Journal: bioRxiv

Article Title: Activation of PPARγ redirects fibro-adipogenic progenitors to replace ectopic bone with fat in models of fibrodysplasia ossificans progressiva and trauma-induced heterotopic ossification

doi: 10.64898/2026.02.26.708276

Figure Lengend Snippet: (A) X-ray and Micro-CT imaging revealed a greater volume of ectopic bone in the hindlimbs of FOP mice treated with the corn oil vehicle control compared to those treated with rosiglitazone. (B) Quantification of ectopic bone showed an approximately 10-fold decrease in ectopic bone volume following rosiglitazone treatment. (n = 8) Statistical significance between two groups was determined using Student’s t -test ( p < 0.05). (C) H&E, Picrosirius Red, and Safranin-O/Fast Green staining of FOP mouse hindlimbs showed a reduction in FOP lesions and an increase in soft tissue–resident adipocytes after rosiglitazone treatment. Chondrocytes are represented by the red staining of Saffranin-O whereas the Fast Green stain represents the bone. (D) Immunofluorescence imaging of rosiglitazone-treated FOP mice showed an increase in soft tissue–resident adipocytes, indicated by PPARγ and Perilipin-1–positive cells. In contrast, hindlimbs of control mice exhibited adipogenic signals only within the bone marrow, consistent with bone marrow–resident adipocytes. Soft tissue–resident adipocytes were absent in control mice. pSMAD1/5 staining revealed abundant positive cells in the bone marrow of control mice and in the soft tissue of rosiglitazone-treated mice. Soft tissue resident adipocytes were also positive for PDGFRα, suggesting that the adipocytes were derived from FAPs.

Article Snippet: The sections were probed with antibodies for Perilipin-1 (Cell Signaling Technology, cat# 3467S, 1:100), PPARγ (Proteintech, cat 16643-1-AP, 1:100), pSMAD1/5 (Cell Signaling Technology, cat# 9516S, 1:100).

Techniques: Micro-CT, Imaging, Control, Staining, Immunofluorescence, Derivative Assay

Journal: bioRxiv

Article Title: Activation of PPARγ redirects fibro-adipogenic progenitors to replace ectopic bone with fat in models of fibrodysplasia ossificans progressiva and trauma-induced heterotopic ossification

doi: 10.64898/2026.02.26.708276

Figure Lengend Snippet: (A) Schematic representation of the procedure used to induce heterotopic ossification (HO) in wild-type (WT) mice via Achilles tendon tenotomy. Tissue was harvested 3 weeks post tenotomy. (B) Micro-CT imaging showed ectopic bone in the soft tissue and surrounding the calcaneus of the right hindlimb where tenotomy was performed. (C) H&E and Safranin-O/Fast Green staining of tenotomized WT mice showed a reduction in HO lesions and an increase in soft tissue–resident adipocytes following rosiglitazone treatment. (D) Immunofluorescence imaging of rosiglitazone-treated tenotomy mice revealed an increase in soft tissue–resident adipocytes, indicated by PPARγ and Perilipin-1–positive cells. In contrast, control mice displayed adipogenic signals only within the bone marrow, consistent with bone marrow–resident adipocytes. Soft tissue–resident adipocytes were absent in control mice. pSMAD1/5 staining showed abundant positive cells in the bone marrow of control mice and in the soft tissue of rosiglitazone-treated mice.

Article Snippet: The sections were probed with antibodies for Perilipin-1 (Cell Signaling Technology, cat# 3467S, 1:100), PPARγ (Proteintech, cat 16643-1-AP, 1:100), pSMAD1/5 (Cell Signaling Technology, cat# 9516S, 1:100).

Techniques: Micro-CT, Imaging, Staining, Immunofluorescence, Control

Journal: bioRxiv

Article Title: Activation of PPARγ redirects fibro-adipogenic progenitors to replace ectopic bone with fat in models of fibrodysplasia ossificans progressiva and trauma-induced heterotopic ossification

doi: 10.64898/2026.02.26.708276

Figure Lengend Snippet: (A) Schematic representation of the procedure used to induce heterotopic ossification (HO) in wild-type (WT) mice via Achilles tendon tenotomy, followed by local rosiglitazone injection. Tissue was harvested 3 weeks post tenotomy. (B) H&E and Safranin-O/Fast Green staining of tenotomized WT mice showed a reduction in HO lesions and an increase in soft tissue–resident adipocytes after rosiglitazone treatment. (C) Immunofluorescence imaging of rosiglitazone-treated tenotomy mice revealed an increase in soft tissue–resident adipocytes, as indicated by PPARγ and Perilipin-1–positive cells. In contrast, control mice showed adipogenic signals only within the bone marrow, consistent with bone marrow–resident adipocytes, while soft tissue–resident adipocytes were absent. pSMAD1/5 staining showed abundant positive cells in the bone marrow of control mice and in the soft tissue of rosiglitazone-treated mice.

Article Snippet: The sections were probed with antibodies for Perilipin-1 (Cell Signaling Technology, cat# 3467S, 1:100), PPARγ (Proteintech, cat 16643-1-AP, 1:100), pSMAD1/5 (Cell Signaling Technology, cat# 9516S, 1:100).

Techniques: Injection, Staining, Immunofluorescence, Imaging, Control