Carbonic Anhydrase Research Articles

Benzoxaborinine, New Chemotype for Carbonic Anhydrase Inhibition: Ex Novo Synthesis, Crystallography, In Silico Studies, and Anti-Melanoma Cell Line Activity.

The benzoxaborinine scaffold, a homologue of benzoxaborole with an additional carbon atom in the boracycle, shows significant potential in developing new therapeutic agents. This study reports the synthesis, inhibition assays against four human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms, and anti-melanoma evaluation of 7-aryl(thio)ureido-substituted benzoxaborinines. Some derivatives, particularly compound 11, exhibited potent inhibitory activity (below 65 nM) against hCA IX and XII and stronger antiproliferative effects than SLC-0111 on human melanoma cells under hypoxia. Crystallographic studies of benzoxaborinine 3 adducts with hCA I and II demonstrated the binding mode of this chemotype, revealing that although both benzoxaborinine 3 and benzoxaborole 10 share a similar zinc-binding mode, the expanded ring in benzoxaborinine led to a different orientation within the active site. These findings suggest that benzoxaborinines hold promise for designing novel carbonic anhydrase inhibitors.

A robust synthetic biology toolkit to advance carboxysome study and redesign.

Carboxysomes are polyhedral protein organelles that microorganisms use to facilitate carbon dioxide assimilation. They are composed of a modular protein shell which envelops an enzymatic core mainly comprised of physically coupled Rubisco and carbonic anhydrase. While the modular construction principles of carboxysomes make them attractive targets as customizable metabolic platforms, their size and complexity can be a hinderance. In this work, we design and validate a plasmid set - the pXpressome toolkit -in which α-carboxysomes are robustly expressed and remain intact and functional after purification. We tested this toolkit by introducing mutations which influence carboxysome structure and performance. We find that deletion of vertex-capping genes results in formation of larger carboxysomes while deletion of facet forming genes produces smaller particles, suggesting that adjusting the ratio of these proteins can rationally affect morphology. Through a series of fluorescently labeled constructs, we observe this toolkit leads to more uniform expression and better cell health than previously published carboxysome expression systems. Overall, the pXpressome toolkit facilitates the study and redesign of carboxysomes with robust performance and improved phenotype uniformity. The pXpressome toolkit will support efforts to remodel carboxysomes for enhanced carbon fixation or serve as a platform for other nanoencapsulation goals.

Association between the use of prostaglandin analogues and ocular surface disease: a systematic review.

Patients with glaucoma often experience chronic ocular surface diseases, potentially underestimated in frequency and severity. To provide updated estimates of ocular surface diseases linked to prostaglandin analogue antiglaucoma eye medication, a systematic review was conducted. Twenty-seven publications were selected from databases like PubMed, Scopus, and Web of Science, following a search strategy targeting glaucoma and prostaglandins while excluding certain medications '(Glaucoma AND prostaglandins OR 'prostaglandin analogues')('eye drops' OR 'artificial tears' OR 'ocular surface' OR 'dry eye' OR 'dry eye syndrome' OR 'ocular surface disease' OR 'tear film') NOT ('beta blockers' OR 'alpha adrenergic agonists' OR 'carbonic anhydrase inhibitors' OR 'rho-quinase')'. The review revealed a correlation between prostaglandin analogue use and ocular surface damage, assessing parameters such as tear break-up time, Schirmer test value, ocular surface staining, hyperaemia score, and meibomian gland characteristics. Some studies explored switching patients to alternative glaucoma medications, noting varied effects on ocular surface parameters. Comparisons suggested better tolerance and outcomes with preservative-free options over prostaglandins. Additionally, the impact of treatment duration and diquafosol on ocular health, including meibomian gland loss, was examined across different formulations. Although a link between prostaglandin analogues (with or without preservatives) and ocular surface damage was established, inconsistencies in methodologies and assessment across studies were noted. This comprehensive review, spanning a decade of glaucoma research, underscores the need for re-evaluation of treatment strategies in ophthalmology. It stresses the significance of informed decision-making for enhanced glaucoma care, taking into account the observed effects of various medications on eye health.

Overexpressing Carbonic Anhydrase Transgenic Rice Plants Maintain the Regular Soil Functions and Microbial Activities of Soil

Background: Genetically modified (GM) crops are focused on establishing desirable traits to support the food demand of increasing populations. The effect of transgenic plants on soil diversity has been highlighted by a lot of researchers. Some of them showed the negative effect of transgenic crop on soil microbes and the food chain. So there is an urgent need to develop transgenic plants with no harmful effects on environmental health. Methods: We have examined the effects salt tolerant carbonic anhydrase overexpressing transgenic rice plants on the physiology of rhizospheric microbes and their enzymatic activities. In the present study, we have used pot experiments in the greenhouse of Centurion University of Technology and management, Bhubaneswar, Odisha, India. Result: No significant variation in the soil properties viz., pH, Eh, organic C, P, K, N, Ca, Mg, S, Na and Fe+2 were observed. The population of bacteria, fungi and nematodes were remained same in the soil. The enzymatic activities like soil dehydrogenase, nitrate reductase, urease and alkaline phosphatase were not significantly affected. Further, plant growth promotion (PGP) functions such as HCN, siderophore, salicylic acid, GA, IAA, zeatin, were, not influenced considerably. The present study ecologically pertinent of salt tolerant CA transgenic rice to usual functions of the rhizospheric organisms.

Integrated approach of machine learning, Mendelian randomization and experimental validation for biomarker discovery in diabetic nephropathy.

To identify potential biomarkers and explore the mechanisms underlying diabetic nephropathy (DN) by integrating machine learning, Mendelian randomization (MR) and experimental validation. Microarray and RNA-sequencing datasets (GSE47184, GSE96804, GSE104948, GSE104954, GSE142025 and GSE175759) were obtained from the Gene Expression Omnibus database. Differential expression analysis identified the differentially expressed genes (DEGs) between patients with DN and controls. Diverse machine learning algorithms, including least absolute shrinkage and selection operator, support vector machine-recursive feature elimination, and random forest, were used to enhance gene selection accuracy and predictive power. We integrated summary-level data from genome-wide association studies on DN with expression quantitative trait loci data to identify genes with potential causal relationships to DN. The predictive performance of the biomarker gene was validated using receiver operating characteristic (ROC) curves. Gene set enrichment and correlation analyses were conducted to investigate potential mechanisms. Finally, the biomarker gene was validated using quantitative real-time polymerase chain reaction in clinical samples from patients with DN and controls. Based on identified 314 DEGs, seven characteristic genes with high predictive performance were identified using three integrated machine learning algorithms. MR analysis revealed 219 genes with significant causal effects on DN, ultimately identifying one co-expressed gene, carbonic anhydrase II (CA2), as a key biomarker for DN. The ROC curves demonstrated the excellent predictive performance of CA2, with area under the curve values consistently above 0.878 across all datasets. Additionally, our analysis indicated a significant association between CA2 and infiltrating immune cells in DN, providing potential mechanistic insights. This biomarker was validated using clinical samples, confirming the reliability of our findings in clinical practice. By integrating machine learning, MR and experimental validation, we successfully identified and validated CA2 as a promising biomarker for DN with excellent predictive performance. The biomarker may play a role in the pathogenesis and progression of DN via immune-related pathways. These findings provide important insights into the molecular mechanisms underlying DN and may inform the development of personalized treatment strategies for this disease.

6477 Surprise Finding For A Thyroid Nodule: Metastatic Renal Cell Carcinoma

Abstract Disclosure: A. Xu: None. E. Hsu: None. Introduction: A patient with an incidental and asymptomatic thyroid nodule underwent fine needle aspiration biopsy (FNA) after the nodule increased in size. Without a definite pathology after three FNA attempts, thyroidectomy was performed, where pathology found metastatic renal cell carcinoma (RCC). Clinical Case: A 64 year old woman had a past medical history of obesity, type 2 diabetes, RCC (stage I: pT1bN0M0) treated with right radical nephrectomy five years prior and thought to be in remission, remote smoking history smoking, and coronary artery disease with coronary artery bypass graft (CABG) two months prior, on anticoagulation. The patient reported a distant history of right thyroid lobectomy over a decade prior for unclear reasons, but she was adamant that the pathology was benign. Two years prior to presentation, CT chest done for RCC surveillance had detected a left thyroid nodule. Ultrasound at the time revealed a 3.6 x 1.9 x 2.3 cm solid, isoechoic nodule in the upper left lobe, which was not taller than wide, and had smooth margins and no echogenic foci. A repeat ultrasound at the time of presentation showed interval growth of the nodule, now measuring 4.3 x 2.1 x 2.9 cm. FNA was unsatisfactory, yielding predominantly blood. Patient felt well and had no compressive neck symptoms. We opted to wait two months and repeat FNA, which resulted as atypia of undetermined significance - Bethesda category III (AUS). We recommended completion thyroidectomy, but patient preferred to avoid surgery. We decided to wait two months and repeat FNA with molecular testing. This third FNA resulted AUS again; however, due to non-medical reasons, molecular testing was not performed. Another ultrasound showed slight growth of the nodule, 5.1 x 2.9 x 2.0 cm, which appeared hypoechoic now, but was still not taller than wide, with smooth margins and no echogenic foci. Completion thyroidectomy was performed, with pathology showing metastatic clear cell renal cell carcinoma. Immunostains were positive for carbonic anhydrase and renal cell carcinoma marker and negative for TTF-1. Whole-body PET-CT showed no hypermetabolic foci, and a repeat PET-CT one year later still showed no evidence of metastatic disease. Other than a hospitalization for COVID-19, patient is doing well and asymptomatic now over a year after her thyroidectomy. Oncology will continue routine surveillance imaging for her metastatic renal cell carcinoma thought to be in remission. Clinical Lessons: This case of metastatic renal cell carcinoma to the thyroid adds to the small body of literature showing the thyroid as a possible site of RCC metastasis. The long time interval between initial RCC presentation and metastasis to the thyroid makes this diagnosis more difficult; however, clinicians should be aware of the possibility, making thyroidectomy a stronger option in cases where FNA cytology is indeterminate. Presentation: 6/2/2024

Novel Schiff Bases: Synthesis, Characterization, Bioactivity, Cytotoxicity, and Computational Evaluations

Hypopharyngeal cancer is rare subtype of head and neck cancers with relatively poor prognosis. Current therapeutic modalities lack the potential to provide patients with better clinical outcome and quality of life. This study was conducted on the synthesis of 2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl-4-(2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl)-4-oxobutanoates (3) using biologically important 1,2,4-triazole. The condensation of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with 4-formyl-2-methoxyphenyl-4-(4-formyl-2-methoxyphenyl)-4-oxobutanoate yielded the biologically active 2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl-4-(2-methoxy-4-((3-alkyl(aryl)-5-oxo-1H-1,2,4-triazol-4(5H)-ylimino)-methyl)-phenyl)-4-oxobutanoates (3). The compounds obtained were analyzed via FT-IR,1H-/13C-NMR spectrometers, elemental analysis, and HRMS spectroscopic techniques. Furthermore, we aimed at investigating the potential of compounds 3a-g against FaDu hypopharyngeal cancer cells. We demonstrated that compounds 3c, 3e, and 3 g had relatively lower IC50 values compared to the remaining tested compounds and more importantly their IC50 values were comparable to 5-FU, which suggests them as important therapeutic agent candidates. These newly synthesized compounds were assessed for their inhibitory activities toward two human carbonic anhydrase isoforms I and II (hCA I and II). Then, molecular docking calculations were made to compare the biological activities of studied molecules against cancer proteins. Compound 3c has a docking score of −7.15 against squamous cell carcinoma protein with ID: 2DO4 and −5.49 docking score against squamous cell carcinoma protein with ID:5PJZ. ADME/T analysis was performed to examine the drug properties of studied molecules.

6477 Surprise Finding for a Thyroid Nodule: Metastatic Renal Cell Carcinoma

Abstract Disclosure: A. Xu: None. E. Hsu: None. Introduction: A patient with an incidental and asymptomatic thyroid nodule underwent fine needle aspiration biopsy (FNA) after the nodule increased in size. Without a definite pathology after three FNA attempts, thyroidectomy was performed, where pathology found metastatic renal cell carcinoma (RCC). Clinical Case: A 64 year old woman had a past medical history of obesity, type 2 diabetes, RCC (stage I: pT1bN0M0) treated with right radical nephrectomy five years prior and thought to be in remission, remote smoking history smoking, and coronary artery disease with coronary artery bypass graft (CABG) two months prior, on anticoagulation. The patient reported a distant history of right thyroid lobectomy over a decade prior for unclear reasons, but she was adamant that the pathology was benign. Two years prior to presentation, CT chest done for RCC surveillance had detected a left thyroid nodule. Ultrasound at the time revealed a 3.6 x 1.9 x 2.3 cm solid, isoechoic nodule in the upper left lobe, which was not taller than wide, and had smooth margins and no echogenic foci. A repeat ultrasound at the time of presentation showed interval growth of the nodule, now measuring 4.3 x 2.1 x 2.9 cm. FNA was unsatisfactory, yielding predominantly blood. Patient felt well and had no compressive neck symptoms. We opted to wait two months and repeat FNA, which resulted as atypia of undetermined significance - Bethesda category III (AUS). We recommended completion thyroidectomy, but patient preferred to avoid surgery. We decided to wait two months and repeat FNA with molecular testing. This third FNA resulted AUS again; however, due to non-medical reasons, molecular testing was not performed. Another ultrasound showed slight growth of the nodule, 5.1 x 2.9 x 2.0 cm, which appeared hypoechoic now, but was still not taller than wide, with smooth margins and no echogenic foci. Completion thyroidectomy was performed, with pathology showing metastatic clear cell renal cell carcinoma. Immunostains were positive for carbonic anhydrase and renal cell carcinoma marker and negative for TTF-1. Whole-body PET-CT showed no hypermetabolic foci, and a repeat PET-CT one year later still showed no evidence of metastatic disease. Other than a hospitalization for COVID-19, patient is doing well and asymptomatic now over a year after her thyroidectomy. Oncology will continue routine surveillance imaging for her metastatic renal cell carcinoma thought to be in remission. Clinical Lessons: This case of metastatic renal cell carcinoma to the thyroid adds to the small body of literature showing the thyroid as a possible site of RCC metastasis. The long time interval between initial RCC presentation and metastasis to the thyroid makes this diagnosis more difficult; however, clinicians should be aware of the possibility, making thyroidectomy a stronger option in cases where FNA cytology is indeterminate. Presentation: 6/2/2024

8623 Atypical VHL Genetic Variant Causing Paraganglioma

Abstract Disclosure: G. Mangu: None. J.J. Faria Briceno: None. R. Yatavelli: None. Abstract: Pheochromocytomas and paragangliomas (PPGLs) are rare chromaffin cell tumors that originate from the adrenal medulla and extra-adrenal paraganglia respectively. Previous studies have shown that incidental PPGLs are seen in older patients with mild symptoms. They have lower levels of plasma catecholamines and lower incidence of malignancy than patients with nonincidental PPGLs. We report a case of an incidental paraganglioma in a young female with atypical pathogenic variant in the VHL gene which is known to cause familial erythrocytosis but NOT VHL syndrome or PPGL. Case Presentation: A 33-year-old African American female with no significant medical history presented to the emergency room with the chief complaint of right lower quadrant pain for 2 days, which started with her menstruation. The vitals were BP 128/67, pulse 67 and physical examination was unremarkable. CT showed a 4.0 x 3.0 cm heterogenous enhancing left adrenal mass and MRI with adrenal protocol revealed 3.4 x 3.1 cm mass consistent with pheochromocytoma. Labs revealed elevated plasma nor metanephrines and 24-hour urine normetanephrines were 1020 mcg. She was asymptomatic without hypertension, palpitations, or chest pain. She underwent laparoscopic left adrenalectomy after appropriate alpha blockade. The pathology report showed left periadrenal paraganglioma with immunohistochemistry staining significant for Carbonic anhydrase IX (CAIX) membranous expression which is mostly seen in paragangliomas associated with von Hippel-Lindau syndrome. Clinically, she did not have any stigmata for hereditary PPGL syndrome. Her genetic testing revealed a pathogenic heterozygous variant in the VHL gene, Exon 3, c.598C.T (pArg200Trp), which is a missense variant expected to disrupt VHL protein function. Although she has a germline mutation in VHL, it is not the garden variant which is associated with classic VHL syndrome. It has been reported to cause autosomal recessive erythrocytosis but not PPGL. Conclusion: The pathogenic heterozygous variant in VHL gene, Exon 3, c.598C.T (pArg200Trp) is known to cause autosomal recessive familial erythrocytosis type 2 in the Chuvash population, termed as Chuvash Polycythemia. Our patient did not have polycythemia but had iron deficiency anemia from menorrhagia. Several studies have reported that this variant does not cause VHL syndrome, however it has been reported in a single family with VHL syndrome but WITHOUT pheochromocytoma. To our knowledge, incidental adrenergic paraganglioma associated with this mutation has not been reported in the literature. Presentation: 6/3/2024

Prognostic implications of metabolism-related genes in acute myeloid leukemia.

Acute myeloid leukemia(AML) is a diverse malignancy with a prognosis that varies, being especially unfavorable in older patients and those with high-risk characteristics. Metabolic reprogramming has become a significant factor in AML development , presenting new opportunities for prognostic assessment and therapeutic intervention. Metabolism-related differentially expressed genes (mDEGs) were identified by integrating KEGG metabolic gene lists with AML gene expression data from GSE63270. Using TCGA data, we performed consensus clustering and survival analysis to investigate the prognostic significance of mDEGs. A metabolic risk model was constructed using LASSO Cox reg ression and enhanced by a nomogram incorporated clinical characteristics. The model was validated through receiver operating characteristic (ROC) curves and survival statistics. Gene network analysis was conducted to identify critical prognostic factors. The tumor immune microenvironment was evaluated using CIBERSORT and ESTIMATE algorithms, followed by correlation analysis between immune checkpoint gene expression and risk scores. Drug sensitivity predictions and in vitro assays were performed to explore the effects of mDEGs on cell proliferation and chemoresistance. An 11-gene metabolic prognostic model was established and validated. High-risk patients had worse overall survival in both training and validation cohorts (p < 0.05). The risk score was an independent prognostic factor. High-risk patients showed increased immune cell infiltration and potential response to checkpoint inhibitors but decreased drug sensitivity. The model correlated with sensitivity to drugs such as venetoclax. Carbonic anhydrase 13 (CA13) was identified as a key gene related to prognosis and doxorubicin resistance. Knocking down CA13 reduced proliferation and increased cell death with doxorubicin treatment. A novel metabolic gene signature was developed to stratify risk and predict prognosis in AML, serving as an independent prognostic factor. CA13 was identified as a potential therapeutic target. This study provides new insights into the prognostic and therapeutic implications of metabolic genes in AML.

Application of carbonic anhydrase IX in sporadic hemangioblastoma of the central nervous system and hemangioblastoma associated with von Hippel-Lindau disease.

This research aims to examine the expression of carbonic anhydrase IX (CAIX) protein in hemangioblastoma of the central nervous system and its potential application in pathological diagnosis and differential diagnosis. Immunohistochemistry was used to identify the expression of CAIX and the α-inhibin protein. The sensitivity and specificity of CAIX and α-inhibin for identifying hemangioblastoma of the central nervous system were compared. In addition, 86 patients with meningiomas were gathered to detect CAIX protein expression. Hemangioblastoma and angiomatous, microcystic the two subtypes of meningiomas, were compared for CAIX and EMA protein expression. In hemangioblastoma, there were significant differences in the median positive percentage and staining intensity of CAIX and α-inhibin (p < 0.05). There was no discernible difference in the expression of the CAIX protein between sporadic hemangioblastoma of the central nervous system and those linked to von Hippel‒Lindau disease. In comparison to angiomatous and microcystic meningiomas, the positive rate of CAIX in hemangioblastomas was substantially greater (p < 0.001). The expression of EMA in microcystic meningioma (6/6) and angiomatous meningioma (17/17) was significantly different from hemangioblastoma (0/30) (p < 0.0001). Hemangioblastoma might be diagnosed with high specificity and sensitivity through CAIX immunohistochemistry. The combination of CAIX with EMA is useful for the diagnosis and differential diagnosis of hemangioblastoma.

Exploring the binding mode of phenyl and vinyl boronic acids to human carbonic anhydrases

Boronic acids are an interesting but still poorly studied class of carbonic anhydrase inhibitors. Previous investigations proved that derivatives incorporating aromatic, arylalkyl, and arylalkenyl moieties are low micromolar to millimolar inhibitors for several α- and β-CAs involved in pathologic states.Here we report a high-resolution X-ray study on two classes of boronic acids (phenyl and vinyl) in complex with hCA II. Our results unambiguously clarify the binding mode of these molecules to the human carbonic anhydrase active site, which occurs through their tetrahedral anionic form, regardless of the nature of the organic scaffold. Data here presented contribute to the understanding of the inhibition mechanism of boronic acids that can be fruitfully used for the rational design of novel and effective isozyme-specific carbonic anhydrase inhibitors.

Interactions of novel 1,3-diaryltriazene-sulfamethazines with carbonic anhydrases: Kinetic studies and in silico simulations

Sulfonamides, recognized as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, are crucial in treating diverse diseases, including epilepsy, glaucoma, bacterial infections, and various pathological processes, e.g., high blood pressure, rheumatoid arthritis, ulcerative colitis, pain, and inflammation. Additionally, therapeutically, 1,3-diaryl-substituted triazenes and sulphamethazines (SM) are integral components in various drug structures, and the synthesis of novel compounds within these two categories holds substantial significance. Herein, ten 1,3-diaryltriazene-substituted sulphamethazine derivatives SM(1-10), which were created by reacting the diazonium salt of sulphamethazine with substituted aromatic amines, were synthesized and the physiologically and pharmacologically relevant human (h) isoforms hCA I and II, cytosolic isozymes, were included in the study. The synthesized compounds showed excellent inhibition versus hCAs; the 4-butoxy (SM7, KI of 5.69 ± 0.59 nM) compound exhibited a potent inhibitory effect against the hCA I compared with the reference drug acetazolamide (AAZ, KI of 116.00 ± 8.48 nM). The 4-cyano (SM4, KI of 5.87 ± 0.57 nM) compound displayed higher potency than AAZ (KI of 57.25 ± 4.15 nM) towards hCA II. Meanwhile, among the synthesized molecules, the 3,4-dimethoxy (SM9, KI of 74.98 ± 10.49 nM, SI of 9.94) compound (over hCA I) displayed a noticeable selectivity for hCA isoform II. The target compounds in the molecular docking investigation were determined to take part in various hydrophilic and hydrophobic interactions with nearby amino acids and fit nicely into the active sites of the hCAs. This research has yielded compounds displaying varying affinity toward hCA isoenzymes, ultimately serving as potent and selective hCA inhibitors. Given its substantial biological inhibitory potency, this particular derivative series is determined to hold the potential to serve as a promising lead compound against these hCAs.

Carbonic anhydrase 2 is important for chondrocyte function and metabolic homeostasis

ObjectivesAberrant chondrocyte metabolism significantly contributes to cartilage degeneration and osteoarthritis (OA) genesis. However, the mechanisms driving the metabolic shift in OA chondrocytes remain unclear. Interestingly, carbonic anhydrase 2 (CA2) is implicated in metabolic regulation, and its expression dramatically increases in OA chondrocytes, but its exact role and mechanism are poorly understood. This study investigates the mechanistic role of CA2 in chondrocyte metabolic homeostasis under inflammatory conditions. MethodsRNA-seq was performed on CA2-deficient C28/I2 cells to identify pathways affected by the loss of CA2 function. We examined CA2's impact on chondrocyte metabolism, anabolism, and catabolism using C28/I2 cells and primary chondrocytes under normoxia and hypoxia and in a model of inflammatory OA. ResultsRNA-seq revealed enrichment of glycolysis, apoptosis, and TNF signaling pathways in CA2-deficient cells. Under hypoxia, CA2 expression increased 10-fold in a HIF-1α-independent manner. Knockdown of CA2 reduced extracellular lactate production, increased ADP/ATP ratio, impaired glycolysis, reduced glycolytic capacity, and lowered expression of glycolysis rate-limiting enzymes but did not disrupt pHi and ROS production. CA2 deficiency altered chondrocyte anabolic and catabolic equilibrium by affecting PI3K/AKT and RELA/p65 signaling. Chondrocyte migration was impeded, proliferation suppressed, and the cell cycle arrested at G0/G1 in cells lacking CA2. Forced expression of CA2 stabilized chondrocyte metabolism and restored cellular functions. ConclusionsOur research uncovered a novel mechanistic role for CA2 in regulating chondrocyte energy metabolism and inflammation, underscoring its potential as a critical mediator in OA pathogenesis. Further research using a murine model of experimental OA is warranted to capture the functional implications of CA2.

The physiological significance of plasma-accessible carbonic anhydrase in the respiratory systems of fishes.

Carbonic anhydrase (CA) activity is ubiquitously found in all vertebrate species, tissues and cellular compartments. Most species have plasma-accessible CA (paCA) isoforms at the respiratory surfaces, where the enzyme catalyzes the conversion of plasma bicarbonate to carbon dioxide (CO2) that can be excreted by diffusion. A notable exception are the teleost fishes that appear to lack paCA at their gills. The present review: (i) recapitulates the significance of CA activity and distribution in vertebrates; (ii) summarizes the current evidence for the presence or absence of paCA at the gills of fishes, from the basal cyclostomes to the derived teleosts and extremophiles such as the Antarctic icefishes; (iii) explores the contribution of paCA to organismal CO2 excretion in fishes; and (iv) the functional significance of its absence at the gills, for the specialized system of O2 transport in most teleosts; (v) outlines the multiplicity and isoform distribution of membrane-associated CAs in fishes and methodologies to determine their plasma-accessible orientation; and (vi) sketches a tentative time line for the evolutionary dynamics of branchial paCA distribution in the major groups of fishes. Finally, this review highlights current gaps in the knowledge on branchial paCA function and provides recommendations for future work.

Exploration of new thiazolidinones derived from natural verbenone: Design, synthesis, characterization, and in silico evaluation of alkaline phosphatase and carbonic anhydrase-II inhibition activity

Hybrid compounds featuring isoxazole and thiazolidinone nuclei, alongside verbenone, have become pivotal in pharmacological research due to their versatile properties and straightforward synthesis methods. In this study, the hybrid compounds 3–5 were thoroughly analyzed using high-resolution mass spectrometry (HRMS) and 1H- and 13C NMR spectroscopy, confirming the presence of the isoxazoline and thiazolidinone cores. Additionally, text of in vitro cytotoxicity, computational molecular docking and dynamics studies were performed to study the cytotoxic profile and the modes of possible interactions between the synthesized compounds and the biological targets. The cytotoxicity test indicated that product 5 exhibited the highest activity, with IC50 values ranging from 25.87±3.21 to 28.12±3.54 µM against MDA-MB-231 and A-549 cancer cell lines. From a theoretical point of view, the comparative analysis of compounds 3–5 against the references in the in silico study revealed significant interactions for these compounds with the isoenzymes of alkaline phosphatase and carbonic anhydrase.

An overview of the latest outlook of sulfamate derivatives as anticancer candidates (2020-2024).

Considering the emergence of new anticancer drugs, in this review we emphasized and highlighted the recent reports and advances related to sulfamate-incorporating compounds with potential anticancer activity during the last 5 years (2020-2024). Additionally, we discussed their structure-activity relationship, clarifying their potent bioactivity as anticancer agents. Sulfamate derivatives hold promise as effective therapeutic candidates against cancer. By targeting biological targets associated with the development of cancer, such as steroid sulfatases (STS), carbonic anhydrases (CAs), microtubules, NEDD8-activating enzyme, small ubiquitin-like modifiers(SUMO)-activating enzyme (SAE), cyclin-dependent kinases (CDKs), breast cancer susceptibility gene 1 (BRCA1), and so on, this can furnish small molecules as anticancer lead candidates serving the drug discovery field. For example, compound 2, an STS inhibitor, demonstrated superior activity compared to its reference, irosustat, by fivefold. In addition, compound 21, an SAE, is under phase I clinical trials. Continued research into sulfamate derivatives holds potential for the development of novel therapeutic agents targeting various diseases.

Synthesis and investigation of selective human carbonic anhydrase IX, XII inhibitors using coumarins bearing a sulfonamide or biotin moiety

The role of carbonic anhydrases isoforms (CAs) IX and XII in the pathogenesis and progression of many types of solid tumors is well known. In this context, selective CA inhibitors (CAIs) towards the mentioned isoforms is a validated strategy for the development of agents to target cancer. For this purpose, novel coumarin derivatives based on the hybridization with arylsulfonamide or biotin scaffolds were synthesized and tested as inhibitors of four different human carbonic anhydrases isoforms: hCA I, II, IX and XII. Coumarin-sulfonamide derived 27, with a thiourea moiety and triazole as linker, showed the highest inhibition activity against hCA XII with an inhibition constant (KI) of 7.5 nM and afforded a very good selectivity over hCA I. Compound 32 was the most potent inhibitor against hCA IX (KI = 6.3 nM), 4-fold stronger than the drug acetazolamide AAZ (KI = 25 nM), used herein as a reference compound, and showed remarkable selectivity over hCA I and II. The coumarin-biotin derivatives 37-39 showed outstanding selectivity towards on-target enzymes (hCA IX and XII) and appear as plausible leads for designing of CAIs.

Phosphorylation strongly affects the inhibition of human carbonic anhydrase I CO2 hydration activity

Human carbonic anhydrases (hCAs) have essential roles in respiration, acid-base balance, and fluid secretion, with implications in diseases such as glaucoma, epilepsy, obesity, and cancer. Of the fifteen known hCAs, human CA I (hCA I) is particularly abundant in erythrocytes, playing a critical role in CO2 transport. Despite extensive research on hCA I, the impact of post-translational modifications (PTMs), particularly phosphorylation, on its catalytic activity and inhibitor binding remains poorly understood. Although multiple phosphorylation sites have been identified in hCA I in vivo through high-throughput proteomics studies including at the highly conserved Ser51 residue, the functional consequences of these modifications are not well characterized. We investigated the effects of a phosphomimetic mutation at Ser51 on hCA I, examining its catalytic efficiency and susceptibility to inhibition by sulfonamides and anions. Using a recombinant expression system and a stopped-flow kinetic assay, we characterized the CO2 hydration activity and inhibition profiles of S51E hCA I compared to the wild type enzyme. Our results demonstrate that the S51E mutation increases the catalytic turnover rate (kcat) from 2.0 × 105 s−1 to 2.6 × 105 s−1 but significantly decreases substrate affinity, raising the Michaelis constant (KM) from 4.0 mM to 13.9 mM, reducing overall catalytic efficiency by over 50 %. Inhibition studies with a panel of 41 sulfonamides revealed that the S51E mutation dramatically alters inhibitor sensitivity, particularly for the most effective inhibitors. For example, 15 of the 16 most effective sulfonamide inhibitors for hCA I (with KIs <350 nM) were an average of over 35-fold less effective in inhibiting S51E hCA I than the wild type. The KI of the anticonvulsant zonisamide increased from 31 nM for the wild type hCA I to 4.0 μM. The inhibition profile with a panel of 37 small anions further indicated that the S51E mutant exhibited significantly reduced susceptibility to inhibition by 24 out of 37 tested anions, with some KI values increasing by up to 11,000-fold for inhibitors like hydrogen sulfide. This study underscores the significant impact that phosphorylation may have on hCA I function and inhibition. By characterizing the effects of phosphorylation on the CO2 hydration activity and inhibitor sensitivity of hCA I, these findings represent early steps in developing more selective proteoform-specific inhibitors, which could lead to more effective treatments for diseases involving carbonic anhydrases.

Novel thiazolotriazole and triazolothiadiazine scaffolds as selective tumor associated carbonic anhydrase inhibitors endowed with cathepsin B inhibition.

The present research focused on the tail-approach synthesis of novel extended thiazolotriazoles (8a-8j) and triazolothiadiazines (11a-11j) including aminotriazole intermediate 10. After successful synthesis, all the compounds were evaluated for their inhibition potential against cytosolic isoforms of human carbonic anhydrase (hCA I, II), tumor-linked transmembrane isoforms (hCA IX, XII), and cathepsin B. As per the inhibition data, the newly synthesized compounds showed poor inhibition against hCA I. Many of the compounds showed effective inhibition toward hCA IX and/or XII in low nanomolar concentration. Despite the strong to moderate inhibition of hCA II by these compounds, more than half of them demonstrated better inhibition against hCA IX and/or XII, comparatively. Further, insights of CA inhibition data of these extended analogs and their comparison with earlier reported thiazolotriazole and triazolothiadiazine derivatives might help in the rational design of novel potent and selective hCA IX and XII inhibitors. The novel compounds were also found to possess anti-cathepsin B potential at a low concentration of 10-7 M. Broadly, compounds of series 11a-11j presented more effective inhibition against cathepsin B than their counterparts in series 8a-8j. Moreover, these in vitro results with respect to cathepsin B inhibition were also supported by the in silico insights obtained via molecular modeling studies.