IntroductionBioremediation is an emerging, sustainable strategy that relies on microbial processes to detoxify environmental pollutants. Among these pollutants, heavy metals (HMs) are pervasive, non-degradable toxic elements that pose serious risks to human health. In this study, we individually evaluated three probiotic lactobacilli strains—Lactiplantibacillus plantarum LP14, Lactobacillus crispatus LCR04, and Lactobacillus acidophilus LA12—for their capacity to detoxify cadmium, chromium, mercury, and lead in the gastrointestinal (GI) tract, as well as their capacity to mitigate heavy metal-induced intestinal damage, with a single-strain product strategy in mind.MethodsAfter initial selection of the strains for their in vitro detoxifying potential, we employed a dynamic Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model and each strain’s survival, growth, and heavy metal detoxification capacity was assessed under sequential gastric, small-intestinal, and colonic conditions.ResultsStrain- and metal-specific differences in HMs sequestration emerged: L. plantarum LP14 and L. crispatus LCR04 showed robust persistence and significantly reduced HMs bioavailability, whereas L. acidophilus LA12 displayed minimal detoxification under GI simulation. Mechanistically, only the strains that proliferated in the colonic phase achieved substantial HM removal, underscoring the importance of metabolic activity in situ. In a gut ex vivo system (GEVS), heavy metal exposure alone compromised epithelial barrier integrity and triggered pro-inflammatory responses. Pre-incubation of the HMs with each of the probiotic strains markedly alleviated these effects, restoring intestinal permeability and cytokine profiles.DiscussionOverall, the results demonstrate a novel probiotic-based intestinal bioremediation strategy and highlight the translational potential of targeted single-strain probiotic interventions, reducing heavy metal exposure to protect gut health.
Blueberries, widely recognized as a "superfood," are rich in bioactive compounds whose functionality may be further enhanced through fermentation. This study investigated the nutritional and functional potential of blueberry juice fermented with Leuconostoc mesenteroides VUCC R-037 (or LM2), a native isolate, and Lactiplantibacillus plantarum DSM 25710 (or LP09), an industrial probiotic strain. Fermentation kinetics, microbial viability, and metabolic activity were monitored by microcalorimetry and selective plating, while compositional and functional changes in the fermented blueberry juice (FBJ) (such as total phenolics, antioxidant capability, putative cytotoxicity) were assessed through HPLC, chemical assays (FRAP), and in vitro cellular models (MTT and cytochrome c assay). Strain-specific contributions shaped the final product with LM2 promoting stronger acidification and acetic acid production, while LP09, favoured lactic acid accumulation and increased ferric reducing antioxidant capacity. Additionally, LM2 enhanced radical scavenging activity with co-cultures revealing complementary effects. FBJ supported probiotic viability, showed no cytotoxicity in CaCo-2 intestinal epithelial cells, preserved epithelial barrier integrity, and mitigated oxidative stress. Assays for impact of the FBJ on the gut microbiota was carried out in the micro-MatrixTM ex vivo distal colon model, where it selectively reduced Clostridium perfringens and Escherichia spp., suggesting a role in beneficial gut microbiota modulation. Overall, fermentation with native and probiotic lactic acid bacteria improved the biochemical, functional, and cytoprotective profile of blueberry juice, highlighting its promise as a novel functional beverage. While further clinical validation is forthcoming, these results strengthen the case for fruit-based fermented products as innovative vehicles to deliver both health-promoting microbes and bioactive compounds to consumers.
The protein activating molecule in Beclin1-regulated autophagy1 (AMBRA1), discovered in 2007, is crucial for autophagy and plays roles in nervous system development, cell survival, and proliferation. Here, we investigated AMBRA1's involvement in various cellular processes using a systems-based "omics" approach, focusing on melanoma.Transcriptomic analysis of AMBRA1 overexpression or knock-down was shown to result in significant dysregulation of several transcripts. We identified several novel roles for AMBRA1 in a range of cellular pathways including cancer signaling pathways such as MAPK, angiogenesis, tissue growth factor signaling, axon guidance, and Wnt signaling. Furthermore, using yeast two-hybrid assays, we identified novel binding partners which provide evidence of new roles for AMBRA1 in different cellular processes. Ultimately, we conclude that AMBRA1 loss upregulates metastatic genes/proteins highlighting AMBRA1 as a tumor suppressor gene in melanoma.
Coeliac disease is an autoimmune disease that is primarily associated with chronic inflammation of the gut, but can also affect organs outside the gut, from the liver to the skin and CNS. The disease is triggered in predisposed individuals by a peptide mixture (PT) derived from the digestion of gliadin, a component of wheat, which is ingested with food. Although the induction of endoplasmic reticulum stress in intestinal epithelial cells (IECs) upon exposure to PT is known, the underlying molecular mechanisms remain unclear. Identifying the key players in this signaling pathway could therefore help to develop a new effective therapeutic strategy for the treatment of CD patients. Two CD models were used to identify the molecular mechanism linking extracellular PT and endoplasmic reticulum (ER) stress in the IECs of predisposed individuals exposed to gliadin. These models were an in vitro model based on CaCo-2 cells and an ex vivo model based on our previously described gut ex vivo system (GEVS), both exposed to PT. Our results clearly show that the interaction of gliadin peptides with the transmembrane CXCR3 receptor on IECs leads to a rapid induction of PLC activity that generates IP3 molecules. This second messenger binds to the IP3R located in ER membranes, resulting in calcium efflux from the organelle. The PT-dependent ER stress observed in the IECs of CD patients results from the excessive release of calcium from the ER. Importantly, inhibition of this signaling pathway abrogates ER stress, which in turn attenuates downstream signs of CD, such as TG2 expression and gut permeability dysregulation, as well as inhibits inflammation.
Celiac disease (CD) is an autoimmune disorder that primarily affects the gut of genetically predisposed individuals and is triggered by gliadin peptides (PT) produced by the digestion of gluten. Although inappropriate activation of the immune system is thought to be the main trigger of CD, the interaction between PT and intestinal epithelial cells (IECs) remains a key step. Recently, the possible involvement of ER stress in the pathogenesis of CD has been pointed out, although its role is still largely unclear. Therefore, discovering the molecular mechanism(s) activated in IECs exposed to PT represents a unique opportunity to better understand the disease and define new potential therapeutic targets. In this study we used three different experimental set-ups: intestinal biopsies from CD patients and non-CD control subjects, an in vitro model, based on human CaCo-2 cells, and an ex vivo model, based on our recently described mouse gut-ex-vivo system (GEVS), with the latter two systems were studied after stimulation with gliadin peptides (PT). To understand the signaling pathways involved we monitor the expression of a number of proteins by qPCR, Western blotting, IF, ELISA or a combination of tests. Specifically, we have analyzed the level of CD, ER stress, tissue permeability, and inflammation markers. Indeed, our study demonstrated a prompt induction of the transcription factors ATF4, ATF6 and XBP1 in IECs upon PT exposure. Thus, the upregulation of TG2 and downregulation of CFTR were prevented by ER stress inhibition/buffering by a pharmacological chaperone, also leading to restored physiological expression of OCL, CLD-2 and CLD-15, while preventing the expression of IFNγ, IL-15 and IL-17 A. Overall, our analysis has highlighted the key role of ER stress in the pathogenesis of CD and identified the chemical chaperones as a new potential valuable therapeutic treatment for CD patients.
Myelination in the central nervous system(CNS)is a highly intricate process,exclusive to vertebrates,that relies on the coordinated interaction between oligodendrocytes(OLs)and neurons.In addition to their role in forming myelin,accumulating evidence indicates that OLs provide crucial trophic support to axons,contributing to normal CNS function.Notably,OL injury and loss are observed in a variety of human conditions,including stroke,traumatic injuries of the brain and spinal cord,as well as neurodegenerative disorders such as multiple sclerosis(MS).
Human osteosarcoma (OS) is a rare tumor predominantly affecting long bones and characterized by a poor prognosis. Currently, the first line of intervention consists of the surgical resection of primary tumors combined with radiotherapy and chemotherapy, with a profound impact on the patient’s life. Since the surgical removal of OS frequently results in a large resection of bones, the use of biomaterials to sustain the stability of the remaining tissue and to stimulate bone regeneration is challenging. Moreover, residual neoplastic cells might be responsible for tumor recurrence. Here, we explored the potential of tellurium-ion-doped bioactive glass as a novel therapeutic intervention to both eradicate residual malignant cells and promote bone regeneration. Bioactive glass (BAG) has been extensively studied and employed in the field of regenerative medicine due to its osseointegration properties and ability to improve bone tissue regeneration. We found that the incorporation of tellurium (Te) in BAG selectively kills OS cells through ferroptosis while preserving the viability of hBMSCs and stimulating their osteodifferentiation. However, the mechanism of Te toxicity is still unclear: (i) Te-BAG generates lipid-ROS through LOXs activity but not iron overload; (ii) Te-dependent ferroptosis is mediated by GPX4 down-regulation; and (iii) the anti-ferroptotic activity of FSP1 is abrogated, whose expression confers the resistance of OS to the canonical induction of ferroptosis. Overall, our data show that Te-doped bioglass could represent an interesting biomaterial with both pro-ferroptotic activity towards residual cancer cells and pro-osteoregenerative activity.
Alzheimer’s disease (AD) is a complex neurodegenerative disorder significantly impairing cognitive faculties, memory, and physical abilities. To characterize the modulation of the gut microbiota in an in vivo AD model, we performed shotgun metagenomics sequencing on 3xTgAD mice at key time points (i.e., 2, 6, and 12 months) of AD progression. Fecal samples from both 3xTgAD and wild-type mice were collected, DNA extracted, and sequenced. Quantitative taxon abundance assessment using MetaPhlAn 4 ensured precise microbial community representation. The analysis focused on species-level genome bins (SGBs) including both known and unknown SGBs (kSGBs and uSGBs, respectively) and also comprised higher taxonomic categories such as family-level genome bins (FGBs), class-level genome bins (CGBs), and order-level genome bins (OGBs). Our bioinformatic results pinpointed the presence of extensive gut microbial diversity in AD mice and showed that the largest proportion of AD- and aging-associated microbiome changes in 3xTgAD mice concern SGBs that belong to the Bacteroidota and Firmicutes phyla, along with a large set of uncharacterized SGBs. Our findings emphasize the need for further advanced bioinformatic studies for accurate classification and functional analysis of these elusive microbial species in relation to their potential bridging role in the gut-brain axis and AD pathogenesis.
Human osteosarcoma (OS) is a relatively rare malignancy preferentially affecting long body bones which prognosis is often poor also due to the lack of effective therapies. Clinical management of this cancer basically relies on surgical removal of primary tumor coupled with radio/chemotherapy. Unfortunately, most osteosarcoma cells are resistant to conventional therapy, with the undergoing epithelial-mesenchymal transition (EMT) giving rise to gene expression reprogramming, thus increasing cancer cell invasiveness and metastatic potential. Alternative clinical approaches are thus urgently needed. In this context, the recently described ferroptotic cell death represents an attractive new strategy to efficiently kill cancer cells, since most chemoresistant and mesenchymal-shaped tumors display high susceptibility to pro-ferroptotic compounds. However, cancer cells have also evolved anti-ferroptotic strategies, which somehow sustain their survival upon ferroptosis induction. Indeed, here we show that osteosarcoma cell lines display heterogeneous sensitivity to ferroptosis execution, correlating with the mesenchymal phenotype, which is consistently affected by the expression of the well-known anti-ferroptotic factor ferroptosis suppressor protein 1 (FSP1). Interestingly, inhibiting the activity or expression of FSP1 restores cancer cell sensitivity to ferroptosis. Moreover, we also found that: i) AKRs might also contribute to resistance; ii) NRF2 enhances FSP1 expression upon ferroptosis induction; while iii) p53 contributes to the regulation of FSP1 basal expression in OS cells.In conclusion, FSP1 expression can potentially be used as a valuable predictive marker of OS sensitivity to ferroptosis and as a new potential therapeutic target.
Ferroptosis is a recently characterized form of cell death that has gained attention for its roles in both pathological and physiological contexts. The existence of multiple anti-ferroptotic pathways in both neoplastic and healthy cells, along with the critical regulation of iron metabolism involved in lipid peroxides (lipid-ROS) production—the primary mediators of this cell death process—underscores the necessity of precisely controlling or preventing accidental/unwanted ferroptosis. Conversely, dysregulated iron metabolism and alterations in the expression or activity of key anti-ferroptotic components are linked to the development and progression of various human diseases, including multiple sclerosis (MS). In MS, the improper activation of ferroptosis has been associated with the progressive loss of myelinating oligodendrocytes (myOLs). Our study demonstrates that the physiological and maturation-dependent increase in iron accumulation within oligodendrocytes acts as a pro-ferroptotic signal, countered by the concurrent expression of AKR1C1. Importantly, MS-related neuroinflammation contributes to the down-regulation of AKR1C1 through miRNA-mediated mechanisms, rendering mature oligodendrocytes more vulnerable to ferroptosis. Together, these findings highlight the role of ferroptosis in MS-associated oligodendrocyte loss and position AKR1C1 as a potential therapeutic target for preserving oligodendrocyte integrity and supporting neuronal function in MS patients.
Mastering new and efficient ways to obtain successful drug delivery systems (DDS) with controlled release became a paramount quest in the scientific community. Increase of malignant bone tumors and the necessity to optimize an approach of localized drug delivery require research to be even more intensified. Octacalcium phosphate (OCP), with a number of advantages over current counterparts is extensively used in bone engineering. The aim of the present research was to synthesize bioactive and biocompatible doxorubicin (DOX) containing OCP particles. DOX-OCP was successfully obtained in situ in an exhaustive range of added drug (1-20 wt%, theoretical loading). Based on XRD, above 10 wt% of DOX, OCP formation was inhibited and the obtained product was low crystalline alpha-TCP. In-vitro drug release was performed in pH 7.4 and 6.0. In both pH environments DOX had a continuous release over six weeks. However, the initial drug burst for pH 7.4, in the first 24 h, ranged from 15.9 +/- 1.3 % to 33.5 +/- 12 % and for pH 6.0 23.7 +/- 1.5 % to 36.2 +/- 12 %.The DOX-OCP exhibited an inhibitory effect on viability of osteosarcoma cell lines MG63, U2OS and HOS. In contrast, MC3T3-E1 cells (IC50 > 0.062 mu M) displayed increased viability and proliferation from 3rd to 7th day. Testing of the DDS on ferroptotic markers (CHAC1, ACSL4 and PTGS2) showed that OCP-DOX does not induce ferroptotic cell death. Moreover, the evaluation of protein levels of cleaved PARP, by western blotting analysis, corroborated that apoptosis is the main pathway of programmed cell death in osteosarcoma cells induced by DOX-OCP.
In recent years, 4-phenylbutyric acid (4-PBA), an FDA-approved drug, has increasingly been used as a nonspecific chemical chaperone in vitro and in vitro, but its pharmacodynamics is still not clear. In this context, we developed and validated a Liquid Chromatography–High Resolution Mass Spectrometry (LC-HRMS) method to quantify 4-PBA in NeuroBasal-A and Dulbecco’s Modified Eagle widely used cell culture media. Samples were injected on a Luna® 3 µm PFP(2) 100 Å (100 × 2.0 mm) column maintained at 40 °C. Water and methanol both with 0.1% formic acid served as mobile phases in a step gradient mode. The mass acquisition was performed by selected ion monitoring (SIM) in negative mode for a total run time of 10.5 min at a flow rate of 0.300 mL/min. The analogue 4-(4-Nitrophenyl)-Butyric Acid served as internal standard. Validation parameters were verified according to FDA and EMA guidelines. The quantification ranges from 0.38–24 µM. Inter and intraday RSDs (Relative Standard Deviations) were within 15%. The developed LC-HRMS method allowed the estimation of 4-PBA absorption and adsorption kinetics in vitro in two experimental systems: (i) 4-PBA improvement of protein synthesis in an Alzheimer’s disease astrocytic cell model; and (ii) 4-PBA reduction of endoplasmic reticulum stress in thapsigargin-treated melanoma cell lines.
Protein misfolding is prominent in early cellular pathology of Alzheimer's disease (AD), implicating pathophysiological significance of endoplasmic reticulum stress/unfolded protein response (ER stress/UPR) and highlighting it as a target for drug development. Experimental data from animal AD models and observations on human specimens are, however, inconsistent. ER stress and associated UPR are readily observed in in vitro AD cellular models and in some AD model animals. In the human brain, components and markers of ER stress as well as UPR transducers are observed at Braak stages III-VI associated with severe neuropathology and neuronal death. The picture, however, is further complicated by the brain region- and cell type-specificity of the ADrelated pathology. Terms 'disturbed' or 'non-canonical' ER stress/UPR were used to describe the discrepancies between experimental data and the classic ER stress/UPR cascade. Here we discuss possible 'disturbing' or 'interfering' factors which may modify ER stress/UPR in the early AD pathogenesis. We focus on the dysregulation of the ER Ca2+ homeostasis, store-operated Ca2+ entry, and the interaction between the ER and mitochondria. We suggest that a detailed study of the CNS cell type-specific alterations of Ca2+ homeostasis in early AD may deepen our understanding of AD-related dysproteostasis.
Cancer cells within tumor masses are chronically exposed to stress caused by nutrient deprivation, oxygen limitation, and high metabolic demand. They also accumulate hundreds of mutations, potentially generating aberrant proteins that can induce proteotoxic stress. Finally, cancer cells are exposed to various damages during chemotherapy. In a growing tumor, transformed cells eventually adapt to these conditions, eluding the death-inducing outcomes of signaling cascades triggered by chronic stress. One such extreme outcome is ferroptosis, a form of iron-dependent non-apoptotic cell death mediated by lipid peroxidation. Not surprisingly, the tumor suppressor p53 is involved in this process, with evidence suggesting that it acts as a pro-ferroptotic factor and that its ferroptosis-inducing activity may be relevant for tumor suppression. Missense alterations of the TP53 gene are extremely frequent in human cancers and give rise to mutant p53 proteins (mutp53) that lose tumor suppressive function and can acquire powerful oncogenic activities. This suggests that p53 mutation provides a selective advantage during tumor progression, raising interesting questions on the impact of p53 mutant proteins in modulating the ferroptotic process. Here, we explore the role of p53 and its cancer-related mutants in ferroptosis, using a perspective centered on the resistance/sensitivity of cancer cells to exogenous and endogenous stress conditions that can trigger ferroptotic cell death. We speculate that an accurate molecular understanding of this particular axis may improve cancer treatment options.
The key role played by host-microbiota interactions on human health, disease onset and progression, and on host response to treatments has increasingly emerged in the latest decades. Indeed, dysbiosis has been associated to several human diseases such as obesity, diabetes, cancer and also neurodegenerative disease, such as Parkinson, Huntington and Alzheimer's disease (AD), although whether causative, consequence or merely an epiphenomenon is still under investigation. In the present study, we performed a metabologenomic analysis of stool samples from a mouse model of AD, the 3xTgAD. We found a significant change in the microbiota of AD mice compared to WT, with a longitudinal divergence of the F/B ratio, a parameter suggesting a gut dysbiosis. Moreover, AD mice showed a significant decrease of some amino acids, while data integration revealed a dysregulated production of desaminotyrosine (DAT) and dihydro-3-coumaric acid. Collectively, our data show a dysregulated gut microbiota associated to the onset and progression of AD, also indicating that a dysbiosis can occur prior to significant clinical signs, evidenced by early SCFA alterations, compatible with gut inflammation.
BACKGROUND:IBD is a spectrum of pathologies characterized by dysregulated immune activation leading to uncontrolled response against the intestine, thus resulting in chronic gut inflammation and tissue damage. Due to its complexity, the molecular mechanisms responsible for disease onset and progression are still elusive, thus requiring intense research effort. In this context, the development of models replicating the etiopathology of IBD and allowing the testing of new potential therapies is critical.METHODS:Colon from C57BL/6 or BALB/c mice was cultivated in a Gut-Ex-Vivo System (GEVS), exposed for 5 h to DNBS 1.5 or 2.5 mg/mL, in presence or absence of two probiotic formulations (P1 = Bifidobacterium breve BR03 (DSM16604) and B632 (DSM24706); P2 = Lacticaseibacillus rhamnosus LR04 (DSM16605), Lactiplantibacillus plantarum LP14 (DSM33401) and Lacticaseibacillus paracasei LPC09), and the main hallmarks of IBD were evaluated.RESULTS:Gene expression analysis revealed the following DNBS-induced effects: (i) compromised tight junction organization, responsible for tissue permeability dysregulation; (ii) induction of ER stress, and (iii) tissue inflammation in colon of C57BL/6 mice. Moreover, the concomitant DNBS-induced apoptosis and ferroptosis pathways were evident in colon from both BALB/c and C57BL/6 mice. Finally, the co-administration of probiotics completely prevented the detrimental effects of DNBS.CONCLUSIONS:Overall, we have provided results demonstrating that GEVS is a consistent, reliable, and cost-effective system for modeling DNBS-induced IBD, useful for studying the onset and progression of human disease at the molecular level, while also reducing animal suffering. Moreover, we have confirmed the beneficial effect of probiotics administration in promoting the remission of IBD.
Background: IBD is a spectrum of pathologies characterized by dysregulated immune activation leading to uncontrolled response against intestinal, thus resulting in chronic gut inflammation and tissue damage. Due to its complexity, the molecular mechanisms responsible for disease onset and progression are still elusive, thus requiring intense research effort. In this context, the development of models recapitulating the etiopathology of IBD is critical.Methods: Colon from C57BL/6 or BALB/c mice were cultivated in a gut-ex-vivo system (GEVS), exposed 5h to DNBS 1,5 or 2,5 mg/ml, and the main hallmarkers of IBD were evaluated.Results: Gene expression analysis revealed a DNBS-induced: i) compromised Tight junction organization, responsible for tissue permeability dysregulation; induction of ER stress, and iii) tissue inflammation in colon of C57BL/6 mice. Moreover, the concomitant DNBS-induced apoptosis and ferroptosis pathways was evident in colon from both BALB/c and C57BL/6 mice.Conclusions: Overall, we have provided results demonstrating that GEVS is a consistent, reliable, and cost-effective system for modeling DNBS-induced IBD, useful for studying the onset and progression of human disease at the molecular level, while also reducing animal suffering.