👤 Giuliano Tocci

Although recommended for cardiovascular (CV) risk stratification in adults, the role of lipoprotein(a) [Lp(a)] in hypertension is not fully established. To evaluate Lp(a) levels in adult outpatients with essential arterial hypertension. A retrospective, observational study was conducted in outpatients of both sexes, aged ≥ 18 years, with treated or untreated essential hypertension, who were consecutively evaluated at the Hypertension Unit, Excellence Hypertension Center, Sant'Andrea Hospital, Rome, Italy. Participants underwent office and out-of-office blood pressure (BP) measurements, as well as assessment of hypertension-mediated organ damage (HMOD). BP measurements were performed, and hypertension phenotypes were classified according to 2023 European hypertension guidelines. Lp(a) levels were measured, and the study population was stratified according to a Lp(a) cut-off value of ≥50 mg/dl. Due to the non-uniform distribution, absolute Lp(a) values were logarithmically transformed. A total of 230 patients with available Lp(a) values were included (42.6% women, mean age 66.3 ± 11.5 years, BMI 27.1 ± 4.5 kg/m2, office BP 137.1 ± 18.1/83.7 ± 11.0 mmHg, 24-hour BP 129.8 ± 14.5/79.6 ± 9.8 mmHg, Lp(a) 51.4 ± 65.3 mg/dL), among whom 32.2% had Lp(a) ≥50 mg/dl. There were significantly higher proportions of men (74.3% vs. 49.4%; P < 0.001), dyslipidaemia (97.3% vs. 75.0%; P < 0.001) and comorbidities (55.4% vs. 30.8%; P < 0.001) in patients with high Lp(a) than in those with normal Lp(a), who also received more frequently lipid lowering therapies (P < 0.001) and aspirin (P = 0.003). However, lower office systolic BP values (133.5±18.8 vs. 138.8±17.6 mmHg: P = 0.036) were observed in patients with Lp(a) ≥50 mg/dL than in those with < 50 mg/dl. Also, no significant differences for Lp(a) levels were observed among various hypertension phenotypes, as defined by office (P = 0.156) or out-of-office BP values (P = 0.065). No significant correlations were found between Lp(a) and office or out-of-office BP levels, both in treated and untreated hypertensive outpatients. In our population, Lp(a) levels were not associated with either office or out-of-office BP values, irrespective of antihypertensive treatment status. The role of Lp(a) in hypertension warrants further investigation. Show less

The NEDD4-like E3 ubiquitin ligase, WWP2, is involved in a range of host processes from cell differentiation to T cell immunity. Ligase activity is tightly regulated, with WWP2 being held in an autoinhibited state. The binding of a PY motif-containing adaptor, an Ndfip, via the WW domains of NEDD4-like E3 ubiquitin ligases leads to their disinhibition. Here, we show that the canonical Ndfip, NDFIP2, requires multiple PY motifs for interaction with and activation of WWP2. In contrast, the single PY-motif containing Ndfips TMEM127 and SUSD6 functions as a co-disinhibitory pair. TMEM127 and the Salmonella protein SteD also function as a co-disinhibitory pair. However, SteD requires a different region of WWP2, the C2 domain, for interaction with WWP2, and this interaction results in disinhibition of WWP2. These findings demonstrate a range of ways that Ndfips can disinhibit WWP2. To our knowledge, these are the first examples of two Ndfips functioning as co-disinhibitory pairs, and of a bacterial effector that disinhibits an E3 ubiquitin ligase. Show less

The Salmonella enterica effector SteD depletes mature MHC class II (mMHCII) molecules from the surface of infected antigen-presenting cells through ubiquitination of the cytoplasmic tail of the mMHCII β chain. This requires the Nedd4 family HECT E3 ubiquitin ligase Wwp2 and a tumor-suppressing transmembrane protein adaptor Tmem127. Here, through a proteomic screen of dendritic cells, we found that SteD targets the plasma membrane protein CD97 for degradation by a similar mechanism. SteD enhanced ubiquitination of CD97 on K555 and mutation of this residue eliminated the effect of SteD on CD97 surface levels. We showed that CD97 localises to and stabilises the immunological synapse between dendritic cells and T cells. Removal of CD97 by SteD inhibited dendritic cell-T cell interactions and reduced T cell activation, independently of its effect on MHCII. Therefore, SteD suppresses T cell immunity by two distinct processes. Show less

The Salmonella enterica effector SteD depletes mature MHC class II (mMHCII) molecules from the surface of infected antigen-presenting cells through ubiquitination of the cytoplasmic tail of the mMHCII β chain. Here, through a genome-wide mutant screen of human antigen-presenting cells, we show that the NEDD4 family HECT E3 ubiquitin ligase WWP2 and a tumor-suppressing transmembrane protein of unknown biochemical function, TMEM127, are required for SteD-dependent ubiquitination of mMHCII. Although evidently not involved in normal regulation of mMHCII, TMEM127 was essential for SteD to suppress both mMHCII antigen presentation in mouse dendritic cells and MHCII-dependent CD4 Show less