Investigation of the Presence of Telocyte-like Cells in Human Patellar Fat Pad Tissue

BIO Web of Conferences, cilt.129, ss.17025, 2024 (Düzenli olarak gerçekleştirilen hakemli kongrenin bildiri kitabı)

Aims:

This research aims to advance our understanding of the heterogenity of IPFP cells and detect

the presence of TCs by employing techniques such as immunohistochemistry and

immunofluorescence. Through the investigation of their morphology and identification of

telocytes in the IPFP stroma, this study endeavors to provide novel insights into IPFP

architecture and its implications for regenerative medicine.

Methods:

In this study, IPFP tissues were obtained from 5-10 patients preparing for knee replacement

surgery at Sadi Konuk Training and Research Hospital, Orthopedics and Traumatology Clinic.

After obtainiing the specimen one small piece of it underwent tissue preparation procedures

for light microscopy and immunohistochemical staining was performed using CD34 which is

the most common marker for telocyte identification. The rest of the specimen was used for

cell culture from which these cells were isolated using tissue digestion agent such as

collagenase II and cell strainers of different diameters in order to separate them from other

stromal cells with the cell adhesion method and subculturing the media in which the telocytes

were present during 96 hours. The cells were photographed at different incubation times

such as at 24h, 48, and 96h and were examined under the inverted microscope. Finally the

cells resembling to telocytes with their long projections were analyzed by double

immunofluorescence staining used CD34/c- kit, CD34/vimentin, CD34/PDGFR- α and β, and

CD34/ α-SMA markers for telocyte identification. This comprehensive approach aimed to

illuminate telocyte presence and distribution in the IPFP stroma, offering future insights into

IPFP physiology and pathophysiology.

Results:

In this study, the existence of telocytes within the IPFP was identified by their different shape

and immunophenotypes. We identified telocytes by immunohistochemical analysis, labeling

with CD34, the most extensively utilized telocyte marker. We used immunofluorescence

analysis with double labeling of CD34/c-kit, CD34/vimentin, and CD34/PDGFR α and β,

CD34/α-SMA in order to distinguish these cells from fibroblasts and pericytes in cell culture.

We found out that TCs were strongly positive for CD34, PDGFR α and β, and vimentin and

weakly positive for α-SMA. On the other hand fibroblasts and were found to be CD34

negative, while strongly positive for vimentin and PDGFR α and β. Notably, our findings

delineate telocyte cells from fibroblasts and pericytes, underscoring their unique cellular

identity within the IPFP microenvironment. TCs were recognized for their long and thin

prolongations and small cell bodies primarily situated around blood vessels and dispersed

throughout the IPFP stroma.

Conclusion:

Our study adds greatly to our understanding of IPFP telocyte biology by shedding light on

their presence, distribution, and morphological properties. As a result, these cells have the

potential to be a unique progenitor cell source for cartilage regeneration, and they need full

attention from researchers in the tissue engineering field.