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Biology subjects

Nuthalapati, P.

Publications and source records attributed to Nuthalapati, P..

3 recordsLinked to original sources

Viscoelastic HyA Hydrogel Promotes Recovery of Muscle Quality and Vascularization in a Murine Model of Delayed Rotator Cuff Repair

Rotator cuff tears are among the most common musculotendinous injuries with high risk of permanent functional disability. Following surgical repair, sub-optimal patient outcomes are directly correlated with poor muscle quality; namely, injury site fatty infiltration (FI), fibrosis, and muscle atrophy. Muscle resident fibro-adipogenic progenitor cells (FAPs) have been identified as key regulators of post-injury skeletal muscle regeneration and repair by maintaining a promyogenic environment. In this work, human-derived FAPs (hFAPs) were encapsulated into hyaluronic acid (HyA)-based hydrogels functionalized with bsp-RGD(15) cell adhesion peptide, heparin, and a matrix metalloproteinase (MMP)-cleavable crosslinker. Hydrogel-encapsulated hFAPs increased expression of the promyogenic marker UCP1 and production of the anti-inflammatory cytokine IL-10, while downregulating the expression of the fibrotic marker SMA over time. A murine model of unilateral rotator cuff transection, denervation, and delayed repair was treated with the HyA hydrogel or PBS and compared to a contralateral, non-injured control limb. Muscle histology 6 weeks post-repair revealed that the hydrogel reduced fibrosis, FI, and muscle atrophy while supporting vascularization of the injured tissue region. Collectively, these results suggest that the hydrogel alone can promote muscle regeneration in a clinically relevant delayed repair model of rotator cuff tear, which we hypothesize is due to controlled FAP differentiation into promyogenic lineages.

bioengineering↗

Adipocyte progenitors are primary contributors to the disrupted epithelial niche that is sustained following abrupt mammary gland involution

A short duration of breastfeeding is a risk factor for the development of high-mortality, postpartum, triple-negative breast cancer. The intrinsic properties of cancer-initiating epithelial cells that persist following breastfeeding cessation and mammary gland remodeling are poorly understood. Previously, we showed that Platelet-Derived Growth Factor Receptor alpha (PDGFR)-expressing stromal mammary adipocyte progenitors (MAPs) differentiate into epithelial luminal progenitors in the adult gland. In the current study, we demonstrate that MAP-derived luminal progenitors retain a mesenchymal transcriptomic signature. In an abrupt involution model that mimics a short breastfeeding duration, MAP-derived luminal progenitors persist and dominate luminal epithelia, undergoing transcriptomic alterations that signify a distinct ferrometabolic state linked to cancer. Concurrently, MAPs adopt an alternative interferon-mediated profibrotic and invasive stromal fate. Our work uncovers MAPs to be the primary cellular origin of a pathological stromal and epithelial microenvironment following abrupt involution, presenting a potential therapeutic target in postpartum breast cancer.

cancer biology↗

Obesity modifies cell fate plasticity of Pdgfrα-expressing mammary adipocyte progenitors to promote an aberrant mammary microenvironment

Excess fat gain culminating in obesity is a mounting global pandemic associated with a myriad of diseases including a higher risk of developing multiple cancers such as breast cancer. The underlying biological basis for obesity-linked breast cancer is attributed to alterations in adipose tissue-derived endocrine, metabolic and inflammatory factors. However, the precise cell types responsible for generating a cancer-susceptible mammary gland in obesity are not well understood. Using diet-induced obesity in conjunction with genetic reporter mouse models, we reveal elevated mammary adipocyte progenitors (MAPs) expressing Platelet-Derived Growth Factor Receptor alpha (PDGFR) in the mammary tissue microenvironment during obesity. Single-cell RNA sequencing analysis demonstrate intensified obesity-driven trajectories of MAPs to immune and epithelial progenitor cells. Further, lineage tracing indicates an invasive cellular state of MAPs that confers greater access of MAP descendants into the mammary epithelium concomitant with their transition into immune and epithelial cell fates. MAPs in obesity exhibit heightened activation of cancer-associated and inflammatory pathways where Egfr is identified as a common target upregulated in MAPs. Mechanistic studies on purified MAPs with a major obesity diet component and EGFR stimulation corroborate dynamic EGFR-mediated MAP responses. Our findings uncover MAPs as key contributors to forging an aberrant mammary gland in obesity, providing insight into the potential utility of targeting this cell lineage for eradicating cancer risk related to augmented adiposity.

cell biology↗