Midterm survival after aortic repair versus conservative treatment in patients with penetrating aortic ulcer.

Background: The clinical outcomes and survival of patients with penetrating aortic ulcers (PAU) were evaluated in a tertiary care hospital, comparing those who underwent aortic repair to those treated conservatively. Patients and methods: A retrospective single-centre analysis included all patients that underwent a computed tomography angiography (CT-A) scan with the diagnosis of a PAU between January 2009 and May 2019. "PAU" was identified in 1,493 of 112,506 CT-A scan reports in 576 patients. Clinical and angiomorphological data were collected. The primary outcome was overall survival (OS), with secondary outcomes focusing on identifying risk factors for poor OS. Survival probabilities were analysed by the Kaplan-Meier method using the log-rank test. A Cox hazard model using survival as dependent variable with stepwise backward eliminations based on the likelihood ratios was employed. Results: 315 PAUs were identified in 278 patients. The prevalence in the cohort was 0.8%. The mean age of the patients was 74.4 years, and they were predominantly male (n = 208, 74.8%). The mean ulcer depth was 11.8 mm (range 2-50 mm). Out of the patients, 232 were asymptomatic (83.5%). Among 178 PAUs (56.5%), high-risk factors, such as ulcer depth >10 mm, aortic diameter >40 mm, and ulcer length >20 mm, were observed. Aortic repair was associated with a better mean OS compared to conservatively managed patients (72.6 versus 32.2 months, p = 0.001). The Cox hazard model showed that ulcer depth >1 mm was associated with poor OS (HR 0.67, p = 0.048), while aortic repair was related to a better OS (HR 4.365, p<0.013). Conclusions: Aortic repair is associated with better OS, but this finding should be interpreted with caution because of differences in age and comorbidities between the groups. Further evaluation is warranted through prospective studies with randomized groups. Further assessment for angiomorphological parameters is recommended to identify patients at increased risk for poor OS.

PACE: randomized, controlled, multicentre, multinational, phase III study of PLX-PAD for critical limb ischaemia in patients unsuitable for revascularization: randomized clinical trial.

BACKGROUND: Revascularization is the primary treatment modality for chronic limb-threatening ischaemia (CLTI), but is not feasible in all patients. PLX-PAD is an off-the-shelf, placental-derived, mesenchymal stromal cell-like cell therapy. This study aimed to evaluate whether PLX-PAD would increase amputation-free survival in people with CLTI who were not candidates for revascularization. METHODS: People with CLTI and minor tissue loss (Rutherford 5) who were unsuitable for revascularization were entered into a randomized, parallel-group, placebo-controlled, multinational, blinded, trial, in which PLX-PAD was compared with placebo (2 : 1 randomization), with 30 intramuscular injections (0.5 ml each) into the index leg on days 0 and 60. Planned follow-up was 12-36 months, and included vital status, amputations, lesion size, pain and quality-of-life assessments, haemodynamic parameters, and adverse events. RESULTS: Of 213 patients enrolled, 143 were randomized to PLX-PAD and 70 to placebo. Demographics and baseline characteristics were balanced. Most patients were Caucasian (96.2%), male (76.1%), and ambulatory (85.9%). Most patients (76.6%) reported at least one adverse event, which were mostly expected events in CLTI, such as skin ulcer or gangrene. The probability of major amputation or death was similar for placebo and PLX-PAD (33 and 28.6% respectively; HR 0.93, 95% c.i. 0.53 to 1.63; P = 0.788). Revascularization and complete wound healing rates were similar in the two groups. A post hoc analysis of a subpopulation of 121 patients with a baseline haemoglobin A1c level below 6.5% showed improved 12-month amputation-free survival (HR 0.46, 0.21 to 0.99; P = 0.048). CONCLUSION: Although there was no evidence that PLX-PAD reduced amputation-free survival in the entire study population, benefit was observed in patients without diabetes mellitus or whose diabetes was well controlled; this requires confirmation in further studies. Trial registration: NCT03006770 (http://www.clinicaltrials.gov); 2015-005532-18 (EudraCT Clinical Trials register - Search for 2015-005532-18).

The T-type calcium channelosome.

T-type calcium channels perform crucial physiological roles across a wide spectrum of tissues, spanning both neuronal and non-neuronal system. For instance, they serve as pivotal regulators of neuronal excitability, contribute to cardiac pacemaking, and mediate the secretion of hormones. These functions significantly hinge upon the intricate interplay of T-type channels with interacting proteins that modulate their expression and function at the plasma membrane. In this review, we offer a panoramic exploration of the current knowledge surrounding these T-type channel interactors, and spotlight certain aspects of their potential for drug-based therapeutic intervention.

Outcome After Conservative and Endovascular Treatment of Stanford Type B Aortic Intramural Hematomas - A Single-Center Retrospective Study.

OBJECTIVES: Aortic intramural hematoma (IMH) is a rare disease. Thus far, only limited data is available and the indications for conservative and endovascular treatment are not well defined. The aim of this study was to investigate clinical presentation, course, CT imaging features and outcome of patients with type B aortic IMHs. METHODS: We included all patients with type B IMHs between 2012 and 2021 in this retrospective monocentric study. Clinical data, localization, thickness of IMHs and the presence of ulcer-like projections (ULPs) was evaluated before and after treatment. RESULTS: Thirty five patients (20 females; 70.3 y ± 11 y) were identified. Almost all IMHs (n = 34) were spontaneous and symptomatic with back pain (n = 34). At the time of diagnosis, TEVAR was deemed indicated in 9 patients, 26 patients were treated primarily conservatively. During the follow-up, in another 16 patients TEVAR was deemed indicated. Endovascularly and conservatively treated patients both showed decrease in thickness after treatment. Patients without ULPs showed more often complete resolution of the IMH than patients with ULPs (endovascularly treated 90.9% (10/11) vs 71.4% (5/7); conservatively treated 71.4% (10/14) vs 33.3% (1/3); P = .207). Complications after TEVAR occurred in 32% and more frequently in patients treated primarily conservatively (37.5% vs 22.2%). No in-hospital mortality was observed during follow-up. CONCLUSIONS: Prognosis of IMH seems favourable in both surgically as well as conservatively treated patients. However, it is essential to identify patients at high risk for complications under conservative treatment, who therefore should be treated by TEVAR. In our study, ULPs seem to be an adverse factor for remodeling.

Pathophysiology of ion channels in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) stands as the most prevalent and severe form of motor neuron disease, affecting an estimated 2 in 100,000 individuals worldwide. It is characterized by the progressive loss of cortical, brainstem, and spinal motor neurons, ultimately resulting in muscle weakness and death. Although the etiology of ALS remains poorly understood in most cases, the remodelling of ion channels and alteration in neuronal excitability represent a hallmark of the disease, manifesting not only during the symptomatic period but also in the early pre-symptomatic stages. In this review, we delve into these alterations observed in ALS patients and preclinical disease models, and explore their consequences on neuronal activities. Furthermore, we discuss the potential of ion channels as therapeutic targets in the context of ALS.

Electrophysiological characterization of a Cav3.2 calcium channel missense variant associated with epilepsy and hearing loss.

T-type calcium channelopathies encompass a group of human disorders either caused or exacerbated by mutations in the genes encoding different T-type calcium channels. Recently, a new heterozygous missense mutation in the CACNA1H gene that encodes the Cav3.2 T-type calcium channel was reported in a patient presenting with epilepsy and hearing loss-apparently the first CACNA1H mutation to be associated with a sensorineural hearing condition. This mutation leads to the substitution of an arginine at position 132 with a histidine (R132H) in the proximal extracellular end of the second transmembrane helix of Cav3.2. In this study, we report the electrophysiological characterization of this new variant using whole-cell patch clamp recordings in tsA-201 cells. Our data reveal minor gating alterations of the channel evidenced by a mild increase of the T-type current density and slower recovery from inactivation, as well as an enhanced sensitivity of the channel to external pH change. To what extend these biophysical changes and pH sensitivity alterations induced by the R132H mutation contribute to the observed pathogenicity remains an open question that will necessitate the analysis of additional CACNA1H variants associated with the same pathologies.

MRI detects increased aortic stiffening and myocardial dysfunction after TEVAR of blunt injury in young patients.

Background: Thoracic endovascular aortic repair (TEVAR) is a well-established technique for the management of blunt thoracic aortic injury (BTAI). Despite improvements in vascular imaging, graft material properties, and implant techniques, stent-graft deployment artificially induces aortic stiffening. This study aimed to evaluate the midterm effect of thoracic endovascular aortic repair after blunt thoracic aortic injury on aortic stiffness and cardiac function in young patients using cardiovascular magnetic resonance (CMR) imaging. Patients and methods: From all patients who underwent TEVAR for BTAI between 2009 and 2019 in a single institution, 10 patients with no other comorbidities affecting arterial stiffness were sex-, age-, height-, and body surface area-matched to 10 healthy controls. Comprehensive CMR examination was performed in all controls and patients. The mean follow-up period was 5.4±1.8 years; the mean age at the time of TEVAR was 30.3±8.7 years. Results: Four patients who underwent TEVAR developed arterial hypertension. 4D flow CMR-based analysis demonstrated higher global pulse wave velocity (PWV) in TEVAR patients than in controls (p=0.012). Segmental analysis showed a higher PWV in the descending and abdominal aorta. The indexed diameter of the ascending aorta was larger in TEVAR patients than in controls (p=0.007). The CINE acquisitions demonstrated increased left ventricular myocardial thickness (p<0.001). The 3D global diastolic strain rate and diastolic longitudinal velocity (e') decreased, and the A-wave velocity increased. Native myocardial T1 values were significantly higher in TEVAR patients (p=0.037). Conclusions: Young patients with TEVAR after BTAI are at an increased risk of developing vascular and myocardial dysfunction due to increased aortic stiffness. CMR follow-up allows for a comprehensive and radiation-free evaluation of vascular stiffness and associated myocardial changes, especially at the early and subclinical stages.

Secretory carrier-associated membrane protein 5 regulates cell-surface targeting of T-type calcium channels.

Missense mutations in the human secretary carrier-associated membrane protein 5 (SCAMP5) cause a variety of neurological disorders including neurodevelopmental delay, epilepsy, and Parkinson's disease. We recently documented the importance of SCAMP2 in the regulation of T-type calcium channel expression in the plasma membrane. Here, we show that similar to SCAMP2, the co-expression of SCAMP5 in tsA-201 cells expressing recombinant Cav3.1, Cav3.2, and Cav3.3 channels nearly abolished whole-cell T-type currents. Recording of intramembrane charge movements revealed that SCAMP5-induced inhibition of T-type currents is primarily caused by the reduced expression of functional channels in the plasma membrane. Moreover, we show that SCAMP5-mediated downregulation of Cav3.2 channels is essentially preserved with disease-causing SCAMP5 R91W and G180W mutations. Hence, this study extends our previous findings with SCAMP2 and indicates that SCAMP5 also contributes to repressing the expression of T-type channels in the plasma membrane.

A multicentric consortium study demonstrates that dimethylarginine dimethylaminohydrolase 2 is not a dimethylarginine dimethylaminohydrolase.

Dimethylarginine dimethylaminohydrolase 1 (DDAH1) protects against cardiovascular disease by metabolising the risk factor asymmetric dimethylarginine (ADMA). However, the question whether the second DDAH isoform, DDAH2, directly metabolises ADMA has remained unanswered. Consequently, it is still unclear if DDAH2 may be a potential target for ADMA-lowering therapies or if drug development efforts should focus on DDAH2's known physiological functions in mitochondrial fission, angiogenesis, vascular remodelling, insulin secretion, and immune responses. Here, an international consortium of research groups set out to address this question using in silico, in vitro, cell culture, and murine models. The findings uniformly demonstrate that DDAH2 is incapable of metabolising ADMA, thus resolving a 20-year controversy and providing a starting point for the investigation of alternative, ADMA-independent functions of DDAH2.

Electrophysiological and computational analysis of Cav3.2 channel variants associated with familial trigeminal neuralgia.

Trigeminal neuralgia (TN) is a rare form of chronic neuropathic pain characterized by spontaneous or elicited paroxysms of electric shock-like or stabbing pain in a region of the face. While most cases occur in a sporadic manner and are accompanied by intracranial vascular compression of the trigeminal nerve root, alteration of ion channels has emerged as a potential exacerbating factor. Recently, whole exome sequencing analysis of familial TN patients identified 19 rare variants in the gene CACNA1H encoding for Cav3.2T-type calcium channels. An initial analysis of 4 of these variants pointed to a pathogenic role. In this study, we assessed the electrophysiological properties of 13 additional TN-associated Cav3.2 variants expressed in tsA-201 cells. Our data indicate that 6 out of the 13 variants analyzed display alteration of their gating properties as evidenced by a hyperpolarizing shift of their voltage dependence of activation and/or inactivation resulting in an enhanced window current supported by Cav3.2 channels. An additional variant enhanced the recovery from inactivation. Simulation of neuronal electrical membrane potential using a computational model of reticular thalamic neuron suggests that TN-associated Cav3.2 variants could enhance neuronal excitability. Altogether, the present study adds to the notion that ion channel polymorphisms could contribute to the etiology of some cases of TN and further support a role for Cav3.2 channels.

Low-Dose vs High-Dose Paclitaxel-Coated Balloons for Femoropopliteal Lesions: 2-Year Results From the COMPARE Trial.

BACKGROUND: So far only 1-year data have been reported for direct comparisons of paclitaxel-coated balloons (PCBs) using different coating technologies. OBJECTIVES: The aim of this study was to report the 24-month results on the efficacy and safety of low-dose vs high-dose PCBs with nominal paclitaxel densities of 2.0 and 3.5 µg/mm2 and different coating technologies for femoropopliteal interventions from the COMPARE (Compare I Pilot Study for the Treatment of Subjects With Symptomatic Femoropopliteal Artery Disease) trial. Procedural characteristics of clinically driven (CD) target lesion revascularization (TLR) were analyzed. METHODS: Within a prospective, multicenter, clinical trial, 414 patients with symptomatic femoropopliteal lesions (Rutherford categories 2-4, maximum lesion length 30 cm) were randomly assigned in a 1:1 ratio to endovascular treatment with either a low-dose (Ranger) or a high-dose (IN.PACT) PCB after stratification for lesion length. Two-year follow-up included assessment of primary patency (defined as absence of CD TLR or binary restenosis with a peak systolic velocity ratio >2.4 by duplex ultrasound), safety, and functional and clinical outcomes. RESULTS: At 2 years, the Kaplan-Meier estimates of primary patency were 70.6% and 71.4% for the low-dose and high-dose PCBs (log-rank P = 0.96), respectively. One major amputation occurred in the high-dose group, and rates of all-cause mortality (3.6% vs 2.2%; P = 0.55) and CD TLR (17.3% vs 13.0%; P = 0.31) were similar between the groups. Among a total of 57 CD TLRs, 44.6% were performed for reocclusion and 28.1% for in-stent restenosis. Functional and clinical benefits over baseline were sustained in both groups. CONCLUSIONS: The 2-year results of the COMPARE trial demonstrate a sustained treatment benefit of both low-dose and high-dose PCBs for femoropopliteal interventions including a wide range of lesion lengths. (Compare I Pilot Study for the Treatment of Subjects With Symptomatic Femoropopliteal Artery Disease; NCT02701543).

Screening an In-House Isoquinoline Alkaloids Library for New Blockers of Voltage-Gated Na+ Channels Using Voltage Sensor Fluorescent Probes: Hits and Biases.

Voltage-gated Na+ (NaV) channels are significant therapeutic targets for the treatment of cardiac and neurological disorders, thus promoting the search for novel NaV channel ligands. With the objective of discovering new blockers of NaV channel ligands, we screened an In-House vegetal alkaloid library using fluorescence cell-based assays. We screened 62 isoquinoline alkaloids (IA) for their ability to decrease the FRET signal of voltage sensor probes (VSP), which were induced by the activation of NaV channels with batrachotoxin (BTX) in GH3b6 cells. This led to the selection of five IA: liriodenine, oxostephanine, thalmiculine, protopine, and bebeerine, inhibiting the BTX-induced VSP signal with micromolar IC50. These five alkaloids were then assayed using the Na+ fluorescent probe ANG-2 and the patch-clamp technique. Only oxostephanine and liriodenine were able to inhibit the BTX-induced ANG-2 signal in HEK293-hNaV1.3 cells. Indeed, liriodenine and oxostephanine decreased the effects of BTX on Na+ currents elicited by the hNaV1.3 channel, suggesting that conformation change induced by BTX binding could induce a bias in fluorescent assays. However, among the five IA selected in the VSP assay, only bebeerine exhibited strong inhibitory effects against Na+ currents elicited by the hNav1.2 and hNav1.6 channels, with IC50 values below 10 µM. So far, bebeerine is the first BBIQ to have been reported to block NaV channels, with promising therapeutical applications.

Overexpression of alanine-glyoxylate aminotransferase 2 protects from asymmetric dimethylarginine-induced endothelial dysfunction and aortic remodeling.

Elevated plasma concentrations of asymmetric dimethylarginine (ADMA) are associated with an increased risk of mortality and adverse cardiovascular outcomes. ADMA can be metabolized by dimethylarginine dimethylaminohydrolases (DDAHs) and by alanine-glyoxylate aminotransferase 2 (AGXT2). Deletion of DDAH1 in mice leads to elevation of ADMA in plasma and increase in blood pressure, while overexpression of human DDAH1 is associated with a lower plasma ADMA concentration and protective cardiovascular effects. The possible role of alternative metabolism of ADMA by AGXT2 remains to be elucidated. The goal of the current study was to test the hypothesis that transgenic overexpression of AGXT2 leads to lowering of plasma levels of ADMA and protection from vascular damage in the setting of DDAH1 deficiency. We generated transgenic mice (TG) with ubiquitous overexpression of AGXT2. qPCR and Western Blot confirmed the expression of the transgene. Systemic ADMA levels were decreased by 15% in TG mice. In comparison with wild type animals plasma levels of asymmetric dimethylguanidino valeric acid (ADGV), the AGXT2 associated metabolite of ADMA, were six times higher. We crossed AGXT2 TG mice with DDAH1 knockout mice and observed that upregulation of AGXT2 lowers plasma ADMA and pulse pressure and protects the mice from endothelial dysfunction and adverse aortic remodeling. Upregulation of AGXT2 led to lowering of ADMA levels and protection from ADMA-induced vascular damage in the setting of DDAH1 deficiency. This is especially important, because all the efforts to develop pharmacological ADMA-lowering interventions by means of upregulation of DDAHs have been unsuccessful.

Secretory carrier-associated membrane protein 2 (SCAMP2) regulates cell surface expression of T-type calcium channels.

Low-voltage-activated T-type Ca2+ channels are key regulators of neuronal excitability both in the central and peripheral nervous systems. Therefore, their recruitment at the plasma membrane is critical in determining firing activity patterns of nerve cells. In this study, we report the importance of secretory carrier-associated membrane proteins (SCAMPs) in the trafficking regulation of T-type channels. We identified SCAMP2 as a novel Cav3.2-interacting protein. In addition, we show that co-expression of SCAMP2 in mammalian cells expressing recombinant Cav3.2 channels caused an almost complete drop of the whole cell T-type current, an effect partly reversed by single amino acid mutations within the conserved cytoplasmic E peptide of SCAMP2. SCAMP2-induced downregulation of T-type currents was also observed in cells expressing Cav3.1 and Cav3.3 channel isoforms. Finally, we show that SCAMP2-mediated knockdown of the T-type conductance is caused by the lack of Cav3.2 expression at the cell surface as evidenced by the concomitant loss of intramembrane charge movement without decrease of total Cav3.2 protein level. Taken together, our results indicate that SCAMP2 plays an important role in the trafficking of Cav3.2 channels at the plasma membrane.

Cavß surface charged residues contribute to the regulation of neuronal calcium channels.

Voltage-gated calcium channels are essential regulators of brain function where they support depolarization-induced calcium entry into neurons. They consist of a pore-forming subunit (Cavα1) that requires co-assembly with ancillary subunits to ensure proper functioning of the channel. Among these ancillary subunits, the Cavß plays an essential role in regulating surface expression and gating of the channels. This regulation requires the direct binding of Cavß onto Cavα1 and is mediated by the alpha interacting domain (AID) within the Cavα1 subunit and the α binding pocket (ABP) within the Cavß subunit. However, additional interactions between Cavα1 and Cavß have been proposed. In this study, we analyzed the importance of Cavß3 surface charged residues in the regulation of Cav2.1 channels. Using alanine-scanning mutagenesis combined with electrophysiological recordings we identified several amino acids within the Cavß3 subunit that contribute to the gating of the channel. These findings add to the notion that additional contacts besides the main AID/ABP interaction may occur to fine-tune the expression and properties of the channel.

Divergent Dimethylarginine Dimethylaminohydrolase Isoenzyme Expression in the Central Nervous System.

The endogenous methylated derivative of ʟ-arginine, Nω,Nω'-dimethyl-ʟ-arginine (asymmetric dimethylarginine, ADMA), an independent risk factor in many diseases, inhibits the activity of nitric oxide synthases and, consequently, modulates the availability of nitric oxide. While most studies on the biological role of ADMA have focused on endothelial and inducible nitric oxide synthases modulation and its contribution to cardiovascular, metabolic, and renal diseases, a role in regulating neuronal nitric oxide synthases and pathologies of the central nervous system is less understood. The two isoforms of dimethylarginine dimethylaminohydrolase (DDAH), DDAH1 and DDAH2, are thought to be the main enzymes responsible for ADMA catabolism. A current impediment is limited knowledge on specific tissue and cellular distribution of DDAH enzymes within the brain. In this study, we provide a detailed characterization of the regional and cellular distribution of DDAH1 and DDAH2 proteins in the adult murine and human brain. Immunohistochemical analysis showed a wide distribution of DDAH1, mapping to multiple cell types, while DDAH2 was detected in a limited number of brain regions and exclusively in neurons. Our results provide key information for the investigation of the pathophysiological roles of the ADMA/DDAH system in neuropsychiatric diseases and pave the way for the development of novel selective therapeutic approaches.