The present invention provides a C-terminal CDNF fragment sequence or a sequence which has at least 80 % homology or sequence identity to said sequence. The C-terminal CDNF fragment protects ER stressed neurons, motoneurons and dopaminergic neurons and the fragment is capable of penetrating neuronal cell membrane as well as the blood-brain-barrier. The present invention further provides said fragment and pharmaceutical compositions comprising said fragment for use in treatments of degenerative diseases and disorders including central nervous system diseases, diabetes and retinal disorders. The present invention is also providing a C-terminal MANF fragment sequence or a sequence which has at least 80 % homology or sequence identity to the said sequence and pharmaceutical compositions comprising said MANF fragment for use in the treatment of degenerative diseases and disorders including central nervous system diseases, diabetes and retinal disorders.本發明提供C端腦部多巴胺神經滋養因子(CDNF)片段序列或與該序列具有至少80%之同源性或序列同一性的序列。C端CDNF片段保護經ER應激之神經元、運動神經元及多巴胺神經元，且該片段能夠穿透神經元細胞膜以及血腦障壁。本發明進一步提供該片段及包含該片段之醫藥組成物，彼等係用於治療退化性疾病及包括中樞神經系統疾病、糖尿病和視網膜失調之失調。本發明亦提供C端中腦星狀細胞-衍生之神經滋養因子(MANF)片段序列或與該序列具有至少80%之同源性或序列同一性的序列及包含該MANF片段之醫藥組成物，彼等係用於治療退化性疾病及包括中樞神經系統疾病、糖尿病和視網膜失調之失調。
