Nova spoznanja o lastnostih in vlogi mišičnih mezenhimskih stromalnih/ matičnih celic v primerjavi z istovrstnimi kostnimi celicami pri osteoporozi in osteoartrozi : doktorska disertacija

Čamernik, Klemen (author), Marc, Janja (mentor), Zupan, Janja (comentor)

S staranjem prebivalstva dobivajo vedno večji pomen mišično-skeletne bolezni, kot so osteoartroza (OA), osteoporoza (OP) in sarkopenija. Na kosteh in mišicah prihaja tekom življenje do mikroskopskih poškodb, vendar kljub temu telesu še naprej zagotavljajo podporo, ki je potrebna za vsakodnevne aktivnosti. Naše trenutno razumevanje je, da lahko regenerativno sposobnost mišično-skeletnega sistema pripišemo mezenhimskim stromalnim/ matičnim celicam (MSC). MSC različnim tkivom služijo kot zaloga predniških celic, iz katerih nastanejo funkcionalne celice, kot so osteoblasti, hondrociti, miociti in druge. S staranjem in pri nekaterih boleznih mišično-skeletnega sistema, pa se ta regenerativna sposobnost MSC izgubi oziroma preusmeri v razvoj drugih vrst celic, predvsem adipocitov in fibroblastov. Vedno več dokazov obstaja, da imajo tkivno specifične MSC različne lastnosti. Ni pa še pojasnjeno, kako se te lastnosti spreminjajo med staranjem in pri boleznih. Študije, v okviru katerih neposredno primerjajo MSC iz različnih tkiv mišično-skeletnega sistema pri istem bolniku so redke, prav tako pa je slabo opredeljen tudi vpliv mišično-skeletnih bolezni na same MSC je. Zato je bil cilj te doktorske naloge ovrednotiti MSC, izoliranih iz dveh vrst tkiv, in sicer iz skeletne mišice ter spongiozne kostnine bolnikov z OA ali OP. Kontrolne vzorce teh tkiv smo pridobili post mortem od oseb brez mišično-skeletnih bolezni. Izolirane MSC smo ovrednotili na nivoju njihovega fenotipa ter sposobnosti proliferacije in diferenciacije in vitro. Želeli smo odkriti funkcionalne razlike med njimi, s pomočjo katerih bi lahko pojasnili patološke spremembe pri mišično-skeletnih boleznih ter ob tem odkriti nove tarče za njihovo učinkovitejše zdravljenje in diagnosticiranje. V okviru doktorske naloge smo kot prvi podrobno ovrednotili lastnosti mišičnih MSC pri bolnikih s primarno OA in OP. Pri tem smo pokazali, da sta hitrost rasti ter čas podvojevanja mišičnih in kostnih MSC in vitro primerljiva in neodvisna od vrste bolezni. Ob tem je bila sposobnost tvorbe kolonij gojenih mišičnih MSC oziroma samoobnavljanja tako pri OA kot tudi pri OP višja od tiste, ki smo jo določili pri kostnih MSC. Dokazali smo, da je bil pri bolnikih z OP adipogeni potencial mišičnih MSC močno povečan, kar bi lahko kazalo na njihovo vlogo pri razvoju sarkopenije. Poleg tega smo kot prvi pokazali povezavo med podskupino MSC, ki izražajo gen za CD271 in stopnjo adipogenosti mišičnih MSC. Ta površinski molekulski označevalec bi morda lahko v prihodnosti predstavljal nov parameter v diagnostiki mišično-skeletnih bolezni. V 2 skeletni mišici smo potrdili tudi prisotnost MSC, ki izražajo Gremlin1 in jih pri preiskovancih z OA povezali s sposobnostjo njihoivega samopomnoževanja in vitro. Dodatno smo potrdili že znano povezavo med CD56-pozitivno podskupino mišičnih matičnih celic in njihovim miogenim potencialom. Z izsledki naših raziskav smo dokazali, da so lastnosti mišičnih MSC primerljive z lastnostmi kostnih MSC pri zdravih in pri dveh kroničnih boleznih.

• Language: Slovenian
• Keywords: mišične mezenhimske stromalne celice, kostne mezenhimske stromalne celice, CD271, Gremlin 1, mišično-skeletne bolezni, kostno tkivo, matične celice, skeletne mišice
• Work type: Dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FFA - Faculty of Pharmacy
• Place of publishing: Ljubljana
• Publisher: [K. Čamernik]
• Year: 2020
• Number of pages: 191 str.
• PID: 20.500.12556/RUL-137094
• UDC: 576.3:616.74(043.3)
• COBISS.SI-ID: 32110851
• Publication date in RUL: 01.06.2022

Secondary language

• Language: English
• Title: New insights into characterization and role of muscle-derived mesenchymal stromal/ stem cells in comparison to their bone-derived counterparts in osteoporosis and osteoarthritis

Abstract

With aging, musculoskeletal disorders such as osteoarthritis (OA), osteoporosis (OP) and sarcopenia are gaining importance. Microscopic injuries occur throughout the life of bones and muscles, but in spite of this they continue to provide the body with the support needed for daily activities. Our current understanding is that the regenerative capacity of the skeletal muscle system can be attributed to mesenchymal stromal / stem cells (MSCs). MSCs can serve different tissues as a reservoir of progenitors that form functional cells such as osteoblasts, chondrocytes, myocytes, and others. However, with aging and disorders of the musculoskeletal system, this regenerative ability of MSCs is lost or redirected to the production of other non-functional cell types, such as adipocytes and fibroblasts. There is increasing evidence that tissue specific MSCs have different properties. However, it is not clear how these traits are affected by aging and disease. Studies that directly compare MSCs from different tissues of the skeletal muscle system in the same patient are rare, and the impact of skeletal muscle diseases such as OA, OP and sarcopenia on MSCs is poorly understood. Thus, the purpose of this doctoral thesis was to evaluate MSCs isolated from the skeletal muscle of the gluteus medius and spongy bones of the femoral head of patients with OA and OP at the level of their phenotype and the ability to proliferate and differentiate in vitro in order to detect functional differences between them that could explain pathological changes in musculoskeletal diseases and discover new targets for their more effective treatment and diagnosis. In this doctoral thesis, we were the first to thoroughly evaluate the properties of muscle derived MSCs in patients with primary osteoarthritis and osteoporosis. We have shown that growth rates and doubling times of muscle and bone MSCs in vitro are comparable and independent of the type of disease. The ability to form colonies of cultured muscular MSCs (clonigenicity) was higher in OA and OP compared to bone MSCs. We have shown that in patients with OP, the adipogenic potential of muscle MSCs is greatly increased, which could indicate a role for these cells in the formation of fatty infiltrates. We were also the first to show an association between a subset of MSCs expressing the CD271 gene and the degree of adipogenicity of muscle MSCs. In the future this surface marker could possibly represent a new therapeutic target or a new indicator in the diagnosis of musculoskeletal diseases. We also confirmed the presence of Gremlin1-expressing MSCs in skeletal muscle and showed its association with increased in vitro clonigenicity in OA patients. In addition, we further confirmed the already known 4 association between the CD56-positive subset of muscle stem cells and their myogenic potential. The results of our research have shown that skeletal muscle is an appropriate and effective source of MSCs suitable for use in regenerative medicine, including in elderly patients with chronic musculoskeletal disorders.