Search Results (227)

Cardiovascular disease remains the leading cause of mortality in kidney transplant recipients (KTRs). Arterial hypertension is present in a vast majority of patients after kidney transplantation, constituting the most prevalent cardiovascular comorbidity, and is a significant modifiable risk factor for other cardiovascular complications and graft loss. The 2024 Kidney Disease: Improving Global Outcomes (KDIGO) guidelines do not address blood pressure control strategies in KTRs, and the prior 2021 KDIGO recommendations targeting values below 130/80 mmHg rely primarily on data extrapolated from non-KTR populations. This represents an existing evidence gap in the management of post-transplant hypertension. Dihydropyridine calcium channel blockers and angiotensin receptor blockers remain first-line antihypertensive medications, although most studies assessing their effectiveness in KTRs date back more than 15 years. The current treatment guidelines are based largely on limited and outdated data. Optimal selection and individualization of immunosuppressive therapy and—when feasible—its modification in some KTRs may be important in improving blood pressure control. This includes, for example, a reduction in the calcineurin inhibitor or steroid dose, as well as the use of mTOR inhibitors or belatacept. The lack of large, up-to-date randomized trials in the KTR population underscores the pressing need for further extensive research focused on this patient group. Full article

Calcium sparks can arise as both voltage-dependent and voltage-independent ligand-activated release events in amphibian skeletal muscle. To assess their gating behavior, calcium sparks were recorded from intact frog skeletal muscle fibers using high-temporal-resolution confocal microscopy (line scans: 15 and 50 µs/line). Sparks were triggered by 1 mmol/L caffeine to open ryanodine receptors (RyRs) or by subthreshold depolarization to a −65 mV membrane potential to activate dihydropyridine receptors (DHPRs). Both treatments increased the frequency of sparks and altered their morphology. The sparks were significantly greater after caffeine treatment than in depolarized cells. The signal mass of sparks (i.e., the amount of calcium released) resembled the amplitude in shape. Additionally, the calcium release flux followed a staggered function during the activation of sparks. The detailed analysis of the sparks’ time profile revealed that the events were activated in a stepwise manner. The average step size (in F/F₀; 0.071 ± 0.003) remained constant regardless of the scanning speed. The number of steps during the activation of sparks followed a linear function based on the spark’s amplitude. Our results suggest that the activation of neighboring release units may occur sequentially, and the amplitude of the sparks depends linearly on the number of activated RyR channels. Full article

Background: In patients with type 2 diabetes mellitus (T2DM), angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) are first-line antihypertensive treatments with important cardiovascular benefits, but their impacts on coronary-specific inflammation are unknown. Pericoronary adipose tissue (PCAT) attenuation, as assessed by coronary computed tomography angiography (CCTA), serves as a specific biomarker for coronary inflammation. Here, we aim to assess whether treatment with ACE-I or ARB is correlated with lower PCAT attenuation. Methods: In this retrospective observational study, we analyzed 223 patients with T2DM and coronary atherosclerosis who underwent CCTA from 1 January 2017 to 1 September 2024 at our institution. PCAT attenuation was measured in the proximal right coronary artery. Propensity score matching and multivariate linear regression analyses were performed for comparisons. Results: Of the 223 patients (mean age of 64.9 ± 8.8 years, 69.1% male), 122 patients were on ACE-I or ARB (ACE-I/ARB). ACE-I/ARB users had similar PCAT attenuation as their counterparts after propensity score matching (−72.1 ± 7.5 and −71.7 ± 8.1 HU, respectively; p = 0.722). Subgroup analysis in patients with glomerular filtration rate (GFR) < 90 mL/min revealed lower PCAT attenuation in ACE-I/ARB users (−74.8 ± 6.6 vs. −71.4 ± 7.1 HU; p = 0.038), with a significant interaction between these two factors in the multivariate analysis (p = 0.047). Other antihypertensive treatments (beta blockers, dihydropyridine calcium channel blockers, and thiazides) were not linked with lower coronary inflammation. Conclusions: In T2DM patients with coronary atherosclerosis, we did not find an association between ACE-I/ARB treatment and lower coronary inflammation as defined by PCAT attenuation, although such a relationship may exist in those with reduced GFRs. Full article

Multidrug (MDR) resistances against various classes of antibiotics used in S. aureus and MRSA infections have emerged. With limited options for novel antibacterial compounds, there is a strong focus on finding agents against MDR phenomenon, namely causative efflux pumps. We synthesised novel benzo-annelated 1,4-dihydropyridines with various substitution patterns both at the 4- and N-alkyl substituents and, additionally, at the annelated aromatic residues. MDR efflux pump-inhibiting activity was evaluated in S. aureus strains including MRSA and was measured in a fluorescent assay system using ethidium bromide as the overall substrate of S. aureus efflux pumps. Favourable substituents for inhibiting efflux pump activity in S. aureus have been 4-methoxy and 4- and 3-chloro at the 4-phenyl position of the 1,4-dihydropyridine ring combined with an N-benzyl residue. The most favourable substituents for the activity inMRSA strains have been those 4-phenyl chloro substituents combined with additional pyrido residues attached to the benzo substituent at the 1,4-dihydropyridine core. Benzo-annelated 1,4-dihydropyridines are a novel class of inhibitors of MDR relevant efflux pumps in S. aureus strains including MRSA. Full article

Amphiphilic cationic lipids based on the 1,4-dihydropyridine (1,4-DHP) scaffold represent a versatile platform for the development of self-assembling delivery systems. In this work, a series of ten new amphiphilic 1,4-DHP derivatives bearing branched ester substituents at the 3,5-positions and quaternized cationic groups at the 2,6-positions were designed and synthesized. The effect of branched ester chain length and branching on nanoparticle formation was investigated. The self-assembling properties of the synthesized amphiphiles were evaluated by dynamic light scattering using an ethanol injection method. All compounds formed positively charged nanoparticles with hydrodynamic diameters ranging from 52 to 439 nm and polydispersity index from 0.194 to 0.452. Amphiphiles 14b–17b with 2-hexyldecyl substituents formed smaller particles, with an average diameter below 100 nm. Several derivatives exhibited good stability over a 14-day storage period at room temperature. To clarify structure–property relationships, lipophilicity (AlogP), polar surface area (PSA), and pK_a values were calculated using Schrödinger computational tools. The compounds displayed high lipophilicity AlogP 8.98–19.32, while PSA values remained within a narrow range. The calculated pK_a values ranged from 7.20 to 10.99. The results demonstrate that both the length and architecture of branched ester chains significantly influence nanoparticle size, homogeneity, and stability, highlighting branched-chain 1,4-DHP amphiphiles as promising synthetic lipid candidates for further development of delivery systems after evaluation of biological properties. Full article

Objectives: As widely used first-line antihypertensive drugs, dihydropyridine calcium channel blockers (DHP-CCBs) have relatively few studies comparing their adverse reactions based on real-world data. This study aims to identify and compare the potential adverse drug reaction (ADR) signals of four DHP-CCBs (amlodipine, felodipine, nicardipine, and nifedipine) through the US Food and Drug Administration Adverse Event Reporting System (FAERS), providing a reference for further drug safety assessment and clinical medication risk awareness. Methods: Adverse event reports from medical professionals (Q3 2014–Q4 2024) were analyzed using signal detection methods, including reporting odds ratio (ROR), proportional reporting ratio (PRR), information component (IC), and the Medicines and Healthcare Products Regulatory Agency (MHRA) methods. Risk signals for the four DHP-CCBs were compared with both the full database and the DHP-CCBs background. For high-risk signals in amlodipine, multivariate logistic regression was used for validation. The analysis reveals distinct ADR profiles for the four DHP-CCBs. Results: Amlodipine is strongly linked to suicide-related risks, confirmed by logistic regression. Nicardipine and nifedipine show significant risks for pregnancy-related events, such as premature delivery and exposure during pregnancy. Nicardipine is also associated with hyponatremia, hyperkalemia, and lactic acidosis. These adverse events are not yet included in the FDA labeling for any of the DHP-CCBs. Although palpitations and angioedema are listed for felodipine, their signal strength is much higher compared to the other DHP-CCBs. Conclusions: The ADR risk profiles of the four DHP-CCBs differ significantly. This study identified several high-risk adverse events not included in current labels. Clinical use should consider each drug’s risk profile and patient-specific factors, with particular attention to serious risk signals. For pregnant and postpartum women, the benefits and risks of using nicardipine and nifedipine should be carefully evaluated. Full article

The depolarization of the sarcolemma is one of the first effects of unloading on skeletal muscle. We hypothesized that unloading-induced activation of the dihydropyridine receptor (DHPR), a voltage-sensitive L-type Ca²⁺ channel, and depolarization of the sarcolemma trigger intracellular Ca²⁺ release from the sarcoplasmic reticulum and activation of Ca²⁺-dependent signaling pathways, resulting in muscle atrophy. Nifedipine, a DHPR calcium channel blocker, was used to study the role of DHPR in the regulation of signaling pathways during three days of rat soleus muscle unloading/hindlimb suspension. Inhibition of the DHPR during unloading attenuates the decrease in soleus muscle contractile properties, prevents the accumulation of ATP, ROS, and Ca²⁺ content in the sarcoplasm and the mitochondria, and blocks the decrease in PGC1alpha mRNA expression and Junctophilin-1 (JP1) proteolysis. In nifedipine-treated rats, the improvement of the unloaded soleus muscle contractile properties could be mediated by blocking the calpain-mediated degradation of the cytoskeletal proteins. DHPR blocking could be one of the future directions for the preservation of contractile properties of inactive/unloaded muscle. Full article

Indane-1,3-dione and 1,4-dihydropyridine (1,4-DHP) scaffolds are of significant interest in medicinal chemistry. Herein, we report the synthesis characterization of a new lipid-like indane-1,3-dione–1,4-DHP betaine, 2-(3′,5′-bis((dodecyloxy)carbonyl)-2′,6′-dimethyl-1′,4′-dihydro-[3,4′-bipyridin]-1-ium-1-yl)-1,3-dioxo-2,3-dihydro-1H-inden-2-ide (3). Compound 3 was synthesized from 2,2-dicyanomethylideneindan-1,3-dione (1) oxide and a didodecyl-substituted 1,4-DHP derivative 2 and characterized by UV–Vis spectroscopy, ¹H-NMR, ¹³C-NMR, and HRMS. The obtained results demonstrate a promising strategy for the design of delivery agents, exploiting the lipid-like properties of the synthesized betaine. Full article

1,4-Dihydropyridines (1,4-DHPs) are privileged heterocycles with broad relevance in medicinal chemistry and redox-related applications. However, conventional Hantzsch syntheses typically require prolonged thermal heating and often suffer from limited efficiency and regioselectivity. Herein, we report a sustainable and efficient microwave-assisted protocol for the synthesis of 1,4-DHPs, employing phosphotungstic acid (HPW) as a heteropolyacid catalyst in PEG-400 as a green reaction medium. The multicomponent cyclocondensation proceeds rapidly under microwave irradiation, affording the desired 1,4-DHP derivatives in good to excellent yields within short reaction times. Compared with classical acid-catalyzed conditions, the HPW/PEG-400 system markedly enhances regioselectivity toward the 1,4-DHP framework while simultaneously reducing energy input. Moreover, the catalytic system exhibits good recyclability, underscoring its potential as a practical and environmentally responsible platform for the synthesis of bioactive 1,4-dihydropyridine scaffolds. Full article

Background/Objectives: Recent reports have demonstrated the antiparasitic activity of 1,4-dihydropyridine (1,4-DHPs). This study aimed to assess the in vitro antischistosomal activity of 24 1,4-DHPs against Schistosoma mansoni adult worms. Methods: Sixteen hexahydroquinolines (1–16) and eight Hantzsch esters (17–24) previously obtained through a multicomponent Hantzsch reaction were tested in vitro against Schistosoma mansoni adult worms. In silico studies with the most active compounds were also carried out. Results: Among the tested compounds, the Hantzsch esters 20 (diethyl 4-(4-bromophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate) and 21 (diethyl 4-(3-fluorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate) provided the lowest IC₅₀ (15.2 and 13.1 µM, respectively) and the highest selectivity for this parasite (SI = 2.31 and >4.59, respectively). Conclusions: Docking studies revealed that compound 21 has a high affinity for the S. mansoni target (PDB ID: 6UY4). Furthermore, ADMET predictions indicated that compound 21 meets the drug-likeness criteria without violating any Lipinski, Veber, or Egan’s rules. Full article

We report an efficient and transition-metal-free protocol for the propargylation of 4-(4-chlorophenyl)-2-oxo-6-phenyl-1,2-dihydropyridine-3-carbonitrile using propargyl bromide in the presence of cesium carbonate in dimethylsulfoxide under mild conditions. This synthetic transformation proceeds with marked chemoselectivity, furnishing the O-propargylated pyridine and the N-propargylated 2-pyridone in 75% and 8% yields, respectively. Both products were fully characterized by IR and NMR spectroscopy, as well as high-resolution mass spectrometry, confirming their molecular structures. Full article

Background/Objectives: Microalgae are recognized as prolific producers of bioactive metabolites with pharmaceutical potential. This study aimed to isolate and characterize cytotoxic constituents from selected cytotoxic microalgae, collected in Hue city, Vietnam. Methods: Microalgal samples were collected from freshwater bodies, morphologically identified, and maintained in laboratory culture. Thirteen strains were successfully isolated and cultivated in BG11, Z8, and BBM media to determine optimal growth conditions. Cytotoxic effects of extracts/compounds were determined using the sulforhodamine B assay on human lung cancer (SK-LU-1) and human liver cancer (HepG2) cell lines. The methanol extract was partitioned with n-hexane and CH₂Cl₂, followed by extensive chromatographic separation and HPLC purification to afford twelve compounds, including two new and ten known compounds. The structures were elucidated by HR-ESI-MS and NMR spectra, chemical methods, and comparing compounds in the literature. Results: From the phytoplankton samples collected across six freshwater bodies in Hue city, Vietnam, thirteen microalgal strains were successfully isolated and purified under laboratory conditions. These strains were morphologically and taxonomically identified to be Microcystis aeruginosa HU05, Microcystis viridis HU13, Anabaena circinalis HU08, Aphanizomenon flos-aquae HU02, Dolichospermum smithii HU04, Calothrix braunii HU14, Nostoc muscorum HU12, Nostoc punctiforme HU11, Raphidiopsis raciborskii HU03, Lyngbya spiralis HU15, Planktothrix stagnina HU16, Phormidium subtilis HU06, and Scenedesmus quadricauda HU07. All methanol extracts of those microalgae were evaluated for cytotoxic activity. The MeOH extracts of M. viridis (HU13) and D. smithii (HU04) exhibited significant cytotoxic effects, with IC₅₀ values of 6.19 ± 0.80 and 4.89 ± 0.76 µg/mL for M. viridis, and 9.51 ± 0.84 and 8.32 ± 0.94 µg/mL for D. smithii against SK-LU-1 and HepG2 cell lines, respectively. Furthermore, chemical studies of D. smithii HU04 led to the isolation of two new compounds, smithioside A (1) and smithioside B (2) and ten known ones, 3,4,5-trimethoxyphenyl-1-O-β-D-glucopyranoside (3), 4′-hydroxy-3′-methoxyphenol-β-D-[6-O-(4″-hydroxy-3″,5″-dimethoxylbenzoate)]-glucopyranoside (4), 4′-hydroxy-2′,6′-dimethoxyphenol 1-O-β-D-(6-O-syringoyl)glucopyranoside (5), mallophenol B (6), pisoninol II (7), guaiacylglycerol (8), (E)-asarone (9), deacetylsarmentamide B (10), (E)-2-hexenyl-β-D-glucopyranoside (11), and 5,6-dihydropyridin-2(1H)-one (12). The cytotoxic activity of all isolated compounds was also evaluated against SK-LU-1 and HepG2 cancer cell lines. Compound 12 showed the strongest activity, with IC₅₀ values of 9.13 ± 0.89 µM (SK-LU-1) and 7.64 ± 0.46 µM (HepG2). Compounds 5 and 6 exhibited moderate cytotoxic activity on both human cancer cell lines with IC₅₀ values ranging from 25.99 to 51.47 µM. Conclusions: These results highlight the potential of Dolichospermum smithii HU04 as a source of bioactive compounds, particularly in anticancer applications. These findings suggest that D. smithii HU04 extracts could be developed for therapeutic purposes targeting cancer. Full article

Background: Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease. Arterial hypertension represents the leading modifiable risk factor for cardiovascular morbidity and mortality globally. Their coexistence is frequent, affecting approximately 40–60% of adults with HCM, yet the implications of this overlap remain insufficiently investigated. Methods: We conducted a narrative review of the existing literature addressing the clinical profile and management strategies in patients with concomitant HCM and hypertension. Particular emphasis was placed on pharmacologic treatment and the role of emerging therapies for this population. Results: Patients with both conditions are generally older, with more cardiometabolic comorbidities and greater functional limitation than those with isolated HCM. Hypertension may confound diagnosis and is linked to a higher prevalence of atrial fibrillation and stroke. Its effect on ventricular arrhythmias, sudden cardiac death and mortality is less clear. Management is challenging, as vasodilatory antihypertensives can exacerbate left ventricular outflow tract obstruction. β-blockers and non-dihydropyridine calcium channel blockers are preferred, while novel agents such as myosin inhibitors and SGLT2 inhibitors show potential but require further study. Conclusions: The coexistence of HCM and hypertension is frequent but insufficiently studied, with major implications for diagnosis and treatment. Further research is essential to optimize management and outcomes. Full article

Excitation–contraction (EC) coupling in skeletal muscle requires a physical interaction between the voltage-gated calcium channel, dihydropyridine receptor (DHPR), and the ryanodine receptor (RyR1) Ca²⁺ release channel. Although the exact mode of communication that links these two membrane proteins remains to be fully resolved, both the α_1s and β_1a subunits of DHPR are two of a select number of critical proteins involved in this process. A detailed in vitro interaction study of these two proteins reveals that their association occurs between the β_1a SH3 domain and the polyproline motifs located in a critical region of the α_1s II-III loop. We demonstrate that subtle changes in the composition of the β_1a SH3 domain influences the ability of β proteins to bind to II-III loop proteins and investigate the effect of these changes on EC skeletal coupling. Furthermore, investigation into the composition of the II-III loop shows that previously identified amino acids demonstrated to be important in EC coupling are implicated in in vitro binding. In summary, we ascribe a role for the DHPR β_1a which involves the engagement of its SH3 domain with the α_1s II-III loop and propose a scenario whereby this interaction may facilitate skeletal muscle EC coupling. Full article