Emerging Topics in Metal Complexes: Pharmacological Activity.

This Special Issue (SI), "Emerging Topics in Metal Complexes: Pharmacological Activity", includes reports updating our knowledge on metals with multidirectional biological properties and metal-containing compounds/complexes for their potential therapeutic applications, with a focus on strategies improving their pharmacological features [...].

The p.E152K-STIM1 mutation deregulates Ca2+ signaling contributing to chronic pancreatitis.

Since deregulation of intracellular Ca2+ can lead to intracellular trypsin activation, and stromal interaction molecule-1 (STIM1) protein is the main regulator of Ca2+ homeostasis in pancreatic acinar cells, we explored the Ca2+ signaling in 37 STIM1 variants found in three pancreatitis patient cohorts. Extensive functional analysis of one particular variant, p.E152K, identified in three patients, provided a plausible link between dysregulated Ca2+ signaling within pancreatic acinar cells and chronic pancreatitis susceptibility. Specifically, p.E152K, located within the STIM1 EF-hand and sterile α-motif domain, increased the release of Ca2+ from the endoplasmic reticulum in patient-derived fibroblasts and transfected HEK293T cells. This event was mediated by altered STIM1-sarco/endoplasmic reticulum calcium transport ATPase (SERCA) conformational change and enhanced SERCA pump activity leading to increased store-operated Ca2+ entry (SOCE). In pancreatic AR42J cells expressing the p.E152K variant, Ca2+ signaling perturbations correlated with defects in trypsin activation and secretion, and increased cytotoxicity after cholecystokinin stimulation.This article has an associated First Person interview with the first author of the paper.

Role of microbiome in kidney stone disease.

PURPOSE OF REVIEW: The process of renal stone formation is complex, multifactorial, and variable depending on the type of stone. The microbiome, whether by direct or indirect action, is a factor that both promotes the formation and protects from developing of renal stones. It is a highly variable factor due to the great interindividual and intraindividual variability that it presents. In recent years, with the incorporation of nonculture-based techniques such as the high-throughput sequencing of 16S rRNA bacterian gene, both intestinal and urinary microbiota have been deeply studied in various diseases such as the kidney stone disease. RECENT FINDINGS: This review has examined the new insights on the influence of the intestinal and urinary microbiome in nephrolithiasis disease and its usefulness as a diagnostic and prognostic tool, highlighting its contribution to the pathogenesis, its ability to modulate it and to influence disease development. SUMMARY: The incidence of urolithiasis has been increasing considerably. These patients represent a significant expense for national health systems. With the knowledge of the influence of the urobiome and intestinal microbiota on the urolithiasis, it could be possible to modulate it to interrupt its development.

Role, Cost, and Availably of Urinary pH Monitoring for Kidney Stone Disease-A Systematic Review of the Literature.

PURPOSE OF REVIEW: Urinary pH is an important factor related to renal stone disease, and it plays an essential role in stone prevention. Monitoring of urinary pH by patients at home provides information that can help to assess the treatment needed by each patient. We conducted a systematic review is to assess the available evidence concerning urinary pH monitoring methods along with their accuracy, cost, and usefulness by patients with urolithiasis. RECENT FINDINGS: A total of 9 articles were included (1886 urinary pH measurements). They reported information about urinary dipsticks, portable electronic pH meters and electronic strip readers, amongst other methods. Accuracy was compared with a laboratory pH meter (gold standard). Urinary dipsticks were found to be not accurate enough to guide clinical decision making and portable electronic pH meters showed promising results. Urinary dipsticks are neither precise nor accurate enough. Portable electronic pH meters seem to be more accurate, easy to use, and cost-effective. They are a reliable source for patients to use at home in order to prevent future episodes of nephrolithiasis.

CNS-Related Effects Caused by Vanadium at Realistic Exposure Levels in Humans: A Comprehensive Overview Supplemented with Selected Animal Studies.

Neurodegenerative disorders, which are currently incurable diseases of the nervous system, are a constantly growing social concern. They are progressive and lead to gradual degeneration and/or death of nerve cells, resulting in cognitive deterioration or impaired motor functions. New therapies that would ensure better treatment results and contribute to a significant slowdown in the progression of neurodegenerative syndromes are constantly being sought. Vanadium (V), which is an element with a wide range of impacts on the mammalian organism, is at the forefront among the different metals studied for their potential therapeutic use. On the other hand, it is a well-known environmental and occupational pollutant and can exert adverse effects on human health. As a strong pro-oxidant, it can generate oxidative stress involved in neurodegeneration. Although the detrimental effects of vanadium on the CNS are relatively well recognized, the role of this metal in the pathophysiology of various neurological disorders, at realistic exposure levels in humans, is not yet well characterized. Hence, the main goal of this review is to summarize data on the neurological side effects/neurobehavioral alterations in humans, in relation to vanadium exposure, with the focus on the levels of this metal in biological fluids/brain tissues of subjects with some neurodegenerative syndromes. Data collected in the present review indicate that vanadium cannot be excluded as a factor playing a pivotal role in the etiopathogenesis of neurodegenerative illnesses, and point to the need for additional extensive epidemiological studies that will provide more evidence supporting the relationship between vanadium exposure and neurodegeneration in humans. Simultaneously, the reviewed data, clearly showing the environmental impact of vanadium on health, suggest that more attention should be paid to chronic diseases related to vanadium and to the assessment of the dose-response relationship.

Elucidating the Therapeutic Potential of Bis(Maltolato)OxoVanadium(IV): The Protective Role of Copper in Cellular Metabolism.

Vanadium (V) is a trace mineral whose biological activity, role as a micronutrient, and pharmacotherapeutic applications remain unknown. Over the last years, interest in V has increased due to its potential use as an antidiabetic agent mediated by its ability to improve glycemic metabolism. However, some toxicological aspects limit its potential therapeutic application. The present study aims to evaluate the effect of the co-treatment with copper (Cu) and bis(maltolato)oxovanadium(IV) (BMOV) as a possible strategy to reduce the toxicity of BMOV. Treating hepatic cells with BMOV reduced cell viability under the present conditions, but cell viability was corrected when cells were co-incubated with BMOV and Cu. Additionally, the effect of these two minerals on nuclear and mitochondrial DNA was evaluated. Co-treatment with both metals reduced the nuclear damage caused by BMOV. Moreover, treatment with these two metals simultaneously tended to reduce the ND1/ND4 deletion of the mitochondrial DNA produced with the treatment using BMOV alone. In conclusion, these results showed that combining Cu and V could effectively reduce the toxicity associated with V and enhance its potential therapeutic applications.

Bioactive Properties of Tagetes erecta Edible Flowers: Polyphenol and Antioxidant Characterization and Therapeutic Activity against Ovarian Tumoral Cells and Caenorhabditis elegans Tauopathy.

Tagetes erecta is an edible flower deeply rooted in traditional Mexican culture. It holds a central role in the most popular and iconic Mexican celebration, "the Day of the Dead". Furthermore, it is currently receiving interest as a potential therapeutic agent, motivated mainly by its polyphenol content. The present study aims to evaluate the biological activity of an extract synthesized from the petals of the edible flower T. erecta. This extract showed significant antioxidant scores measured by the most common in vitro methodologies (FRAP, ABTS, and DPPH), with values of 1475.3 µM trolox/g extr, 1950.3 µM trolox/g extr, and 977.7 µM trolox/g extr, respectively. In addition, up to 36 individual polyphenols were identified by chromatography. Regarding the biomedical aspects of the petal extract, it exhibited antitumoral activity against ovarian carcinoma cells evaluated by the MTS assay, revealing a lower value of IC50 compared to other flower extracts. For example, the extract from T. erecta reported an IC50 value half as low as an extract from Rosa × hybrida and six times lower than another extract from Tulbaghia violacea. This antitumoral effect of T. erecta arises from the induction of the apoptotic process; thus, incubating ovarian carcinoma cells with the petal extract increased the rate of apoptotic cells measured by flow cytometry. Moreover, the extract also demonstrated efficacy as a therapeutic agent against tauopathy, a feature of Alzheimer's disease (AD) in the Caenorhabditis elegans experimental model. Treating worms with the experimental extract prevented disfunction in several motility parameters such as wavelength and swimming speed. Furthermore, the T. erecta petal extract prevented the release of Reactive Oxygen Species (ROS), which are associated with the progression of AD. Thus, treatment with the extract resulted in an approximate 20% reduction in ROS production. These findings suggest that these petals could serve as a suitable source of polyphenols for biomedical applications.

Early calcium and cardiac contraction defects in a model of phospholamban R9C mutation in zebrafish.

The phospholamban mutation Arg 9 to Cys (R9C) has been found to cause a dilated cardiomyopathy in humans and in transgenic mice, with ventricular dilation and premature death. Emerging evidence suggests that phospholamban R9C is a loss-of-function mutation with dominant negative effect on SERCA2a activity. We imaged calcium and cardiac contraction simultaneously in 3 and 9 days-post-fertilization (dpf) zebrafish larvae expressing plnbR9C in the heart to unveil the early pathological pathway that triggers the disease. We generated transgenic zebrafish lines expressing phospholamban wild-type (Tg(myl7:plnbwt)) and phospholamban R9C (Tg(myl7:plnbR9C)) in the heart of zebrafish. To measure calcium and cardiac contraction in 3 and 9 dpf larvae, Tg(myl7:plnbwt) and Tg(myl7:plnbR9C) fish were outcrossed with a transgenic line expressing the ratiometric fluorescent calcium biosensor mCyRFP1-GCaMP6f. We found that PlnbR9C raised calcium transient amplitude, induced positive inotropy and lusitropy, and blunted the ß-adrenergic response to isoproterenol in 3 dpf larvae. These effects can be attributed to enhanced SERCA2a activity induced by the PlnbR9C mutation. In contrast, Tg(myl7:plnbR9C) larvae at 9 dpf exhibited ventricular dilation, systolic dysfunction and negative lusitropy, hallmarks of a dilated cardiomyopathy in humans. Importantly, N-acetyl-L-cysteine rescued this deleterious phenotype, suggesting that reactive oxygen species contribute to the pathological pathway. These results also imply that dysregulation of calcium homeostasis during embryo development contributes to the disease progression at later stages. Our in vivo model in zebrafish allows characterization of pathophysiological mechanisms leading to heart disease, and can be used for screening of potential therapeutical agents.

Isotope pattern deconvolution as a successful alternative to calibration curve for application in wastewater-based epidemiology.

An isotope pattern deconvolution (IPD) quantification method has been applied for the determination of five substances (amphetamine, benzoylecgonine, cocaine, methamphetamine and MDMA) in wastewater for the application in wastewater-based epidemiology (WBE). A previously validated method that used a calibration curve for quantification was modified to apply IPD. The two approaches were compared in terms of analytical uncertainty in recovery studies of quality control samples, i.e. six wastewater samples from different geographical origins spiked at two concentration levels. Both methods were reliable as they passed (z-score < 2) in an interlaboratory exercise. After 60 individual determinations, IPD provided 11 results outside recovery limits (70-120%) while the previous method produced 31 adverse results. All mean values for IPD were accurate whereas 6 out of 10 results showed RSD values higher than 30% or recoveries outside limits when using the former method. Moreover, the calculated method bias for the latter doubles that of IPD, which, in turn, makes the combined uncertainty (u(c)) much higher. Consequently, a simple change of data treatment-IPD quantification methodology-resulted in a lower uncertainty of the estimated illicit drug concentration, one of the main steps contributing to the final uncertainty in the normalized daily drug consumption through WBE. The current study demonstrated that the employment of IPD can also be very interesting for future applications of WBE, especially when matrix effects are high, complicating accurate quantification. In addition, when a high number of samples and/or compounds need to be analysed, IPD is faster than calibration and, eventually, cost-effective when isotopically labelled internal standard is highly expensive.

Distance disintegration characterizes node-level topological dysfunctions in cocaine addiction.

Previous investigations have used global graph theory measures in order to disentangle the complexity of the neural reorganizations occurring in cocaine use disorder (CUD). However, how these global topological alterations map into individual brain network areas remains unknown. In this study, we used resting state functional magnetic resonance imaging (fMRI) data to investigate node-level topological dysfunctions in CUD. The sample was composed of 32 individuals with CUD and 32 healthy controls, matched in age, years of education and intellectual functioning. Graph theory measures of optimal connectivity distance, node strength, nodal efficiency and clustering coefficient were estimated in each participant using voxel-wise functional connectivity connectomes. CUD individuals as compared with healthy controls showed higher optimal connectivity distances in ventral striatum, insula, cerebellum, temporal cortex, lateral orbitofrontal cortex, middle frontal cortex and left hippocampus. Furthermore, clinical measures quantifying severity of dependence were positively related with optimal connectivity distances in the right rolandic operculum and the right lateral orbitofrontal cortex, whereas length of abstinence was negatively associated with optimal connectivity distances in the right temporal pole and the left insula. Our results reveal a topological distancing of cognitive and affective related areas in addiction, suggesting an overall reduction in the communication capacity of these regions.

Do nutrients and other bioactive molecules from foods have anything to say in the treatment against COVID-19?

The repositioning of therapeutic agents already approved by the regulatory agencies for the use of drugs is very interesting due to the immediacy of their use; similarly, the possibility of using molecules derived from foods, whether nutrients or not, is of great importance, also because of their immediate therapeutic applicability. Candidates for these natural therapies against COVID-19 should show certain effects, such as restoring mitochondrial function and cellular redox balance. This would allow reducing the susceptibility of risk groups and the cascade of events after SARS-CoV-2 infection, responsible for the clinical picture, triggered by the imbalance towards oxidation, inflammation, and cytokine storm. Possible strategies to follow through the use of substances of food origin would include: a) the promotion of mitophagy to remove dysfunctional mitochondria originating from free radicals, proton imbalance and virus evasion of the immune system; b) the administration of transition metals whose redox activity would lead to their own oxidation and the consequent generation of a reduced environment, which would normalize the oxidative state and the intracellular pH; c) the administration of molecules with demonstrated antioxidant capacity; d) the administration of compounds with anti-inflammatory and vasodilatory activity; e) the administration of immunomodulatory compounds.

Mapping Calcium Dynamics in the Heart of Zebrafish Embryos with Ratiometric Genetically Encoded Calcium Indicators.

Zebrafish embryos have been proposed as a cost-effective vertebrate model to study heart function. Many fluorescent genetically encoded Ca2+ indicators (GECIs) have been developed, but those with ratiometric readout seem more appropriate to image a moving organ such as the heart. Four ratiometric GECIs based on troponin C, TN-XXL, Twitch-1, Twitch-2B, and Twitch-4 were expressed transiently in the heart of zebrafish embryos. Their emission ratio reported the Ca2+ levels in both the atrium and the ventricle. We measured several kinetic parameters of the Ca2+ transients: systolic and diastolic ratio, the amplitude of the systolic Ca2+ rise, the heart rate, as well as the rise and decay times and slopes. The systolic ratio change decreased in cells expressing high biosensor concentration, possibly caused by Ca2+ buffering. The GECIs were able to report the effect of nifedipine and propranolol on the heart, which resulted in changes in heart rate, diastolic and systolic Ca2+ levels, and Ca2+ kinetics. As a result, Twitch-1 and Twitch-4 (Kd 0.25 and 2.8 µM, respectively) seem the most promising GECIs for generating transgenic zebrafish lines, which could be used for modeling heart disorders, for drug screening, and for cardiotoxicity assessment during drug development.

Designing Single-Molecule Magnets as Drugs with Dual Anti-Inflammatory and Anti-Diabetic Effects.

We have designed and synthesized two novel cobalt coordination compounds using bumetanide (bum) and indomethacin (ind) therapeutic agents. The anti-inflammatory effects of cobalt metal complexes with ind and bum were assayed in lipopolysaccharide stimulated RAW 264.7 macrophages by inhibition of nitric oxide production. Firstly, we determined the cytotoxicity and the anti-inflammatory potential of the cobalt compounds and ind and bum ligands in RAW 264.7 cells. Indomethacin-based metal complex was able to inhibit the NO production up to 35% in a concentration-dependent manner without showing cytotoxicity, showing around 6-37 times more effective than indomethacin. Cell cycle analysis showed that the inhibition of NO production was accompanied by a reversion of the differentiation processes in LPS-stimulated RAW 264.7 cells, due to a decreased of cell percentage in G0/G1 phase, with the corresponding increase in the number of cells in S phase. These two materials have mononuclear structures and show slow relaxation of magnetization. Moreover, both compounds show anti-diabetic activity with low in vitro cell toxicities. The formation of metal complexes with bioactive ligands is a new and promising strategy to find new compounds with high and enhanced biochemical properties and promises to be a field of great interest.

Aerobic interval exercise improves renal functionality and affects mineral metabolism in obese Zucker rats.

Obesity, metabolic syndrome, and renal injury are considered risk factors for type 2 diabetes, as well as kidney disease. Functional and structural changes in the kidney as consequence of obesity and metabolic syndrome may lead to impaired mineral metabolism in what is known as chronic kidney disease-mineral and bone disorder. Lifestyle interventions such as physical activity are good strategies to manage these pathologies and therefore, prevent the loss of kidney functionality and related complications in mineral metabolism. In this study, we have used 40 male Zucker rats that were randomly allocated into four different experimental groups, two of them (an obese and a lean one) performed an aerobic interval training protocol, and the other two groups were sedentary. At the end of the experimental period (8 wk), urine, plasma, and femur were collected for biochemical and mineral composition analysis, whereas the kidney was processed for histological studies. The obese rats exhibited albuminuria, glomerulosclerosis, and hypertrophy in glomeruli and renal tubule in some areas, together with alterations in mineral content of plasma but not of femur. The training protocol prevented the generation of albuminuria and glomerulosclerosis, showing a significant action on plasma and bone mineral levels. Therefore, the specific training protocol used in this study was able to prevent the development of diabetic nephropathy and affected the metabolism of certain minerals.

Visualization of Mitochondrial Ca2+ Signals in Skeletal Muscle of Zebrafish Embryos with Bioluminescent Indicators.

Mitochondria are believed to play an important role in shaping the intracellular Ca2+ transients during skeletal muscle contraction. There is discussion about whether mitochondrial matrix Ca2+ dynamics always mirror the cytoplasmic changes and whether this happens in vivo in whole organisms. In this study, we characterized cytosolic and mitochondrial Ca2+ signals during spontaneous skeletal muscle contractions in zebrafish embryos expressing bioluminescent GFP-aequorin (GA, cytoplasm) and mitoGFP-aequorin (mitoGA, trapped in the mitochondrial matrix). The Ca2+ transients measured with GA and mitoGA reflected contractions of the trunk observed by transmitted light. The mitochondrial uncoupler FCCP and the inhibitor of the mitochondrial calcium uniporter (MCU), DS16570511, abolished mitochondrial Ca2+ transients whereas they increased the frequency of cytosolic Ca2+ transients and muscle contractions, confirming the subcellular localization of mitoGA. Mitochondrial Ca2+ dynamics were also determined with mitoGA and were found to follow closely cytoplasmic changes, with a slower decay. Cytoplasmic Ca2+ kinetics and propagation along the trunk and tail were characterized with GA and with the genetically encoded fluorescent Ca2+ indicator, Twitch-4. Although fluorescence provided a better spatio-temporal resolution, GA was able to resolve the same kinetic parameters while allowing continuous measurements for hours.

Industrial-Scale Decontamination Procedure Effects on the Content of Acaricides, Heavy Metals and Antioxidant Capacity of Beeswax.

Beeswax is useful for the beekeeping sector but also for the agro-food, pharmaceutical or cosmetics sectors. Frequently, this bee product is contaminated with pesticides reducing its utility and causing the decline in its market. This study aimed to prove the effectiveness of an industrial-scale decontamination method in removing acaricides from beeswax. Chlorfenvinphos and coumaphos decrease was higher than 90%, whereas tau fluvalinate decrease was only 30%. No changes were observed in the beeswax content of hydrocarbons and monoesters, whereas a decrease in the concentrations of Ca, Fe, Zn, Hg, Mn and P, and an increase in the concentrations of As and Si were found after the decontamination. Filtration reduced total phenolics, flavonoids and the antioxidant capacity of the lipophilic extract. These results demonstrate that the industrial method used was as effective as the method previously tested on a laboratory scale. The study also contributes to a better knowledge and characterization of beeswax, specially related to trace and ultra-trace elements and antioxidant capacity. Moreover, it offers the chance to further develop a method to effectively detect wax adulterations based on the chemical elements profile.

Gold nanoparticles: Distribution, bioaccumulation and toxicity. In vitro and in vivo studies.

Concerns about the bioaccumulation and toxicity of gold nanoparticles inside humans have recently risen. HT-29 and HepG2 cell lines and Wistar rats were exposed to 10, 30 or 60 nm gold nanoparticles to determine their tissue distribution, subcellular location and deleterious effects. Cell viability, ROS production and DNA damage were evaluated in vitro. Lipid peroxidation and protein carbonylation were determined in liver. ICP-MS measurements showed the presence of gold in intestine, kidney, liver, spleen, feces and urine. Subcellular locations of gold nanoparticles were observed in colon cells and liver samples by transmission electron microscopy. Inflammatory markers in liver and biochemical parameters in plasma were measured to assess the inflammatory status and presence of tissue damage. The size of the nanoparticles determined differences in the biodistribution and the excretion route. The smallest nanoparticles showed more deleterious effects, confirmed by their location inside the cell nucleus and the higher DNA damage.

Actin Filaments Are Involved in the Coupling of V0-V1 Domains of Vacuolar H+-ATPase at the Golgi Complex.

We previously reported that actin-depolymerizing agents promote the alkalization of the Golgi stack and thetrans-Golgi network. The main determinant of acidic pH at the Golgi is the vacuolar-type H(+)-translocating ATPase (V-ATPase), whose V1domain subunitsBandCbind actin. We have generated a GFP-tagged subunitB2construct (GFP-B2) that is incorporated into the V1domain, which in turn is coupled to the V0sector. GFP-B2 subunit is enriched at distal Golgi compartments in HeLa cells. Subcellular fractionation, immunoprecipitation, and inversal FRAP experiments show that the actin depolymerization promotes the dissociation of V1-V0domains, which entails subunitB2translocation from Golgi membranes to the cytosol. Moreover, molecular interaction between subunitsB2andC1and actin were detected. In addition, Golgi membrane lipid order disruption byd-ceramide-C6 causes Golgi pH alkalization. We conclude that actin regulates the Golgi pH homeostasis maintaining the coupling of V1-V0domains of V-ATPase through the binding of microfilaments to subunitsBandCand preserving the integrity of detergent-resistant membrane organization. These results establish the Golgi-associated V-ATPase activity as the molecular link between actin and the Golgi pH.

Reduced activity in functional networks during reward processing is modulated by abstinence in cocaine addicts.

Cocaine addiction is characterized by alterations in motivational and cognitive processes. Recent studies have shown that some alterations present in cocaine users may be related to the activity of large functional networks. The aim of this study was to investigate how these functional networks are modulated by non-drug rewarding stimuli in cocaine-dependent individuals. Twenty abstinent cocaine-dependent and 21 healthy matched male controls viewed erotic and neutral pictures while undergoing a functional magnetic resonance imaging scan. Group independent component analysis was then performed in order to investigate how functional networks were modulated by reward in cocaine addicts. The results showed that cocaine addicts, compared with healthy controls, displayed diminished modulation of the left frontoparietal network in response to erotic pictures, specifically when they were unpredicted. Additionally, a positive correlation between the length of cocaine abstinence and the modulation of the left frontoparietal network by unpredicted erotic images was found. In agreement with current addiction models, our results suggest that cocaine addiction contributes to reduce sensitivity to rewarding stimuli and that abstinence may mitigate this effect.