Senolytic-Resistant Senescent Cells Have a Distinct SASP Profile and Functional Impact: The Path to Developing Senosensitizers

Tripathi, U.; Suda, M.; Kulshreshtha, V.; Piatkowski, B. T.; Palmer, A. K.; Giorgadze, N.; Inman, C.; Gasek, N.; Xu, M.; Johnson, K. O.; Pirtskhalava, T.; Chaib, S.; Prata, L. P. G. L.; Zhu, Y.; Kandhaya-Pillai, R.; Tullius, S. G.; Wyles, S. P.; Majji, R.; Yalamanchili, H. K.; Allison, D. B.; Tchkonia, T.; Kirkland, J. L.

doi:10.1101/2025.08.27.672709

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bioRxiv · 10.1101/2025.08.27.672709

Senolytic-Resistant Senescent Cells Have a Distinct SASP Profile and Functional Impact: The Path to Developing Senosensitizers

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Abstract

The senescent cell (SC) fate is linked to aging, multiple disorders and diseases, and physical dysfunction. Senolytics, agents that selectively eliminate 30-70% of SCs, act by transiently disabling the senescent cell anti-apoptotic pathways (SCAPs), which defend those SCs that are pro-apoptotic and pro-inflammatory from their own senescence-associated secretory phenotype (SASP). Consistent with this, a JAK/STAT inhibitor, Ruxolitinib, which attenuates the pro-inflammatory SASP of senescent human preadipocytes, caused them to become "senolytic-resistant". Administering senolytics to obese mice selectively decreased abundance of the subset of SCs that is pro-inflammatory. In cell cultures, the 30-70% of human senescent preadipocytes or human umbilical vein endothelial cells (HUVECs) that are senolytic-resistant (to Dasatinib or Quercetin, respectively) had increased p16INK4a, p21CIP1, senescence-associated {beta}-galactosidase (SA{beta}gal), {gamma}H2AX, and proliferative arrest similarly to the total SC population (comprising senolytic-sensitive plus -resistant SCs). However, the SASP of senolytic-resistant SCs entailed less pro-inflammatory/ apoptotic factor production, induced less inflammation in non-senescent cells, and was equivalent or richer in growth/ fibrotic factors. Senolytic-resistant SCs released less mitochondrial DNA (mtDNA) and more highly expressed the anti-inflammatory immune evasion signal, glycoprotein non-melanoma-B (GPNMB). Transplanting senolytic-resistant SCs intraperitoneally into younger mice caused less physical dysfunction than transplanting the total SC population. Because Ruxolitinib attenuates SC release of pro-apoptotic SASP factors, while pathogen-associated molecular pattern factors (PAMPs) can amplify the release of these factors rapidly (acting as "senosensitizers"), senolytic-resistant and senolytic-sensitive SCs appear to be interconvertible.

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Tripathi, U., Suda, M., Kulshreshtha, V., Piatkowski, B. T., Palmer, A. K., Giorgadze, N., Inman, C., Gasek, N., Xu, M., Johnson, K. O., Pirtskhalava, T., Chaib, S., Prata, L. P. G. L., Zhu, Y., Kandhaya-Pillai, R., Tullius, S. G., Wyles, S. P., Majji, R., Yalamanchili, H. K., Allison, D. B., Tchkonia, T., Kirkland, J. L.. 2025-08-30. Senolytic-Resistant Senescent Cells Have a Distinct SASP Profile and Functional Impact: The Path to Developing Senosensitizers. https://doi.org/10.1101/2025.08.27.672709

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