Tracer-based lipidomics enables the discovery of disease-specific candidate biomarkers in mitochondrial ß-oxidation disorders.

Carnitine derivatives of disease-specific acyl-CoAs are the diagnostic hallmark for long-chain fatty acid ß-oxidation disorders (lcFAOD), including carnitine shuttle deficiencies, very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD), long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) and mitochondrial trifunctional protein deficiency (MPTD). The exact consequence of accumulating lcFAO-intermediates and their influence on cellular lipid homeostasis is, however, still unknown. To investigate the fate and cellular effects of the accumulating lcFAO-intermediates and to explore the presence of disease-specific markers, we used tracer-based lipidomics with deuterium-labeled oleic acid (D9-C18:1) in lcFAOD patient-derived fibroblasts. In line with previous studies, we observed a trend towards neutral lipid accumulation in lcFAOD. In addition, we detected a direct connection between the chain length and patterns of (un)saturation of accumulating acylcarnitines and the various enzyme deficiencies. Our results also identified two disease-specific candidate biomarkers. Lysophosphatidylcholine(14:1) (LPC(14:1)) was specifically increased in severe VLCADD compared to mild VLCADD and control samples. This was confirmed in plasma samples showing an inverse correlation with enzyme activity, which was better than the classic diagnostic marker C14:1-carnitine. The second candidate biomarker was an unknown lipid class, which we identified as S-(3-hydroxyacyl)cysteamines. We hypothesized that these were degradation products of the CoA moiety of accumulating 3-hydroxyacyl-CoAs. S-(3-hydroxyacyl)cysteamines were significantly increased in LCHADD compared to controls and other lcFAOD, including MTPD. Our findings suggest extensive alternative lipid metabolism in lcFAOD and confirm that lcFAOD accumulate neutral lipid species. In addition, we present two disease-specific candidate biomarkers for VLCADD and LCHADD, that may have significant relevance for disease diagnosis, prognosis, and monitoring.

Highly Electroactive Co2+-Based Metal-Organic Frameworks as an Efficient Coreaction Accelerator for Amplifying Near-Infrared Electrochemiluminescence of Gold Nanoclusters in Biomarkers Immunoassay.

Metal nanoclusters (NCs) as a new kind of luminophore have acquired sufficient interest, but their widespread application is restricted on account of their relatively low electrochemiluminescence (ECL) efficiency. Then, aqueous metal NCs with high ECL efficiency were strongly anticipated, especially for the ultrasensitive analysis of biomarkers. Herein, a near-infrared (NIR) ECL biosensing strategy for the test of neuron-specific enolase (NSE) was proposed by utilizing N-acetyl-l-cysteine (NAC)- and cysteamine (Cys)-stabilized gold NCs (NAC/Cys-AuNCs) as ECL emitters with the NIR ECL emission around 860 nm and a metal-organic framework/palladium nanocubes (ZIF-67/PdNCs) hybrid as the coreaction accelerator through their admirable electrocatalytic activity. The NIR emission would reduce photochemical injury to the samples and even realize nondestructive analysis with highly strong susceptibility and suitability. Furthermore, the utilization of ZIF-67/PdNCs could improve the ECL response of NAC/Cys-AuNCs by facilitating the oxidation of the coreactant triethylamine (TEA), leading to the production of a larger quantity of reducing intermediate radical TEA•+. Consequently, NAC/Cys-AuNCs with ZIF-67/PdNCs displayed 2.7 fold enhanced ECL emission compared with the single NAC/Cys-AuNCs using TEA as the coreactant. In addition, HWRGWVC (HWR), a heptapeptide, was introduced to immobilize antibodies for the specially binding Fc fragment of the antibodies, which improved the binding efficiency and sensitivity. As a result, a "signal-on" immunosensor for NSE analysis was obtained with an extensive linear range of 0.1 to 5 ng/mL and a low limit of detection (0.033 fg/mL) (S/N = 3). This study provides a wonderful method for the development of an efficient nondestructive immunoassay.

Plasma chitotriosidase enzyme activity as a novel therapeutic monitor for cysteamine treatment in nephropathic cystinosis: A retrospective validation study.

BACKGROUND: Cystine-depleting therapy in nephropathic cystinosis is currently monitored via the white blood cell cystine assay, although its application and usefulness are limited by practical and technical issues. Therefore, alternative biomarkers that are widely available, more economical and less technically demanding, while reliably reflecting long-term adherence to cysteamine treatment, are desirable. Recently, we proposed chitotriosidase enzyme activity as a potential novel biomarker for the therapeutic monitoring of cysteamine treatment in cystinosis. In this study, we aimed to validate our previous findings and to confirm the value of chitotriosidase in the management of cystinosis therapy. MATERIALS & METHODS: A retrospective study was conducted on 12 patients treated at the National Institutes of Health Clinical Center and followed up for at least 2 years. Plasma chitotriosidase enzyme activity was correlated with corresponding clinical and biochemical data. RESULTS: Plasma chitotriosidase enzyme activity significantly correlated with WBC cystine levels, cysteamine total daily dosage and a Composite compliance score. Moreover, plasma chitotriosidase was a significant independent predictor for WBC cystine levels, and cut-off values were established in both non-kidney transplanted and kidney transplanted cystinosis patients to distinguish patients with a good versus poor compliance with cysteamine treatment. Our observations are consistent with those of our previous study and validate our findings. CONCLUSIONS: Chitotriosidase enzyme activity is a valid potential alternative biomarker for monitoring cysteamine treatment in nephropathic cystinosis patients. SYNOPSIS: Chitotriosidase enzyme activity is a valid potential alternative biomarker for monitoring cysteamine treatment in nephropathic cystinosis patients.

Formation and Properties of DNA Adducts Generated by Reactions of Abasic Sites with 1,2-Aminothiols Including Cysteamine, Cysteine Methyl Ester, and Peptides Containing N-Terminal Cysteine Residues.

The reaction of 1,2-aminothiol groups with aldehyde residues in aqueous solution generates thiazolidine products, and this process has been developed as a catalyst-free click reaction for bioconjugation. The work reported here characterized reactions of the biologically relevant 1,2-aminothiols including cysteamine, cysteine methyl ester, and peptides containing N-terminal cysteine residues with the aldehyde residue of apurinic/apyrimidinic (AP) sites in DNA oligomers. These 1,2-aminothiol-containing compounds rapidly generated adducts with AP sites in single-stranded and double-stranded DNA. NMR and MALDI-TOF-MS analyses provided evidence that the reaction generated a thiazolidine product. Conversion of an AP site to a thiazolidine-AP adduct protected against the rapid cleavage normally induced at AP sites by the endonuclease action of the enzyme APE1 and the AP-lyase activity of the biogenic amine spermine. In the presence of excess 1,2-aminothiols, the thiazolidine-AP adducts underwent slow strand cleavage via a ß-lyase reaction that generated products with 1,2-aminothiol-modified sugar residues on the 3'-end of the strand break. In the absence of excess 1,2-aminothiols, the thiazolidine-AP adducts dissociated to release the parent AP-containing oligonucleotide. The properties of the thiazolidine-AP adducts described here mirror critical properties of SRAP proteins HMCES and YedK that capture AP sites in single-stranded regions of cellular DNA and protect them from cleavage.

Detection with NO Modification: (N═O)-Au Interactions for Instantaneous Label-Free Detection of N-Nitrosodiphenylamine.

Increasing concerns have been raised about dangerous, yet nearly undetectable levels of nitrosamines in foods, medications, and drinking water. Their ubiquitous presence and carcinogenicity necessitates a method of sensitive and selective detection of these potent toxins. While the detection of two major nitrosamines─N-nitrosodimethylamine and N-nitrosodiethylamine─has seen success, low detection limits are scarcer for the other members of this class. One member, N-nitrosodiphenylamine (NDPhA), has had little progress not only in its detection in low quantities but also in its detection at all. NDPhA has unique difficulty in its identification due to its aromaticity, making it far more problematic to distinguish in the common GC-MS or LC-MS/MS methods used for nitrosamine sensing. Despite this detection barrier, it has been listed among the top 6 carcinogenic nitrosamines by the Food and Drug Administration as of 2023. Due to its evasive nature, a unique methodology must be applied to facilitate its sensitive identification. Herein, we describe the use of surface-enhanced Raman spectroscopy for the first account of liquid-phase detection of NDPhA using cysteamine-functionalized gold nanostars and a portable Raman spectrometer. Our methodology requires no chemical modification to the nitrosated structure as well as the usage of two well-understood biocompatible materials: cysteamine and gold nanoparticles.

Fibrosing colonopathy associated with cysteamine bitartrate delayed-release capsules in cystinosis patients.

BACKGROUND: The objective of this report is to identify and characterize cases of fibrosing colonopathy, a rare and underrecognized adverse event, associated with cysteamine delayed-release (DR) in patients with nephropathic cystinosis. METHODS: We searched the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) and the medical literature for postmarketing reports of fibrosing colonopathy associated with cysteamine through August 2, 2023. RESULTS: We identified four cases of fibrosing colonopathy reported with the use of cysteamine DR. The time to onset ranged from 12 to 31 months. In one case, the patient required surgery to have a resection of a section of the strictured colon and a diverting ileostomy. Fibrosing colonopathy was diagnosed by histopathology in two of the cases. CONCLUSIONS: Our case series identified the risk of fibrosing colonopathy in patients taking cysteamine DR and prompted regulatory action by the FDA. As outlined in changes to the U.S. prescribing information for cysteamine DR, healthcare professionals should be aware of the potential risk of fibrosing colonopathy with cysteamine DR, especially as symptoms can be non-specific leading to misdiagnosis or delayed diagnosis. If the diagnosis of fibrosing colonopathy is confirmed, consideration should be given to permanently discontinuing cysteamine DR and switching to cysteamine immediate-release treatment.

Extrarenal complications of cystinosis.

Cystinosis is a rare autosomal recessive disease with an incidence 1 per 100,000-200,000 live births. It is caused by pathogenic variants of the cystinosin (CTNS) gene that lead to impaired cystine transport from lysosomes to cystosol, resulting in cystine accumulation in lysosomes and subsequent cellular dysfunction. The initial manifestation, cystine accumulation in proximal tubular cells (PTCs), causes renal Fanconi syndrome, which presents with proximal renal tubular acidosis and generalized dysfunction of the proximal tubule, including the presence of polyuria, glycosuria, phosphaturia, aminoaciduria, tubular proteinuria, growth retardation, and rickets. Eventually, glomerular involvement, glomerular proteinuria, focal segmental glomerulosclerosis (FSGS), and progression to kidney failure occur. Although the kidneys are the first organs affected, and play a key role in morbidity and mortality, extrarenal multiorgan involvement can occur in patients with cystinosis, which is seen not only in adults but in early ages in untreated patients, patients with insufficient treatment, and in those that don't comply with treatment. The treatment of cystinosis consists of supportive treatment for Fanconi syndrome, and specific lifelong cystine-depleting therapy using oral cysteamine. There is strong evidence that as early as possible, initiation and ongoing appropriate therapy with cysteamine are essential for delaying the progression to kidney failure, end-organ damage, and extrarenal involvement. The present review aimed to evaluate the extra renal complications of cystinosis.

Cysteamine Isobionic-Amide Complex Versus Kligman's Formula for the Treatment of Melasma: Equal Efficacy and Rapid Onset of Action.

BACKGROUND: Modified Kligman's formula (mKF) is the gold standard treatment for melasma; however, its prolonged use is not recommended due to side effects. Cysteamine is a potent, safe, and effective depigmenting agent. Here, we conducted a double-blind, randomized, and placebo-controlled clinical trial to assess the efficacy of cysteamine isobionic-amide -- a complex with enhanced depigmenting efficacy -- and compared it to mKF for the treatment of melasma. METHODS: This study involved a total of 80 patients divided into 3 groups: cysteamine-isobionic amide, placebo, or mKF. The modified Melasma Area Severity Index (mMASI) score and spectrophotometric evaluation were conducted at baseline, week 4, week 8, and week 16. Dermatological assessment, patients’ feedback, and satisfaction including quality-of-life scores were also collected. RESULTS: At week 4, cysteamine isobionic-amide and mKF groups showed an equivalent onset of action in terms of mMASI and skin pigmentation contrast reduction. The 2 groups significantly reduced melasma severity and improved the overall skin condition with a comparable efficacy at week 16. Quality of life of melasma patients was significantly improved in the cysteamine isobionic-amide group at week 8 and further at week 16 (P<0.001) compared to the mKF group. Patients’ feedback and satisfaction were higher with the cysteamine isobionic-amide product compared to mKF. CONCLUSION: Cysteamine isobionic-amide provided a rapid onset of action and was as effective as the mKF for the treatment of melasma. The data suggest that cysteamine isobionic-amide could potentially be an acceptable alternative to mKF for the long-term treatment of melasma. J Drugs Dermatol. 2024;23(2):9-16.  doi:10.36849/JDD.7428.

Efficacy, Safety, Satisfaction, Adherence to Treatment With Nano-Formulated Cysteamine Tranexamic Acid Cream to Treat Melasma.

BACKGROUND: Melasma is a chronic pigmentary disorder. In this study, an innovative cream combining cysteamine and tranexamic acid (TXA) was assessed. OBJECTIVE: To evaluate the safety, efficacy, and patient satisfaction of a novel nano-formulated cysteamine and TXA combination cream in treating subjects with epidermal melasma. METHODS:   Fifty (50) randomized subjects participated and received cysteamine and TXA combination cream. The cream was applied for 30 minutes daily for a 3-month duration. Treatment effectiveness, safety, patient satisfaction, and adherence were evaluated. RESULTS: A continuous improvement in melasma was observed, with modified Melasma Area and Severity Index (mMASI) scores improving by 40%, 57%, and 63% at 30, 60, and 90 days, respectively. The primary endpoint of a decrease in mMASI scores was met, with 91% of participants experiencing melasma improvement. Patient Satisfaction and Patient Adherence scores indicated satisfaction. Convenience exhibited the strongest correlation with patient adherence.  Conclusion: Nano-formulated cysteamine and TXA combination cream showed significant efficacy in decreasing mMASI score while demonstrating a strong safety profile and patient satisfaction.  J Drugs Dermatol. 2024;23(7):529-537.     doi:10.36849/JDD.7765R1.

Comparing the Efficacy and Tolerability of Moderate to Severe Hyperpigmentation and Skin Unevenness.

Dyschromia is the result of irregular facial pigmentation. These cutaneous manifestations can have a significant impact on the quality of life of those affected, especially among females and skin of color. In this randomized, double-blinded, two-cell, single-center, 16-week clinical study, all subjects had moderate to severe (scores 4-9 on the modified Griffiths Scale) hyperpigmentation and skin unevenness of the face such that approximately 20% of subjects had post-inflammatory hyperpigmentation (PIH), 40% had overall mottled hyperpigmentation, and 40% had superficial melasma (Superficial Melasma was determined by Wood's Lamp Assessment). Study participants received either Product A (proprietary new formulation - Cysteamine HSA) or Product B (current marketed product - Cyspera®) and used the test product either in the morning or at night, beginning with every other day application, and then advanced to every day, or as tolerated. The results revealed that both Product A (Cysteamine HSA) and Product B (Cyspera®) had statistically significant improvement in facial hyperpigmentation and skin unevenness, however, Product A (Cysteamine HSA) had better tolerability results for scaling, peeling, burning, stinging, erythema, and dryness, indicating that Product A (Cysteamine HSA) outperformed Product B (Cyspera®). J Drugs Dermatol. 2024;23(1):1260-1265.     doi:10.36849/JDD.7584.

A Comparative Pharmacokinetic Study for Cysteamine-Containing Eye Drops as an Orphan Topical Therapy in Cystinosis.

Cystinosis is a low-prevalence lysosomal storage disease. The pathomechanism involves abnormal functioning of the cystinosine lysosomal cystine transporter (CTNS), causing intraliposomal accumulation of the amino acid cysteine disulfide, which crystallizes and deposits in several parts of the body. The most common ophthalmic complication of cystinosis is the deposition of "gold dust" cystine crystals on the cornea, which already occurs in infancy and leads to severe photosensitivity and dry eyes as it gradually progresses with age. In the specific treatment of cystinosis, preparations containing cysteamine (CYA) are used. The availability of commercialized eyedrops for the targeted treatment is scarce, and only Cystadrops® are commercially available with strong limitations. Thus, magistral CYA-containing compounded eyedrops (CYA-CED) could have a key role in patient care; however, a rationally designed comprehensive study on the commercialized and magistral products is still missing. This work aims to build up a comprehensive study about commercialized and magistral CYA eye drops, involving pharmacokinetic and physicochemical characterization (applying mucoadhesivity, rheology test, investigation of drug release, and parallel artificial membrane permeability assays), as well as ex vivo tests, well supported by statistical analysis.

Brown adipose Vanin-1 is required for the maintenance of mitochondrial homeostasis and prevents diet-induced metabolic dysfunction.

BACKGROUND: Energy-dissipating brown adipocytes have significant potential for improving systemic metabolism. Vanin-1, a membrane-bound pantetheinase, is involved in various biological processes in mice. However, its role in BAT mitochondrial function is still unclear. In this study, we aimed to elucidate the impact of Vanin-1 on BAT function and contribution during overnutrition-induced obesity. METHODS: Vanin-1 expression was analyzed in different adipose depots in mice. The cellular localization of Vanin-1 was analyzed by confocal microscopy and western blots. Mice lacking Vanin-1 (Vanin-1-/-) were continuously fed either a chow diet or a high-fat diet (HFD) to establish an obesity model. RNA-seq analysis was performed to identify the molecular changes associated with Vanin-1 deficiency during obesity. BAT-specific Vanin-1 overexpression mice were established to determine the effects of Vanin-1 in vivo. Cysteamine treatment was used to examine the effect of enzymatic reaction products of Vanin-1 on BAT mitochondria function in Vanin-1-/- mice. RESULTS: The results indicate that the expression of Vanin-1 is reduced in BAT from both diet-induced and leptin-deficient obese mice. Study on the subcellular location of Vanin-1 shows that it has a mitochondrial localization. Vanin-1 deficiency results in increased adiposity, BAT dysfunction, aberrant mitochondrial structure, and promotes HFD induced-BAT whitening. This is attributed to the impairment of the electron transport chain (ETC) in mitochondria due to Vanin-1 deficiency, resulting in reduced mitochondrial respiration. Overexpression of Vanin-1 significantly enhances energy expenditure and thermogenesis in BAT, renders mice resistant to diet-induced obesity. Furthermore, treatment with cysteamine rescue the mitochondrial dysfunction in Vanin-1-/- mice. CONCLUSIONS: Collectively, these findings suggest that Vanin-1 plays a crucial role in promoting mitochondrial respiration to counteract diet-induced obesity, making it a potential therapeutic target for obesity.

Effects of sodium selenite, cysteamine, bacterially synthesized Se-NPs, and cysteamine loaded on Se-NPs on ram sperm cryopreservation.

During the cryopreservation of sperm, the production of highly reactive oxygen species (ROS) can reduce their viability and fertility. However, the addition of antioxidants can help reduce the harmful effects of ROS. One such antioxidant is selenium, which is a co-factor of the glutathione peroxidase enzyme that is effective in scavenging ROS. Cysteamine can also take part in the structure of this enzyme. The use of nanoparticles can be less toxic to cells than their salt form. To this end, researchers synthesized Se-NPs using the streptococcus bacteria and loaded cysteamine onto the synthesized Se-NPs. The biosynthesis of Se-NPs and cysteamine loaded on Se-NPs was confirmed by UV-visible spectroscopy, X-ray diffraction (EDX), Fourier transforms infrared (FTIR) spectroscopy, and Field Emission Scanning Electron Microscope (FE-SEM). For cryopreservation, ram semen samples were diluted, and different concentrations (0, 1, 5, 25, and 125 µg/mL) of cysteamine, Se-NPs, cysteamine loaded on Se-NPs, and sodium selenite were added. An extender containing no supplement was considered as control group. After cooling the semen samples, they were frozen and stored in liquid nitrogen for evaluation. The samples were thawed and analyzed for mobility, viability, membrane and DNA integrity, and sperm abnormalities, as well as malondialdehyde level (MDA) and superoxide dismutase (SOD). The data was processed using SPSS, and a significance level of p < 0.05 was considered. The results of this experiment showed that adding 1 µg/mL of cysteamine loaded on Se-NPs to the diluent significantly increased the motility, viability, and membrane integrity and SOD of spermatozoa compared to the other treatment groups and control group, and reduced the abnormality, apoptosis, and MDA level of spermatozoa in comparison with the other treatment groups and control group (p < 0.05). In conclusion, the addition of cysteamine loaded on Se-NPs was found to improve the quality of ram sperm after cryopreservation.

Combination of 5% cysteamine and 4% nicotinamide in melasma: Efficacy, tolerability, and safety.

BACKGROUND: Melasma is a chronic dermatosis that impacts the patient's quality of life and can present considerable challenges in terms of effective treatment. OBJECTIVE: To evaluate the effectiveness, tolerability, and safety of 5% cysteamine combined with 4% nicotinamide in female subjects with melasma. METHODS: This single-center, single-arm, prospective, open-label study evaluated patients with melasma using a combination cream of 5% cysteamine and 4% nicotinamide in a progressive regimen (60 min in the first month, 120 min in the second month, and 180 min in the third month). RESULTS: Overall, 35 treated subjects exhibited reduced modified Melasma Area and Severity Index (mMASI) (p < 0.001) and decreased MelasQoL scores (p < 0.001), accompanied by improved brightness, luminosity, homogeneity, and spot intensity (p < 0.001). Photographic and colorimetric analysis revealed smaller spots and improved homogeneity. LIMITATIONS: Adherence to progressive daily treatment could not be evaluated long-term. CONCLUSION: A combination cream comprising 5% cysteamine and 4% nicotinamide was effective, tolerable, and safe for treating melasma.

Unveiling thiol biomarkers: Glutathione and cysteamine.

The physiological and clinical importance of Glutathione and Cysteamine is emphasized by their participation in a range of conditions, such as diabetes, cancer, renal failure, Parkinson's disease, and hypothyroidism. This necessitates the requirement for accessible, expedited, and cost-efficient testing that can facilitate clinical diagnosis and treatment options. This article examines numerous techniques used to detect both glutathione and cysteamine. The discussed methods include electroanalytical techniques such as voltammetry and amperometry, which are examined for their sensitivity and ability to provide real-time analysis. Furthermore, this study investigates the accuracy of gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) in measuring the concentrations of glutathione and cysteamine. Additionally, the potential of new nanotechnology-based methods, such as plasmonic nanoparticles and quantum dots, to improve the sensitivity of detecting glutathione and cysteamine is emphasized.

Cysteamine Nanoemulsion Delivery by Inhalation to Attenuate Adverse Effects of Exposure to Cigarette Smoke: A Metabolomics Study in Wistar Rats.

There is a pressing need for novel pharmacological interventions and drug delivery innovations to attenuate the cigarette smoke-associated oxidative stress and lung disease. We report here on the attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and metabolomics of Wistar rats exposed to cigarette smoke for 28 days. The animals were treated for 15 days with plain cysteamine given orally or cysteamine as nanoemulsion given orally or via inhalation. The study design also included two control groups as follows: rats exposed to cigarette smoke but did not receive a treatment (diseased control group) and rats neither exposed to cigarette smoke nor a treatment (normal control group). The targeted metabolomics using Parallel Reaction Monitoring showed that in the diseased control group, ornithine, nicotinamide, xanthine, hypoxanthine, and caprolactam were increased compared with the normal control group. In addition, (±)8(9)-DiHET, which was initially downregulated in the diseased control group, exhibited a reversal of this trend with cysteamine nanoemulsion given via inhalation. The cysteamine nanoemulsion delivered by inhalation highlighted the importance of the route of drug administration for targeting the lungs. To the best of our knowledge, this is the first work to use ATR-FTIR and metabolomics in Wistar rat lung tissues, suggesting how cysteamine nanoemulsion can potentially reduce cigarette smoke-induced oxidative damage. The metabolites reported herein have potential implications for discovery of novel theranostics and, thus, to cultivate diagnostic and therapeutic innovation for early prevention and treatment of cigarette smoke-associated lung diseases.

Ligand-based design and synthesis of new trityl histamine and trityl cysteamine derivatives as SIRT2 inhibitors for cancer therapy.

The relentless pursuit of novel therapeutic agents against cancer has led to the identification of multiple molecular targets, among which Sirtuin 2 (SIRT2) has garnered significant attention. This study presents an extensive SAR study of our reported trityl scaffold-based SIRT2 inhibitors. This study encompasses a range of different medicinal chemistry approaches to improve the activity of the lead compounds TH-3 and STCY1. The rationally designed and synthesized structures were confirmed using NMR and high-resolution mass spectroscopy before performing SIRT2 inhibition assay, NCI60 cytotoxicity test, and cell cycle analysis. Indeed, our strategies afforded hitherto unreported SIRT2 inhibitors with high activity, particularly 2a, 4a, 7c, and 7f. Remarkably, the presence of a lipophilic para substitution on the phenyl group of a freely rotating or a locked trityl moiety enhanced activity SIRT2 inhibition. Concomitantly, the synthesized compounds showed prominent activity against different cancer lines from the NCI60 assay. Of interest, compound 7c stands out as a potent and highly selective antiproliferative agent against leukemia and colon cancer panels. Furthermore, 7c treatment resulted in cell cycle arrest in MCF-7 cells at G2 phase and did not cause in vitro DNA cleavage.

Residual Cystine Transport Activity for Specific Infantile and Juvenile CTNS Mutations in a PTEC-Based Addback Model.

Cystinosis is a rare, autosomal recessive, lysosomal storage disease caused by mutations in the gene CTNS, leading to cystine accumulation in the lysosomes. While cysteamine lowers the cystine levels, it does not cure the disease, suggesting that CTNS exerts additional functions besides cystine transport. This study investigated the impact of infantile and juvenile CTNS mutations with discrepant genotype/phenotype correlations on CTNS expression, and subcellular localisation and function in clinically relevant cystinosis cell models to better understand the link between genotype and CTNS function. Using CTNS-depleted proximal tubule epithelial cells and patient-derived fibroblasts, we expressed a selection of CTNSmutants under various promoters. EF1a-driven expression led to substantial overexpression, resulting in CTNS protein levels that localised to the lysosomal compartment. All CTNSmutants tested also reversed cystine accumulation, indicating that CTNSmutants still exert transport activity, possibly due to the overexpression conditions. Surprisingly, even CTNSmutants expression driven by the less potent CTNS and EFS promoters reversed the cystine accumulation, contrary to the CTNSG339R missense mutant. Taken together, our findings shed new light on CTNS mutations, highlighting the need for robust assessment methodologies in clinically relevant cellular models and thus paving the way for better stratification of cystinosis patients, and advocating for the development of more personalized therapy.

Hydrogel-forming viscous liquid in response to ROS restores the gut mucosal barrier of colitis mice via regulating oxidative redox homeostasis.

The disrupted oxidative redox homeostasis plays a critical role in the progress of ulcerative colitis (UC). Herein, hydrogel-forming viscous liquid (HSD) composed of cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) has been designed for UC. When the viscous HSD liquid was infused into colitis colon, SOD would convert the pathological superoxide (O2·-) to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion toward colitis colon. H2O2-treated HSD presented the higher storage modulus and stronger adhesion force toward porcine colon than the untreated HSD. Besides, H2O2-treated HSD presented the slower erosion profile in the colitis-mimicking medium (pH 3-5), while its rapid degradation was displayed in physiologic condition (pH7.4). The combination of pH-resistant erosion and ROS-responsive adhesion for HSD rendered it with the specifical retention on the inflamed colonic mucosa of DSS-induced colitis mice. Rectally administrating HSD could effectively hinder the body weight loss, reduce the disease activity index and improve the colonic shorting of DSS-induced colitis mice. Moreover, the pro-inflammatory cytokines (IL-1ß, IL-6 and TNF-α) were substantially decreased, the colonic epitheliums were well rearranged and the tight junction proteins were greatly recovered after HSD treatment. Besides, HSD also modulated the gut flora, markedly augmenting the abundance of Firmicutes, Barnesiella and Lachnospiraceae. Moreover, HSD treatment could regulate oxidative redox homeostasis via activating Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH). Collectively, HSD might be a promising therapy for UC treatments. STATEMENT OF SIGNIFICANCE: Herein, a hydrogel-forming viscous liquid (HSD) was designed by cysteamine-grafted hyaluronic acid (HS) and superoxide dismutase (SOD) for UC treatments. When the viscous HSD liquid was infused into a colitis colon, SOD would convert the pathological superoxide to hydrogen peroxides (H2O2), which was subsequently scavenged by HS. Accordingly, the sol-gel transition of HSD was initiated by scavenging H2O2, enhancing its adhesion to the colitis colon. The colonic epitheliums of DSS-induced colitis mice were well rearranged and the tight junction proteins (Zonula-1 and Claudin-5) were greatly recovered after the HSD treatment. Moreover, the HSD treatment could regulate oxidative redox homeostasis via activating the Nrf2-HO-1 pathway to reduce ROS and malondialdehyde and upregulate antioxidant enzymes (SOD, GPx and GSH).

Neurologic involvement in cystinosis: Focus on brain lesions and new evidence of four-repeat (4R-) Tau immunoreactivity.

Nephropathic cystinosis is a rare autosomal recessive storage disorder caused by CTNS gene mutations, leading to autophagy-lysosomal pathway impairment and cystine crystals accumulation. Neurologic involvement is highly variable and includes both neurodevelopmental and neurodegenerative disturbances, as well as focal neurologic deficits. By presenting longitudinal data of a 28-year-old patient with a large infratentorial lesion, we summarized the pathology, clinical and imaging features of neurological involvement in cystinosis patients. Brain damage in form of cystinosis-related cerebral lesions occurs in advanced disease phases and is characterized by the accumulation of cystine crystals, subsequent inflammation with vasculitis-like features, necrosis, and calcification. Epilepsy is a frequent comorbidity in affected individuals. Steroids might play a role in the symptomatic treatment of "stroke-like" episodes due to edematous-inflammatory lesions, but probably do not change the overall prognosis. Lifelong compliance to depleting therapy with cysteamine still represents the main therapeutic option. However, consequences of CTNS gene defects are not restricted to cystine accumulation. New evidence of four-repeat (4R-) Tau immunoreactivity suggests concurrent progressive neurodegeneration in cystinosis patients, highlighting the need of innovative therapeutic strategies, and shedding light on the crosstalk between proteinopathies and autophagy-lysosomal system defects. Eventually, emerging easily accessible biomarkers such as serum neurofilament light chains (NfL) might detect subclinical neurologic involvement in cystinosis patients.