REG-O3 chimeric peptide combining growth hormone and somatostatin sequences improves joint function and prevents cartilage degradation in rat model of traumatic knee osteoarthritis.

OBJECTIVE: REG-O3 is a 24-aminoacid chimeric peptide combining a sequence derived from growth hormone (GH) and an analog of somatostatin (SST), molecules displaying cartilage repair and anti-inflammatory properties, respectively. This study aimed to investigate the disease-modifying osteoarthritis drug (DMOAD) potential of REG-O3 by analyzing its effect on pain, joint function and structure, upon injection into osteoarthritic rat knee joint. DESIGN: Osteoarthritis was induced in the right knee of mature male Lewis rats (n = 12/group) by surgical transection of the anterior cruciate ligament (ACLT) combined with partial medial meniscectomy (pMMx). Treatments were administered intra-articularly from fourteen days after surgery through three consecutive injections one week apart. The effect of REG-O3, solubilized in a liposomal solution and injected at either 5, 25 or 50 µg/50 µL, was compared to liposomal (LIP), dexamethasone and hyaluronic acid (HA) solutions. The study endpoints were the pain/function measured once a week throughout the entire study, and the joint structure evaluated eight weeks after surgery using OARSI score. RESULTS: ACLT/pMMx surgery induced a significant modification of weight bearing in all groups. When compared to liposomal solution, REG-O3 was able to significantly improve weight bearing as efficiently as dexamethasone and HA. REG-O3 (25 µg) was also able to significantly decrease OARSI histological global score as well as degeneration of both cartilage and matrix while the other treatments did not. CONCLUSION: This study provides evidence of a remarkable protecting effect of REG-O3 on pain/knee joint function and cartilage/matrix degradation in ACLT/pMMx model of rat osteoarthritis. REG-O3 thus displays an interesting profile as a DMOAD.

Phenotypic variability in a French family with a novel mutation in the BEST1 gene causing multifocal best vitelliform macular dystrophy.

AIMS: To describe genetic and clinical findings in a French family affected by best vitelliform macular dystrophy (BVMD). METHODS: We screened eight at-risk members of a family, including a BVMD-affected proband, by direct sequencing of 11 bestrophin-1 (BEST1) exons. Individuals underwent ophthalmic examination and autofluorescent fundus imaging, indocyanine green angiography, electro-oculogram (EOG), electroretinogram (ERG), multifocal ERG, optical coherence tomography (OCT), and where possible, spectral domain OCT. RESULTS: The sequence analysis of the BEST1 gene revealed one previously unknown mutation, c.15C>A (p.Y5X), in two family members and one recently described mutation, c.430A>G (p.S144G), in five family members. Fundus examination and electrophysiological responses provided no evidence of the disease in the patient carrying only the p.Y5X mutation. Three patients with the p.S144G mutation did not show any preclinical sign of BVMD except altered EOGs. Two individuals of the family exhibited a particularly severe phenotype of multifocal BVMD-one individual carrying the p.S144G mutation heterozygously and one individual harboring both BEST1 mutations (p.S144G inherited from his mother and p.Y5X from his father). Both of these family members had multifocal vitelliform autofluorescent lesions combined with abnormal EOG, and the spectral domain OCT displayed a serous retinal detachment. In addition, ERGs demonstrated widespread retinal degeneration and multifocal ERGs showed a reduction in the central retina function, which could be correlated with the decreased visual acuity and visual field scotomas. CONCLUSIONS: A thorough clinical evaluation found no pathological phenotype in the patient carrying the isolated p.Y5X mutation. The patients carrying the p.S144G variation in the protein exhibited considerable intrafamilial phenotypic variability. Two young affected patients in this family exhibited an early onset, severe, multifocal BVMD with a diffuse distribution of autofluorescent deposits throughout the retina and rapid evolution toward the loss of central vision. The other genetically affected relatives had only abnormal EOGs and displayed no or extremely slow electrophysiological evolution.

Eight previously unidentified mutations found in the OA1 ocular albinism gene.

BACKGROUND: Ocular albinism type 1 (OA1) is an X-linked ocular disorder characterized by a severe reduction in visual acuity, nystagmus, hypopigmentation of the retinal pigmented epithelium, foveal hypoplasia, macromelanosomes in pigmented skin and eye cells, and misrouting of the optical tracts. This disease is primarily caused by mutations in the OA1 gene. METHODS: The ophthalmologic phenotype of the patients and their family members was characterized. We screened for mutations in the OA1 gene by direct sequencing of the nine PCR-amplified exons, and for genomic deletions by PCR-amplification of large DNA fragments. RESULTS: We sequenced the nine exons of the OA1 gene in 72 individuals and found ten different mutations in seven unrelated families and three sporadic cases. The ten mutations include an amino acid substitution and a premature stop codon previously reported by our team, and eight previously unidentified mutations: three amino acid substitutions, a duplication, a deletion, an insertion and two splice-site mutations. The use of a novel Taq polymerase enabled us to amplify large genomic fragments covering the OA1 gene. and to detect very likely six distinct large deletions. Furthermore, we were able to confirm that there was no deletion in twenty one patients where no mutation had been found. CONCLUSION: The identified mutations affect highly conserved amino acids, cause frameshifts or alternative splicing, thus affecting folding of the OA1 G protein coupled receptor, interactions of OA1 with its G protein and/or binding with its ligand.