Protective effect of LIF-huMSCs on the retina of diabetic model rats

RDH12-associated retinal degeneration caused by a homozygous pathogenic variant of 146C>T and literature review

AIM

To describe the clinical, electrophysiological, and genetic features of an unusual case with an RDH12 homozygous pathogenic variant and reviewed the characteristics of the patients reported with the same variant.

METHODS

The patient underwent a complete ophthalmologic examination including best-corrected visual acuity, anterior segment and dilated fundus, visual field, spectral-domain optical coherence tomography (OCT) and electroretinogram (ERG). The retinal disease panel genes were sequenced through chip capture high-throughput sequencing and Sanger sequencing was used to confirm the result. Then we reviewed the characteristics of the patients reported with the same variant.

RESULTS

A 30-year male presented with severe early retinal degeneration who complained night blindness, decreased visual acuity, vitreous floaters and amaurosis fugax. The best corrected vision was 0.04 OD and 0.12 OS, respectively. The fundus photo and OCT showed bilateral macular atrophy but larger areas of macular atrophy in the left eye. Autofluorescence shows bilateral symmetrical hypo-autofluorescence. ERG revealed that the amplitudes of a- and b-wave were severely decreased. Multifocal ERG showed decreased amplitudes in the local macular area. A homozygous missense variant c.146C>T (chr14:68191267) was found. The clinical characteristics of a total of 13 patients reported with the same pathologic variant varied.

CONCLUSION

An unusual patient with a homozygous pathogenic variant in the c.146C>T of RDH12 which causes late-onset and asymmetric retinal degeneration are reported. The clinical manifestations of the patient with multimodal retinal imaging and functional examinations have enriched our understanding of this disease.

Exendin-4 promotes retinal ganglion cell survival and function by inhibiting calcium channels in experimental diabetes

Progressive damage of retinal ganglion cells (RGCs) is observed in early diabetic retinopathy. Intracellular Ca2+ overload mediated by Ca2+ influx through voltage-gated Ca2+ channels (VGCCs) is involved in neurodegeneration, whereas glucagon-like peptide-1 (GLP-1) provides neuroprotection. However, whether GLP-1 plays a neuroprotective role in diabetic retinas by modulating VGCCs remains unknown. We found that eye drops of exendin-4, a long-acting GLP-1 receptor (GLP-1R) agonist, prevented the increase of L-type Ca2+ current (ILCa) densities of RGCs induced by 4-week hyperglycemia and promoted RGC survival by suppressing L-type VGCC (L-VGCC) activity in streptozotocin-induced diabetic rats. Moreover, exendin-4-induced suppression of ILCa in RGCs may be mediated by a GLP-1R/Gs/cAMP-PKA/ryanodine/Ca2+/calmodulin/calcineurin/PP1 signaling pathway. Furthermore, exendin-4 functionally improved the light-evoked spiking ability of diabetic RGCs. These results suggest that GLP-1R activation enhances cAMP to PP1 signaling and that PP1 inactivates L-VGCCs by dephosphorylating them, thereby reducing Ca2+ influx, which could protect RGCs against excitotoxic Ca2+ overload.

Human umbilical cord mesenchymal stem cells in diabetes mellitus and its complications: applications and research advances

Diabetes mellitus and its complications pose a major threat to global health and affect the quality of life and life expectancy of patients. Currently, the application of traditional therapeutic drugs for diabetes mellitus has great limitations and can only temporarily control blood glucose but not fundamentally cure it. Mesenchymal stem cells, as pluripotent stromal cells, have multidirectional differentiation potential, high self-renewal, immune regulation, and low immunogenicity, which provide a new idea and possible development direction for diabetes mellitus treatment. Regenerative medicine with mesenchymal stem cells treatment as the core treatment will become another treatment option for diabetes mellitus after traditional treatment. Recently, human umbilical cord mesenchymal stem cells have been widely used in basic and clinical research on diabetes mellitus and its complications because of their abundance, low ethical controversy, low risk of infection, and high proliferation and differentiation ability. This paper reviews the therapeutic role and mechanism of human umbilical cord mesenchymal stem cells in diabetes mellitus and its complications and highlights the challenges faced by the clinical application of human umbilical cord mesenchymal stem cells to provide a more theoretical basis for the application of human umbilical cord mesenchymal stem cells in diabetes mellitus patients.

Potential Protective Function of Adiponectin in Diabetic Retinopathy

Adiponectin, one of the most ubiquitous adipokines found in the blood, plays a major role in glucolipid metabolism and energy metabolism and regulation. In recent years, a growing body of research indicates that adiponectin also plays a significant role in diabetic retinopathy. In the present review, we specifically address the protective effects of adiponectin on the development and progression of diabetic retinopathy through improvement in insulin resistance, alleviation of oxidative stress, limiting of inflammation, and prevention of vascular remodeling, with the aim to explore new potential approaches and targets for the prevention and treatment of diabetic retinopathy.

Current Status of Mesenchymal Stem/Stromal Cells for Treatment of Neurological Diseases

Neurological disorders include a wide spectrum of clinical conditions affecting the central and peripheral nervous systems. For these conditions, which affect hundreds of millions of people worldwide, generally limited or no treatments are available, and cell-based therapies have been intensively investigated in preclinical and clinical studies. Among the available cell types, mesenchymal stem/stromal cells (MSCs) have been widely studied but as yet no cell-based treatment exists for neurological disease. We review current knowledge of the therapeutic potential of MSC-based therapies for neurological diseases, as well as possible mechanisms of action that may be explored to hasten the development of new and effective treatments. We also discuss the challenges for culture conditions, quality control, and the development of potency tests, aiming to generate more efficient cell therapy products for neurological disorders.