Gut microbiota Turicibacter strains differentially modify bile acids and host lipids.

Bacteria from the Turicibacter genus are prominent members of the mammalian gut microbiota and correlate with alterations in dietary fat and body weight, but the specific connections between these symbionts and host physiology are poorly understood. To address this knowledge gap, we characterize a diverse set of mouse- and human-derived Turicibacter isolates, and find they group into clades that differ in their transformations of specific bile acids. We identify Turicibacter bile salt hydrolases that confer strain-specific differences in bile deconjugation. Using male and female gnotobiotic mice, we find colonization with individual Turicibacter strains leads to changes in host bile acid profiles, generally aligning with those produced in vitro. Further, colonizing mice with another bacterium exogenously expressing bile-modifying genes from Turicibacter strains decreases serum cholesterol, triglycerides, and adipose tissue mass. This identifies genes that enable Turicibacter strains to modify host bile acids and lipid metabolism, and positions Turicibacter bacteria as modulators of host fat biology.

Improved Chromatography and MS-Based Detection of Glyphosate and Aminomethylphosphonic Acid Using iTrEnDi.

Glyphosate (GLY), a synthetic, nonselective systemic herbicide that is particularly effective against perennial weeds, is the most used weedkiller in the world. There are growing concerns over GLY accumulation in the environment and the attendant human health-associated risks, and despite increased attention in the media, GLY and its breakdown product aminomethylphosphonic acid (AMPA) remain elusive to many analytical strategies. Chemical derivatization coupled with high-performance liquid chromatography-mass spectrometry (HPLC-MS) addresses the challenge of quantifying low levels of GLY and AMPA in complex samples. Here we demonstrate the use of in situ trimethylation enhancement using diazomethane (iTrEnDi) to derivatize GLY and AMPA into permethylated products ([GLYTr]+ and [AMPATr]+, respectively) prior to analysis via HPLC-MS. iTrEnDi produced quantitative yields and resulted in a 12-340-fold increases in HPLC-MS-based sensitivity for [GLYTr]+ and [AMPATr]+, respectively, compared with underivatized counterparts. The limits of detection of derivatized compounds were found to be 0.99 ng/L for [GLYTr]+ and 1.30 ng/L for [AMPATr]+, demonstrating significant sensitivity improvements compared to previously established derivatization techniques. iTrEnDi is compatible with the direct derivatization of Roundup formulations. Finally, as proof of principle, a simple aqueous extraction followed by iTrEnDi enabled the detection of [GLYTr]+ and [AMPATr]+ on the exterior of field-grown soybeans that were sprayed with Roundup. Overall, iTrEnDi ameliorates issues relating to low proton affinity and chromatographic retention, boosting HPLC-MS-based sensitivity and enabling the elucidation of elusive analytes such as GLY and AMPA within agricultural systems.

Tissue-engineered vocal fold replacement in swine: Methods for functional and structural analysis.

We have developed a cell-based outer vocal fold replacement (COVR) as a potential therapy to improve voice quality after vocal fold (VF) injury, radiation, or tumor resection. The COVR consists of multipotent human adipose-derived stem cells (hASC) embedded within a three-dimensional fibrin scaffold that resembles vocal fold epithelium and lamina propria layers. Previous work has shown improved wound healing in rabbit studies. In this pilot study in pigs, we sought to develop methods for large animal implantation and phonatory assessment. Feasibility, safety, and structural and functional outcomes of the COVR implant are described. Of eight pigs studied, six animals underwent COVR implantation with harvest between 2 weeks and 6 months. Recovery of laryngeal tissue structure was assessed by vibratory and histologic analyses. Recovery of voice function was assessed by investigating acoustic parameters that were derived specifically for pigs. Results showed improved lamina propria qualities relative to an injured control animal at 6 months. Acoustic parameters reflected voice worsening immediately after surgery as expected; acoustics displayed clear voice recovery in the animal followed for 6 months after COVR. These methods form the basis for a larger-scale long-term pre-clinical safety and efficacy study.

Small molecules disaggregate alpha-synuclein and prevent seeding from patient brain-derived fibrils.

The amyloid aggregation of alpha-synuclein within the brain is associated with the pathogenesis of Parkinson's disease (PD) and other related synucleinopathies, including multiple system atrophy (MSA). Alpha-synuclein aggregates are a major therapeutic target for treatment of these diseases. We identify two small molecules capable of disassembling preformed alpha-synuclein fibrils. The compounds, termed CNS-11 and CNS-11g, disaggregate recombinant alpha-synuclein fibrils in vitro, prevent the intracellular seeded aggregation of alpha-synuclein fibrils, and mitigate alpha-synuclein fibril cytotoxicity in neuronal cells. Furthermore, we demonstrate that both compounds disassemble fibrils extracted from MSA patient brains and prevent their intracellular seeding. They also reduce in vivo alpha-synuclein aggregates in C. elegans. Both compounds also penetrate brain tissue in mice. A molecular dynamics-based computational model suggests the compounds may exert their disaggregating effects on the N terminus of the fibril core. These compounds appear to be promising therapeutic leads for targeting alpha-synuclein for the treatment of synucleinopathies.

Genistein Inhibits Clostridioides difficile Infection via Estrogen Receptors and Lysine-Deficient Protein Kinase 1.

BACKGROUND: Clostridioides difficile infection (CDI) is a debilitating nosocomial disease. Postmenopausal women may have an increased risk of CDI, suggesting estrogen influence. Soybean products contain a representative estrogenic isoflavone, genistein. METHODS: The anti-inflammatory and antiapoptotic effects of genistein were determined using primary human cells and fresh colonic tissues. The effects of oral genistein therapy among mice and hamsters were evaluated. RESULTS: Within 10 days of CDI, female c57BL/6J mice in a standard environment (regular diet) had a 50% survival rate, while those with estrogen depletion and in an isoflavone-free environment (soy-free diet) had a 25% survival rate. Oral genistein improved their 10-day survival rate to 100% on a regular diet and 75% in an isoflavone-free environment. Genistein reduced macrophage inflammatory protein-1α (MIP-1α) secretion in fresh human colonic tissues exposed to toxins. Genistein inhibited MIP-1α secretion in primary human peripheral blood mononuclear cells, abolished apoptosis and BCL-2-associated X (BAX) expression in human colonic epithelial cells, and activated lysine-deficient protein kinase 1 (WNK1) phosphorylation in both cell types. The anti-inflammatory and antiapoptotic effects of genistein were abolished by inhibiting estrogen receptors and WNK1. CONCLUSIONS: Genistein reduces CDI disease activity by inhibiting proinflammatory cytokine expression and apoptosis via the estrogen receptor/G-protein estrogen receptor/WNK1 pathways.

Low-dose exposure to PBDE disrupts genomic integrity and innate immunity in mammary tissue.

The low-dose mixture hypothesis of carcinogenesis proposes that exposure to an environmental chemical that is not individually oncogenic may nonetheless be capable of enabling carcinogenesis when it acts in concert with other factors. A class of ubiquitous environmental chemicals that are hypothesized to potentially function in this low-dose capacity are synthesized polybrominated diphenyl ethers (PBDEs). PBDEs can affect correlates of carcinogenesis that include genomic instability and inflammation. However, the effect of low-dose PBDE exposure on such correlates in mammary tissue has not been examined. In the present study, low-dose long-term (16 weeks) administration of PBDE to mice modulated transcriptomic indicators of genomic integrity and innate immunity in normal mammary tissue. PBDE increased transcriptome signatures for the Nuclear Factor Erythroid 2 Like 2 (NFE2L2) response to oxidative stress and decreased signatures for non-homologous end joining DNA repair (NHEJ). PBDE also decreased transcriptome signatures for the cyclic GMP-AMP Synthase - Stimulator of Interferon Genes (cGAS-STING) response, decreased indication of Interferon Stimulated Gene Factor 3 (ISGF3) and Nuclear Factor Kappa B (NF-κB) transcription factor activity, and increased digital cytometry estimates of immature dendritic cells (DCs) in mammary tissue. Replication of the PBDE exposure protocol in mice susceptible to mammary carcinogenesis resulted in greater tumor development. The results support the notion that ongoing exposure to low levels of PBDE can disrupt facets of genomic integrity and innate immunity in mammary tissue. Such effects affirm that synthesized PBDEs are a class of environmental chemicals that reasonably fit the low-dose mixture hypothesis.

Integrated Multiomics Analysis of Salivary Exosomes to Identify Biomarkers Associated with Changes in Mood States and Fatigue.

Fatigue and other deleterious mood alterations resulting from prolonged efforts such as a long work shift can lead to a decrease in vigilance and cognitive performance, increasing the likelihood of errors during the execution of attention-demanding activities such as piloting an aircraft or performing medical procedures. Thus, a method to rapidly and objectively assess the risk for such cognitive fatigue would be of value. The objective of the study was the identification in saliva-borne exosomes of molecular signals associated with changes in mood and fatigue that may increase the risk of reduced cognitive performance. Using integrated multiomics analysis of exosomes from the saliva of medical residents before and after a 12 h work shift, we observed changes in the abundances of several proteins and miRNAs that were associated with various mood states, and specifically fatigue, as determined by a Profile of Mood States questionnaire. The findings herein point to a promising protein biomarker, phosphoglycerate kinase 1 (PGK1), that was associated with fatigue and displayed changes in abundance in saliva, and we suggest a possible biological mechanism whereby the expression of the PGK1 gene is regulated by miR3185 in response to fatigue. Overall, these data suggest that multiomics analysis of salivary exosomes has merit for identifying novel biomarkers associated with changes in mood states and fatigue. The promising biomarker protein presents an opportunity for the development of a rapid saliva-based test for the assessment of these changes.

Arachidonic acid metabolism and inflammatory biomarkers associated with exposure to polycyclic aromatic hydrocarbons.

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with systemic inflammation, yet what mechanisms regulate PAHs' inflammatory effects are less understood. This study evaluated the change of arachidonic acid (ARA) metabolites and inflammatory biomarkers in response to increased exposure to PAHs among 26 non-smoking healthy travelers from Los Angeles to Beijing. Traveling from Los Angeles to Beijing significantly increased urinary metabolites of dibenzofuran (800%), fluorene (568%), phenanthrene (277%), and pyrene (176%), accompanied with increased C-reactive protein, fibrinogen, IL-8, and IL-10, and decreased MCP-1, sCD40L, and sCD62P levels in the blood. Meanwhile, the travel increased the levels of ARA lipoxygenase metabolites that were positively associated with a panel of pro-inflammatory biomarkers. Concentrations of cytochrome P450 metabolite were also increased in Beijing and were negatively associated with sCD62P levels. In contrast, concentrations of ARA cyclooxygenase metabolites were decreased in Beijing and were negatively associated with anti-inflammatory IL-10 levels. Changes in both inflammatory biomarkers and ARA metabolites were reversed 4-7 weeks after participants returned to Los Angeles and were associated with urinary PAH metabolites, but not with other exposures such as secondhand smoke, stress, or diet. These results suggested possible roles of ARA metabolic alteration in PAHs-associated inflammatory effects.

Cardiomyocytes disrupt pyrimidine biosynthesis in nonmyocytes to regulate heart repair.

Various populations of cells are recruited to the heart after cardiac injury, but little is known about whether cardiomyocytes directly regulate heart repair. Using a murine model of ischemic cardiac injury, we demonstrate that cardiomyocytes play a pivotal role in heart repair by regulating nucleotide metabolism and fates of nonmyocytes. Cardiac injury induced the expression of the ectonucleotidase ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which hydrolyzes extracellular ATP to form AMP. In response to AMP, cardiomyocytes released adenine and specific ribonucleosides that disrupted pyrimidine biosynthesis at the orotidine monophosphate (OMP) synthesis step and induced genotoxic stress and p53-mediated cell death of cycling nonmyocytes. As nonmyocytes are critical for heart repair, we showed that rescue of pyrimidine biosynthesis by administration of uridine or by genetic targeting of the ENPP1/AMP pathway enhanced repair after cardiac injury. We identified ENPP1 inhibitors using small molecule screening and showed that systemic administration of an ENPP1 inhibitor after heart injury rescued pyrimidine biosynthesis in nonmyocyte cells and augmented cardiac repair and postinfarct heart function. These observations demonstrate that the cardiac muscle cell regulates pyrimidine metabolism in nonmuscle cells by releasing adenine and specific nucleosides after heart injury and provide insight into how intercellular regulation of pyrimidine biosynthesis can be targeted and monitored for augmenting tissue repair.

Accumulation of Seminolipid in Sertoli Cells Is Associated with Increased Levels of Reactive Oxygen Species and Male Subfertility: Studies in Aging Arsa Null Male Mice.

Seminolipid (also known as sulfogalactosylglycerolipid-SGG), present selectively in male germ cells, plays important roles in spermatogenesis and sperm-egg interaction. The proper degradation of SGG in apoptotic germ cells is also as important. Sertoli cells first phagocytose apoptotic germ cells, then Sertoli lysosomal arylsulfatase A (ARSA) desulfates SGG, the first step of SGG degradation. We have reported that aging male Arsa-/- mice become subfertile with SGG accumulation in Sertoli cell lysosomes, typical of a lysosomal storage disorder (LSD). Since reactive oxygen species (ROS) levels are increased in other glycolipid-accumulated LSDs, we quantified ROS in Arsa-/- Sertoli cells. Our analyses indicated increases in superoxide and H2O2 in Arsa-/- Sertoli cells with elevated apoptosis rates, relative to WT counterparts. Excess H2O2 from Arsa-/- Sertoli cells could travel into testicular germ cells (TGCs) to induce ROS production. Our results indeed indicated higher superoxide levels in Arsa-/- TGCs, compared with WT TGCs. Increased ROS levels in Arsa-/- Sertoli cells and TGCs likely caused the decrease in spermatogenesis and increased the abnormal sperm population in aging Arsa-/- mice, including the 50% decrease in sperm SGG with egg binding ability. In summary, our study indicated that increased ROS production was the mechanism through which subfertility manifested following SGG accumulation in Sertoli cells.

Carbon Monoxide Inhibits Cytochrome P450 Enzymes CYP3A4/2C8 in Human Breast Cancer Cells, Increasing Sensitivity to Paclitaxel.

Paclitaxel (PTX) is a first-line treatment in breast cancer, though resistance develops quickly and frequently. Cytochrome P450 enzymes CYP3A4 and CYP2C8, which metabolically inactivate PTX in hepatic tissue, are overexpressed in malignant breast tissues. CYP3A4 expression correlates with PTX therapy failure and poor outcomes, though no direct evidence of CYP3A4 contributing to PTX sensitivity exists. Because CYP3A4/2C8 is susceptible to carbon monoxide (CO)-mediated inhibition and CO (a gaseous signaling molecule) has previously exhibited drug-sensitizing effects in cancer cells, we hypothesized that CO-mediated inhibition of CYP3A4/2C8 could lead to enhanced drug sensitivity. Using a photo-activated CO-releasing molecule, we have assessed the ability of CO to alter the pharmacokinetics of PTX in breast cancer cells via inhibition of CYP3A4/2C8 and determined that CO does enhance sensitivity of breast cancer cells to PTX. Inhibition of CYP3A4/2C8 by CO could therefore be a promising therapeutic strategy to enhance PTX response in breast cancer.

Electronic and Tobacco Cigarettes Alter Polyunsaturated Fatty Acids and Oxidative Biomarkers.

[Figure: see text].

Skeletal muscle regeneration via the chemical induction and expansion of myogenic stem cells in situ or in vitro.

Muscle loss and impairment resulting from traumatic injury can be alleviated by therapies using muscle stem cells. However, collecting sufficient numbers of autologous myogenic stem cells and expanding them efficiently has been challenging. Here we show that myogenic stem cells (predominantly Pax7+ cells)-which were selectively expanded from readily obtainable dermal fibroblasts or skeletal muscle stem cells using a specific cocktail of small molecules and transplanted into muscle injuries in adult, aged or dystrophic mice-led to functional muscle regeneration in the three animal models. We also show that sustained release of the small-molecule cocktail in situ through polymer nanoparticles led to muscle repair by inducing robust activation and expansion of resident satellite cells. Chemically induced stem cell expansion in vitro and in situ may prove to be advantageous for stem cell therapies that aim to regenerate skeletal muscle and other tissues.

Immortalized stem cell-derived hepatocyte-like cells: An alternative model for studying dengue pathogenesis and therapy.

Suitable cell models are essential to advance our understanding of the pathogenesis of liver diseases and the development of therapeutic strategies. Primary human hepatocytes (PHHs), the most ideal hepatic model, are commercially available, but they are expensive and vary from lot-to-lot which confounds their utility. We have recently developed an immortalized hepatocyte-like cell line (imHC) from human mesenchymal stem cells, and tested it for use as a substitute model for hepatotropic infectious diseases. With a special interest in liver pathogenesis of viral infection, herein we determined the suitability of imHC as a host cell target for dengue virus (DENV) and as a model for anti-viral drug testing. We characterized the kinetics of DENV production, cellular responses to DENV infection (apoptosis, cytokine production and lipid droplet metabolism), and examined anti-viral drug effects in imHC cells with comparisons to the commonly used hepatoma cell lines (HepG2 and Huh-7) and PHHs. Our results showed that imHC cells had higher efficiencies in DENV replication and NS1 secretion as compared to HepG2 and Huh-7 cells. The kinetics of DENV infection in imHC cells showed a slower rate of apoptosis than the hepatoma cell lines and a certain similarity of cytokine profiles to PHHs. In imHC, DENV-induced alterations in levels of lipid droplets and triacylglycerols, a major component of lipid droplets, were more apparent than in hepatoma cell lines, suggesting active lipid metabolism in imHC. Significantly, responses to drugs with DENV inhibitory effects were greater in imHC cells than in HepG2 and Huh-7 cells. In conclusion, our findings suggest superior suitability of imHC as a new hepatocyte model for studying mechanisms underlying viral pathogenesis, liver diseases and drug effects.

Development of a Potent Brain-Penetrant EGFR Tyrosine Kinase Inhibitor against Malignant Brain Tumors.

The epidermal growth factor receptor (EGFR) is genetically altered in nearly 60% of glioblastoma tumors; however, tyrosine kinase inhibitors (TKIs) against EGFR have failed to show efficacy for patients with these lethal brain tumors. This failure is attributed to the inability of clinically tested EGFR TKIs to cross the blood-brain barrier (BBB) and achieve adequate pharmacological levels to inhibit various oncogenic forms of EGFR that drive glioblastoma. Through SAR analysis, we developed compound 5 (JCN037) from an anilinoquinazoline scaffold by ring fusion of the 6,7-dialkoxy groups to reduce the number of rotatable bonds and polar surface area and by introduction of an ortho-fluorine and meta-bromine on the aniline ring for improved potency and BBB penetration. Relative to the conventional EGFR TKIs erlotinib and lapatinib, JCN037 displayed potent activity against EGFR amplified/mutant patient-derived cell cultures, significant BBB penetration (2:1 brain-to-plasma ratio), and superior efficacy in an EGFR-driven orthotopic glioblastoma xenograft model.

A sensitive LC-MS assay using derivatization with boron trifluoride to quantify curcuminoids in biological samples.

A procedure is described to measure curcumin (C), demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC), tetrahydrocurcumim (TC) and their glucuronidated metabolites (CG, DMCG, and BDMCG) in plasma, brain, liver and tumor samples. The procedure involves converting the analytes to their boron difluoride derivatives and analyzing them by combined liquid chromatography coupled to an ion trap mass spectrometer operating in the negative ion MSn scan mode. The method has superb limits of detection of 0.01 nM for all curcuminoids and 0.5 nM for TC and the glucuroniated metabolites, and several representative chromatograms of biological samples containing these analytes are provided. In addition, the pharmacokinetic profile of these compounds in one human who daily consumed an over-the-counter curcuminoid product shows the peak and changes in circulating concentrations achieved by this mode of administration.

A randomized, phase 1, placebo-controlled trial of APG-157 in oral cancer demonstrates systemic absorption and an inhibitory effect on cytokines and tumor-associated microbes.

BACKGROUND: Although curcumin's effect on head and neck cancer has been studied in vitro and in vivo, to the authors' knowledge its efficacy is limited by poor systemic absorption from oral administration. APG-157 is a botanical drug containing multiple polyphenols, including curcumin, developed under the US Food and Drug Administration's Botanical Drug Development, that delivers the active components to oromucosal tissues near the tumor target. METHODS: A double-blind, randomized, placebo-controlled, phase 1 clinical trial was conducted with APG-157 in 13 normal subjects and 12 patients with oral cancer. Two doses, 100 mg or 200 mg, were delivered transorally every hour for 3 hours. Blood and saliva were collected before and 1 hour, 2 hours, 3 hours, and 24 hours after treatment. Electrocardiograms and blood tests did not demonstrate any toxicity. RESULTS: Treatment with APG-157 resulted in circulating concentrations of curcumin and analogs peaking at 3 hours with reduced IL-1ß, IL-6, and IL-8 concentrations in the salivary supernatant fluid of patients with cancer. Salivary microbial flora analysis showed a reduction in Bacteroidetes species in cancer subjects. RNA and immunofluorescence analyses of tumor tissues of a subject demonstrated increased expression of genes associated with differentiation and T-cell recruitment to the tumor microenvironment. CONCLUSIONS: The results of the current study suggested that APG-157 could serve as a therapeutic drug in combination with immunotherapy. LAY SUMMARY: Curcumin has been shown to suppress tumor cells because of its antioxidant and anti-inflammatory properties. However, its effectiveness has been limited by poor absorption when delivered orally. Subjects with oral cancer were given oral APG-157, a botanical drug containing multiple polyphenols, including curcumin. Curcumin was found in the blood and in tumor tissues. Inflammatory markers and Bacteroides species were found to be decreased in the saliva, and immune T cells were increased in the tumor tissue. APG-157 is absorbed well, reduces inflammation, and attracts T cells to the tumor, suggesting its potential use in combination with immunotherapy drugs.

Primary Sertoli Cell Cultures From Adult Mice Have Different Properties Compared With Those Derived From 20-Day-Old Animals.

Cultures of Sertoli cells isolated from 20-day-old mice are widely used in research as substitutes for adult Sertoli cell cultures. This practice is based on the fact that Sertoli cells cease to proliferate and become mature in vivo by 16 to 20 days after birth. However, it is important to verify whether cultured Sertoli cells derived from 20-day-old mice do not proliferate ex vivo and whether they have the same properties as cultured adult Sertoli cells. Herein we described an isolation/culture method of Sertoli cells from 10-week-old adult mice with > 90% purity. Properties of these cultured adult Sertoli cells were then compared with those of cultured Sertoli cells derived from 20-day-old mice (also > 90% purity). By cell counting, bromo-2-deoxyuridine incorporation, and metaphase plate detection, we demonstrated that only adult Sertoli cells did not proliferate throughout 12 culture days. In contrast, Sertoli cells derived from 20-day-old mice still proliferated until Day 10 in culture. The morphology and profiles of intracellular lipidomics and spent medium proteomics of the 2 cultures were also different. Cultured adult Sertoli cells were larger in size and contained higher levels of triacylglycerols, cholesteryl esters, and seminolipid, and the proteins in their spent medium were mainly engaged in cellular metabolism. In contrast, proteins involved in cell division, including anti-Mullerian hormone, cell division cycle protein 42 (CDC42), and collagen isoforms, were at higher levels in Sertoli cell cultures derived from 20-day-old mice. Therefore, cultured Sertoli cells derived from 10-week-old mice, rather than those from 20-day-old animals, should be used for studies on properties of adult Sertoli cells.

The mechanism of ß-N-methylamino-l-alanine inhibition of tRNA aminoacylation and its impact on misincorporation.

ß-N-methylamino-l-alanine (BMAA) is a nonproteinogenic amino acid that has been associated with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD). BMAA has been found in human protein extracts; however, the mechanism by which it enters the proteome is still unclear. It has been suggested that BMAA is misincorporated at serine codons during protein synthesis, but direct evidence of its cotranslational incorporation is currently lacking. Here, using LC-MS-purified BMAA and several biochemical assays, we sought to determine whether any aminoacyl-tRNA synthetase (aaRS) utilizes BMAA as a substrate for aminoacylation. Despite BMAA's previously predicted misincorporation at serine codons, following a screen for amino acid activation in ATP/PPi exchange assays, we observed that BMAA is not a substrate for human seryl-tRNA synthetase (SerRS). Instead, we observed that BMAA is a substrate for human alanyl-tRNA synthetase (AlaRS) and can form BMAA-tRNAAla by escaping from the intrinsic AlaRS proofreading activity. Furthermore, we found that BMAA inhibits both the cognate amino acid activation and the editing functions of AlaRS. Our results reveal that, in addition to being misincorporated during translation, BMAA may be able to disrupt the integrity of protein synthesis through multiple different mechanisms.

Extracellular Vesicles From Auditory Cells as Nanocarriers for Anti-inflammatory Drugs and Pro-resolving Mediators.

Drug- and noise-related hearing loss are both associated with inflammatory responses in the inner ear. We propose that intracochlear delivery of a combination of pro-resolving mediators, specialized proteins and lipids that accelerate the return to homeostasis by modifying the immune response rather than by inhibiting inflammation, might have a profound effect on the prevention of sensorineural hearing loss. However, intracochlear delivery of such agents requires a reliable and effective method to convey them, fully active, directly to the target cells. The present study provides evidence that extracellular vesicles (EVs) from auditory HEI-OC1 cells may incorporate significant quantities of anti-inflammatory drugs, pro-resolving mediators and their polyunsaturated fatty acid precursors as cargo, and potentially could work as carriers for their intracochlear delivery. EVs generated by HEI-OC1 cells were divided by size into two fractions, small (≤150 nm diameter) and large (>150 nm diameter), and loaded with aspirin, lipoxin A4, resolvin D1, and the polyunsaturated fatty acids (PUFA) arachidonic, eicosapentaenoic, docosahexanoic, and linoleic. Bottom-up proteomics revealed a differential distribution of selected proteins between small and large vesicles. Only 17.4% of these proteins were present in both fractions, whereas 61.5% were unique to smaller vesicles and only 3.7% were exclusively found in the larger ones. Importantly, the pro-resolving protein mediators Annexin A1 and Galectins 1 and 3 were only detected in small vesicles. Lipidomic studies, on the other hand, showed that small vesicles contained higher levels of eicosanoids than large ones and, although all of them incorporated the drugs and molecules investigated, small vesicles were more efficiently loaded with PUFA and the large ones with aspirin, LXA4 and resolvin D1. Importantly, our data indicate that the vesicles contain all necessary enzymatic components for the de novo generation of eicosanoids from fatty acid precursors, including pro-inflammatory agents, suggesting that their cargo should be carefully tailored to avoid interference with their therapeutic purpose. Altogether, these results support the idea that both small and large EVs from auditory HEI-OC1 cells could be used as nanocarriers for anti-inflammatory drugs and pro-resolving mediators.