Noninvasive monitoring of diabetes-induced cutaneous nerve fiber loss and hypoalgesia in thy1-YFP transgenic mice.
Progressive loss of pain perception and cutaneous nerve fibers are frequently observed in diabetic patients. We evaluated the feasibility of using thy1-YFP mice that express the yellowish-green fluorescent protein (YFP) in all of their sensory/motor neurons for noninvasive monitoring of cutaneous nerve fiber loss during diabetes. Fluorescent fibers in skin sections from the leg of thy1-YFP mice stained positive for the neuron-specific protein gene product 9.5 (PGP9.5), indicating that the cutaneous fluorescent fibers are indeed nerve fibers. In diabetic thy1-YFP mice, significant small cutaneous nerve fiber loss in the leg was observed at 3 months following the onset of diabetes, but loss of heat-induced pain perception occurred as early as 1 month following the onset of diabetes, indicating that functional impairment of sensory nerves precedes cutaneous nerve fiber loss. Immunostaining of skin sections of mice killed at 6 months following the onset of diabetes showed that parallel to the loss of small fluorescent nerve fibers, there was a significant decrease in fibers stained positive for calcitonin gene-related peptide, substance P, and purinoreceptor subtype in diabetic thy1-YFP mice. These mice will be useful for noninvasive monitoring of cutaneous nerve fiber degeneration and loss of heat-induced pain perception during diabetes and for the assessment of efficacy of therapeutic treatment of diabetic neuropathy.
Chen
Yuk Shan
YS
Department of Anatomy, The University of Hong Kong, Hong Kong, China.
Chung
Stephen S M
SS
Chung
Sookja K
SK
D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D001786:Blood Glucose; D003921:Diabetes Mellitus, Experimental / Q000150:complications* / Q000503:physiopathology*; D005786:Gene Expression Regulation; D017930:Genes, Reporter / Q000235:genetics; D008164:Luminescent Proteins / Q000032:analysis* / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D009412:Nerve Fibers / Q000473:pathology*; D010146:Pain / Q000503:physiopathology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012867:Skin / Q000294:innervation*; D018800:Thy-1 Antigens / Q000235:genetics*; D013997:Time Factors; D043222:Ubiquitin Thiolesterase / Q000378:metabolism
D001426:Bacterial Proteins; D001786:Blood Glucose; D008164:Luminescent Proteins; D018800:Thy-1 Antigens; C054562:yellow fluorescent protein, Bacteria; D043222:Ubiquitin Thiolesterase; C496976:Uchl1 protein, mouse