Metagenomic analysis of carbohydrate-active enzymes and their contribution to marine sediment biodiversity.

Marine sediments constitute the world's most substantial long-term carbon repository. The microorganisms dwelling in these sediments mediate the transformation of fixed oceanic carbon, but their contribution to the carbon cycle is not fully understood. Previous culture-independent investigations into sedimentary microorganisms have underscored the significance of carbohydrates in the carbon cycle. In this study, we employ a metagenomic methodology to investigate the distribution and abundance of carbohydrate-active enzymes (CAZymes) in 37 marine sediments sites. These sediments exhibit varying oxygen availability and were isolated in diverse regions worldwide. Our comparative analysis is based on the metabolic potential for oxygen utilisation, derived from genes present in both oxic and anoxic environments. We found that extracellular CAZyme modules targeting the degradation of plant and algal detritus, necromass, and host glycans were abundant across all metagenomic samples. The analysis of these results indicates that the oxic/anoxic conditions not only influence the taxonomic composition of the microbial communities, but also affect the occurrence of CAZyme modules involved in the transformation of necromass, algae and plant detritus. To gain insight into the sediment microbial taxa, we reconstructed metagenome assembled genomes (MAG) and examined the presence of primary extracellular carbohydrate active enzyme (CAZyme) modules. Our findings reveal that the primary CAZyme modules and the CAZyme gene clusters discovered in our metagenomes were prevalent in the Bacteroidia, Gammaproteobacteria, and Alphaproteobacteria classes. We compared those MAGs to organisms from the same taxonomic classes found in soil, and we found that they were similar in its CAZyme repertoire, but the soil MAG contained a more abundant and diverse CAZyme content. Furthermore, the data indicate that abundant classes in our metagenomic samples, namely Alphaproteobacteria, Bacteroidia and Gammaproteobacteria, play a pivotal role in carbohydrate transformation within the initial few metres of the sediments.

Glucose consumption rate-dependent transcriptome profiling of Escherichia coli provides insight on performance as microbial factories.

BACKGROUND: The modification of glucose import capacity is an engineering strategy that has been shown to improve the characteristics of Escherichia coli as a microbial factory. A reduction in glucose import capacity can have a positive effect on production strain performance, however, this is not always the case. In this study, E. coli W3110 and a group of four isogenic derivative strains, harboring single or multiple deletions of genes encoding phosphoenolpyruvate:sugar phosphotransferase system (PTS)-dependent transporters as well as non-PTS transporters were characterized by determining their transcriptomic response to reduced glucose import capacity. RESULTS: These strains were grown in bioreactors with M9 mineral salts medium containing 20 g/L of glucose, where they displayed specific growth rates ranging from 0.67 to 0.27 h-1, and specific glucose consumption rates (qs) ranging from 1.78 to 0.37 g/g h. RNA-seq analysis revealed a transcriptional response consistent with carbon source limitation among all the mutant strains, involving functions related to transport and metabolism of alternate carbon sources and characterized by a decrease in genes encoding glycolytic enzymes and an increase in gluconeogenic functions. A total of 107 and 185 genes displayed positive and negative correlations with qs, respectively. Functions displaying positive correlation included energy generation, amino acid biosynthesis, and sugar import. CONCLUSION: Changes in gene expression of E. coli strains with impaired glucose import capacity could be correlated with qs values and this allowed an inference of the physiological state of each mutant. In strains with lower qs values, a gene expression pattern is consistent with energy limitation and entry into the stationary phase. This physiological state could explain why these strains display a lower capacity to produce recombinant protein, even when they show very low rates of acetate production. The comparison of the transcriptomes of the engineered strains employed as microbial factories is an effective approach for identifying favorable phenotypes with the potential to improve the synthesis of biotechnological products.

Association study of genetic polymorphisms in proteins involved in oseltamivir transport, metabolism, and interactions with adverse reactions in Mexican patients with acute respiratory diseases.

Oseltamivir, a pro-drug, is the best option for treatment and chemoprophylaxis for influenza outbreaks. However, many patients treated with oseltamivir developed adverse reactions, including hypersensitivity, gastritis, and neurological symptoms. The aim of this study was to determine the adverse drug reactions (ADRs) in Mexican patients treated with oseltamivir and whether these ADRs are associated with SNPs of the genes involved in the metabolism, transport, and interactions of oseltamivir. This study recruited 310 Mexican patients with acute respiratory diseases and treated them with oseltamivir (75 mg/day for 5 days) because they were suspected to have influenza A/H1N1 virus infection. Clinical data were obtained from medical records and interviews. Genotyping was performed using real-time polymerase chain reaction and TaqMan probes. The association was assessed under genetic models with contingency tables and logistic regression analysis. Out of 310 patients, only 38 (12.25%) presented ADRs to oseltamivir: hypersensitivity (1.9%), gastritis (10%), and depression and anxiety (0.9%). The polymorphism ABCB1-rs1045642 was associated with adverse drug reactions under the recessive model (P = 0.017); allele C was associated with no adverse drug reactions, while allele T was associated with adverse drug reactions. The polymorphisms SLC15A1-rs2297322, ABCB1-rs2032582, and CES1-rs2307243 were not consistent with Hardy-Weinberg equilibrium, and no other associations were found for the remaining polymorphisms. In conclusion, the polymorphism rs1045642 in the transporter encoded by the ABCB1 gene is a potential predictive biomarker of ADRs in oseltamivir treatment.

The dual role of the centrosome in organizing the microtubule network in interphase.

Here, we address the regulation of microtubule nucleation during interphase by genetically ablating one, or two, of three major mammalian γ-TuRC-binding factors namely pericentrin, CDK5Rap2, and AKAP450. Unexpectedly, we find that while all of them participate in microtubule nucleation at the Golgi apparatus, they only modestly contribute at the centrosome where CEP192 has a more predominant function. We also show that inhibiting microtubule nucleation at the Golgi does not affect centrosomal activity, whereas manipulating the number of centrosomes with centrinone modifies microtubule nucleation activity of the Golgi apparatus. In centrosome-free cells, inhibition of Golgi-based microtubule nucleation triggers pericentrin-dependent formation of cytoplasmic-nucleating structures. Further depletion of pericentrin under these conditions leads to the generation of individual microtubules in a γ-tubulin-dependent manner. In all cases, a conspicuous MT network forms. Strikingly, centrosome loss increases microtubule number independently of where they were growing from. Our results lead to an unexpected view of the interphase centrosome that would control microtubule network organization not only by nucleating microtubules, but also by modulating the activity of alternative microtubule-organizing centers.

Alpha-catenin-dependent recruitment of the centrosomal protein CAP350 to adherens junctions allows epithelial cells to acquire a columnar shape.

Epithelial morphogenesis involves a dramatic reorganisation of the microtubule cytoskeleton. How this complex process is controlled at the molecular level is still largely unknown. Here, we report that the centrosomal microtubule (MT)-binding protein CAP350 localises at adherens junctions in epithelial cells. By two-hybrid screening, we identified a direct interaction of CAP350 with the adhesion protein α-catenin that was further confirmed by co-immunoprecipitation experiments. Block of epithelial cadherin (E-cadherin)-mediated cell-cell adhesion or α-catenin depletion prevented CAP350 localisation at cell-cell junctions. Knocking down junction-located CAP350 inhibited the establishment of an apico-basal array of microtubules and impaired the acquisition of columnar shape in Madin-Darby canine kidney II (MDCKII) cells grown as polarised epithelia. Furthermore, MDCKII cystogenesis was also defective in junctional CAP350-depleted cells. CAP350-depleted MDCKII cysts were smaller and contained either multiple lumens or no lumen. Membrane polarity was not affected, but cortical microtubule bundles did not properly form. Our results indicate that CAP350 may act as an adaptor between adherens junctions and microtubules, thus regulating epithelial differentiation and contributing to the definition of cell architecture. We also uncover a central role of α-catenin in global cytoskeleton remodelling, in which it acts not only on actin but also on MT reorganisation during epithelial morphogenesis.

CRISPR-Cas system presents multiple transcriptional units including antisense RNAs that are expressed in minimal medium and upregulated by pH in Salmonella enterica serovar Typhi.

The CRISPR-Cas system is involved in bacterial immunity, virulence, gene regulation, biofilm formation and sporulation. In Salmonella enterica serovar Typhi, this system consists of five transcriptional units including antisense RNAs. It was determined that these genetic elements are expressed in minimal medium and are up-regulated by pH. In addition, a transcriptional characterization of cas3 and ascse2-1 is included herein.

PhyloFlu, a DNA microarray for determining the phylogenetic origin of influenza A virus gene segments and the genomic fingerprint of viral strains.

Recent evidence suggests that most influenza A virus gene segments can contribute to the pathogenicity of the virus. In this regard, the hemagglutinin (HA) subtype of the circulating strains has been closely surveyed, but the reassortment of internal gene segments is usually not monitored as a potential source of an increased pathogenicity. In this work, an oligonucleotide DNA microarray (PhyloFlu) designed to determine the phylogenetic origins of the eight segments of the influenza virus genome was constructed and validated. Clades were defined for each segment and also for the 16 HA and 9 neuraminidase (NA) subtypes. Viral genetic material was amplified by reverse transcription-PCR (RT-PCR) with primers specific to the conserved 5' and 3' ends of the influenza A virus genes, followed by PCR amplification with random primers and Cy3 labeling. The microarray unambiguously determined the clades for all eight influenza virus genes in 74% (28/38) of the samples. The microarray was validated with reference strains from different animal origins, as well as from human, swine, and avian viruses from field or clinical samples. In most cases, the phylogenetic clade of each segment defined its animal host of origin. The genomic fingerprint deduced by the combined information of the individual clades allowed for the determination of the time and place that strains with the same genomic pattern were previously reported. PhyloFlu is useful for characterizing and surveying the genetic diversity and variation of animal viruses circulating in different environmental niches and for obtaining a more detailed surveillance and follow up of reassortant events that can potentially modify virus pathogenicity.

Global transcriptomic analysis of an engineered Escherichia coli strain lacking the phosphoenolpyruvate: carbohydrate phosphotransferase system during shikimic acid production in rich culture medium.

BACKGROUND: Efficient production of SA in Escherichia coli has been achieved by modifying key genes of the central carbon metabolism and SA pathway, resulting in overproducing strains grown in batch- or fed-batch-fermentor cultures using a complex broth including glucose and YE. In this study, we performed a GTA to identify those genes significantly upregulated in an engineered E. coli strain, PB12.SA22, in mid EXP (5 h), early STA (STA1, 9 h), and late STA (STA2, 44 h) phases, grown in complex fermentation broth in batch-fermentor cultures. RESULTS: Growth of E. coli PB12.SA22 in complex fermentation broth for SA production resulted in an EXP growth during the first 9 h of cultivation depending of supernatant available aromatic amino acids provided by YE because, when tryptophan was totally consumed, cells entered into a second, low-growth phase (even in the presence of glucose) until 26 h of cultivation. At this point, glucose was completely consumed but SA production continued until the end of the fermentation (50 h) achieving the highest accumulation (7.63 g/L of SA). GTA between EXP/STA1, EXP/STA2 and STA1/STA2 comparisons showed no significant differences in the regulation of genes encoding enzymes of central carbon metabolism as in SA pathway, but those genes encoding enzymes involved in sugar, amino acid, nucleotide/nucleoside, iron and sulfur transport; amino acid catabolism and biosynthesis; nucleotide/nucleoside salvage; acid stress response and modification of IM and OM were upregulated between comparisons. CONCLUSIONS: GTA during SA production in batch-fermentor cultures of strain PB12.SA22 grown in complex fermentation broth during the EXP, STA1 and STA2 phases was studied. Significantly, upregulated genes during the EXP and STA1 phases were associated with transport, amino acid catabolism, biosynthesis, and nucleotide/nucleoside salvage. In STA2, upregulation of genes encoding transporters and enzymes involved in the synthesis and catabolism of Arg suggests that this amino acid could have a key role in the fuelling of carbon toward SA synthesis, whereas upregulation of genes involved in pH stress response, such as membrane modifications, suggests a possible response to environmental conditions imposed on the cell at the end of the fermentation.

Emerging Insights in Small-Cell Carcinoma of the Genitourinary Tract: From Diagnosis to Novel Therapeutic Horizons.

Small-cell carcinomas (SCCs) of the genitourinary (GU) tract are rare malignancies with high metastatic potential. The most common primary sites are the bladder and prostate, but case reports of primary SCC of the kidney, ureter, and urethra also exist. The majority of patients present with gross hematuria, irritative or obstructive urinary symptoms, and symptoms of locoregionally advanced or metastatic disease at initial presentation. SCC of the bladder presents with nodal or metastatic involvement in the majority of cases and requires the use of platinum-based chemotherapy in combination with surgery and/or radiation. SCC of the prostate is most commonly seen in the metastatic castrate-resistant setting, and aggressive variant disease presents with a greater propensity for visceral metastases, osteolytic lesions, and relatively low serum prostate-specific antigen for volume of disease burden. Multiple retrospective and prospective randomized studies support the use of a multimodal approach combining platinum-based systemic therapy regimens with radiation and/or surgery for localized disease. This evidence-based strategy is reflected in multiple consensus guidelines. Emerging data suggest that small-cell bladder and prostate cancers transdifferentiate from a common progenitor of conventional urothelial bladder carcinoma and prostatic acinar adenocarcinoma, respectively. Areas of active basic research include efforts to identify the key genetic and epigenetic drivers involved in the emergence of small cell cancers to exploit them for novel therapies. Here, we review these efforts, discuss diagnosis and currently supported management strategies, and summarize ongoing clinical trials evaluating novel therapies to treat this rare, aggressive GU cancer.

TOPORS, implicated in retinal degeneration, is a cilia-centrosomal protein.

We recently reported that mutations in the widely expressed nuclear protein TOPORS (topoisomerase I-binding arginine/serine rich) are associated with autosomal dominant retinal degeneration. However, the precise localization and a functional role of TOPORS in the retina remain unknown. Here, we demonstrate that TOPORS is a novel component of the photoreceptor sensory cilium, which is a modified primary cilium involved with polarized trafficking of proteins. In photoreceptors, TOPORS localizes primarily to the basal bodies of connecting cilium and in the centrosomes of cultured cells. Morpholino-mediated silencing of topors in zebrafish embryos demonstrates in another species a comparable retinal problem as seen in humans, resulting in defective retinal development and failure to form outer segments. These defects can be rescued by mRNA encoding human TOPORS. Taken together, our data suggest that TOPORS may play a key role in regulating primary cilia-dependent photoreceptor development and function. Additionally, it is well known that mutations in other ciliary proteins cause retinal degeneration, which may explain why mutations in TOPORS result in the same phenotype.

Microtubule nucleation at the cis-side of the Golgi apparatus requires AKAP450 and GM130.

We report that microtubule (MT) nucleation at the Golgi apparatus requires AKAP450, a centrosomal gamma-TuRC-interacting protein that also forms a distinct network associated with the Golgi. Depletion of AKAP450 abolished MT nucleation at the Golgi, whereas depletion of the cis-Golgi protein GM130 led to the disorganisation of AKAP450 network and impairment of MT nucleation. Brefeldin-A treatment induced relocalisation of AKAP450 to ER exit sites and concomitant redistribution of MT nucleation capacity to the ER. AKAP450 specifically binds the cis-side of the Golgi in an MT-independent, GM130-dependent manner. Short AKAP450-dependent growing MTs are covered by CLASP2. Like for centrosome, dynein/dynactin complexes are necessary to anchor MTs growing from the Golgi. We further show that Golgi-associated AKAP450 has a role in cell migration rather than in cell polarisation of the centrosome-Golgi apparatus. We propose that the recruitment of AKAP450 on the Golgi membranes through GM130 allows centrosome-associated nucleating activity to extend to the Golgi, to control the assembly of subsets of MTs ensuring specific functions within the Golgi or for transporting specific cargos to the cell periphery.

Anxiolytic-like actions of fatty acids identified in human amniotic fluid.

Eight fatty acids (C12-C18) were previously identified in human amniotic fluid, colostrum, and milk in similar proportions but different amounts. Amniotic fluid is well known to be the natural environment for development in mammals. Interestingly, amniotic fluid and an artificial mixture of fatty acids contained in amniotic fluid produce similar anxiolytic-like actions in Wistar rats. We explored whether the lowest amount of fatty acids contained in amniotic fluid with respect to colostrum and milk produces such anxiolytic-like effects. Although a trend toward a dose-response effect was observed, only an amount of fatty acids that was similar to amniotic fluid fully mimicked the effect of diazepam (2 mg/kg, i.p.) in the defensive burying test, an action devoid of effects on locomotor activity and motor coordination. Our results confirm that the amount of fatty acids contained in amniotic fluid is sufficient to produce anxiolytic-like effects, suggesting similar actions during intrauterine development.

Glycosyltransferases Expression Changes in Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 Grown on Different Carbon Sources.

Leuconostoc mesenteroides strains are common contributors in fermented foods producing a wide variety of polysaccharides from sucrose through glycosyltransferases (GTFs). These polymers have been proposed as protective barriers against acidity, dehydration, heat, and oxidative stress. Despite its presence in many traditional fermented products and their association with food functional properties, regulation of GTFs expression in Ln. mesenteroides is still poorly understood. The strain Ln. mesenteroides ATCC 8293 contains three glucansucrases genes not found in operons, and three fructansucrases genes arranged in two operons, levLX and levC-scrB, a Glycoside-hydrolase. We described the first differential gene expression analysis of this strain when cultivated in different carbon sources. We observed that while GTFs are expressed in the presence of most sugars, they are down-regulated in xylose. We ruled out the regulatory effect of CcpA over GTFs and did not find regulatory elements with a direct effect on glucansucrases in the condition assayed. Our findings suggest that only operon levLX is repressed in xylose by LexA and that both fructansucrases operons can be regulated by the VicK/VicR system and PerR. It is essential to further explore the effect of environmental conditions in Ln. mesenteroides bacteria to better understand GTFs regulation and polymer function.

The benzoyl-CoA pathway serves as a genomic marker to identify the oxygen requirements in the degradation of aromatic hydrocarbons.

The first step of anaerobic benzoate degradation is the formation of benzoyl-coenzyme A by benzoate-coenzyme A ligase (BCL). The anaerobic route is steered by benzoyl-CoA reductase, which promotes benzoyl-CoA breakdown, which is subsequently oxidized. In certain bacteria at low oxygen conditions, the aerobic metabolism of monoaromatic hydrocarbons occurs through the degradation Box pathway. These pathways have undergone experimental scrutiny in Alphaproteobacteria and Betaproteobacteria and have also been explored bioinformatically in representative Betaproteobacteria. However, there is a gap in our knowledge regarding the distribution of the benzoyl-CoA pathway and the evolutionary forces propelling its adaptation beyond that of representative bacteria. To address these questions, we used bioinformatic procedures to identify the BCLs and the lower pathways that transform benzoyl-CoA. These procedures included the identification of conserved motifs. As a result, we identified two motifs exclusive to BCLs, describing some of the catalytic properties of this enzyme. These motifs helped to discern BCLs from other aryl-CoA ligases effectively. The predicted BCLs and the enzymes of lower pathways were used as genomic markers for identifying aerobic, anaerobic, or hybrid catabolism, which we found widely distributed in Betaproteobacteria. Despite these enhancements, our approach failed to distinguish orthologs from a small cluster of paralogs exhibiting all the specified features to predict an ortholog. Nonetheless, the conducted phylogenetic analysis and the properties identified in the genomic context aided in formulating hypotheses about how this redundancy contributes to refining the catabolic strategy employed by these bacteria to degrade the substrates.

Woman Varayoc of Peruvian Andes.

This study focuses on the importance of the symbolism of social control by the woman as the Varayoc (an office of authority of Incan origin) in a community in the Peruvian Andes. The objective is to explain the survival of the office of the Varayoc-traditionally held exclusively by men-and the acceptance of Andean women to it as a recognition of gender equality. In this field investigation, we interviewed and observed the most important activities of a woman Varayoc administering justice and present in all communal tasks. We conclude that women in the Peruvian Andes are approaching a status of equality with men in their position as the Varayoc, while maintaining the Incan tradition of local governance through the symbolism of the rod of command, which is also called Varayoc. It is evident that more women in the Andean community are interested in assuming political leadership with the symbolism of the ancestral Varayoc.

Primary plasma cell leukemia in Latin America: demographic, clinical, and prognostic characteristics. A study of GELAMM group.

Primary plasma cell leukemia (pPCL) is an infrequent and aggressive plasma cell disorder. The prognosis is still very poor, and the optimal treatment remains to be established. A retrospective, multicentric, international observational study was performed. Patients from 9 countries of Latin America (LATAM) with a diagnosis of pPCL between 2012 and 2020 were included. 72 patients were included. Treatment was based on thalidomide in 15%, proteasome inhibitors (PI)-based triplets in 38% and chemotherapy plus IMIDs and/or PI in 29%. The mortality rate at 3 months was 30%. The median overall survival (OS) was 18 months. In the multivariate analysis, frontline PI-based triplets, chemotherapy plus IMIDs and/or PI therapy, and maintenance were independent factors of better OS. In conclusion, the OS of pPCL is still poor in LATAM, with high early mortality. PI triplets, chemotherapy plus IMIDs, and/or PI and maintenance therapy were associated with improved survival.

Omicron-BA.1 Dispersion Rates in Mexico Varied According to the Regional Epidemic Patterns and the Diversity of Local Delta Subvariants.

PURPOSE: The Omicron subvariant BA.1 of SARS-CoV-2 was first detected in November 2021 and quickly spread worldwide, displacing the Delta variant. In this work, a characterization of the spread of this variant in Mexico is presented. METHODS: The time to fixation of BA.1, the diversity of Delta sublineages, the population density, and the level of virus circulation during the inter-wave interval were determined to analyze differences in BA.1 spread. RESULTS: BA.1 began spreading during the first week of December 2021 and became dominant in the next three weeks, causing the fourth COVID-19 epidemiological surge in Mexico. Unlike previous variants, BA.1 did not exhibit a geographically distinct circulation pattern. However, a regional difference in the speed of the replacement of the Delta variant was observed. CONCLUSIONS: Viral diversity and the relative abundance of the virus in a particular area around the time of the introduction of a new lineage seem to have influenced the spread dynamics, in addition to population density. Nonetheless, if there is a significant difference in the fitness of the variants, or if the time allowed for the competition is sufficiently long, it seems the fitter virus will eventually become dominant, as observed in the eventual dominance of the BA.1.x variant in Mexico.

Age-related differences in the dynamics of hippocampal proteasome recovery.

Regulation of proteasome abundance to meet cell needs under stress conditions is critical for maintaining cellular homeostasis. However, the effects of aging on this homeostatic response remain unknown. In this report, we analyzed in young and aged rat hippocampus, the dynamics of proteasome recovery induced by proteasome stress. Proteasome inhibition in young rats leads to an early and coordinate transcriptional and translational up-regulation of both the catalytic subunits of constitutive proteasome and the proteasome maturation protein. By contrast, aged rats up-regulated the inducible catalytic subunits and showed a lower and shorter expression of proteasome maturation protein. This resulted in a faster recovery of proteasome activity in young rats. Importantly, proteasome inhibition highly affected pyramidal cells, leading to the accumulation of ubiquitinated proteins in perinuclear regions of aged, but not young pyramidal neurons. These data strongly suggest that age-dependent differences in proteasome level and composition could contribute to neurodegeneration induced by proteasome dysfunction in normal and pathological aging.

Lipopolysaccharide-induced neuroinflammation leads to the accumulation of ubiquitinated proteins and increases susceptibility to neurodegeneration induced by proteasome inhibition in rat hippocampus.

BACKGROUND: Neuroinflammation and protein accumulation are characteristic hallmarks of both normal aging and age-related neurodegenerative diseases. However, the relationship between these factors in neurodegenerative processes is poorly understood. We have previously shown that proteasome inhibition produced higher neurodegeneration in aged than in young rats, suggesting that other additional age-related events could be involved in neurodegeneration. We evaluated the role of lipopolysaccharide (LPS)-induced neuroinflammation as a potential synergic risk factor for hippocampal neurodegeneration induced by proteasome inhibition. METHODS: Young male Wistar rats were injected with 1 µL of saline or LPS (5 mg/mL) into the hippocampus to evaluate the effect of LPS-induced neuroinflammation on protein homeostasis. The synergic effect of LPS and proteasome inhibition was analyzed in young rats that first received 1 µL of LPS and 24 h later 1 µL (5 mg/mL) of the proteasome inhibitor lactacystin. Animals were sacrificed at different times post-injection and hippocampi isolated and processed for gene expression analysis by real-time polymerase chain reaction; protein expression analysis by western blots; proteasome activity by fluorescence spectroscopy; immunofluorescence analysis by confocal microscopy; and degeneration assay by Fluoro-Jade B staining. RESULTS: LPS injection produced the accumulation of ubiquitinated proteins in hippocampal neurons, increased expression of the E2 ubiquitin-conjugating enzyme UB2L6, decreased proteasome activity and increased immunoproteasome content. However, LPS injection was not sufficient to produce neurodegeneration. The combination of neuroinflammation and proteasome inhibition leads to higher neuronal accumulation of ubiquitinated proteins, predominant expression of pro-apoptotic markers and increased neurodegeneration, when compared with LPS or lactacystin (LT) injection alone. CONCLUSIONS: Our results identify neuroinflammation as a risk factor that increases susceptibility to neurodegeneration induced by proteasome inhibition. These results highlight the modulation of neuroinflammation as a mechanism for neuronal protection that could be relevant in situations where both factors are present, such as aging and neurodegenerative diseases.

GMAP210 and IFT88 are present in the spermatid golgi apparatus and participate in the development of the acrosome-acroplaxome complex, head-tail coupling apparatus and tail.

We describe the localization of the golgin GMAP210 and the intraflagellar protein IFT88 in the Golgi of spermatids and the participation of these two proteins in the development of the acrosome-acroplaxome complex, the head-tail coupling apparatus (HTCA) and the spermatid tail. Immunocytochemical experiments show that GMAP210 predominates in the cis-Golgi, whereas IFT88 prevails in the trans-Golgi network. Both proteins colocalize in proacrosomal vesicles, along acrosome membranes, the HTCA and the developing tail. IFT88 persists in the acrosome-acroplaxome region of the sperm head, whereas GMAP210 is no longer seen there. Spermatids of the Ift88 mouse mutant display abnormal head shaping and are tail-less. GMAP210 is visualized in the Ift88 mutant during acrosome-acroplaxome biogenesis. However, GMAP210-stained vesicles, mitochondria and outer dense fiber material build up in the manchette region and fail to reach the abortive tail stump in the mutant. In vitro disruption of the spermatid Golgi and microtubules with Brefeldin-A and nocodazole blocks the progression of GMAP210- and IFT88-stained proacrosomal vesicles to the acrosome-acroplaxome complex but F-actin distribution in the acroplaxome is not affected. We provide the first evidence that IFT88 is present in the Golgi of spermatids, that the microtubule-associated golgin GMAP210 and IFT88 participate in acrosome, HTCA, and tail biogenesis, and that defective intramanchette transport of cargos disrupts spermatid tail development.