Pneumocystis jirovecii in Spanish Patients With Heart Failure

Mechanisms of lung endothelial cell injury and survival in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive, chronic, and incurable inflammatory pulmonary vascular disease characterized by significant sex bias and largely unexplored microbial-associated molecular mechanisms that may influence its development and sex prevalence across various subgroups. PAH can be subclassified as idiopathic, heritable, or associated with conditions such as connective tissue diseases, congenital heart defects, liver disease, infections, and chronic exposure to drugs or toxins. During PAH progression, lung vascular endothelial cells (ECs) undergo dramatic morphofunctional transformations in response to acute and chronic inflammation. These transformations include the appearance and expansion of abnormal vascular cell phenotypes such as those derived from apoptosis-resistant cell growth and endothelial-to-mesenchymal transition (EndoMT). Compelling evidence indicates that these endothelial phenotypes seem to be triggered by chronic lung vascular injury and dysfunction, often characterized by reduced secretion of vasoactive molecules like nitric oxide (NO) and exacerbated response to vasoconstrictors such as Endothelin-1 (ET-1), both long-term known contributors of PAH pathogenesis. This review sheds light on the mechanisms of EC dysfunction, apoptosis, and EndoMT in PAH, aiming to unravel the intricate interactions between ECs, pathogens, and other cell types that drive the onset and progression of this devastating disease. Ultimately, we hope to provide an overview of the complex functions of lung vascular ECs in PAH, inspiring novel therapeutic strategies that target these dysfunctional cells to improve the treatment landscape for PAH, particularly in the face of current and emerging global pathogenic threats.

Huertas C, Calderón EJ, Eritja R, Lechuga LM. Fast and Accurate Pneumocystis Pneumonia Diagnosis in Human Samples Using a Label-Free Plasmonic Biosensor

Pneumocystis jirovecii is a fungus responsible for human Pneumocystis pneumonia, one of the most severe infections encountered in immunodepressed individuals. The diagnosis of Pneumocystis pneumonia continues to be challenging due to the absence of specific symptoms in infected patients. Moreover, the standard diagnostic method employed for its diagnosis involves mainly PCR-based techniques, which besides being highly specific and sensitive, require specialized personnel and equipment and are time-consuming. Our aim is to demonstrate an optical biosensor methodology based on surface plasmon resonance to perform such diagnostics in an efficient and decentralized scheme. The biosensor methodology employs poly-purine reverse-Hoogsteen hairpin probes for the detection of the mitochondrial large subunit ribosomal RNA (mtLSU rRNA) gene, related to P. jirovecii detection. The biosensor device performs a real-time and label-free identification of the mtLSU rRNA gene with excellent selectivity and reproducibility, achieving limits of detection of around 2.11 nM. A preliminary evaluation of clinical samples showed rapid, label-free and specific identification of P. jirovecii in human lung fluids such as bronchoalveolar lavages or nasopharyngeal aspirates. These results offer a door for the future deployment of a sensitive diagnostic tool for fast, direct and selective detection of Pneumocystis pneumonia disease.