Viscoelastic characterization of diabetic and non-diabetic human adipose tissue

Article type: Research Article

Authors: Juliar, Benjamin A.^a | Strieder-Barboza, Clarissa^{b; c} | Karmakar, Monita^b | Flesher, Carmen G.^b | Baker, Nicki A.^b | Varban, Oliver A.^b | Lumeng, Carey N.^{c; d; e} | Putnam, Andrew J.^a | O’Rourke, Robert W.^{b; f;}

Affiliations: [a] Department of Biomedical Engineering, University of Michigan Medical School, Ann Arbor, MI, USA | [b] Department of Surgery, University of Michigan Medical School, Ann Arbor, MI, USA | [c] Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, \unskip\break Ann Arbor, MI, USA | [d] Graduate Program in Immunology, University of Michigan Medical School, Ann Arbor, MI, USA | [e] Graduate Program in Cellular and Molecular Biology, University of Michigan Medical School, \unskip\break Ann Arbor, MI, USA | [f] Department of Surgery, Ann Arbor Veterans Affairs Healthcare System, Ann Arbor, MI, USA

Correspondence: [*] Corresponding author: Robert W. O’Rourke, Department of Surgery, Section of General Surgery, University of Michigan, 2210 Taubman Center-5343, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-5343, USA. Tel.: +1 734 647 9024; Fax: +1 734 232 6188; E-mail: [email protected]

Abstract: BACKGROUND:Obesity-induced chronic inflammation and fibrosis in adipose tissue contributes to the progression of type 2 diabetes mellitus (DM). While fibrosis is known to induce mechanical stiffening of numerous tissue types, it is unknown whether DM is associated with alterations in adipose tissue mechanical properties. OBJECTIVE:The purpose of this study was to investigate whether DM is associated with differences in bulk viscoelastic properties of adipose tissue from diabetic (DM) and non-diabetic (NDM) obese subjects. METHODS:Bulk shear rheology was performed on visceral (VAT) and subcutaneous (SAT) adipose tissue, collected from obese subjects undergoing elective bariatric surgery. Rheology was also performed on the remaining extracellular matrix (ECM) from decellularized VAT (VAT ECM). Linear mixed models were used to assess whether correlations existed between adipose tissue mechanical properties and DM status, sex, age, and body mass index (BMI). RESULTS:DM was not associated with significant differences in adipose tissue viscoelastic properties for any of the tissue types investigated. Tissue type dependent differences were however detected, with VAT having significantly lower shear storage and loss moduli than SAT and VAT ECM independent of DM status. CONCLUSION:Although DM is typically associated with adipose tissue fibrosis, it is not associated with differences in macroscopic adipose tissue mechanical properties.

Keywords: Rheology, diabetes mellitus, subcutaneous adipose tissue, visceral adipose tissue, decellularized adipose tissue

DOI: 10.3233/BIR-190234

Journal: Biorheology, vol. 57, no. 1, pp. 15-26, 2020