Trypanosoma cruzi causes Chagas disease, a neglected disease that can be divided, overall, into acute and chronic phases. Understanding the mechanisms underlying its progression is based on the parasite-host interactions occurring during the infection. Although the pathophysiology of the main symptomatic forms of Chagas disease has been the subject of several studies, little is known about their relationship with the development of different types of cancer. Therefore, knowledge regarding the molecular aspects of infection in the host, as well as the influence of the immune response in the parasite and the host, can help to understand the association between Chagas disease and tumor development. This review aims to summarize the main molecular mechanisms related to T. cruzi-dependent carcinogenic development and the mechanisms associated with tumor protection mediated by different parasite components.

The established correlation between obesity and cognitive impairment portrays pharmacological products aimed at both disorders as an important therapeutic advance. Modulation of dysregulated adipokines and neurotransmitters is hence a critical aspect of the assessment of in-use drugs. At the cellular level, repairments in brain barrier integrity and cognitive flexibility are the main checkpoints. The aim of this study was to investigate whether melatonin and histidine, alone or in combination, could produce weight loss, meanwhile improve the cognitive processes. In this study, obese rat model was established by feeding high fat diet (HFD) composed of 25% fats (soybean oil) for 8 weeks, accompanied by melatonin (10 mg/kg), histidine (780 mg/kg), and combination of both in conventional form and nanoform. At the end of the study, adiposity hormones, neuronal monoamines and amino acids, brain derived neurotrophic factor (BDNF) and zonula occluden-1 (ZO-1) were assessed. HFD feeding resulted in significant weight gain and poor performance on cognitive test. Coadministration of histidine in the nanoform increased the level of ZO-1; an indicator of improving the brain barrier integrity, along with adjusting the adipokines and neurotransmitters levels, which had a positive impact on learning tasks. Cotreatment with melatonin resulted in an increase in the level of BDNF, marking ameliorated synaptic anomalies and learning disabilities, while reducing weight gain. On the other hand, the combination of melatonin and histidine reinstated the synaptic plasticity as well as brain barrier junctions, as demonstrated by increased levels of BDNF and ZO-1, positively affecting weight loss and the intellectual function.

Ribosomopathies are rare congenital disorders associated with defective ribosome biogenesis due to pathogenic variations in genes that encode proteins related to ribosome function and biogenesis. Defects in ribosome biogenesis result in a nucleolar stress response involving the TP53 tumor suppressor protein and impaired protein synthesis leading to a deregulated translational output. Despite the accepted notion that ribosomes are omnipresent and essential for all cells, most ribosomopathies show tissue-specific phenotypes affecting blood cells, hair, spleen, or skin. On the other hand, defects in mitochondrial ribosome biogenesis are associated with a range of clinical manifestations affecting more than one organ. Intriguingly, the deregulated ribosomal function is also a feature in several human malignancies with a selective upregulation or downregulation of specific ribosome components. Here, we highlight the clinical conditions associated with defective ribosome biogenesis in the nucleus and mitochondria with a description of the affected genes and the implicated pathways, along with a note on the treatment strategies currently available for these disorders.

Fibroblasts function to secrete and modify components of the extracellular matrix. During wound healing, fibroblasts migrate to the site of injury and differentiate into contractile myofibroblasts; this differentiation is characterised by an increased contractile capacity. Fully differentiated myofibroblasts can be distinguished from fibroblasts via the higher expression of α-smooth muscle actin as well as a denser cytoskeleton. Impaired wound healing has been characterised by a lack of myofibroblasts; as a result, tissue does not fully regain its strength and function. Under pathological conditions, this may be associated with the effect that a pro-inflammatory microenvironment has on fibroblast and skeletal muscle progenitor cell migration and differentiation. Given their distinct roles in tissue maintenance and repair, the communication between fibroblasts versus myofibroblasts with other cellular mediators of repair is likely to influence cell behaviour and the outcome of wound repair. An in vitro test model is required to investigate this intercellular influence, but the establishment of such a model is hampered by the difficulty in retaining the dedifferentiated fibroblastic phenotype under regular serum-containing cell culture conditions. We present a model that supports the establishment and retention in culture of fibroblast and myofibroblast phenotypes for use in a simple, inexpensive, yet relevant in vitro 2D assay. This model is then applied in a co-culture setting to determine whether the presence of myoblasts affects the ability of fibroblasts versus myofibroblasts to close an in vitro wound. Our results emphasize the importance of considering the impact of paracrine communication between all cells during wound healing.

Osteoblasts are essential for bone formation and can perceive external mechanical stimuli, which are translated into biochemical responses that ultimately alter cell phenotypes and respond to environmental stimuli, described as mechanical transduction. These cells actively participate in osteogenesis and the formation and mineralisation of the extracellular bone matrix. This review summarises the basic physiological and biological mechanisms of five different physical stimuli, i.e. light, electricity, magnetism, force and sound, to induce osteogenesis; further, it summarises the effects of changing culture conditions on the morphology, structure and function of osteoblasts. These findings may provide a theoretical basis for further studies on bone physiology and pathology at the cytological level and will be useful in the clinical application of bone formation and bone regeneration technology.

Despite the use of the highly specific anti-HER2 receptor (trastuzumab) therapy, HER2-positive breast cancers account for 20-30% of all breast cancer carcinomas, with HER2 status a challenge to treatment interventions. The heparan sulfate proteoglycans (HSPGs) are prominently expressed in the extracellular matrix (ECM), mediate breast cancer proliferation, development, and metastasis with most studies to date conducted in animal models. This study examined HSPGs in HER2-positive human breast cancer cell lines and their contribution to cancer cell proliferation. The study examined the cells following enhancement (via the addition of heparin) and knockdown (KD; using short interfering RNA, siRNA) of HSPG core proteins. The interaction of HSPG core proteins and AKT signalling molecules was examined to identify any influence of this signalling pathway on cancer cell proliferation. Our findings illustrated the HSPG syndecan-4 (SDC4) core protein significantly regulates cell proliferation with increased BC cell proliferation following heparin addition to cultures and decreased cell number following SDC4 KD. In addition, along with SDC4, significant changes in CK19/AKT signalling were identified as mediators of BC HER2-positive BC cell proliferation. This study provides evidence for a cell growth regulatory axis involving HSPGs/CK19 and AKT that represents a potential molecular target to prevent proliferation of HER2-positive breast cancer cells.

The translocator protein (TSPO) is a ubiquitous transmembrane protein of great pharmacological interest thanks to its high affinity to many drug ligands. The only high-resolution 3D-structure known for mammalian TSPO was obtained by NMR for the mouse mTSPO in DPC detergent only in presence of the high-affinity PK 11195 ligand. An atomic structure of free-ligand mTSPO is still missing to better understand the interaction of ligands with mTSPO and their effects on the protein conformation. Here, we decipher the solution structures of the recombinant mTSPO without ligand both in (i) SDS, the detergent used to extract and purify the protein from E. coli inclusion bodies, and (ii) DPC, the detergent used to solve the PK 11195-binding mTSPO NMR structure. We report partially refolded and less flexible mTSPO helices in DPC compared to SDS. Besides, DPC stabilizes the tertiary structure of mTSPO, as shown by a higher intrinsic Trp fluorescence and changes in indole environment. We evaluate by SEC-MALLS that ∼135 SDS and ∼100 DPC molecules are bound to mTSPO. SEC-small-angle X-ray (SAXS) and neutron (SANS) scattering confirm a larger mTSPO-detergent complex in SDS than in DPC. Using the contrast-matching technique in SEC-SANS, we demonstrate that mTSPO conformation is more compact and less flexible in DPC than in SDS. Combining ab initio modeling with SANS, we confirm that mTSPO conformation is less elongated in DPC than in SDS. However, the free-ligand mTSPO envelope in DPC is not as compact as the PK 11195-binding protein NMR structure, the ligand stiffening the protein.

ABC transporters have long been known to mediate resistance phenotypes in all kingdoms of life, and ATP-driven tripartite efflux pump from Gram-negative bacteria have attracted increasing interest. We give a special focus on MacAB TolC, a prototypical member of the recently described Type VII ABC transporter superfamily, from Escherichia coli. We provide original experimental evidence for the in vitro, substrate-induced ATPase activity and show a maximal activity when the tripartite pump is fully assembled in lipid nanodiscs. These results are evaluated and interpreted in the context of the structural and functional data that have accumulated over the years.

We have synthesized biocompatible ionic liquids (ILs) with choline as cation and amino acids as anions to explore their potential towards prevention of fibrillation in insulin and the obtain corresponding mechanistic insights. This has been achieved by examining the effect of these ILs on insulin at the nucleation, elongation and maturation stages of the fibrillation process. A combination of high sensitivity isothermal titration calorimetry (ITC) and differential scanning calorimetry (DSC) have been employed along with spectroscopy and microscopy to evaluate interaction of the ILs at each stage of fibrillation quantitatively. Choline glycinate is observed to provide maximum stabilization to insulin compared to that provided by choline prolinate, choline leucinate, and choline valinate. This increased thermal stabilization has direct correlation with the extent of reduction in the fibrillation of insulin by ILs determined using Thioflavin T and 8-anilinonaphthalene sulfonate based fluorescence assays. ITC has permitted understanding nature of interaction of the ILs with the protein at different fibrillation stages in terms of standard molar enthalpy of interaction whereas DSC has enabled understanding the extent of reduction in thermal stability of the protein at these stages. These ILs are able to completely inhibit formation of insulin aggregates at a concentration of 50 mM. Stabilization of proteins by ILs could be explained based on involvement of preferential hydration process. The work provides biocompatible IL based approach in achieving stability and prevention of fibrillation in insulin.

Mesenchymal stem/stromal cells (MSCs) are multipotent somatic cells that have been widely explored in the field of regenerative medicine. MSCs possess the ability to secrete soluble factors as well as lipid bound extracellular vesicles (EVs). MSCs have gained increased interest and attention as a result of their therapeutic properties, which are thought to be attributed to their secretome. However, while the use of MSCs as whole cells pose heterogeneity concerns and survival issues post-transplantation, such limitations are absent in cell-free EV-based treatments. EVs derived from MSCs are promising therapeutic agents for a range of clinical conditions and disorders owing to their immunomodulatory, pro-regenerative, anti-inflammatory, and antifibrotic activity. Recent successes with preclinical studies using EVs for repair and regeneration of damaged tissues such as cardiac tissue, lung, liver, pancreas, bone, skin, cornea, and blood diseases are discussed in this review. We also discuss delivery strategies of EVs using biomaterials as delivery vehicles through systemic or local administration. Despite its effectiveness in preclinical investigations, the application of MSC-EV in clinical settings will necessitate careful consideration surrounding issues such as: i) scalability and isolation, ii) biodistribution, iii) targeting specific tissues, iv) quantification and characterization, and v) safety and efficacy of dosage. The future of EVs in regenerative medicine is promising yet still needs further investigation on enhancing the efficacy, scalability, and potency for clinical applications.

Knowledge of the 3D structure of proteins is a valuable asset for understanding their precise biological mechanisms. However, the cost of production of 3D structures and experimental difficulties limit their obtaining. The proposal of 3D structural models is consequently an appealing alternative. The release of the AlphaFold Deep Learning approach has revolutionized the field. The recent near-complete human proteome proposal makes it possible to analyse large amounts of data and evaluate the results of the approach in greater depth. The 3D human proteome was thus analysed in light of the classic secondary structures, and many less-used protein local conformations (PolyProline II helices, type of γ-turns, of β-turns and of β-bulges, curvature of the helices, and a structural alphabet). Without questioning the global quality of the approach, this analysis highlights certain local conformations, which maybe poorly predicted and they could therefore be better addressed.

Nei Like DNA Glycosylase 1 (NEIL1) is a DNA glycosylase, which specifically processes oxidative DNA damage by initiating base excision repair. NEIL1 recognizes and removes bases, primarily oxidized pyrimidines, which have been damaged by endogenous oxidation or exogenous mutagenic agents. NEIL1 functions through a combined glycosylase/AP (apurinic/apyrimidinic)-lyase activity, whereby it cleaves the N-glycosylic bond between the DNA backbone and the damaged base via its glycosylase activity and hydrolysis of the DNA backbone through beta-delta elimination due to its AP-lyase activity. In our study we investigated our hypothesis proposing that the cancer resistance of the bowhead whale can be associated with a better DNA repair with NEIL1 being upregulated or more active. Here, we report the molecular cloning and characterization of three transcript variants of bowhead whale NEIL1 of which two were homologous to human transcripts. In addition, a novel NEIL1 transcript variant was found. A differential expression of NEIL mRNA was detected in bowhead eye, liver, kidney, and muscle. The A-to-I editing of NEIL1 mRNA was shown to be conserved in the bowhead and two adenosines in the 242Lys codon were subjected to editing. A mass spectroscopy analysis of liver and eye tissue failed to demonstrate the existence of a NEIL1 isoform originating from RNA editing. Recombinant bowhead and human NEIL1 were expressed in E. coli and assayed for enzymatic activity. Both bowhead and human recombinant NEIL1 catalyzed, with similar efficiency, the removal of a 5-hydroxyuracil lesion in a DNA bubble structure. Hence, these results do not support our hypothesis but do not refute the hypothesis either.

Osteosarcoma is the most common malignant tumor of bone, with rapid progressive growth, early distant metastases, and frequent recurrence after surgical treatment. Osteosarcoma is characterized by changes in the ratio and expression of different cytochrome P450 (CYP) isoforms that can affect the effectiveness of anticancer therapies. The inducible expression of CYP1 genes depends on the ligand-dependent functionality of the aryl hydrocarbon receptor (AHR). In this study, we examined the AHR/CYP1 signaling pathway in four osteosarcoma cell lines (MG63, HOS, SAOS2, and U2OS) induced by the known AHR ligands: indirubin, indole-3-carbinol, and beta-naphthoflavone. Using qPCR and Western blot analysis, we explored the effects of these ligands on the expression of the CYP1 genes and studied the correlation between these responses and the changes in the mRNA and protein levels of AHR and the AHR nuclear translocator (ARNT) in these osteosarcoma cell lines. The results show that the AHR/CYP1 signaling pathway retains its function only in MG63 and HOS cells, and is impaired in SAOS2 and U2OS cells. Our data should be taken into account when recommending new strategies for the treatment of osteosarcoma and when evaluating new drugs against osteosarcoma in vitro.

Data emerged from the last 20 years of basic research on tumor antigens positioned the type I MAGE (Melanoma Antigen GEnes - I or MAGE-I) family as cancer driver factors. MAGE-I gene expression is mainly restricted to normal reproductive tissues. However, abnormal re-expression in cancer unbalances the cell status towards enhanced oncogenic activity or reduced tumor suppression. Anomalous MAGE-I gene re-expression in cancer is attributed to altered epigenetic-mediated chromatin silencing. Still, emerging data indicate that MAGE-I can be regulated at protein level. Results from different laboratories suggest that after its anomalous re-expression, specific MAGE-I proteins can be regulated by well-known signaling pathways or key cellular processes that finally potentiate the cancer cell phenotype. Thus, MAGE-I proteins both regulate and are regulated by cancer-related pathways. Here, we present an updated review highlighting the recent findings on the regulation of MAGE-I by oncogenic pathways and the potential consequences in the tumor cell behavior.

Varespladib (LY315920) is a potent inhibitor of human group IIA phospholipase A2 (PLA2) originally developed to control inflammatory cascades of diseases associated with high or dysregulated levels of endogenous PLA2. Recently, varespladib was also found to inhibit snake venom PLA2 and PLA2-like toxins. Herein, ex vivo neuromuscular blocking activity assays were used to test the inhibitory activity of varespladib. The binding affinity between varespladib and a PLA2-like toxin was quantified and compared with other potential inhibitors for this class of proteins. Crystallographic and bioinformatic studies showed that varespladib binds to PrTX-I and BthTX-I into their hydrophobic channels, similarly to other previously characterized PLA2-like myotoxins. However, a new finding is that an additional varespladib binds to the MDiS region, a particular site that is related to muscle cell disruption by these toxins. The present results further advance the characterization of the molecular interactions of varespladib with PLA2-like myotoxins and provide additional evidence for this compound as a promising inhibitor candidate for different PLA2 and PLA2-like toxins.

Thermoneutral housing has been shown to promote more accurate and robust development of several pathologies in mice. Raising animal housing temperatures a few degrees may create a relatively straightforward opportunity to improve translatability of mouse models. In this commentary, we discuss the changes of physiology induced in mice housed at thermoneutrality, and review techniques for measuring systemic thermogenesis, specifically those affecting storage and mobilization of lipids in adipose depots. Environmental cues are a component of the information integrated by the brain to calculate food consumption and calorie deposition. We show that relative humidity is one of those cues, inducing a rapid sensory response that is converted to a more chronic susceptibility to obesity. Given high inter-institutional variability in the regulation of relative humidity, study reproducibility may be improved by consideration of this factor. We evaluate a "humanized" environmental cycling protocol, where mice sleep in warm temperature housing, and are cool during the wake cycle. We show that this protocol suppresses adaptation to cool exposure, with consequence for adipose-associated lipid storage. To evaluate systemic cues in mice housed at thermoneutral temperatures, we characterized the circulating lipidome, and show that sera are highly depleted in some HDL-associated phospholipids, specifically phospholipids containing the essential fatty acid, 18:2 linoleic acid, and its derivative, arachidonic acid (20:4) and related ether-phospholipids. Given the role of these fatty acids in inflammatory responses, we propose they may underlie the differences in disease progression observed at thermoneutrality.

We report herein the synthesis of zwitterionic sulfobetaine (SB) and dimethylamine oxide (AO) detergents whose alkyl chain is made of either a perfluorohexyl (F6H3) or a perfluoropentyl (F5H5) group linked to a hydrogenated spacer arm. In aqueous solution, the critical micellar concentrations (CMCs) measured by surface tensiometry (SFT) and isothermal titration calorimetry (ITC) were found in the millimolar range (1.3-2.4 mM). The morphologies of the aggregates were evaluated by dynamic light scattering (DLS), analytical ultracentrifugation (AUC), small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM), demonstrating that the two perfluoropentyl derivatives formed small micelles less than 10 nm in diameter, whereas the perfluorohexyl derivatives formed larger and more heterogeneous micelles. The two SB detergents were able to solubilize synthetic lipid vesicles in a few hours; by contrast, the perfluoropentyl AO induced much faster solubilization, whereas the perfluorohexyl AO did not show any solubilization. All detergents were tested for their abilities to stabilize three membrane proteins, namely, bacteriorhodopsin (bR), the Bacillus subtilis ABC transporter BmrA, and the Streptococcus pneumoniae enzyme SpNOX. The SB detergents outperformed the AO derivatives as well as their hydrogenated analogs in stabilizing these proteins. Among the four new compounds, F5H5SB combines many desirable properties for membrane-protein study, as it is a powerful yet gentle detergent.

Accumulation of D-2-hydroxyglutaric acid (D-2-HG) is the biochemical hallmark of D-2-hydroxyglutaric aciduria type I and, particularly, of D-2-hydroxyglutaric aciduria type II (D2HGA2). D2HGA2 is a metabolic inherited disease caused by gain-of-function mutations in the gene isocitrate dehydrogenase 2. It is clinically characterized by neurological abnormalities and a severe cardiomyopathy whose pathogenesis is still poorly established. The present work investigated the potential cardiotoxicity D-2-HG, by studying its in vitro effects on a large spectrum of bioenergetics parameters in heart of young rats and in cultivated H9c2 cardiac myoblasts. D-2-HG impaired cellular respiration in purified mitochondrial preparations and crude homogenates from heart of young rats, as well as in digitonin-permeabilized H9c2 cells. ATP production and the activities of cytochrome c oxidase (complex IV), alpha-ketoglutarate dehydrogenase, citrate synthase and creatine kinase were also inhibited by D-2-HG, whereas the activities of complexes I, II and II-III of the respiratory chain, glutamate, succinate and malate dehydrogenases were not altered. We also found that this organic acid compromised mitochondrial Ca2+ retention capacity in heart mitochondrial preparations and H9c2 myoblasts. Finally, D-2-HG reduced the viability of H9c2 cardiac myoblasts, as determined by the MTT test and by propidium iodide incorporation. Noteworthy, L-2-hydroxyglutaric acid did not change some of these measurements (complex IV and creatine kinase activities) in heart preparations, indicating a selective inhibitory effect of the enantiomer D. In conclusion, it is presumed that D-2-HG-disrupts mitochondrial bioenergetics and Ca2+ retention capacity, which may be involved in the cardiomyopathy commonly observed in D2HGA2.