Medication-related osteonecrosis of the jaw (MRONJ) is a complex condition associated with the use of antiresorptive drugs, such as bisphosphonates and denosumab. The condition is characterized by the presence of exposed bone in the maxillofacial region that fails to heal. MRONJ remains highly intractable, as its pathogenic mechanisms are not yet fully understood. It is therefore essential to elucidate the molecular mechanisms underlying the disease. MiRNA expression analysis and proteomic studies were performed on a selected cohort of patients with MRONJ on jawbone tissue, using qRT-PCR and 2D electrophoresis followed by mass spectrometry. MiRNAs and proteomics data validation was carried out by Western blot analysis of differentially expressed proteins highlighted by a proteome study and predicted targets of differentially expressed miRNAs. Nineteen miRNAs were overexpressed and two downregulated in jawbone tissue from all MRONJ patients. Notably, five of these dysregulated miRNAs are involved in the regulation of angiogenesis and desmosome functions, suggesting a potential link to the molecular alterations observed at the protein level. Proteomic analysis revealed decreased concentrations of the pigment epithelium-derived factor, and of desmoglein-1, a desmosomal cadherin. Validation analysis confirmed the dysregulation of pathways involved in bone remodeling and necroptosis. The pathophysiology of MRONJ arises from a complex interplay of factors, including impaired bone remodeling, affected angiogenesis, and altered cell adhesion and differentiation mechanisms, ultimately leading to necroptosis. Through proteomic analysis and validation of miRNA expression, our study proposes specific molecular alteration in MRONJ-compromised bone tissue, involving desmosomal component imbalance and angiogenesis inhibition.

Parkinson's disease (PD) is characterized by progressive dopaminergic neuronal loss driven by mitochondrial dysfunction, oxidative stress, and proteostasis collapse, for which current therapies remain symptomatic. This study investigated the neuroprotective effects of Eucalyptus citriodora essential oil (ECEO) on 6-hydroxydopamine (6-OHDA)-induced toxicity in N2a neuroblastoma cells. GC-MS analysis showed that ECEO was dominated by oxygenated monoterpenes, mainly citronellal (60.7%), isopulegol (16%), and citronellol (5.7%). In silico analysis of these constituents showed favorable ADMET profiles, predicted blood-brain barrier permeability, and non-overlapping multitarget engagement across enzymes, GPCRs and nuclear receptors. At the cellular level, ECEO pretreatment significantly restored cell viability (86.7% of control), reduced LDH release, attenuated ROS and NO, and limited mitochondrial depolarization. Quantitative 2D-gel/MALDI-TOF/TOF proteomics identified 94 differentially abundant proteins, of which 20 showed validated PD-related associations (KEGG, Gene4PD, and DisGeNET databases). ECEO pretreatment modulated 12 of these proteins across mechanistically coherent pathways: (i) reversal of 6-OHDA-induced reprogramming of energy metabolism, by normalizing the glycolytic enzymes PKM and PGK1 and restoring the TCA enzyme SUCLG2; (ii) reinforcement of proteostasis through PSMB4 and PSMA3 induction, VCP upregulation and attenuation of ER stress marker HSPA5/BiP; (iii) preservation of mitochondrial and cytoskeletal integrity through PHB1 induction and bilateral TUBB5 restoration. Overall, our results suggest that ECEO exerts significant neuroprotective effects in a cellular PD model by coordinately modulating energy metabolism, proteostasis, antioxidant defense, and structural integrity. Given its predominance in oxygenated monoterpenes the neuroprotective activity of ECEO may result from the combined contribution of the major constituents supporting further investigation in age-related neurodegeneration.

Abstract Bacterial Outer Membrane Vesicles (OMVs), spherical bilayered nanoparticles naturally released by all Gram-negative bacteria, are gaining increasing interest not only in the design of prophylactic vaccines but also in cancer immunotherapy. In particular, thanks to their potent built-in adjuvanticity and to their intrinsic capacity to directly kill tumor cells, OMVs have been successfully tested in intratumoral in situ vaccination (ISV), a strategy in which immunostimulatory formulations are injected directly into tumors to convert the tumor microenvironment (TME) into an immune-reactive state. Previous studies have shown that OMVs induce robust inflammation and a Th1-skewed immune response, resulting in complete tumor remission in a substantial fraction of mice bearing syngeneic tumors. Here, we show that OMVs from our Escherichia coli Δ60 strain can be efficiently engineered with multiple cytokines and chemokines. Moreover, CCL3, Flt3L, TNFα, and IL-2 not only accumulated on the OMV surface but also retained their in vitro biological activity. Furthermore, OMVs displaying these cytokines exhibited potent antitumor activity, and in particular the intratumoral injection of the combined TNFα- and IL-2-engineered OMVs eradicated tumors in over 95% of mice across several syngeneic models. Immunostaining and flow cytometry analyses revealed that injection of engineered OMVs markedly remodeled the TME, promoting the recruitment of inflammatory myeloid cells and γδ T cells, the persistence of local CD8⁺ and CD4⁺ αβ T cells, and the reduction of regulatory T cells. Overall, these results highlight cytokine-bearing OMVs as a versatile and highly effective platform for intratumoral immunotherapy.

Central Core Disease (CCD) is a congenital myopathy predominantly caused by mutations in the gene encoding ryanodine receptor type-1 (RYR1), the intracellular Ca2+ release channel embedded in the skeletal muscle sarcoplasmic reticulum membrane. The I4898T mutation represents one of the most common RYR1 mutations associated with CCD. Unfortunately, there are no approved therapies for CCD or for other myopathies caused by mutations in this gene. This study aims to perform a top-down differential proteomic analysis on soleus muscle samples from wild-type mice (WT) and heterozygous knock-in mice carrying the I4895T (IT) mutation in RyR1, to investigate the pathogenic mechanisms and molecular pathways involved in this myopathy and to shed light on new potential biomarkers useful for future therapies. Proteomic analysis revealed 50 dysregulated protein species, and multivariate analysis showed that IT mice exhibit a distinct proteomic signature compared to WT mice, characterized by alterations in proteins associated with contractile and structural dysfunction, metabolism, and stress response. In particular, a significant increase in myosin fragments was observed in IT mice, likely due to muscle breakdown. In contrast, myotilin was downregulated, suggesting a weakening of the muscle cytoskeletal structure. There was a notable downregulation of proteins involved in glycolysis and the TCA cycle; conversely, there was an increase in proteins related to anaerobic glycolysis, suggesting a shift from aerobic to anaerobic glycolysis. Furthermore, proteins involved in fatty acid beta-oxidation and oxidative phosphorylation were also found to be upregulated in IT mice, indicating an attempt by the muscle to maximize energy production. Finally, we found a significant decrease in PGC1α, which could serve as potential therapy target and biomarker in CCD.

The transcription factor IIH (TFIIH) is a key player in transcription and DNA repair by nucleotide excision repair. It is made of 10 subunits organized in core-TFIIH and CAK sub-complexes bridged by XPD. Pathogenic variants in the ERCC2/XPD gene give rise to xeroderma pigmentosum (XP) or trichothiodystrophy (TTD), two distinct clinical entities with opposite skin cancer proneness. Here, we show that TTD variants cause a partial dissociation of the CAK from the chromatin and from the core-TFIIH. Mass spectrometry analysis reveals that the chromatin-bound CAK, as a component of the entire TFIIH, participates in a protein assembly containing the RNA-binding proteins DDX1, SFPQ, NONO as well as RNA polymerase II (Pol II). Gene silencing experiments demonstrate that the protein assembly is required to process the DNA:RNA hybrids formed during Pol II extension and to protect the cell from transcriptional stress. TTD-specific variants in ERCC2/XPD result in TFIIH instability, altered interaction of the CAK with DDX1-SFPQ-NONO, and R-loop accumulation. Therefore, the limited amount of TFIIH that distinguishes TTD from XP gives rise to transcriptional stress and extensive gene expression deregulations, thus accounting for the wide spectrum of TTD clinical features.

The production of food with a naturally enriched protein content is a strategic response to the growing global demand for sustainable protein sources. Wood distillate (WD), a by-product of the pyrolysis of woody biomass, has previously been shown to increase the protein concentration and bioavailability in chickpea seeds. Here, we evaluated the effect of 0.5% (v/v) WD soil drenching on chickpea productivity, nutritional profile, and proteomic pattern. WD treatment significantly improved the yield by increasing plant biomass (+144%), number of pods and seeds (+148% and +147%), and seed size (diameter: +6%; weight: +25%). Nutritional analyses revealed elevated levels of soluble proteins (+15%), starch (+11%), fructose (+135%), and polyphenols (+14%) and a greater antioxidant capacity (25%), alongside a reduction in glucose content, albeit not statistically significant, suggesting an unchanged or even lowered glycemic index. Although their concentration decreased, Ca (−31%), K (−12%), P (−5%), and Zn (−14%) in WD-treated plants remained within normal ranges. To preliminary assess the quality and safety of the protein enrichment, a differential proteomic analysis was performed on coarse flours from individual seeds. Despite the higher protein content, the overall protein profiles of the WD-treated seeds showed limited variation, with only a few storage proteins, identified as legumin and vicilin-like isoforms, being differentially abundant. These findings indicate a general protein concentration increase without a major alteration in the proteoform composition or differential protein synthesis. Overall, WD emerged as a promising and sustainable biostimulant for chickpea cultivation, capable of enhancing both yield and nutritional value, while maintaining the proteomic integrity and, bona fide, food safety.

Background: Non-muscle invasive bladder cancer (NMIBC) comprises high-grade (HG) and low-grade (LG) variants, classified by aggressiveness, recurrence risk, and stage—either non-invasive (pTa) or invading the lamina propria (pT1). Cystoscopy remains the diagnostic gold standard, with no less-invasive alternatives, while molecular mechanisms driving tumorigenesis and treatment response are poorly understood. Methods: To address this gap, we conducted a preliminary top-down proteomic study on fresh biopsies from pTa-LG and pT1-HG NMIBC at initial diagnosis to identify molecular differences and potential prognostic biomarkers. Results: Distinct protein profiles were observed between stages. Highly abundant proteins in pT1-HG were associated with nitric oxide biosynthesis, signal transduction, inhibition of apoptosis, protein folding, and immune response. Proteins of low abundance were related to cellular localization, cytoskeleton organization, cell adhesion, phagocytosis, and tissue development. Notably, multiple proteoforms of PDC6I/ALIX, a protein implicated in the regulation of apoptosis, proliferation, and PD-L1 surface presentation, were significantly downregulated in pT1-HG tumors. Furthermore, the abundance of proteins such as GANAB, GALE, THIC, SEPT8, and MYDGF/C19orf10 correlated with tumor size, suggesting their potential as prognostic biomarkers. Conclusions: These proteins, taken together, indicate that they may serve as valuable prognostic markers, offering a path toward more personalized management of NMIBC beyond the traditional one-size-fits-all approach.

Idiopathic pulmonary fibrosis (IPF) is a progressive and debilitating interstitial lung disease characterized by limited therapeutic options, with only two FDA-approved palliative agents currently available. Given its poor prognosis and the high incidence of lung transplantation, there is a pressing need to develop innovative and effective therapeutics. Histone deacetylase 6 (HDAC6) has been identified as a key driver of fibrotic progression in IPF, and selective inhibitors of this isoform were able to revert the fibrotic phenotypes. Proteolysis targeting chimeras (PROTACs) are heterobifunctional molecules that can trigger the degradation of a specific target in cells, including HDAC6 enzyme. Therefore, the application of PROTAC technology may represent a novel therapeutic strategy for IPF. We showcase the design, synthesis, and biological evaluation of a library of first-in-class antifibrotic HDAC6-targeting PROTACs, incorporating our in-house inhibitor 1 as the HDAC6 ligand. Newly developed PROTACs 5a and 5c showed effective degradation of HDAC6 in A549 lung cells and IMR-90 lung fibroblasts. 5a and 5c exhibited significant antifibrotic effects against the TGF-beta 1 induced fibrotic phenotype on IMR-90 cells, a model that mimics IPF conditions. The generation of putative ternary complexes involving PROTAC molecules, the E3-ligase cereblon (CRBN) and the HDAC6 target protein was supported by molecular modelling techniques, including protein-protein docking and molecular dynamics simulations. Mechanistic investigations, based on pull-down experiments, confirmed that the newly synthetized compounds were able to reduce HDAC6 levels through a proteasome-and CRBN-dependent mechanism as confirmed by experiments with neddylation and proteasome inhibitors. This pioneering exploration of targeted protein degradation in IPF-like conditions provides compelling evidence of its therapeutic promise, paving the way for a broader application of PROTACs in treating rare diseases.

Abstract Background The main drawback of BRAF/MEK inhibitors (BRAF/MEKi)-based targeted therapy in the management of BRAF-mutated cutaneous metastatic melanoma (MM) is the development of therapeutic resistance. We aimed to assess in this context the role of mTORC2, a signaling complex defined by the presence of the essential RICTOR subunit, regarded as an oncogenic driver in several tumor types, including MM. Methods After analyzing The Cancer Genome Atlas MM patients’ database to explore both overall survival and molecular signatures as a function of intra-tumor RICTOR levels, we investigated the effects of RICTOR downregulation in BRAFV600E MM cell lines on their response to BRAF/MEKi. We performed proteomic screening to identify proteins modulated by changes in RICTOR expression, and Seahorse analysis to evaluate the effects of RICTOR depletion on mitochondrial respiration. The combination of BRAFi with drugs targeting proteins and processes emerged in the proteomic screening was carried out on RICTOR-deficient cells in vitro and in a xenograft setting in vivo. Results Low RICTOR levels in BRAF-mutated MM correlate with a worse clinical outcome. Gene Set Enrichment Analysis of low-RICTOR tumors display gene signatures suggestive of activation of the mitochondrial Electron Transport Chain (ETC) energy production. RICTOR-deficient BRAFV600E cells are intrinsically tolerant to BRAF/MEKi and anticipate the onset of resistance to BRAFi upon prolonged drug exposure. Moreover, in drug-naïve cells we observed a decline in RICTOR expression shortly after BRAFi exposure. In RICTOR-depleted cells, both mitochondrial respiration and expression of nicotinamide phosphoribosyltransferase (NAMPT) are enhanced, and their pharmacological inhibition restores sensitivity to BRAFi. Conclusions Our work unveils an unforeseen tumor-suppressing role for mTORC2 in the early adaptation phase of BRAFV600E melanoma cells to targeted therapy and identifies the NAMPT-ETC axis as a potential therapeutic vulnerability of low RICTOR tumors. Importantly, our findings indicate that the evaluation of intra-tumor RICTOR levels has a prognostic value in metastatic melanoma and may help to guide therapeutic strategies in a personalized manner.

Muscle tissue is one of the most dynamic and plastic tissues of the mammalian body and covers different roles, such as force generation and metabolic control. Muscular proteomics provides an important opportunity to reveal the molecular mechanisms behind muscle pathophysiology. To ensure successful proteomic analysis, it is necessary to have an efficient and reproducible protein extraction method. This study aimed to evaluate the efficacy of two different extraction protocols of muscle samples for two-dimensional gel electrophoresis. In particular, mouse muscle proteins were extracted by an SDS-based buffer (Method A) and by a UREA/CHAPS/DTE/TRIS solution (Method B). The efficacies of the methods were assessed by performing an image analysis of the 2DE gels and by statistical and multivariate analyses. The 2DE gels in both preparations showed good resolution and good spot overlapping. Methods A and B produced 2DE gels with different means of total spots, higher for B. Image analysis showed different patterns of protein abundance between the protocols. The results showed that the two methods extract and solubilize proteins with different chemical–physical characteristics and different cellular localizations. These results attest the efficacy and reproducibility of both protein extraction methods, which can be parallelly applied for comprehensive proteomic profiling of muscle tissue.

The genome sequencing of the tardigrade Ramazzottius varieornatus revealed a unique nucleosome-binding protein named damage suppressor (Dsup), which was discovered to be crucial for the extraordinary abilities of tardigrades in surviving extreme stresses, such as UV. Evidence in Dsup-transfected human cells suggests that Dsup mediates an overall response in DNA damage signaling, DNA repair, and cell cycle regulation, resulting in an acquired resistance to stress. Given these promising outcomes, our study attempts to provide a wider comprehension of the molecular mechanisms modulated by Dsup in human cells and to explore the Dsup-activated molecular pathways under stress. We performed a differential proteomic analysis of Dsup-transfected and control human cells under basal conditions and at 24 h recovery after exposure to UV-C. We demonstrate via enrichment and network analyses, for the first time, that even in the absence of external stimuli, and more significantly, after stress, Dsup activates mechanisms involved with the unfolded protein response, the mRNA processing and stability, cytoplasmic stress granules, the DNA damage response, and the telomere maintenance. In conclusion, our results shed new light on Dsup-mediated protective mechanisms and increases our knowledge of the molecular machineries of extraordinary protection against UV-C stress.

Idiopathic pulmonary fibrosis (IPF) is a form of chronic and irreversible fibrosing interstitial pneumonia of unknown etiology. Although antifibrotic treatments have shown a reduction of lung function decline and a slow disease progression, IPF is characterize by a very high mortality. Emerging evidence suggests that IPF increases the risk of lung carcinogenesis. Both diseases show similarities in terms of risk factors, such as history of smoking, concomitant emphysema, and viral infections, besides sharing similar pathogenic pathways. Lung cancer (LC) diagnosis is often difficult in IPF patients because of the diffuse lung injuries and abnormalities due to the underlying fibrosis. This is reflected in the lack of optimal therapeutic strategies for patients with both diseases. For this purpose, we performed a proteomic study on bronchoalveolar lavage fluid (BALF) samples from IPF, LC associated with IPF (LC-IPF) patients, and healthy controls (CTRL). Molecular pathways involved in inflammation, immune response, lipid metabolism, and cell adhesion were found for the dysregulated proteins in LC-IPF, such as TTHY, APOA1, S10A9, RET4, GDIR1, and PROF1. The correlation test revealed a relationship between inflammation- and lipid metabolism-related proteins. PROF1 and S10A9, related to inflammation, were up-regulated in LC-IPF BAL and serum, while APOA1 and APOE linked to lipid metabolism, were highly abundant in IPF BAL and low abundant in IPF serum. Given the properties of cytokine/adipokine of the nicotinamide phosphoribosyltransferase, we also evaluated its serum abundance, highlighting its down-regulation in LC-IPF. Our retrospective analyses of BAL samples extrapolated some potential biomarkers of LC-IPF useful to improve the management of these contemporary pathologies. Their differential abundance in serum samples permits the measurement of these potential biomarkers with a less invasive procedure.

Today application of sewage sludge (SL) and hydrochar (HC) in agriculture is a common practice for soil conditioning and crop fertilization, however safety concerns for human and environmental health due to the presence of toxic compounds have recently been expressed. Our aim was to test the suitability of proteomics coupled with bioanalytical tools for unravelling mixture effects of these applications in human and environmental safety assessment. We conducted proteomic and bioinformatic analysis of cell cultures used in the DR-CALUX® bioassay to identify proteins differentially abundant after exposure to SL and the corresponding HC, rather than only using the Bioanalytical Toxicity Equivalents (BEQs) obtained by DR-CALUX®. DR-CALUX® cells exposed to SL or HC showed a differential pattern of protein abundance depending on the type of SL and HC extract. The modified proteins are involved in antioxidant pathways, unfolded protein response and DNA damage that have close correlations with the effects of dioxin on biological systems and with onset of cancer and neurological disorders. Other cell response evidence suggested enrichment of heavy metals in the extracts. The present combined approach represents an advance in the application of bioanalytical tools for safety assessment of complex mixtures such as SL and HC. It proved successful in screening proteins, the abundance of which is determined by SL and HC and by the biological activity of legacy toxic compounds, including organohalogens.

Epiretinal membranes (ERMs) are sheets of tissue that pathologically develop in the vitreoretinal interface leading to progressive vision loss. They are formed by different cell types and by an exuberant deposition of extracellular matrix proteins. Recently, we reviewed ERMs’ extracellular matrix components to better understand molecular dysfunctions that trigger and fuel the onset and development of this disease. The bioinformatics approach we applied delineated a comprehensive overview on this fibrocellular tissue and on critical proteins that could really impact ERM physiopathology. Our interactomic analysis proposed the hyaluronic-acid-receptor cluster of differentiation 44 (CD44) as a central regulator of ERM aberrant dynamics and progression. Interestingly, the interaction between CD44 and podoplanin (PDPN) was shown to promote directional migration in epithelial cells. PDPN is a glycoprotein overexpressed in various cancers and a growing body of evidence indicates its relevant function in several fibrotic and inflammatory pathologies. The binding of PDPN to partner proteins and/or its ligand results in the modulation of signaling pathways regulating proliferation, contractility, migration, epithelial–mesenchymal transition, and extracellular matrix remodeling, all processes that are vital in ERM formation. In this context, the understanding of the PDPN role can help to modulate signaling during fibrosis, hence opening a new line of therapy.

The monotherapy with levo-thyroxine (LT4) is the treatment of choice for patients with hypothyroidism after thyroidectomy. However, many athyreotic LT4-treated patients with thyroid hormones in the physiological range experience hypothyroid-like symptoms, showing post-operative, statistically significant lower FT3 levels with respect to that before total thyroidectomy. Since we hypothesized that the lower plasmatic FT3 levels observed in this subgroup could be associated with tissue hypothyroidism, here we compared, by a preliminary proteomic analysis, eight sera of patients with reduced post-surgical FT3 to eight sera from patients with FT3 levels similar to pre-surgery levels, and six healthy controls. Proteomic analysis highlights a different serum protein profile among the considered conditions. By enrichment analysis, differential proteins are involved in coagulation processes (PLMN-1.61, -1.98 in reduced vs. stable FT3, p < 0.02; A1AT fragmentation), complement system activation (CFAH + 1.83, CFAB + 1.5, C1Qb + 1.6, C1S + 7.79 in reduced vs. stable FT3, p < 0.01) and in lipoprotein particles remodeling (APOAI fragmentation; APOAIV + 2.13, p < 0.003), potentially leading to a pro-inflammatory response. This study suggests that LT4 replacement therapy might restore biochemical euthyroid conditions in thyroidectomized patients, but in some cases without re-establishing body tissue euthyroidism. Since our results, this condition is reflected by the serum protein profile.

Idiopathic epiretinal membranes (iERMs) are fibrocellular sheets of tissue that develop at the vitreoretinal interface. The iERMs consist of cells and an extracellular matrix (ECM) formed by a complex array of structural proteins and a large number of proteins that regulate cell–matrix interaction, matrix deposition and remodelling. Many components of the ECM tend to produce a layered pattern that can influence the tractional properties of the membranes. We applied a bioinformatics approach on a list of proteins previously identified with an MS-based proteomic analysis on samples of iERM to report the interactome of some key proteins. The performed pathway analysis highlights interactions occurring among ECM molecules, their cell receptors and intra- or extracellular proteins that may play a role in matrix biology in this special context. In particular, integrin β1, cathepsin B, epidermal growth factor receptor, protein-glutamine gamma-glutamyltransferase 2 and prolow-density lipoprotein receptor-related protein 1 are key hubs in the outlined protein–protein cross-talks. A section on the biomarkers that can be found in the vitreous humor of patients affected by iERM and that can modulate matrix deposition is also presented. Finally, translational medicine in iERM treatment has been summed up taking stock of the techniques that have been proposed for pharmacologic vitreolysis.

Krabbe disease (KD) is a rare autosomal recessive disorder caused by mutations in the galactocerebrosidase gene (GALC). Defective GALC causes aberrant metabolism of galactolipids present almost exclusively in myelin, with consequent demyelinization and neurodegeneration of the central and peripheral nervous system (NS). KD shares some similar features with other neuropathies and heterozygous carriers of GALC mutations are emerging with an increased risk in developing NS disorders. In this work, we set out to identify possible variations in the proteomic profile of KD-carrier brain to identify altered pathways that may imbalance its homeostasis and that may be associated with neurological disorders. The differential analysis performed on whole brains from 33-day-old twitcher (galc −/−), heterozygous (galc +/−), and wild-type mice highlighted the dysregulation of several multifunctional factors in both heterozygous and twitcher mice. Notably, the KD-carrier mouse, despite its normal phenotype, presents the deregulation of vimentin, receptor of activated protein C kinase 1 (RACK1), myelin basic protein (MBP), 2′,3′-cyclic-nucleotide 3′-phosphodiesterase (CNP), transitional endoplasmic reticulum ATPase (VCP), and N-myc downstream regulated gene 1 protein (NDRG1) as well as changes in the ubiquitinated-protein pattern. Our findings suggest the carrier may be affected by dysfunctions classically associated with neurodegeneration: (i) alteration of (mechano) signaling and intracellular trafficking, (ii) a generalized affection of proteostasis and lipid metabolism, with possible defects in myelin composition and turnover, and (iii) mitochondrion and energy supply dysfunctions.

The principal aim of the present study was to develop and apply novel ex vivo tests as an alternative to cell cultures able to evaluate the possible effects of emerging and legacy contaminants in Caretta caretta. To this end, we performed ex vivo experiments on non-invasively collected whole-blood and skin-biopsy slices treated with chrysene, MEHP, or PBDE-47. Blood samples were tested by oxidative stress (TAS), immune system (respiratory burst, lysozyme, and complement system), and genotoxicity (ENA assay) biomarkers, and genotoxic and immune system effects were observed. Skin slices were analyzed by applying a 2D-PAGE/MS proteomic approach, and specific contaminant signatures were delineated on the skin proteomic profile. These reflect biochemical effects induced by each treatment and allowed to identify glutathione S-transferase P, peptidyl-prolyl cis-trans isomerase A, mimecan, and protein S100-A6 as potential biomarkers of the health-threatening impact the texted toxicants have on C. caretta. Obtained results confirm the suitability of the ex vivo system and indicate the potential risk the loggerhead sea turtle is undergoing in the natural environment. In conclusion, this work proved the relevance that the applied ex vivo models may have in testing the toxicity of other compounds and mixtures and in biomarker discovery.