title: Comparative Genomic, MicroRNA, and Tissue Analyses Reveal Subtle Differences between Non-Diabetic and Diabetic Foot Skin.
abstract: Diabetes Mellitus (DM) is a chronic, severe disease rapidly increasing in incidence and prevalence and is associated with numerous complications. Patients with DM are at high risk of developing diabetic foot ulcers (DFU) that often lead to lower limb amputations, long term disability, and a shortened lifespan. Despite this, the effects of DM on human foot skin biology are largely unknown. Thus, the focus of this study was to determine whether DM changes foot skin biology predisposing it for healing impairment and development of DFU. Foot skin samples were collected from 20 patients receiving corrective foot surgery and, using a combination of multiple molecular and cellular approaches, we performed comparative analyses of non-ulcerated non-neuropathic diabetic foot skin (DFS) and healthy non-diabetic foot skin (NFS). MicroRNA (miR) profiling of laser captured epidermis and primary dermal fibroblasts from both DFS and NFS samples identified 5 miRs de-regulated in the epidermis of DFS though none reached statistical significance. MiR-31-5p and miR-31-3p were most profoundly induced. Although none were significantly regulated in diabetic fibroblasts, miR-29c-3p showed a trend of up-regulation, which was confirmed by qPCR in a prospective set of 20 skin samples. Gene expression profiling of full thickness biopsies identified 36 de-regulated genes in DFS (>2 fold-change, unadjusted p-value ≤ 0.05). Of this group, three out of seven tested genes were confirmed by qPCR: SERPINB3 was up-regulated whereas OR2A4 and LGR5 were down-regulated in DFS. However no morphological differences in histology, collagen deposition, and number of blood vessels or lymphocytes were found. No difference in proliferative capacity was observed by quantification of Ki67 positive cells in epidermis. These findings suggest DM causes only subtle changes to foot skin. Since morphology, mRNA and miR levels were not affected in a major way, additional factors, such as neuropathy, vascular complications, or duration of DM, may further compromise tissue's healing ability leading to development of DFUs.
authors: Human Genetics and Genomics Graduate Program in Biomedical Sciences, University of Miami Miller School of Medicine, Miami, FL, United States of America; Wound Healing and Regenerative Medicine Research Program, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School Of Medicine, Miami, FL, United States of America.
authors: Horacio A
authors: HA
authors: Ramirez
authors: Wound Healing and Regenerative Medicine Research Program, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School Of Medicine, Miami, FL, United States of America.
authors: Liang
authors: L
authors: Liang
authors: Wound Healing and Regenerative Medicine Research Program, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School Of Medicine, Miami, FL, United States of America.
authors: Irena
authors: I
authors: Pastar
authors: Wound Healing and Regenerative Medicine Research Program, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School Of Medicine, Miami, FL, United States of America.
authors: Ashley M
authors: AM
authors: Rosa
authors: Wound Healing and Regenerative Medicine Research Program, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School Of Medicine, Miami, FL, United States of America.
authors: Olivera
authors: O
authors: Stojadinovic
authors: University of Miami Hospital, UM Health System, Miami, FL, United States of America.
authors: Thomas G
authors: TG
authors: Zwick
authors: Wound Healing and Regenerative Medicine Research Program, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School Of Medicine, Miami, FL, United States of America; University of Miami Hospital, UM Health System, Miami, FL, United States of America.
authors: Robert S
authors: RS
authors: Kirsner
authors: Cell, Molecular, Developmental Biology, Tufts University, Sackler School of Graduate Biomedical Sciences, Boston, MA, United States of America; Department of Oral and Maxillofacial Pathology, Oral Medicine and Craniofacial Pain School of Dental Medicine, Tufts University, Boston, MA, United States of America.
authors: Anna G
authors: AG
authors: Maione
authors: Cell, Molecular, Developmental Biology, Tufts University, Sackler School of Graduate Biomedical Sciences, Boston, MA, United States of America; Department of Oral and Maxillofacial Pathology, Oral Medicine and Craniofacial Pain School of Dental Medicine, Tufts University, Boston, MA, United States of America.
authors: Jonathan A
authors: JA
authors: Garlick
authors: Human Genetics and Genomics Graduate Program in Biomedical Sciences, University of Miami Miller School of Medicine, Miami, FL, United States of America; Wound Healing and Regenerative Medicine Research Program, Department of Dermatology and Cutaneous Surgery, University of Miami Miller School Of Medicine, Miami, FL, United States of America.
authors: Marjana
authors: M
authors: Tomic-Canic
mesh_terms: D020405:Dermis / Q000473:pathology*; D017719:Diabetic Foot / Q000235:genetics* / Q000473:pathology*; D004817:Epidermis / Q000473:pathology*; D005347:Fibroblasts / Q000378:metabolism; D016523:Foot Ulcer / Q000235:genetics / Q000473:pathology; D020869:Gene Expression Profiling; D023281:Genomics; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D035683:MicroRNAs