Persistent chronic inflammation and delayed epithelialization lead to stalled healing in diabetic ulcers (DUs). PD-L1 shows anti-inflammatory and proliferative activities in healing defects, whereas its function in DU pathogenesis remains unknown. Lower levels of PD-L1 were found in DU tissues, and exogenous PD-L1 has therapeutic effects in the healing process by accelerating re-epithelialization and attenuating prolonged inflammation, which contributed to the delayed wound closure. We detected the downstream effectors of PD-L1 using transcriptional profiles and screened the interacting proteins using immunoprecipitation in combination with mass spectrometry and coimmunoprecipitation assays. The biological functions of eIF3I-PD-L1. IRS4 axis were tested both in vivo and in vitro. Finally, we validated the expression levels of eIF3I, PD-L1, and IRS4 in DU tissues from human clinical samples by immunohistochemistry staining. Mechanistically, PD-L1 binds to eIF3I and promotes cutaneous diabetic wound healing by downregulating IRS4. These findings identify that the eIF3I-PD-L1.IRS4 axis contributes to wound healing defects, which can serve as a potential therapeutic target in DUs.

Transthoracic echocardiography is an essential tool in the diagnosis, assessment, and management of paediatric and adult populations with suspected or confirmed congenital heart disease. Congenital echocardiography is highly operator-dependent, requiring advanced technical acquisition and interpretative skill levels. This document is designed to complement previous congenital echocardiography literature by providing detailed practical echocardiography imaging guidance on sequential segmental analysis, and is intended for implementation predominantly, but not exclusively, within adult congenital heart disease settings. It encompasses the recommended dataset to be performed and is structured in the preferred order for a complete anatomical and functional sequential segmental congenital echocardiogram. It is recommended that this level of study be performed at least once on all patients being assessed by a specialist congenital cardiology service. This document will be supplemented by a series of practical pathology specific congenital echocardiography guidelines. Collectively, these will provide structure and standardisation to image acquisition and reporting, to ensure that all important information is collected and interpreted appropriately.