Search Results (703)

Acute heart failure (AHF) causes abrupt hemodynamic disturbances, including reduced forward flow and venous congestion, which may extend beyond the heart and contribute to peripheral organ stress. Skeletal muscle may be particularly vulnerable to these changes, but the relationship between acute hemodynamic status and circulating markers of skeletal muscle stress and regulation remains unclear. We prospectively enrolled 35 men hospitalized with AHF and non-invasively assessed their cardiac index (CI) by impedance cardiography and right atrial pressure (RAP) by echocardiography. Plasma carbonic anhydrase III (CA3), creatine kinase-MM (CK-MM), lactate, myostatin, and follistatin were measured at admission, discharge, and 30 days after discharge. Patients were analyzed according to low CI, defined as CI < 2.2 L·min⁻¹·m⁻²; elevated RAP, defined as RAP ≥ 8 mmHg; and combined CI/RAP profiles. CA3 and CK-MM were higher in patients with low CI or elevated RAP and were highest in the low-CI/elevated-RAP profile. CA3 and lactate did not significantly change during follow-up, whereas CK-MM modestly increased at 30 days. Myostatin and follistatin were highest at admission and decreased after clinical stabilization. In this pilot cohort of men hospitalized with AHF, estimated lower perfusion and greater venous congestion were associated with higher circulating markers of skeletal muscle stress, while muscle regulatory myokines declined after stabilization. These findings suggest that skeletal muscle-related biomarkers may reflect peripheral consequences of acute hemodynamic disturbance in AHF and warrant further investigation in larger cohorts. Full article

Nitrite is a key environmental challenge in intensive shrimp aquaculture, adversely affecting physiological regulation and survival. Although tolerant Penaeus vannamei families have been established by selective breeding, the basis of family-level variation in tolerance has yet to be clarified. In this study, nitrite-tolerant and nitrite-sensitive families were compared using survival analysis, transcriptomics, targeted qPCR validation, physiological assays, and RNA interference of representative transport-related genes. Under nitrite exposure, the tolerant family exhibited significantly higher survival and a distinct gill transcriptional response, characterized by stronger induction of acid–base and ion-transport genes, including carbonic anhydrase 2 (CA2), the Na⁺/K⁺-ATPase subunits ATP1A and ATP1B, as well as several V-type H⁺-ATPase-related genes. These transcriptional changes were accompanied by elevated ATP content and Na⁺/K⁺-ATPase activity, improved hemolymph pH stability, and reduced nitrite accumulation in both gill and hemolymph. RNAi-mediated knockdown of CA2 or ATP1B attenuated the nitrite-induced transport response, decreased ATP content and NKA activity, exacerbated hemolymph acidification, promoted internal nitrite accumulation, and ultimately reduced shrimp survival under nitrite stress. Family-based validation further showed that the tolerant family displayed higher survival than the sensitive family in the dsEGFP group, whereas this advantage was markedly reduced after CA2 or ATP1B knockdown under nitrite stress. These findings highlight that strengthened branchial ion transport and acid–base regulation represent key physiological mechanisms underlying nitrite tolerance in resistant shrimp families. Full article

A new series of isoxazole-fused thiazole–oxazole derivatives (11a–n) was rationally designed and synthesised with the aim of developing potent carbonic anhydrase (CA) I and II inhibitors. The synthesis was achieved in five steps starting from 4-bromoacetophenone, involving key intermediates such as hydroxylamine hydrochloride, hydrazine hydrate, thioisocyanate, and various phenacyl bromide derivatives, using ethanol, triethylamine, tetrahydrofuran (THF), and dimethylformamide (DMF) as solvents. The synthetic route included the formation of a β-ketoester, isoxazole ester, hydrazine adduct, thiourea derivative, and, ultimately, a thiazole ring. The structures of the final compounds were confirmed by ¹H-NMR, ¹³C-NMR, IR spectroscopy, and elemental analysis. All compounds were examined as inhibitors of human carbonic anhydrase (hCA) I and II, and all of them inhibited hCA I and hCA II. Kinetic investigation results revealed that these compounds inhibited hCA I and hCA II in a non-competitive manner. To further explore the molecular basis of their inhibitory activity, in silico studies, including molecular docking and 300 ns molecular dynamics (MD) simulations, were carried out against both CA I and CA II isoforms. These simulations provided detailed insights into the dynamic behaviour, stability, and key binding interactions of the compounds within the enzyme active sites, supporting their potential as promising carbonic anhydrase inhibitors. Full article

Background/Objectives: Carbonic anhydrase I (CAI) is a zinc-dependent metalloenzyme whose inhibitor discovery requires both effective navigation of chemical space and explicit evaluation of coordination-credible binding hypotheses. We aimed to develop an interpretable and reproducible QSAR-to-structure workflow for CAI inhibitor discovery. The workflow links potency prediction with zinc-site plausibility and early developability to support decision-oriented prioritization of new CAI inhibitor candidates. Methods: CAI inhibitors were retrieved from ChEMBL (CHEMBL261) and modeled as $p{K}_i=9-{\mathrm{l}\mathrm{o}\mathrm{g}}_{10}(K_i [\mathrm{n}\mathrm{M}\left]\right)$. AlvaDesc v3.0.8 generated 4224 2D descriptors, which were reduced using train-only preprocessing, variance filtering, correlation pruning, and bagged-tree ranking to a top-100 panel. Five regressors (elastic net, CART, bagging, GB, and XGB) were benchmarked on a held-out test set. Potent ChEMBL seeds (K_i ≤ 10 nM) were used for a 90% 2D similarity PubChem expansion. Predicted hits were then externally validated using independently available PubChem CAI $K_i$ records. Ten novel candidates lacking CAI $K_i$ data were docked to CAI (PDB: 1AZM) via SwissDock AutoDock Vina in neutral and relevant anionic states, with pose selection constrained by a Zn-donor filter (Zn-N/O $\le 2.6$ Å). SwissADME was used to profile physicochemical space, alerts, and absorption/distribution proxies. Results: The bagging model showed the best test generalization ($R^2=0.646$; RMSE = 0.61; MAE = 0.45). PFI and SHAP converged on sulfur/heteroatom connectivity and polar–lipophilic organization as dominant potency drivers. PubChem expansion yielded 25,315 analogs and 233 candidates at predicted $p{K}_i\ge 8.0$; external validation on 145 CAI-measured hits gave $R^2=0.358$ (RMSE = 0.456; MAE = 0.320). Across 20 ligand/protomer docking runs, 12 produced canonical Zn-anchored poses (10 Zn-N; 2 Zn-O). SwissADME indicated consensus logP values from −0.65 to 3.21, 0/10 PAINS alerts, and predominantly favorable drug-likeness (8/10 with zero Lipinski violations), supporting tiered advancement. Conclusions: Integrating interpretable QSAR, external PubChem validation, coordination-aware docking, and SwissADME yields a practical triage framework for CAI inhibitor discovery. The resulting tiered shortlist identifies two Zn-N-anchored N-alkyl sulfamides (CIDs 103935964 and 112684680) and one Zn-O-anchored carboxylate control (CID 122367674) as highest-priority computational hypotheses for staged biochemical evaluation. Full article

Background/Objectives: The aim of this study was to investigate the effects of intraocular pressure (IOP)-lowering drops on the sublayers of the human tear film as assessed by a novel nanometer-resolution Tear Film Imager (TFI, AdOM, Israel). Methods: In a prospective, cross-sectional study, 98 eyes from 56 adult human subjects were imaged using the TFI. The dataset included data from 18 eyes from 12 subjects treated with preserved IOP-lowering drops and 80 eyes from 44 control subjects not under ocular hypotensive therapy. Subjects in the IOP treatment group used a variety of IOP-lowering medications, including prostaglandin analogs, beta-blockers, carbonic anhydrase inhibitors, alpha agonists, and combination drops. A linear mixed effects model was used to assess the association between IOP-lowering therapy and tear film (TF) metrics, controlling for age and intra-individual correlation. The following parameters were measured: muco-aqueous layer thickness (MALT), muco-aqueous layer thinning rate (MALTR), lipid layer thickness (LLT), lipid map uniformity (LMU), inter-blink intervals (IBI), and lipid break-up time (LBUT). Results: Average ages significantly differed (p = 0.013) between the treatment group (66.5 years) and control group (average age 51.5 years), and thus results were adjusted for age accordingly. IOP was 17.1 mmHg in the treatment group and 16.1 mmHg in the control group. When analyzing the sublayers of the TF, MALTR had a significant association with IOP-lowering therapy after adjusting for age, with a difference of −52.68 nm/s; 95% confidence interval [−96.87, −8.48]; p-value = 0.020. Additionally, IBI was significantly associated with IOP-lowering therapy after log transformation (p = 0.049), with shorter IBI in the treatment group. All other metrics (MALT, LLT, LMU, and LBUT) were statistically insignificant (p > 0.05). Conclusions: These pilot results suggest that IOP-lowering drops may accelerate thinning of the TF, specifically the muco-aqueous layer. Longitudinal studies with significantly larger samples are needed to specify the differential impact of various ocular hypotensive therapies on the human TF and the clinical implications of these findings. Full article

Carbonic anhydrases (CAs) efficiently catalyze CO₂ reversible hydration, critical for carbon capture and sequestration (CCS), but naturally low yield limits industrial use. Yarrowia lipolytica, an unconventional yeast, is an ideal heterologous expression host with robust adaptability, post-translational modification capacity, and versatile genetic tools. In this study, 10 α-, β-, and γ-class CAs were successfully expressed in Y. lipolytica, and two top-performing candidates were identified: Methanosarcina mazei γ-CA (MmaCA) and Sulfurihydrogenibium azorense α-CA (SazCA). Their production was further optimized via promoter and gene dosage adjustment, cultural condition optimization and auxiliary protein co-expression. The optimized intracellular MmaCA activity reached 960 U/mL (64.42-fold improvement), and the extracellular SazCA activity peaked at 925 U/mL (70.08-fold enhancement). CO₂ mineralization experiments confirmed both recombinant CAs significantly accelerated CaCO₃ precipitation, demonstrating a promising CCS application potential. To our knowledge, this is the first systematic investigation of CA heterologously expressed in Y. lipolytica, providing a novel strategy for the highly efficient production of CAs to enable their application in industry. Full article

The continuous increase in atmospheric CO₂ concentration exacerbates global climate change, making carbon reduction an urgent global priority. Carbonic anhydrase (CA), a highly efficient biocatalyst that converts CO₂ into bicarbonate, demonstrates significant potential for carbon capture and resource utilization. However, the stability and catalytic efficiency of native CA in industrial environments are limited, particularly its poor thermal tolerance under flue gas conditions and its sensitivity to impurities, hindering its direct large-scale application. This review systematically summarizes recent advances in modifying microbial CA through protein engineering (e.g., directed evolution, rational design) and immobilization techniques, which have markedly enhanced its thermal stability, adaptability, and reusability. Among these, the integration of machine learning with high-throughput experimentation has emerged as a transformative strategy for CA engineering. Furthermore, we outline CA-driven pathways for CO₂ conversion into high-value chemicals and bioenergy. Finally, future prospects are discussed, including interdisciplinary integration, computational modeling coupled with experimental validation, and comprehensive life-cycle and techno-economic assessments, to facilitate the scaled application of engineered microbial CA in carbon neutrality pathways. Collectively, this review highlights the critical role of engineered CA in bridging biocatalysis with industrial carbon management, offering a viable and sustainable pathway toward carbon neutrality. Full article

Carbonic anhydrase VA (CA5A) deficiency (OMIM 615751) is an ultra-rare inborn error of metabolism, presenting in newborns, infants, and young children with a pentad of encephalopathy, hyperammonemia, lactic acidosis, ketonuria, and hypoglycemia. We present two cases: a case of a healthy Bedouin infant admitted with hyperammonemic encephalopathy that required urgent hemodialysis, and her younger sibling, who presented with a milder episode. Molecular analysis confirmed the diagnosis of CA5A deficiency due to a homozygous missense variant in the CA5A gene. Both patients had a favorable outcome with continued normal development. These were the first identified cases of CA5A deficiency in the Bedouin population, emphasizing the importance of a high index of suspicion, early genetic consultation and diagnosis, and prompt treatment at the earliest possible stage of a hyperammonemic crisis. Full article

Background: Carbonic Anhydrases (CAs) represent regulators of cell adaptation to hypoxia, pH regulation, and metabolic fitness. Among cancers, multiple myeloma (MM) is a plasma cell malignancy sustained by hypoxia-driven metabolic adaptation, extracellular acidification, and redox imbalance. Tight regulation of tumor extracellular pH, mediated by Carbonic Anhydrases IX and XII, is crucial for myeloma survival, progression, and stemness, making these isoforms attractive therapeutic targets. Methods: We designed and synthesized a library of terpenoid-based hybrids by derivatizing chlorothymol and 4-isopropyl-3-methylphenol with either the natural coumarin umbelliferon or the 2,2′-dipicolylamine (DPA) scaffold. This chemical strategy aimed to selectively inhibit tumor-associated CAs IX/XII through coumarin- or DPA-mediated recognition, while terpenoid fragments were introduced to enhance lipophilicity, membrane permeability, and potential redox-modulating properties. The compounds were tested by a Stopped-Flow assay for CA inhibition, in cell-based assays for antiproliferative properties and by means of several antioxidant assays. Results: The most active compounds, connecting the coumarin core to a terpenoid tail, inhibited the targeted CAs in the nanomolar range, showing up higher selectivity over off-target isoforms (I and II). In studies performed on MM cell lines, selected derivatives reduced viability (IC₅₀ = 15.8–85.4 µM) and displayed favorable selectivity over normal cells. In silico investigations suggested that the compounds were able to interact selectively with the target enzymes. Conclusions: Collectively, these results support a dual-targeting strategy in which selective inhibition of tumor-associated CAs, combined with redox modulation, interferes with adaptive mechanisms of MM cells, providing a rational framework for the development of multifunctional agents against metabolically resilient hematological malignancies. Full article

Microalgae are among the most efficient photosynthetic organisms on Earth, and their capacity for CO₂ fixation directly links the global carbon cycle with green energy conversion, positioning them as strategic biological platforms for achieving carbon neutrality. This review provides a comprehensive and multiscale synthesis of the engineering and biological mechanisms underlying microalgal CO₂ fixation, integrating perspectives from gas–liquid mass transfer, CO₂ assimilation pathways, key enzymatic systems, metabolic regulation, and environmental control. From an engineering standpoint, we analyze the limitations governing CO₂ transfer from the gas phase to the aqueous phase and critically evaluate intensification strategies aimed at enhancing inorganic carbon availability in cultivation systems. At the biological and biochemical levels, we dissect carbon concentrating mechanisms (CCMs), including C₄-like pathways, and elucidate the structural organization, regulatory properties, and functional coordination of Rubisco and carbonic anhydrase systems. Particular emphasis is placed on the coupling between enzyme-level regulation and metabolic flux redistribution, supported by insights from metabolic flux analysis and systems-level modeling, to establish theoretical and engineering foundations for improving carboxylation efficiency. Finally, we propose an integrated roadmap for the future development of microalgal CO₂ fixation technologies, highlighting the convergence of synthetic biology, artificial intelligence, and systems engineering to achieve end-to-end optimization from molecular mechanisms to reactor-scale performance, while enabling the valorization of waste gas streams and circular carbon utilization. This review aims to provide a coherent theoretical framework and forward looking perspective for the development of efficient, intelligent, and sustainable microalgal CO₂ fixation systems. Full article

Background/Objectives: Clear-cell renal cell carcinoma (ccRCC) represents the predominant histologic subtype of renal cancer and poses persistent diagnostic challenges, particularly in the evaluation of small renal masses, where conventional imaging and biopsy have relevant limitations. Molecular imaging targeting carbonic anhydrase IX (CAIX) has emerged as a promising non-invasive alternative. This narrative review aims to summarize the biological rationale, diagnostic performance, and potential clinical applications of [⁸⁹Zr]Zr-girentuximab positron emission tomography-computed tomography (girentuximab PET-CT) in ccRCC, as well as to discuss its current limitations and future directions. Methods: A narrative synthesis of published phase 1–3 clinical trials, post hoc analyses, and early clinical series evaluating girentuximab PET-CT was performed, focusing on diagnostic accuracy, clinical impact in localized and metastatic disease, and emerging theranostic applications. Results: The phase 3 ZIRCON trial demonstrated high diagnostic accuracy of girentuximab PET-CT for indeterminate renal masses ≤7 cm, with a sensitivity of 85% and specificity of 87%, as well as performance exceeding 96% for lesions <2 cm. Early studies suggest that this modality may influence clinical decision-making by supporting active surveillance, avoiding biopsy, and refining surgical or ablative strategies, although evidence remains limited by small cohorts and lack of long-term outcome data. Exploratory data indicate improved lesion detection in metastatic ccRCC, but the absence of systematic histopathologic confirmation restricts routine staging use. Conclusions: Girentuximab PET-CT is a highly accurate, CAIX-targeted molecular imaging technique with the potential to transform the diagnostic pathway of ccRCC. While current evidence supports its use in selected localized settings, broader clinical adoption will require prospective validation of its impact on patient outcomes and management strategies. Full article

Eminium rauwolffii (Blume) Schott var. rauwolffii is a member of the Araceae a large and mainly tropical family distributed worldwide. The Eminium species are utilized for various purposes including therapeutic uses in traditional medicine and as food. To analyze the antioxidant properties of water extract of E. rauwolffii (WEER) and ethanol extract of E. rauwolffii (EEER), 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS^•+) radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH^.) free radical scavenging, Fe³⁺-2,4,6-tris(2-pyridyl)-S-triazine (TPTZ) and Cu²⁺ reducing assays were studied. Antioxidant activities and reducing properties of both extracts were compared to standard antioxidants: BHT, BHA, α-Tocopherol, and Trolox. The IC₅₀ values of EEER for radical scavenging were higher than those of standard antioxidants (25.35 ± 1.42 μg/mL for ABTS^•+ and 106.80 ± 1.88 μg/mL for DPPH^•). The total phenolic and flavonoid quantities in WEER and EEER were measured in the range of 189.78 ± 0.01 to 298.54 ± 0.01 mg GAE/g and 89.37 ± 0.01 to 178.95 ± 0.01 mg QE/g, respectively. The IC₅₀ values for EEER and WEER against α-glycosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and carbonic anhydrase I and II (hCA I and II) enzymes were 10.79 ± 5.61 to 13.18 ± 5.77, 36.14 ± 4.61 to 62.63 ± 1.67, 69.37 ± 7.36 to 37.48 ± 0.27, 81.30 ± 5.95 to 62.35 ± 8.03, and 29.34 ± 1.38 to 115.90 ± 3.3 µg/mL respectively. The antioxidant activity and enzymes inhibitory capacity of WEER were close, and comparable to the capacity demonstrated by the standards. The amount of sixteen compounds was identified from EEER. Numerous phytochemicals, including cynaroside, p-coumaric acid, cosmosiin, caffeic acid, and quinic acid, were quantitatively determined using the LC-MS/MS method. This clearly indicates that phenolic- and flavonoid-rich E. rauwolffii may have potential in the management of glaucoma, Alzheimer’s disease, diabetes, cardiovascular, and cancer disorders. Full article

Selective inhibition of the tumour-associated carbonic anhydrase (CA) isoforms IX and XII, which are overexpressed in hypoxic tumours, has emerged as a promising strategy for the development of novel anticancer agents. Among the diverse CA inhibitors reported to date, coumarins have attracted particular attention. These chromenone derivatives, widely distributed in phytochemicals, display a broad range of biological activities and are known to act as suicide inhibitors of CAs. Following the tail approach, we designed a series of hybrid compounds combining a coumarin core with an N-arylthioureido scaffold located at the C-7 position and investigated how structural variations—including substituents on the coumarin and aromatic moieties, tether length, and urea/thiourea isosterism—influence their biological properties (CA inhibition and antiproliferative activity). Substituted coumarins at C-3 and C-4 were efficiently prepared via Pechmann condensation, while the thioureido motif was introduced using various aryl isothiocyanates as key synthetic intermediates. The lead compound, featuring a dimethylated coumarin, a pentyl linker, and an N-(p-tolyl)thioureido residue, inhibited the target enzymes in the low- to mid-nanomolar range (K_i = 6.0 and 49.9 nM, respectively), displaying selectivity indexes (S.I.s) surpassing those of the reference drug acetazolamide (AAZ). Moreover, it exhibited potent antiproliferative activity, with GI₅₀ values in the low micromolar range (1.9–3.5 µM) against both drug-sensitive and multidrug-resistant cancer cell lines. Label-free three-dimensional holotomographic microscopy revealed that this compound triggers slow apoptosis, leading to cell death after approximately 20 h of exposure. Full article

Coumarins represent a distinctive class of non-classical carbonic anhydrase inhibitors that interact with the entrance region of the catalytic pocket rather than directly coordinating the catalytic Zn²⁺ ion. In this study, a series of glycosylated coumarins was synthesized through a copper-catalyzed multicomponent reaction involving propargyl glycosides, salicylaldehyde, and tosyl azide, providing efficient access to iminocoumarin-based glycosides derived from natural carbohydrates. The inhibitory activity of the synthesized compounds was evaluated against human carbonic anhydrase isoforms I, II, IX, and XII using a stopped-flow CO₂ hydrase assay. The compounds showed negligible inhibition of the cytosolic isoforms hCA I and hCA II, while displaying moderate activity toward the tumor-associated isoforms hCA IX and hCA XII, with Ki values ranging from 12.9 to 41.8 μM. Among the series, 6-O-(2H-chromene-2-one-3-yl-methyl)-D-galactopyranose (10a) emerged as the most potent inhibitor of hCA IX and XII. Structure–activity relationship analysis indicated that deprotected glycosyl derivatives exhibit improved inhibitory activity compared to protected analogues. To rationalize these observations, molecular docking followed by molecular dynamics simulations and MM-GBSA binding free energy calculations were performed for both anomeric forms of compound 10a. The computational results revealed a clear preference for the β-anomer, particularly in hCA IX and XII, where favorable interactions with catalytic threonine residues and isoform-specific aromatic residues stabilize the ligand within the active-site entrance. These findings provide a molecular explanation for the experimentally observed selectivity and highlight glycosyl coumarins as potential starting points for further optimization toward selective inhibitors of tumor-associated carbonic anhydrases. Full article

Chronic oxidative stress and lipid imbalance drive metabolic disorders such as obesity and non-alcoholic fatty liver disease, yet few therapies target the upstream redox imbalance in key tissues. Human carbonic anhydrase III (hCA III), a redox-associated enzyme enriched in liver and adipose tissue, has long remained pharmacologically elusive due to its low catalytic activity and lack of modulators. Here, we identify fragment-like nicotinic acid derivatives as non-sulfonamide hCA III modulators and evaluate their associated cellular effects. Using an esterase activity assay, we screened 25 analogues and identified two fragment-like hits, compound 17 (2-thioethyl) and compound 22 (6-morpholino), with IC₅₀ values of 487 and 361 µM, respectively. Orthogonal thermal shift analysis supported compound-protein interaction, and selected hits were subsequently evaluated in HepG2 cells. Both compounds were associated with reduced CA3 mRNA expression after treatment at 1 µM, while their cellular phenotypes diverged, with compound 22 increasing ROS under oxidative stress conditions and compound 17 affecting mitochondrial membrane potential. Taken together, these findings identify tractable nicotinic acid-derived fragment hits and associated cellular phenotypes that warrant further mechanistic investigation. These fragment-like hits provide a practical starting point for studying the redox-linked biology of hCA III. Full article