score verified its enhanced neurological recovery activity simultaneously. NeuN and Iba-1 fluorescence staining showed improved neural survival and decreased microglial activation, along with decreased IL-1β, IL-6, and TNF-α levels through the TLR-4/NF-kB pathway.

CONCLUSIONS

FG-4592 pretreated BMSCs improve neurological function recovery after stroke and are likely to be a promising strategy for stroke management.