The Feasibility to Isolate and Expand Tympanic Membrane Squamous Epithelium Stem Cells From Scarred Perforation Margins
OTOLOGY & NEUROTOLOGY
Authors: Sagiv, Doron; Harari-Steinberg, Orit; Wolf, Michael; Dekel, Benjamin; Omer, Dorit
Abstract
Hypothesis: The scarred rim of chronic tympanic membrane (TM) perforation contains keratinocytes with potential for regeneration while maintaining their morphological and genetic characteristics. Background: The squamous epithelium of the TM has a good regeneration capacity. Successful isolation and expansion of human TM keratinocytes (hTMKR) was reported from a full, en-bloc, healthy TM. Methods: Trimmed margins of the TM perforation (harvested during tympanoplasty) underwent enzymatic digestion (collagenase or trypsin) and were seeded either with serum-containing medium (SCM) or keratinocyte serum-free medium (KSFM) and progenitor cell growth medium (PR) (KSFM:PR, 1:1). Gene expression analysis by real-time qRT-PCR was used to compare between human TM cells derived from scarred perforation margins (hTMKR), normal human skin keratinocytes (NhSKR), and human fibroblasts. Results: Twelve patients were included in the study. In 9 of 12 cases (75%) single-cell isolation with fibroblastic or epithelial cell morphology (or both) was achieved. Cells seeded with KSFM:PR yielded epithelial morphology (hTMKR) while SCM culturing resulted in a fibroblastic morphology (hTMFib). Gene expression analysis revealed significant higher expression of VCAN (p - 0.002) and FOXC2 (p =0.015) at the mRNA levels (normal hTMKR markers) in hTMKR compared to NhSKR. In addition, a comparison of gene expression between hTMKR and hTMFib revealed significantly higher levels of both VCAN (p= 0.045) and SLC6A14 (p = 0.036) among hTMKR. Conclusion: For the first time, we developed a protocol to isolate hTMKR from scarred TM perforation margins. Furthermore, we succeeded in achieving tissue expansion that preserved the characteristic of healthy TM cells. This study bridges "regenerative medicine" approach with clinical and surgical objectives.
Gene expression changes in cancellous bone of type 2 diabetics: a biomolecular basis for diabetic bone disease
LANGENBECKS ARCHIVES OF SURGERY
Authors: Haug, A. T.; Braun, K. F.; Ehnert, S.; Mayer, L.; Stoeckle, U.; Nuessler, A. K.; Pscherer, S.; Freude, T.
Abstract
Diabetes mellitus type 2 (2DM) is associated with altered bone quality. In order to analyze associated changes on a molecular level, we investigated the gene expression of key factors of osteoblast metabolism in type 2 diabetics. Total mRNA and protein of bone samples from 2DM patients and non-diabetic patients were isolated, and subsequently, reverse transcription polymerase chain reaction (RT-PCR) or Western blot was performed. Furthermore, pro- and anti-inflammatory serum cytokine levels were determined using a cytokine array. Expression of runt-related transcription factor 2 (RUNX2) was increased by 53 %. Expression of the bone sialoproteins, secreted phosphoprotein 1 (SPP1; osteopontin), and integrin-binding sialoprotein (IBSP), was elevated by more than 50 %, and activating transcription factor 4 (ATF4) expression was 13 % lower in the investigated diabetes group compared to the control group. Similarly, the expression of versican (VCAN) and decorin (DCN) was upregulated twofold in the diabetic group. At the same time, 2DM patients and controls show alterations in pro- and anti-inflammatory cytokine levels in the serum. This study identifies considerable changes in the expression of transcription factors and extracellular matrix (ECM) components of bone in 2DM patients. Furthermore, the analysis of key differentiation factors of osteoblasts revealed significant alterations in gene expression of these factors, which may contribute to the dysregulation of energy metabolism in 2DM.