Peculiar combinations of individually non-pathogenic missense mitochondrial DNA variants cause low penetrance Leber's hereditary optic neuropathy.

We here report on the existence of Leber's hereditary optic neuropathy (LHON) associated with peculiar combinations of individually non-pathogenic missense mitochondrial DNA (mtDNA) variants, affecting the MT-ND4, MT-ND4L and MT-ND6 subunit genes of Complex I. The pathogenic potential of these mtDNA haplotypes is supported by multiple evidences: first, the LHON phenotype is strictly inherited along the maternal line in one very large family; second, the combinations of mtDNA variants are unique to the two maternal lineages that are characterized by recurrence of LHON; third, the Complex I-dependent respiratory and oxidative phosphorylation defect is co-transferred from the proband's fibroblasts into the cybrid cell model. Finally, all but one of these missense mtDNA variants cluster along the same predicted fourth E-channel deputed to proton translocation within the transmembrane domain of Complex I, involving the ND1, ND4L and ND6 subunits. Hence, the definition of the pathogenic role of a specific mtDNA mutation becomes blurrier than ever and only an accurate evaluation of mitogenome sequence variation data from the general population, combined with functional analyses using the cybrid cell model, may lead to final validation. Our study conclusively shows that even in the absence of a clearly established LHON primary mutation, unprecedented combinations of missense mtDNA variants, individually known as polymorphisms, may lead to reduced OXPHOS efficiency sufficient to trigger LHON. In this context, we introduce a new diagnostic perspective that implies the complete sequence analysis of mitogenomes in LHON as mandatory gold standard diagnostic approach.

Resveratrol as Chemosensitizer Agent: State of Art and Future Perspectives.

Resistance to chemotherapy still remains a major challenge in the clinic, impairing the quality of life and survival rate of patients. The identification of unconventional chemosensitizing agents is therefore an interesting aspect of cancer research. Resveratrol has emerged in the last decades as a fascinating molecule, able to modulate several cancer-related molecular mechanisms, suggesting a possible application as an adjuvant in cancer management. This review goes deep into the existing literature concerning the possible chemosensitizing effect of resveratrol associated with the most conventional chemotherapeutic drugs. Despite the promising effects observed in different cancer types in in vitro studies, the clinical translation still presents strong limitations due to the low bioavailability of resveratrol. Recently, efforts have been moved in the field of drug delivery to identifying possible strategies/formulations useful for a more effective administration. Despite the necessity of a huge implementation in this research area, resveratrol appears as a promising molecule able to sensitize resistant tumors to drugs, suggesting its potential use in therapy-refractory cancer patients.

Serenoa repens and Urtica dioica Fixed Combination: In-Vitro Validation of a Therapy for Benign Prostatic Hyperplasia (BPH).

Benign prostatic hyperplasia (BPH) is an age-related chronic disorder, characterized by the hyperproliferation of prostatic epithelial and stromal cells, which drives prostate enlargement. Since BPH aetiology and progression have been associated with the persistence of an inflammatory stimulus, induced both by Nuclear Factor-kappa B (NF-κB) activation and reactive oxygen species (ROS) production, the inhibition of these pathways could result in a good tool for its clinical treatment. This study aimed to evaluate the antioxidant and anti-inflammatory activity of a combined formulation of Serenoa repens and Urtica dioica (SR/UD) in an in vitro human model of BPH. The results confirmed both the antioxidant and the anti-inflammatory effects of SR/UD. In fact, SR/UD simultaneously reduced ROS production, NF-κB translocation inside the nucleus, and, consequently, interleukin 6 (IL-6) and interleukin 8 (IL-8) production. Furthermore, the effect of SR/UD was also tested in a human androgen-independent prostate cell model, PC3. SR/UD did not show any significant antioxidant and anti-inflammatory effect, but was able to reduce NF-κB translocation. Taken together, these results suggested a promising role of SR/UD in BPH and BPH-linked disorder prevention.

Mitochondrial Involvement in Cisplatin Resistance.

Cisplatin is one of the worldwide anticancer drugs and, despite its toxicity and frequent recurrence of resistance phenomena, it still remains the only therapeutic option for several tumors. Circumventing cisplatin resistance remains, therefore, a major goal for clinical therapy and represents a challenge for scientific research. Recent studies have brought to light the fundamental role of mitochondria in onset, progression, and metastasis of cancer, as well as its importance in the resistance to chemotherapy. The aim of this review is to give an overview of the current knowledge about the implication of mitochondria in cisplatin resistance and on the recent development in this research field. Recent studies have highlighted the role of mitochondrial DNA alterations in onset of resistance phenomena, being related both to redox balance alterations and to signal crosstalk with the nucleus, allowing a rewiring of cell metabolism. Moreover, an important role of the mitochondrial dynamics in the adaptation mechanism of cancer cells to challenging environment has been revealed. Giving bioenergetic plasticity to tumor cells, mitochondria allow cells to evade death pathways in stressful conditions, including chemotherapy. So far, even if the central role of mitochondria is recognized, little is known about the specific mechanisms implicated in the resistance. Nevertheless, mitochondria appear to be promising pharmacological targets for overcoming cisplatin resistance, but further studies are necessary.

Clinical Evidence of Interaction between Nutraceutical Supplementation and Platinum-based Chemotherapy.

Platinum agents, which include cisplatin, oxaliplatin and carboplatin, are chemotherapeutic drugs that represent the first-line treatment for different types of solid tumors, such as ovarian, head and neck, testicular, and bladder cancers. Their beneficial effect is limited by the onset of drug resistance and severe toxicities, involving mainly ototoxicity, neurotoxicity and nephrotoxicity. Recent studies highlight the supplementation of herbal products, vitamins and minerals with antioxidant properties to prevent and protect from side effects. In particular, the introduction of nutraceuticals associated with chemotherapy has improved the patients' quality of life. However, if from one side, complementary and alternative medicine ameliorates chemotherapeutics-induced toxicities, from the other side, it is important to take into consideration the possible interference with drug metabolism. This review aims to consider the current literature focusing on clinical trials that report an association between nutraceutical supplementation and platinum- based chemotherapy to prevent toxicities, highlighting both beneficial and side effects.

Contribution of Mitochondrial Activity to Doxorubicin-Resistance in Osteosarcoma Cells.

Osteosarcoma is considered the most common bone tumor affecting children and young adults. The standard of care is chemotherapy; however, the onset of drug resistance still jeopardizes osteosarcoma patients, thus making it necessary to conduct a thorough investigation of the possible mechanisms behind this phenomenon. In the last decades, metabolic rewiring of cancer cells has been proposed as a cause of chemotherapy resistance. Our aim was to compare the mitochondrial phenotype of sensitive osteosarcoma cells (HOS and MG-63) versus their clones when continuously exposed to doxorubicin (resistant cells) and identify alterations exploitable for pharmacological approaches to overcome chemotherapy resistance. Compared with sensitive cells, doxorubicin-resistant clones showed sustained viability with less oxygen-dependent metabolisms, and significantly reduced mitochondrial membrane potential, mitochondrial mass, and ROS production. In addition, we found reduced expression of TFAM gene generally associated with mitochondrial biogenesis. Finally, combined treatment of resistant osteosarcoma cells with doxorubicin and quercetin, a known inducer of mitochondrial biogenesis, re-sensitizes the doxorubicin effect in resistant cells. Despite further investigations being needed, these results pave the way for the use of mitochondrial inducers as a promising strategy to re-sensitize doxorubicin cytotoxicity in patients who do not respond to therapy or reduce doxorubicin side effects.

Maintenance of intestinal epithelial barrier integrity by a combination of probiotics, herbal extract, and vitamins.

BACKGROUND: Irritable bowel syndrome (IBS) and Inflammatory bowel disease (IBD) are pathological conditions that severely hamper the quality of life of patients. Especially in pediatric and adolescent patients, the use of Complementary and alternative medicine is an appealing approach as an adjuvant for the management of symptoms, limiting the detrimental effect of the conventional therapy. In this work, we tested the effect of Enterokind Junior (EntJ), a mix of two probiotic strains Lactobacillus reuteri DSM 25175 and Lactobacillus acidophilus DSM 24936, Matricaria Chamomilla, and vitamins, in in vitro model of intestinal inflammation. Caco-2 cells were subjected to LPS treatment or THP-1 cells stimulated with LPS treatment, as paradigms of inflammatory conditions. METHODS: The effect of the probiotic formulation was evaluated by measuring Caco-2 monolayer's Transepithelial Electrical resistance (TEER) and paracellular permeability alterations, tight junction proteins expression and localization by confocal microscopy, and release of pro-inflammatory cytokines (TNF-α and IL-8) by ELISA assay. RESULTS: Results demonstrated that upon impairment of intestinal parameters induced by inflammatory stimuli, the combination of probiotic was able to prevent TEER decrease and paracellular permeability alterations and to maintain the tight junction expression and localization. Moreover, the release of proinflammatory cytokines induced by inflammation was reduced by EntJ treatment. CONCLUSIONS: This work, in line with previous observations, supports a protective role of Lactobacillus reuteri DSM 25175, Lactobacillus acidophilus DSM 24936 and the other components in the maintenance of a healthy gut, holding up the use of this combination as an adjuvant for irritable bowel syndrome-related symptoms management.

Anti-inflammatory activity of a fixed combination of probiotics and herbal extract in an in-vitro model of intestinal inflammation by stimulating Caco-2 cells with LPS-conditioned THP-1 cells medium.

BACKGROUND: Inflammatory bowel disease (IBD) is an inflammatory condition of the gastrointestinal tract, characterized by chronic and relapsing immune system activation, often diagnosed in adolescence, with a rising incidence in pediatric populations. IBD results from altered interactions between gut microbes and the intestinal immune system which induce an aberrant immune response, thus anti-inflammatory or immunosuppressive therapies are generally used. Recent interest has been given to the identification of integrative and complementary approaches that could be able to restore and preserve the intestinal barrier function. METHODS: In this work, we tested the effect of a fixed combination of probiotics and herbal extract (Colikind Gocce® [CKG], Schwabe Pharma, Egna-Neumarkt, Bolzano, Italy) in an in-vitro model of intestinal inflammation. Caco-2 cells stimulated with LPS-conditioned monocytes culture medium was used as a paradigm of intestinal inflammation. The possible effect of CKG in maintaining the homeostasis of the intestinal epithelial barrier was investigated by measurement of the trans-epithelial electrical resistance, the paracellular permeability, and the release of inflammatory cytokines (TNF-α, IL-8, and IL-10). RESULTS: Results obtained in this work demonstrated that CKG is able to prevent the impairment of intestinal barrier function induced by inflammation, ameliorating the transepithelial electrical resistance and the paracellular permeability of the Caco-2 monolayer; moreover, CKG is able to counteract the increased release of TNF-a and IL-8 induced by inflammatory stimulus, thus reducing the intestinal inflammation. CONCLUSIONS: This work underlines the protective effect of CKG on intestinal barrier, reducing the damages induced by inflammatory stimulus. This suggests CKG as an interesting product in the management of intestinal inflammatory conditions.

Cisplatin resistance can be curtailed by blunting Bnip3-mediated mitochondrial autophagy.

Cisplatin (CDDP) is commonly used to treat a multitude of tumors including sarcomas, ovarian and cervical cancers. Despite recent investigations allowed to improve chemotherapy effectiveness, the molecular mechanisms underlying the development of CDDP resistance remain a major goal in cancer research. Here, we show that mitochondrial morphology and autophagy are altered in different CDDP resistant cancer cell lines. In CDDP resistant osteosarcoma and ovarian carcinoma, mitochondria are fragmented and closely juxtaposed to the endoplasmic reticulum; rates of mitophagy are also increased. Specifically, levels of the mitophagy receptor BNIP3 are higher both in resistant cells and in ovarian cancer patient samples resistant to platinum-based treatments. Genetic BNIP3 silencing or pharmacological inhibition of autophagosome formation re-sensitizes these cells to CDDP. Our study identifies inhibition of BNIP3-driven mitophagy as a potential therapeutic strategy to counteract CDDP resistance in ovarian carcinoma and osteosarcoma.

Characterization of raloxifene as a potential pharmacological agent against SARS-CoV-2 and its variants.

The new coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic, which so far has caused over 6 million deaths in 2 years, despite new vaccines and antiviral medications. Drug repurposing, an approach for the potential application of existing pharmaceutical products to new therapeutic indications, could be an effective strategy to obtain quick answers to medical emergencies. Following a virtual screening campaign on the most relevant viral proteins, we identified the drug raloxifene, a known Selective Estrogen Receptor Modulator (SERM), as a new potential agent to treat mild-to-moderate COVID-19 patients. In this paper we report a comprehensive pharmacological characterization of raloxifene in relevant in vitro models of COVID-19, specifically in Vero E6 and Calu-3 cell lines infected with SARS-CoV-2. A large panel of the most common SARS-CoV-2 variants isolated in Europe, United Kingdom, Brazil, South Africa and India was tested to demonstrate the drug's ability in contrasting the viral cytopathic effect (CPE). Literature data support a beneficial effect by raloxifene against the viral infection due to its ability to interact with viral proteins and activate protective estrogen receptor-mediated mechanisms in the host cells. Mechanistic studies here reported confirm the significant affinity of raloxifene for the Spike protein, as predicted by in silico studies, and show that the drug treatment does not directly affect Spike/ACE2 interaction or viral internalization in infected cell lines. Interestingly, raloxifene can counteract Spike-mediated ADAM17 activation in human pulmonary cells, thus providing new insights on its mechanism of action. A clinical study in mild to moderate COVID-19 patients (NCT05172050) has been recently completed. Our contribution to evaluate raloxifene results on SARS-CoV-2 variants, and the interpretation of the mechanisms of action will be key elements to better understand the trial results, and to design new clinical studies aiming to evaluate the potential development of raloxifene in this indication.

The SARS-CoV-2 spike protein binds and modulates estrogen receptors.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein binds angiotensin-converting enzyme 2 (ACE2) at the cell surface, which constitutes the primary mechanism driving SARS-CoV-2 infection. Molecular interactions between the transduced S and endogenous proteins likely occur post-infection, but such interactions are not well understood. We used an unbiased primary screen to profile the binding of full-length S against >9,000 human proteins and found significant S-host protein interactions, including one between S and human estrogen receptor alpha (ERα). After confirming this interaction in a secondary assay, we used bioinformatics, supercomputing, and experimental assays to identify a highly conserved and functional nuclear receptor coregulator (NRC) LXD-like motif on the S2 subunit and an S-ERα binding mode. In cultured cells, S DNA transfection increased ERα cytoplasmic accumulation, and S treatment induced ER-dependent biological effects and ACE2 expression. Noninvasive multimodal PET/CT imaging in SARS-CoV-2-infected hamsters using [ 18 F]fluoroestradiol (FES) localized lung pathology with increased ERα lung levels. Postmortem experiments in lung tissues from SARS-CoV-2-infected hamsters and humans confirmed an increase in cytoplasmic ERα expression and its colocalization with S protein in alveolar macrophages. These findings describe the discovery and characterization of a novel S-ERα interaction, imply a role for S as an NRC, and are poised to advance knowledge of SARS-CoV-2 biology, COVID-19 pathology, and mechanisms of sex differences in the pathology of infectious disease.

The SARS-CoV-2 spike protein binds and modulates estrogen receptors.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein binds angiotensin-converting enzyme 2 as its primary infection mechanism. Interactions between S and endogenous proteins occur after infection but are not well understood. We profiled binding of S against >9000 human proteins and found an interaction between S and human estrogen receptor α (ERα). Using bioinformatics, supercomputing, and experimental assays, we identified a highly conserved and functional nuclear receptor coregulator (NRC) LXD-like motif on the S2 subunit. In cultured cells, S DNA transfection increased ERα cytoplasmic accumulation, and S treatment induced ER-dependent biological effects. Non-invasive imaging in SARS-CoV-2-infected hamsters localized lung pathology with increased ERα lung levels. Postmortem lung experiments from infected hamsters and humans confirmed an increase in cytoplasmic ERα and its colocalization with S in alveolar macrophages. These findings describe the discovery of a S-ERα interaction, imply a role for S as an NRC, and advance knowledge of SARS-CoV-2 biology and coronavirus disease 2019 pathology.

Novel Adenosine Triphosphate-Based Nutraceutical Formulation to Prevent Non-Steroidal Anti-Inflammatory Drug Enteric Cell Toxicity: Preliminary In Vitro Evidence.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly prescribed and self-prescribed drugs to treat inflammation and pain associated with several conditions. Although their efficacy and overall safety have been recognized when used according to medical prescriptions and for a short period time, their acute impact on enteric physiology has rarely been studied. NSAIDs are known to cause gastrointestinal side effects due to their intrinsic mechanism of action, which involves prostaglandins synthesis, leading to impaired mucopolysaccharide layer production. Despite this well-known and investigated side effect, the short- and long-term influences of acute administration of these drugs on the biochemical environment of enteric cells are not well understood. This study investigates the rate of adenosine triphosphate (ATP) loss and permeability alterations occurring in a model of human enteric cells, as a consequence of acute administration of NSAIDs as major perpetrators of enteric toxicity. For the first time, we investigate the ability of a novel ATP-containing formulation to prevent ATP hydrolysis in the stomach and ensure its delivery at the proximal duodenal site.

Cholesterol Metabolic Reprogramming in Cancer and Its Pharmacological Modulation as Therapeutic Strategy.

Cholesterol is a ubiquitous sterol with many biological functions, which are crucial for proper cellular signaling and physiology. Indeed, cholesterol is essential in maintaining membrane physical properties, while its metabolism is involved in bile acid production and steroid hormone biosynthesis. Additionally, isoprenoids metabolites of the mevalonate pathway support protein-prenylation and dolichol, ubiquinone and the heme a biosynthesis. Cancer cells rely on cholesterol to satisfy their increased nutrient demands and to support their uncontrolled growth, thus promoting tumor development and progression. Indeed, transformed cells reprogram cholesterol metabolism either by increasing its uptake and de novo biosynthesis, or deregulating the efflux. Alternatively, tumor can efficiently accumulate cholesterol into lipid droplets and deeply modify the activity of key cholesterol homeostasis regulators. In light of these considerations, altered pathways of cholesterol metabolism might represent intriguing pharmacological targets for the development of exploitable strategies in the context of cancer therapy. Thus, this work aims to discuss the emerging evidence of in vitro and in vivo studies, as well as clinical trials, on the role of cholesterol pathways in the treatment of cancer, starting from already available cholesterol-lowering drugs (statins or fibrates), and moving towards novel potential pharmacological inhibitors or selective target modulators.

Further assessment of Salvia haenkei as an innovative strategy to counteract skin photo-aging and restore the barrier integrity.

Skin is the essential barrier of the human body which performs multiple functions. Endogenous factors, in concert with external assaults, continuously affect skin integrity, leading to distinct structural changes that influence not only the skin appearance but also its various physiological functions. Alterations of the barrier functions lead to an increased risk of developing disease and side reactions, thus the importance of maintaining the integrity of the epidermal barrier and slowing down the skin aging process is evident. Salvia haenkei (SH) has been recently identified as a potential anti-senescence agent; its extract is able to decrease the level of senescent cells by affecting the IL1α release and reducing reactive oxygen species (ROS) generation. In this study, SH extract was tested on human keratinocyte cell line (HaCaT) exposed to stress factors related to premature aging of cells such as free radicals and ultraviolet B radiation. We confirmed that SH acts as scavenger of ROS and found its ability to restore the skin barrier integrity by reinforcing the cytoskeleton structure, sealing the tight junctions and increasing the migration rate of cells. Given these results, this work becomes relevant, identifying Salvia haenkei as a compound useful for anti-aging skin treatment in clinical performance.

Cannabidiol Isolated From Cannabis sativa L. Protects Intestinal Barrier From In Vitro Inflammation and Oxidative Stress.

The relevance and incidence of intestinal bowel diseases (IBD) have been increasing over the last 50 years and the current therapies are characterized by severe side effects, making essential the development of new strategies that combine efficacy and safety in the management of human IBD. Herbal products are highly considered in research aimed at discovering new approaches for IBD therapy and, among others, Cannabis sativa L. has been traditionally used for centuries as an analgesic and anti-inflammatory remedy also in different gastrointestinal disorders. This study aims to investigate the effects of different C. sativa isolated compounds in an in vitro model of intestinal epithelium. The ability of treatments to modulate markers of intestinal dysfunctions was tested on Caco-2 intestinal cell monolayers. Our results, obtained by evaluation of ROS production, TEER and paracellular permeability measurements and tight junctions evaluation show Cannabidiol as the most promising compound against intestinal inflammatory condition. Cannabidiol is able to inhibit ROS production and restore epithelial permeability during inflammatory and oxidative stress conditions, suggesting its possible application as adjuvant in IBD management.

Links between cancer metabolism and cisplatin resistance.

Cisplatin is one of the most potent and widely used chemotherapeutic agent in the treatment of several solid tumors, despite the high toxicity and the frequent relapse of patients due to the onset of drug resistance. Resistance to chemotherapeutic agents, either intrinsic or acquired, is currently one of the major problems in oncology. Thus, understanding the biology of chemoresistance is fundamental in order to overcome this challenge and to improve the survival rate of patients. Studies over the last 30 decades have underlined how resistance is a multifactorial phenomenon not yet completely understood. Recently, tumor metabolism has gained a lot of interest in the context of chemoresistance; accumulating evidence suggests that the rearrangements of the principal metabolic pathways within cells, contributes to the sensitivity of tumor to the drug treatment. In this review, the principal metabolic alterations associated with cisplatin resistance are highlighted. Improving the knowledge of the influence of metabolism on cisplatin response is fundamental to identify new possible metabolic targets useful for combinatory treatments, in order to overcome cisplatin resistance.

Interaction Between Mitochondrial DNA Variants and Mitochondria/Endoplasmic Reticulum Contact Sites: A Perspective Review.

Mitochondria contain their own genome, mitochondrial DNA (mtDNA), essential to support their fundamental intracellular role in ATP production and other key metabolic and homeostatic pathways. Mitochondria are highly dynamic organelles that communicate with all the other cellular compartments, through sites of high physical proximity. Among all, their crosstalk with the endoplasmic reticulum (ER) appears particularly important as its derangement is tightly implicated with several human disorders. Population-specific mtDNA variants clustered in defining the haplogroups have been shown to exacerbate or mitigate these pathological conditions. The exact mechanisms of the mtDNA background-modifying effect are not completely clear and a possible explanation is the outcome of mitochondrial efficiency on retrograde signaling to the nucleus. However, the possibility that different haplogroups shape the proximity and crosstalk between mitochondria and the ER has never been proposed neither investigated. In this study, we pose and discuss this question and provide preliminary data to answer it. Besides, we also address the possibility that single, disease-causing mtDNA point mutations may act also by reshaping organelle communication. Overall, this perspective review provides a theoretical platform for future studies on the interaction between mtDNA variants and organelle contact sites.

A Fixed Combination of Probiotics and Herbal Extracts Attenuates Intestinal Barrier Dysfunction from Inflammatory Stress in an In vitro Model Using Caco-2 Cells.

BACKGROUND: Inflammatory Bowel Diseases (IBD), are considered a growing global disease, with about ten million people being affected worldwide. Maintenance of intestinal barrier integrity is crucial for preventing IBD onset and exacerbations. Some recent patents regarding oily formulations containing probiotics (WO2010122107A1 and WO2010103374A9) and the use of probiotics for gastrointestinal complaints (US20110110905A1 and US9057112B2) exist, or are pending application. OBJECTIVE: In this work, we studied the effect of a fixed combination of registered Lactobacillus reuteri and Lactobacillus acidophilus strains and herbal extracts in an in vitro inflammation experimental model. METHODS: Caco-2 cell monolayer was exposed to INF-γ+TNF-α or to LPS; Trans Epithelial Electrical Resistance (TEER) and paracellular permeability were investigated. ZO-1 and occludin Tight Junctions (TJs) were also investigated by mean of immunofluorescence. RESULTS: Pre-treatment with the fixed combination of probiotics and herbal extracts prevented the inflammation-induced TEER decrease, paracellular permeability increase and TJs translocation. CONCLUSIONS: In summary, the fixed combination of probiotics and herbal extracts investigated in this research was found to be an interesting candidate for targeting the re-establishment of intestinal barrier function in IBD conditions.