Phenylsulfonimide PPARα Antagonists Enhance Nrf2 Activation and Promote Oxidative Stress-Induced Apoptosis/Pyroptosis in MCF7 Breast Cancer Cells.

The NF-E2-related factor 2 transcription factor (Nrf2) orchestrates the basal and stress-inducible activation of a vast array of antioxidant genes. A high amount of reactive oxygen species (ROS) promotes carcinogenesis in cells with defective redox-sensitive signaling factors such as Nrf2. In breast cancer (BC), emerging evidence indicates that increased Nrf2 activity enhances cell metastatic potential. An interconnection between peroxisome proliferator-activated receptors (PPARs) and Nrf2 pathways in cancer has been shown. In this light, newly synthesized PPARα antagonists, namely IB42, IB44, and IB66, were tested in the BC cell line MCF7 in parallel with GW6471 as the reference compound. Our results show that the most promising compound of this phenylsulfonimide series (IB66) is able to decrease MCF7 proliferation by blocking cells at the G2/M checkpoint. The underlying mechanism has been investigated, disclosing a caspase 3/Akt-dependent apoptotic/pyroptotic pathway induced by the increased generation of oxidative stress. Moreover, the involvement of Nrf2 and COX2 in IB66-treated MCF7 cell response has been highlighted. The reported data lay the groundwork for the development of alternative targeted therapy involving the Nrf2/PPARα molecular axis, able to overcome BC cell chemoresistance and cause better clinical outcomes, promoting other forms of programmed cell death, such as pyroptosis.

Snail Slime Extracted by a Cruelty Free Method Preserves Viability and Controls Inflammation Occurrence: A Focus on Fibroblasts.

Snail slime (SS) is a viscous secretion obtained from different snail species. SS composition is variable according to factors such as the extraction method. Even if several papers have been published regarding this topic, the molecular mechanisms at the base of SS biological effects remain unexplored. Thus, the aim of this study is to evaluate the capability of SS, extracted with the cruelty-free Muller method, to promote viability and angiogenesis processes and, in parallel, to counteract inflammation occurrence on skin cell populations. SS was administered to keratinocytes, macrophages and fibroblasts, then cell viability, through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, cytotoxicity by lactate dehydrogenase (LDH) assay, morphology by haematoxylin-eosin staining, gene and protein expression through real-time polymerase chain reaction (PCR) and Western blot, cell cycle phases by flow cytometry, and collagen secretion using an enzyme-linked immunosorbent assay (ELISA) test, were measured. Our results evidence SS capability to promote fibroblast viability and to trigger recovery mechanisms by activating the Erk protein. Moreover, an appreciable anti-inflammatory effect due to the significant reduction in cyclooxygenase-2 expression, and a positive modulation of new blood vessel formation demonstrated by increased Angiopoietin 1 gene expression and a higher matrix deposition (evidenced by the augmented amount of released collagen I) can be identified. This evidence led us to assume that the Muller method extracted-SS represents a valuable and promising natural product suitable for cosmetic and skin care formulations.

The Inhibition of the Inducible Nitric Oxide Synthase Enhances the DPSC Mineralization under LPS-Induced Inflammation.

Nitric oxide (NO) is a key messenger in physiological and pathological processes in mammals. An excessive NO production is associated with pathological conditions underlying the inflammation response as a trigger. Among others, dental pulp inflammation results from the invasion of dentin by pathogenic bacteria. Vital functions of pulp mesenchymal stem cells (DPSCs, dental pulp stem cells), such as mineralization, might be affected by the inducible NOS (iNOS) upregulation. In this context, the iNOS selective inhibition can be considered an innovative therapeutic strategy to counteract inflammation and to promote the regeneration of the dentin-pulp complex. The present work aims at evaluating two acetamidines structurally related to the selective iNOS inhibitor 1400W, namely CM544 and FAB1020, in a model of LPS-stimulated primary DPSCs. Our data reveal that CM544 and even more FAB1020 are promising anti-inflammatory compounds, decreasing IL-6 secretion by enhancing CD73 expression-levels, a protein involved in innate immunity processes and thus confirming an immunomodulatory role of DPSCs. In parallel, cell mineralization potential is retained in the presence of compounds as well as VEGF secretion, and thus their angiogenetic potential. Data presented lay the ground for further investigation on the anti-inflammatory potential of acetamidines selectively targeting iNOS in a clinical context.

Hyaluronic Acid Alleviates Oxidative Stress and Apoptosis in Human Tenocytes via Caspase 3 and 7.

Rotator cuff tendinopathy (RCT) is the primary reason for shoulder surgery and its clinical management is still challenging. Hyaluronic acid (HA) has been shown to have anti-inflammatory effects in vitro and in vivo under RCT conditions, characterized by an exaggerated oxidative stress (OS). However, molecular mechanisms underlying HA-related effects are still partially disclosed. With these aims, a cell model of RCT was established by exposing primary human tenocytes to H2O2 for up to 72 h. Four different HAs by molecular weight were administered to measure nitric oxide (NO) and OS, apoptosis, and collagen 1 expression. In parallel, the well-known antioxidant ascorbic acid was administered for comparison. The present study highlights that HAs characterized by a low molecular weight are able to counteract the H2O2-induced OS by decreasing the percentage of apoptotic cells and reversing the activation of caspase 3 and 7. Likewise, NO intracellular levels are comparable to the ones of controls. In parallel, collagen 1 expression was ameliorated by HAs characterized by higher molecular weights compared to AA. These findings confirm that HA plays an antioxidant role comparable to AA depending on the molecular weight, and highlight the molecular mechanisms underlying the HA anti-apoptotic effects.

CD200 as a Potential New Player in Inflammation during Rotator Cuff Tendon Injury/Repair: An In Vitro Model.

Rotator cuff tendon (RCT) disease results from multifactorial mechanisms, in which inflammation plays a key role. Pro-inflammatory cytokines and tendon stem cell/progenitor cells (TSPCs) have been shown to participate in the inflammatory response. However, the underlying molecular mechanism is still not clear. In this study, flow cytometry analyses of different subpopulations of RCT-derived TSPCs demonstrate that after three days of administration, TNFα alone or in combination with IFNγ significantly decreases the percentage of CD146+CD49d+ and CD146+CD49f+ but not CD146+CD109+ TSPCs populations. In parallel, the same pro-inflammatory cytokines upregulate the expression of CD200 in the CD146+ TSPCs population. Additionally, the TNFα/IFNγ combination modulates the protein expression of STAT1, STAT3, and MMP9, but not fibromodulin. At the gene level, IRF1, CAAT (CAAT/EBPbeta), and DOK2 but not NF-κb, TGRF2 (TGFBR2), and RAS-GAP are modulated. In conclusion, although our study has several important limitations, the results highlight a new potential role of CD200 in regulating inflammation during tendon injuries. In addition, the genes analyzed here might be new potential players in the inflammatory response of TSPCs.

Natural and Synthetic Xanthone Derivatives Counteract Oxidative Stress via Nrf2 Modulation in Inflamed Human Macrophages.

Natural products have attracted attention due to their safety and potential effectiveness as anti-inflammatory drugs. Particularly, xanthones owning a unique 9H-xanthen-9-one scaffold, are endowed with a large diversity of medical applications, including antioxidant and anti-inflammatory activities, because their core accommodates a vast variety of substituents at different positions. Among others, α- and γ-mangostin are the major known xanthones purified from Garcinia mangostana with demonstrated anti-inflammatory and antioxidant effects by in vitro and in vivo modulation of the Nrf2 (nuclear factor erythroid-derived 2-like 2) pathway. However, the main mechanism of action of xanthones and their derivatives is still only partially disclosed, and further investigations are needed to improve their potential clinical outcomes. In this light, a library of xanthone derivatives was synthesized and biologically evaluated in vitro on human macrophages under pro-inflammatory conditions. Furthermore, structure-activity relationship (SAR) studies were performed by means of matched molecular pairs (MMPs). The data obtained revealed that the most promising compounds in terms of biocompatibility and counteraction of cytotoxicity are the ones that enhance the Nrf2 translocation, confirming a tight relationship between the xanthone scaffold and the Nrf2 activation as a sign of intracellular cell response towards oxidative stress and inflammation.

Fisetin as a Senotherapeutic Agent: Biopharmaceutical Properties and Crosstalk between Cell Senescence and Neuroprotection.

Like other organs, brain functions diminish with age. Furthermore, for a variety of neurological disorders-including Alzheimer's disease-age is one of the higher-risk factors. Since in many Western countries the average age is increasing, determining approaches for decreasing the effects of aging on brain function is taking on a new urgency. Neuroinflammation and oxidative stress are two convoluted key factors in brain aging and chronic neurodegenerative diseases. The diverseness of factors, causing an age-related decrease in brain functions, requires identifying small molecules that have multiple biological activities that can affect all these factors. One great source of these small molecules is related to polyphenolic flavonoids. Recently, 3,3',4',7-tetrahydroxyflavone (fisetin) has been reported as a potent senotherapeutic capable of extending lifespan by reducing peroxidation levels and enhancing antioxidant cell responses. The neuroprotective effects of fisetin have been shown in several in vitro and in vivo models of neurological disorders due to its actions on multiple pathways associated with different neurological disorders. The present work aims to collect the most recent achievements related to the antioxidant and neuroprotective effects of fisetin. Moreover, in silico pharmacokinetics, pharmacodynamics, and toxicity of fisetin are also comprehensively described along with emerging novel drug delivery strategies for the amelioration of this flavonol bioavailability and chemical stability.

Negative Modulation of the Angiogenic Cascade Induced by Allosteric Kinesin Eg5 Inhibitors in a Gastric Adenocarcinoma In Vitro Model.

Eg5 is a kinesin essential in bipolar spindle formation, overexpressed in tumours, thus representing a new target in cancer therapy. We aimed at evaluating the anti-cancer activity of Eg5 thiadiazoline inhibitors 2 and 41 on gastric adenocarcinoma cells (AGS), focusing on the modulation of angiogenic signalling. Docking studies confirmed a similar interaction with Eg5 to that of the parent compound K858. Thiadiazolines were also tested in combination with Hesperidin (HSD). Cell cycle analysis reveals a reduction of G1 and S phase percentages when 41 is administered as well as HSD in combination with K858. Western blot reveals Eg5 inhibitors capability to reduce PI3K, p-AKT/Akt and p-Erk/Erk expressions; p-Akt/Akt ratio is even more decreased in HSD+2 sample than the p-Erk/Erk ratio in HSD+41 or K858. VEGF expression is reduced when HSD+2 and HSD+41 are administered with respect to compounds alone, after 72 h. ANGPT2 gene expression increases in cells treated with 41 and HSD+2 compared to K858. The wound-healing assay highlights a reduction in the cut in HSD+2 sample compared to 2 and HSD. Thus, Eg5 inhibitors appear to modulate angiogenic signalling by controlling VEGF activity even better if combined with HSD. Overall, Eg5 inhibitors can represent a promising starting point to develop innovative anti-cancer strategies.

New azolyl-derivatives as multitargeting agents against breast cancer and fungal infections: synthesis, biological evaluation and docking study.

Nonsteroidal aromatase inhibitors (NSAIs) are well-established drugs for the therapy of breast cancer. However, they display some serious side effects, and their efficacy can be compromised by the development of chemoresistance. Previously, we have reported different indazole-based carbamates and piperidine-sulphonamides as potent aromatase inhibitors. Starting from the most promising compounds, here we have synthesised new indazole and triazole derivatives and evaluated their biological activity as potential dual agents, targeting both the aromatase and the inducible nitric oxide synthase, being this last dysregulated in breast cancer. Furthermore, selected compounds were evaluated as antiproliferative and cytotoxic agents in the MCF-7 cell line. Moreover, considering the therapeutic diversity of azole-based compounds, all the synthesized compounds were also evaluated as antifungals on different Candida strains. A docking study, as well as molecular dynamics simulation, were carried out to shed light on the binding mode of the most interesting compound into the different target enzymes catalytic sites.

Selective Inhibitors of the Inducible Nitric Oxide Synthase as Modulators of Cell Responses in LPS-Stimulated Human Monocytes.

Inducible nitric oxide synthase (iNOS) is a crucial enzyme involved in monocyte cell response towards inflammation, and it is responsible for the production of sustained amounts of nitric oxide. This free radical molecule is involved in the defense against pathogens; nevertheless, its continuous and dysregulated production contributes to the development of several pathological conditions, including inflammatory and autoimmune diseases. In the present study, we investigated the effects of two new iNOS inhibitors, i.e., 4-(ethanimidoylamino)-N-(4-fluorophenyl)benzamide hydrobromide (FAB1020) and N-{3-[(ethanimidoylamino)methyl]benzyl}-l-prolinamidedihydrochloride (CM554), on human LPS-stimulated monocytes, using the 1400 W compound as a comparison. Our results show that CM544 and FAB1020 are selective and decrease cytotoxicity, IL-6 secretion and LPS-stimulated monocyte migration. Furthermore, the modulation of iNOS, nitrotyrosine and Nrf2 were analyzed at the protein level. Based on the collected preliminary results, the promising therapeutic value of the investigated compounds emerges, as they appear able to modulate the pro-inflammatory LPS-stimulated response in the low micromolar range in human monocytes.

Conjugation with Methylsulfonylmethane Improves Hyaluronic Acid Anti-Inflammatory Activity in a Hydrogen Peroxide-Exposed Tenocyte Culture In Vitro Model.

Rotator cuff tears (RCTs) and rotator cuff disease (RCD) are important causes of disability in middle-aged individuals affected by nontraumatic shoulder dysfunctions. Our previous studies have demonstrated that four different hyaluronic acid preparations (HAPs), including Artrosulfur® hyaluronic acid (HA) (Alfakjn S.r.l., Garlasco, Italy), may exert a protective effect in human RCT-derived tendon cells undergoing oxidative stress damage. Recently, methylsulfonylmethane (MSM) (Barentz, Paderno Dugnano, Italy) has proven to have anti-inflammatory properties and to cause pain relief in patients affected by tendinopathies. This study aims at evaluating three preparations (Artrosulfur® HA, MSM, and Artrosulfur® MSM + HA) in the recovery from hydrogen peroxide-induced oxidative stress damage in human tenocyte. Cell proliferation, Lactate Dehydrogenase (LDH) release, and inducible nitric oxide synthases (iNOS) and prostaglandin E2 (PGE2) modulation were investigated. In parallel, expression of metalloproteinases 2 (MMP2) and 14 (MMP14) and collagen types I and III were also examined. Results demonstrate that Artrosulfur® MSM + HA improves cell escape from oxidative stress by decreasing cytotoxicity and by reducing iNOS and PGE2 secretion. Furthermore, it differentially modulates MMP2 and MMP14 levels and enhances collagen III expression after 24 h, proteins globally related to rapid acceleration of the extracellular matrix (ECM) remodelling and thus tendon healing. By improving the anti-cytotoxic effect of HA, the supplementation of MSM may represent a feasible strategy to ameliorate cuff tendinopathies.

The Selective Acetamidine-Based iNOS Inhibitor CM544 Reduces Glioma Cell Proliferation by Enhancing PARP-1 Cleavage In Vitro.

Gliomas are the most aggressive adult primary brain tumors. Expression of inducible Nitric Oxide Synthase has been reported as a hallmark of chemoresistance in gliomas and several studies have reported that inhibition of inducible Nitric Oxide Synthase could be related to a decreased proliferation of glioma cells. The present work was to analyze the molecular effects of the acetamidine derivative compound 39 (formally CM544, N-(3-{[(1-iminioethyl)amino]methyl}benzyl) prolinamide dihydrochloride), a newly synthetized iNOS inhibitor, in a C6 rat glioma cell model. There is evidence of CM544 selective binding to the iNOS, an event that triggers the accumulation of ROS/RNS, the expression of Nrf-2 and the phosphorylation of MAPKs after 3 h of treatment. In the long run, CM544 leads to the dephosphorylation of p38 and to a massive cleavage of PARP-1, confirming the block of C6 rat glioma cell proliferation in the G1/S checkpoint and the occurrence of necrotic cell death.

The Up-Regulation of Oxidative Stress as a Potential Mechanism of Novel MAO-B Inhibitors for Glioblastoma Treatment.

Gliomas are malignant brain tumors characterized by rapid spread and growth into neighboring tissues and graded I-IV by the World Health Organization. Glioblastoma is the fastest growing and most devastating IV glioma. The aim of this paper is to evaluate the biological effects of two potent and selective Monoamine Oxidase B (MAO-B) inhibitors, Cmp3 and Cmp5, in C6 glioma cells and in CTX/TNA2 astrocytes in terms of cell proliferation, apoptosis occurrence, inflammatory events and cell migration. These compounds decrease C6 glioma cells viability sparing normal astrocytes. Cell cycle analysis, the Mitochondrial Membrane Potential (MMP) and Reactive Oxygen Species (ROS) production were detected, revealing that Cmp3 and Cmp5 induce a G1 or G2/M cell cycle arrest, as well as a MMP depolarization and an overproduction of ROS; moreover, they inhibit the expression level of inducible nitric oxide synthase 2, thus contributing to fatal drug-induced oxidative stress. Cmp5 notably reduces glioma cell migration via down-regulating Matrix Metalloproteinases 2 and 9. This study demonstrated that our novel MAO-B inhibitors increase the oxidative stress level resulting in a cell cycle arrest and markedly reduces glioma cells migration thus reinforcing the hypothesis of a critical role-played by MAO-B in mediating oncogenesis in high-grade gliomas.

Adhesion of human gingival fibroblasts/Streptococcus mitis co-culture on the nanocomposite system Chitlac-nAg.

Composite materials are increasingly used as dental restoration. In the field of biomaterials, infections remain the main reason of dental devices failure. Silver, in the form of nanoparticles (AgNPs), ions and salt, well known for its antimicrobial properties, is used in several medical applications in order to avoid bacterial infection. To reduce both bacterial adhesion to dental devices and cytotoxicity against eukaryotic cells, we coated BisGMA/TEGDMA methacrylic thermosets with a new material, Chitlac-nAg, formed by stabilized AgNPs with a polyelectrolyte solution containing Chitlac. Here we analyzed the proliferative and adhesive ability of human gingival fibroblasts (HGFs) on BisGMA/TEGDMA thermosets uncoated and coated with AgNPs in a coculture model system with Streptococcus mitis. After 48 h, HGFs well adhered onto both surfaces, while S. mitis cytotoxic response was higher in the presence of AgNPs coated thermosets. After 24 h thermosets coated with Chitlac as well as those coated with Chitlac-nAg exerted a minimal cytotoxic effect on HGFs, while after 48 h LDH release raised up to 20 %. Moreover the presence of S. mitis reduced this release mainly when HGFs adhered to Chitlac-nAg coated thermosets. The reduced secretion of collagen type I was significant in the presence of both surfaces with the co-culture system even more when saliva is added. Integrin ß1 localized closely to cell membranes onto Chitlac-nAg thermosets and PKCα translocated into nuclei. These data confirm that Chitlac-nAg have a promising utilization in the field of restorative dentistry exerting their antimicrobial activity due to AgNPs without cytotoxicity for eukaryotic cells.

Cell-protection mechanism through autophagy in HGFs/S. mitis co-culture treated with Chitlac-nAg.

Silver-based products have been proven to be effective in retarding and preventing bacterial growth since ancient times. In the field of restorative dentistry, the use of silver ions/nanoparticles has been explored to counteract bacterial infections, as silver can destroy bacterial cell walls by reacting with membrane proteins. However, it is also cytotoxic towards eukaryotic cells, which are capable of internalizing nanoparticles. In this work, we investigated the biological effects of Chitlac-nAg, a colloidal system based on a modified chitosan (Chitlac), administered for 24-48 h to a co-culture of primary human gingival fibroblasts and Streptococcus mitis in the presence of saliva, developed to mimic the microenvironment of the oral cavity. We sought to determine its efficiency to combat oral hygiene-related diseases without affecting eukaryotic cells. Cytotoxicity, reactive oxygen species production, apoptosis induction, nanoparticles uptake, and lysosome and autophagosome metabolism were evaluated. In vitro results show that Chitlac-nAg does not exert cytotoxic effects on human gingival fibroblasts, which seem to survive through a homoeostasis mechanism involving autophagy. That suggests that the novel biomaterial Chitlac-nAg could be a promising tool in the field of dentistry.

Cytotoxicity and apoptosis induction by e-cigarette fluids in human gingival fibroblasts.

OBJECTIVES: Electronic cigarettes (e-cigarettes) are generally acknowledged as a safer alternative to the use of combusted tobacco products. Nevertheless, there are increasing conflicting claims concerning the effect of these novel industrial products on the health of e-cigarettes users. The aim of this work was to investigate the effects of the liquids of e-cigarettes on human gingival fibroblasts (HGFs) and to compare the effects of nicotine-containing fluid to the fluid itself. MATERIALS AND METHODS: HGFs were treated with different concentrations (0-5 mg/mL) of fluids of e-cigarettes for different times (0-72 h) and cytotoxicity was analyzed by MTT assay. Fluids were administered also after being vaped (e.g., warmed into the cartomizer). Apoptosis occurrence and Bax expression were evaluated by flow cytometry; ROS production was analyzed by fluorescence optical microscopy. RESULTS: Both nicotine-containing and nicotine-free fluids induced an increased ROS production after 24 h, along with an increased Bax expression, followed by apoptosis occurrence after 48 h of exposure. CONCLUSIONS: The cytotoxicity exerted on HGFs by e-cigarettes fluids is not entirely ascribable to nicotine. Since the e-cigarettes are advertised as a safer alternative to traditional ones, especially for the possibility of "smoking" nicotine-free fluids, further studies are necessary to clarify the mechanism involved in the occurrence of cytotoxicity exerted by such compounds. CLINICAL RELEVANCE: Our results suggest a role for e-cigarette fluids in the pathogenesis of oral diseases, such as periodontitis.

Zoledronic acid at subtoxic dose extends osteoblastic stage span of primary human osteoblasts.

OBJECTIVE: This study aimed to check the effect of zoledronic acid (ZA) at subtoxic dose on human osteoblasts (HOs) in terms of cell viability, apoptosis occurrence, and differentiation induction. ZA belongs to the family of bisphosphonates (BPs), largely used in the clinical practice for the treatment of bone diseases, often associated with jaw osteonecrosis onset. Their pharmacological action consists in the direct block of the osteoclast-mediated bone resorption along with indirect action on osteoblasts. MATERIALS AND METHODS: HOs were treated choosing the highest limit concentration (10(-5) M) which does not induce toxic effects. Live/dead staining, flow cytometry, mitochondrial membrane potential assay, osteocalcin western blotting, gp38 RT-PCR, collagen type I, PGE2, and IL-6 ELISA assays were performed. RESULTS: Similar viability level between control and ZA-treated samples is found along with no significant increase of apoptotic and necrotic cells in ZA-treated sample. To establish if an early apoptotic pathway was triggered, Bax expression and mitochondrial membrane potential were evaluated finding a higher protein expression in control sample and a good integrity of mitochondrial membrane in both experimental points. Type I collagen secretion and alkaline phosphatase (ALP) activity appear increased in ZA-treated sample, osteocalcin expression level is reduced in ZA-treated cells, whereas no modifications of gp38 mRNA level are evidenced. No statistical differences are identified in PGE2 secretion level whereas IL-6 secretion is lower in ZA-treated HOs with respect to control ones. CONCLUSIONS: These results highlight that ZA, delaying the osteoblastic differentiation process versus the osteocytic lineage, strengthens its pharmacological activity enhancing bone density. CLINICAL RELEVANCE: The knowledge of ZA effects on osteoblasts at subtoxic dose allows to improve therapeutic protocols in order to strengthen drug pharmacological activity through a combined action on both osteoclastic and osteoblastic cells.

Nitric oxide-mediated cytotoxic effect induced by zoledronic acid treatment on human gingival fibroblasts.

OBJECTIVES: The aim of our work was to evaluate the role of nitric oxide (NO) in the in vitro response of human gingival fibroblasts (HGFs) to 1, 5, 10, and 100 µM doses of zoledronic acid (ZA), a bisphosphonate largely used in the clinical practice and for which several adverse effects are reported. MATERIALS AND METHODS: Phase contrast microscopy and live/dead staining were used to evaluate HGFs morphology; cell viability, collagen type I and interleukin 6 (IL-6) secretion were evaluated by 3-[4,5-dimethyl-thiazol-2-yl-]-2,5-diphenyl tetrazolium bromide (MTT) and enzyme-linked immunosorbent assay (ELISA) assays. Reactive oxygen species (ROS) production and mitochondrial membrane potential were evaluated by flow cytometry; NO production and NOS activity by spectrophotometric analysis; endothelial NOS (eNOS) and neuronal NOS (nNOS) expression by immunofluorescence. RESULTS: Viable fibroblasts are evidenced in control sample while floating dead cells and cells close to detachment phase in ZA-treated sample, in agreement with decreased level of collagen type I. Control sample shows higher number of viable cells respect to ZA-treated one and ROS production increases when ZA is added. Released NO in ZA-treated sample appears higher and NO overproduction is related to increased nNOS activity. IL-6 secretion level is higher in ZA-treated sample than in control one. CONCLUSIONS: Our results suggest ROS involvement in NO overproduction, due to nNOS recruitment, both at low and high doses. In turn, NO release seems to be able to trigger the inflammatory response only when high doses are administered, thus confirming the ZA cytotoxic effect on HGFs. CLINICAL RELEVANCE: The knowledge of ZA-mediated cytotoxicity mechanisms on HGFs allows to better understand drug pharmacological activity.

Modulation of NRF2: Biological Dualism in Cancer, Targets and Possible Therapeutic Applications.

Significance: The nuclear factor erythroid 2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) system is a master regulator of redox homeostasis and cell adaptation to a variety of exogenous and endogenous stressors. Accumulating evidence from the last decade indicates that the impairment of the redox balance leads to oxidative stress (OS), a common alteration occurring in many human acute and chronic inflammatory diseases, such as cancer, diabetes, neurodegeneration, and metabolic disorders, and aging. Recent Advances: Being located at the intersection of crucial signaling pathways, NRF2 can influence several cellular functions, which extend beyond the maintenance of the redox balance and include cellular metabolism, proteostasis, mitochondrial function and inflammation. For this reason, there is a growing interest in the pharmacologic manipulation of NRF2 for therapeutic purposes, which requires the accurate knowledge of the cell context and the specific time frame both of NRF2 activation and inhibition. This appears to be an important prerequisite and reflects the extreme complexity of the NRF2 signaling, characterized by an intrinsic dualism that mediates beneficial or detrimental effects even in the same biological process. Critical Issues: Of crucial importance will be to understand whether the NRF2 activity modulation might be exploited to exert beneficial outcomes in patients suffering from pathological conditions, in which the OS and the deregulation of inflammatory processes play a crucial role. Future Directions: In this review, we discuss the dual involvement of NRF2 in aging, neurodegeneration, metabolic diseases, long-COVID-19, and carcinogenesis and we present an overview of the most recent therapeutic modulators of NRF2, particularly emphasizing on those selected for clinical trials. Antioxid. Redox Signal. 40, 636-662.

Immunophenotyping of hemocytes from infected Galleria mellonella larvae as an innovative tool for immune profiling, infection studies and drug screening.

In recent years, there has been a considerable increasing interest in the use of the greater wax moth Galleria mellonella as an animal model. In vivo pharmacological tests, concerning the efficacy and the toxicity of novel compounds are typically performed in mammalian models. However, the use of the latter is costly, laborious and requires ethical approval. In this context, G. mellonella larvae can be considered a valid option due to their greater ease of use and the absence of ethical rules. Furthermore, it has been demonstrated that the immune system of these invertebrates has similarity with the one of mammals, thus guaranteeing the reliability of this in vivo model, mainly in the microbiological field. To better develop the full potential of this model, we present a novel approach to characterize the hemocyte population from G. mellonella larvae and to highlight the immuno modulation upon infection and treatments. Our approach is based on the detection in isolated hemocytes from G. mellonella hemolymph of cell membrane markers typically expressed by human immune cells upon inflammation and infection, for instance CD14, CD44, CD80, CD163 and CD200. This method highlights the analogies between G. mellonella larvae and humans. Furthermore, we provide an innovative tool to perform pre-clinical evaluations of the efficacy of antimicrobial compounds in vivo to further proceed with clinical trials and support drug discovery campaigns.