Treatment with the dual-incretin agonist DA-CH5 demonstrates potent therapeutic effect in a rat model of Wolfram Syndrome.

Aim: Wolfram Syndrome (WS) is a rare condition caused by mutations in Wfs1, with a poor prognosis and no cure. Mono-agonists targeting the incretin glucagon-like-peptide 1 (GLP-1) have demonstrated disease-modifying potential in pre-clinical and clinical settings. Dual agonists that target GLP-1 and glucose-dependent insulinotropic polypeptide (GIP-1) are reportedly more efficacious; hence, we evaluated the therapeutic potential of dual incretin agonism in a loss-of-function rat model of WS. Methods: Eight-month-old Wfs1 knock-out (KO) and wild-type control rats were continuously treated with either the dual agonist DA-CH5 or saline for four months. Glycemic profile, visual acuity and hearing sensitivity were longitudinally monitored pre-treatment, and then at 10.5 and 12 months. Pancreata and retina were harvested for immunohistological analysis. Results: DA-CH5 therapy reversed glucose intolerance in KO rats and provided lasting anti-diabetogenic protection. Treatment also reversed intra-islet alterations, including reduced endocrine islet area and ß-cell density, indicating its regenerative potential. Although no rescue effect was noted for hearing loss, visual acuity and retinal ganglion cell density were better preserved in DA-CH5-treated rats. Conclusion: We present preclinical evidence for the pleiotropic therapeutic effects of long-term dual incretin agonist treatment; effects were seen despite treatment beginning after symptom-onset, indicating reversal of disease progression. Dual incretins represent a promising therapeutic avenue for WS patients.

Liraglutide, 7,8-DHF and their co-treatment prevents loss of vision and cognitive decline in a Wolfram syndrome rat model.

Wolfram syndrome (WS) is a monogenic progressive neurodegenerative disease and is characterized by various neurological symptoms, such as optic nerve atrophy, loss of vision, cognitive decline, memory impairment, and learning difficulties. GLP1 receptor agonist liraglutide and BDNF mimetic 7,8-dihydroxyflavone (7,8-DHF) have had protective effect to visual pathway and to learning and memory in different rat models of neurodegenerative disorders. Although synergistic co-treatment effect has not been reported before and therefore the aim of the current study was to investigate liraglutide, 7,8-DHF and most importantly for the first time their co-treatment effect on degenerative processes in WS rat model. We took 9 months old WS rats and their wild-type (WT) control animals and treated them daily with liraglutide, 7,8-DHF or with the combination of liraglutide and 7,8-DHF up to the age of 12.5 months (n = 47, 5-8 per group). We found that liraglutide, 7,8-DHF and their co-treatment all prevented lateral ventricle enlargement, improved learning in Morris Water maze, reduced neuronal inflammation, delayed the progression of optic nerve atrophy, had remyelinating effect on optic nerve and thereby improved visual acuity in WS rats compared to WT controls. Thus, the use of the liraglutide, 7,8-DHF and their co-treatment could potentially be used as a therapeutic intervention to induce neuroprotection or even neuronal regeneration.

Early Intervention and Lifelong Treatment with GLP1 Receptor Agonist Liraglutide in a Wolfram Syndrome Rat Model with an Emphasis on Visual Neurodegeneration, Sensorineural Hearing Loss and Diabetic Phenotype.

Wolfram syndrome (WS), also known as a DIDMOAD (diabetes insipidus, early-onset diabetes mellitus, optic nerve atrophy and deafness) is a rare autosomal disorder caused by mutations in the Wolframin1 (WFS1) gene. Previous studies have revealed that glucagon-like peptide-1 receptor agonist (GLP1 RA) are effective in delaying and restoring blood glucose control in WS animal models and patients. The GLP1 RA liraglutide has also been shown to have neuroprotective properties in aged WS rats. WS is an early-onset, chronic condition. Therefore, early diagnosis and lifelong pharmacological treatment is the best solution to control disease progression. Hence, the aim of this study was to evaluate the efficacy of the long-term liraglutide treatment on the progression of WS symptoms. For this purpose, 2-month-old WS rats were treated with liraglutide up to the age of 18 months and changes in diabetes markers, visual acuity, and hearing sensitivity were monitored over the course of the treatment period. We found that treatment with liraglutide delayed the onset of diabetes and protected against vision loss in a rat model of WS. Therefore, early diagnosis and prophylactic treatment with the liraglutide may also prove to be a promising treatment option for WS patients by increasing the quality of life.

Gene Therapy for Modulation of T-Cell-Mediated Immune Response Provoked by Corneal Transplantation.

Corneal transplantation (keratoplasty) is the most common type of tissue replacement in the world. The increased rate of graft rejection after keratoplasty is a central problem for repeated transplantations and in inflamed host corneas. It has been shown that apoptosis of grafted epithelium has a role in corneal allograft rejection. This study focused on the T-cell response triggered in BALB/c mice after allogeneic corneal transplantation with and without anti-apoptotic p35-transduced epithelium. To restrict p35 expression to the epithelial cells, modified allogeneic composite grafts were created. As a result, it was found that the proportion of alloreactive CD4+ T cells in postoperatively removed cervical lymph nodes was reduced in the p35-transduced group compared to the allogeneic control group. Diminished priming of the CD4+ T cells was supported by significantly decreased proliferation and lower interferon gamma secretion when compared to allogeneic engraftments. The reduced priming of CD4+ lymphocytes is the first confirmation of the functionality of p35 in the epithelium of corneal grafts to alter the development of the recipient's immune response. Thus, modification of allosensibilization seems to be a promising tool for reducing graft-mediated immune response following corneal transplantation.