The lymphatic system plays crucial roles in tissue homeostasis, lipid absorption, and immune cell trafficking. Although lymphatic valves ensure unidirectional lymph flows, the flow itself controls lymphatic valve formation. Here, we demonstrate that a mechanically activated ion channel Piezo1 senses oscillating shear stress (OSS) and incorporates the signal into the genetic program controlling lymphatic valve development and maintenance. Time-controlled deletion of Piezo1 using a pan-endothelial Cre driver ( Cdh5[PAC]-CreER ^T2 ) or lymphatic-specific Cre driver ( Prox1-CreER ^T2 ) equally inhibited lymphatic valve formation in newborn mice. Furthermore, Piezo1 deletion in adult lymphatics caused substantial lymphatic valve degeneration. Piezo1 knockdown in cultured lymphatic endothelial cells (LECs) largely abrogated the OSS-induced upregulation of the lymphatic valve signature genes. Conversely, ectopic Piezo1 overexpression upregulated the lymphatic valve genes in the absence of OSS. Remarkably, activation of Piezo1 using chemical agonist Yoda1 not only accelerated lymphatic valve formation in animals, but also triggered upregulation of some lymphatic valve genes in cultured LECs without exposure to OSS. In summary, our studies together demonstrate that Piezo1 is the force sensor in the mechanotransduction pathway controlling lymphatic valve development and maintenance, and Piezo1 activation is a potentially novel therapeutic strategy for congenital and surgery-associated lymphedema.

Background: Diabetic foot infections (DFIs) are a major cause of hospitalization, limb loss, and mortality among patients with diabetic foot ulcers (DFUs). This study evaluated the risk of developing DFIs among patients with newly diagnosed DFUs across insurance categories. Methods: Adults ≥18 years with a new DFU diagnosis were identified in the PearlDiver insurance claims database (2010–2020) using validated ICD-9/10 codes. Insurance status at the index DFU was categorized as Medicaid, Medicare, commercial, or self-pay. Propensity score matching (1:3) based on age, sex, Charlson Comorbidity Index, and major comorbidities was used to compare Medicaid vs. non-Medicaid patients. Results: Among 258,122 patients with new DFUs, 20,638 (8.0%) were Medicaid beneficiaries. Medicaid patients were younger (50.1 ± 10.2 vs. 60.6 ± 12.1 years, p < 0.001) but had similar comorbidity burden compared with commercially insured and Medicare patients. In matched analysis post-matching, Medicaid insurance was independently associated with higher odds of DFI-related hospitalization within 12 months (aOR 1.18, 95% CI 1.14–1.24) and major amputation at 3 years (aOR 1.72, 95% CI 1.39–2.13). Higher CCI, chronic kidney disease, congestive heart failure, COPD, and peripheral vascular disease also predicted adverse outcomes. Conclusions: Medicaid insurance was independently associated with increased risks of DFI and major amputation among patients with newly diagnosed DFUs. These findings highlight infection as a potentially modifiable pathway driving limb loss and emphasize the need to improve early ulcer evaluation and infection management for Medicaid beneficiaries.