Preliminary Assessment of Gastrointestinal Parasites in Two Wild Groups of Endangered Moor Macaques (Macaca maura) from Sulawesi

International Journal of Primatology - Information on parasite biodiversity and abundance can improve our understanding of parasitic infections on endangered wildlife, as parasites can affect host...     

Introducing “best single template” models as reference baseline for the Continuous Automated Model Evaluation (CAMEO)

Critical blind assessment of structure prediction techniques is crucial for the scientific community to establish the state of the art, identify bottlenecks, and guide future developments. In Critical Assessment of Techniques in Structure Prediction (CASP), human experts assess the performance of participating methods in relation to the difficulty of the prediction task in a biennial experiment on approximately 100 targets. Yet, the development of automated computational modeling methods requires more frequent evaluation cycles and larger sets of data. The “Continuous Automated Model EvaluatiOn (CAMEO)” platform complements CASP by conducting fully automated blind prediction evaluations based on the weekly pre-release of sequences of those structures, which are going to be published in the next release of the Protein Data Bank (PDB). Each week, CAMEO publishes benchmarking results for predictions corresponding to a set of about 20 targets collected during a 4-day prediction window. CAMEO benchmarking data are generated consistently for all methods at the same point in time, enabling developers to cross-validate their method's performance, and referring to their results in publications. Many successful participants of CASP have used CAMEO—either by directly benchmarking their methods within the system or by comparing their own performance to CAMEO reference data. CAMEO offers a variety of scores reflecting different aspects of structure modeling, for example, binding site accuracy, homo-oligomer interface quality, or accuracy of local model confidence estimates. By introducing the "bestSingleTemplate" method based on structure superpositions as a reference for the accuracy of 3D modeling predictions, CAMEO facilitates objective comparison of techniques and fosters the development of advanced methods.     

AMPA receptor expression in mouse testis and spermatogonial GC-1 cells: A study on its regulation by excitatory amino acids

Excitatory amino acids (EAAs) are found present in the nervous and reproductive systems of animals. Numerous studies have demonstrated a regulatory role for Glutamate (Glu), d -aspartate ( d -Asp) and N-methyl- d -aspartate (NMDA) in the control of spermatogenesis. EAAs are able to stimulate the Glutamate receptors, including the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR). Here in, we assess expression of the main AMPAR subunits, GluA1 and GluA2/3, in the mouse testis and in spermatogonial GC-1 cells. The results showed that both GluA1 and GluA2/3 were localized in mouse testis prevalently in spermatogonia. The subunit GluA2/3 was more highly expressed compared with GluA1 in both the testis and the GC-1 cells. Subsequently, GC-1 cells were incubated with medium containing l -Glu, d -Glu, d -Asp or NMDA to determine GluA1 and GluA2/3 expressions. At 30 minutes and 2 hours of incubation, EAA-treated GC-1 cells showed significantly higher expression levels of both GluA1 and GluA2/3. Furthermore, p-extracellular signal-regulated kinase (ERK), p-Akt, proliferating cell nuclear antigen (PCNA), and Aurora B expressions were assayed in l -Glu-, d -Glu-, and NMDA-treated GC-1 cells. At 30 minutes and 2 hours of incubation, treated GC-1 cells showed significantly higher expression levels of p-ERK and p-Akt. A consequent increase of PCNA and Aurora B expressions was induced by l -Glu and NMDA, but not by d -Glu. Our study demonstrates a direct effect of the EAAs on spermatogonial activity. In addition, the increased protein expression levels of GluA1 and GluA2/3 in EAA-treated GC-1 cells suggest that EAAs could activate ERK and Akt pathways through the AMPAR. Finally, the increased PCNA and Aurora B levels may imply an enhanced proliferative activity.     

RAGE-TXNIP axis drives inflammation in Alzheimer’s by targeting Aβ to mitochondria in microglia

Alzheimer’s disease (AD) is the most common form of dementia characterized by progressive memory loss and cognitive decline. Although neuroinflammation and oxidative stress are well-recognized features of AD, their correlations with the early molecular events characterizing the pathology are not yet well clarified. Here, we characterize the role of RAGE–TXNIP axis in neuroinflammation in relation to amyloid-beta (Aβ) burden in both in vivo and in vitro models. In the hippocampus of 5xFAD mice microglial activation, cytokine secretion, and glial fibrillary acidic protein-enhanced expression are paralleled with increased TXNIP expression. TXNIP silencing or its pharmacological inhibition prevents neuroinflammation in those mice. TXNIP is also associated with RAGE and Aβ. In particular, RAGE–TXNIP axis is required for targeting Aβ in mitochondria, leading to mitochondrial dysfunction and oxidative stress. Silencing of TXNIP or inhibition of RAGE activation reduces Aβ transport from the cellular surface to mitochondria, restores mitochondrial functionality, and mitigates Aβ toxicity. Furthermore, Aβ shuttling into mitochondria promotes Drp1 activation and exacerbates mitochondrial dysfunction, which induces NLRP3 inflammasome activation, leading to secretion of IL-1β and activation of the pyroptosis-associated protein Gasdermin D (GSDMD). Downregulation of RAGE–TXNIP axis inhibits Aβ-induced mitochondria dysfunction, inflammation, and induction of GSDMD. Herein we unveil a new pathway driven by TXNIP that links the mitochondrial transport of Aβ to the activation of Drp1 and the NLRP3 inflammasome, promoting the secretion of IL-1β and the pyroptosis pathway associated with GSDMD cleavage. Altogether these data shed new light on a novel mechanism of action of RAGE–TXNIP axis in microglia, which is intertwined with Aβ and ultimately causes mitochondria dysfunction and NLRP3 inflammasome cascade activation, suggesting TXNIP as a druggable target to be better deepened for AD.Subject terms: Cellular neuroscience, Inflammasome     

Dysregulated RNA polyadenylation contributes to metabolic impairment in non-alcoholic fatty liver disease

Pre-mRNA processing is an essential mechanism for the generation of mature mRNA and the regulation of gene expression in eukaryotic cells. While defects in pre-mRNA processing have been implicated in a number of diseases their involvement in metabolic pathologies is still unclear. Here, we show that both alternative splicing and alternative polyadenylation, two major steps in pre-mRNA processing, are significantly altered in non-alcoholic fatty liver disease (NAFLD). Moreover, we find that Serine and Arginine Rich Splicing Factor 10 (SRSF10) binding is enriched adjacent to consensus polyadenylation motifs and its expression is significantly decreased in NAFLD, suggesting a role mediating pre-mRNA dysregulation in this condition. Consistently, inactivation of SRSF10 in mouse and human hepatocytes in vitro, and in mouse liver in vivo, was found to dysregulate polyadenylation of key metabolic genes such as peroxisome proliferator-activated receptor alpha (PPARA) and exacerbate diet-induced metabolic dysfunction. Collectively our work implicates dysregulated pre-mRNA polyadenylation in obesity-induced liver disease and uncovers a novel role for SRSF10 in this process.     

Hyperinflammation after anti-SARS-CoV-2 mRNA/DNA vaccines successfully treated with anakinra: Case series and literature review

The current SARS-CoV-2 pandemic diffused worldwide has encouraged the rapid development of vaccines to counter the spread of the virus. At present in Italy, 75.01% of the population completed the vaccination course (AIFA.gov.it) and very few adverse events have been recorded by now. Side-effects related to a theoretical over-reaction of the immune system in response to vaccines administration have been described, and the possibility that an autoimmune or a hyperinflammatory condition may occur was recently observed. Herein, we report four cases of hyperinflammatory syndrome with features indicative of Adult-onset Still’s disease (AOSD) and macrophage activation syndrome (MAS), occurred after anti-SARS-CoV-2 vaccine injection and seen at our Unit between March and May 2021. Since interleukin (IL)-1 is one of the pivotal cytokines involved in AOSD pathogenesis, the inhibition of IL-1 is crucial in ameliorating the clinical symptoms of those patients. Moreover, it has been highlighted the central role of IL-1 as a hallmark of the hyperinflammatory status elicited by SARS-CoV-2 infection. In this case series, we successfully employed the IL-1 receptor antagonist anakinra to curb the cytokine release likely unleashed by the vaccine stimulation in potentially predisposed subjects. We also made a literature search to detect other patients with hyperinflammation temporally related to vaccines injection who benefited from IL-1 inhibition, while other AOSD/MAS-like described syndromes improved with other immunomodulatory strategies.     

The coiled-coil domain of Escherichia coli FtsLB is a structurally detuned element critical for modulating its activation in bacterial cell division

The FtsLB complex is a key regulator of bacterial cell division, existing in either an off state or an on state, which supports the activation of septal peptidoglycan synthesis. In Escherichia coli, residues known to be critical for this activation are located in a region near the C-terminal end of the periplasmic coiled-coil domain of FtsLB, raising questions about the precise role of this conserved domain in the activation mechanism. Here, we investigate an unusual cluster of polar amino acids found within the core of the FtsLB coiled coil. We hypothesized that these amino acids likely reduce the structural stability of the domain and thus may be important for governing conformational changes. We found that mutating these positions to hydrophobic residues increased the thermal stability of FtsLB but caused cell division defects, suggesting that the coiled-coil domain is a “detuned” structural element. In addition, we identified suppressor mutations within the polar cluster, indicating that the precise identity of the polar amino acids is important for fine-tuning the structural balance between the off and on states. We propose a revised structural model of the tetrameric FtsLB (named the “Y-model”) in which the periplasmic domain splits into a pair of coiled-coil branches. In this configuration, the hydrophilic terminal moieties of the polar amino acids remain more favorably exposed to water than in the original four-helix bundle model (“I-model”). We propose that a shift in this architecture, dependent on its marginal stability, is involved in activating the FtsLB complex and triggering septal cell wall reconstruction.     

Synthesis and enantioselectivity of the enantiomers of PG9 and SM21, new potent analgesic and cognition-enhancing drugs

The enantiomers of two α-tropanyl esters, SM₂₁ (1) and PG₉ (2), derived from (+)-R-hyoscyamine, that act by increasing the central cholinergic tone, were obtained by esterification after resolution of the corresponding racemic acids [(−)-S-1, (−)-R-2 and (+)-S-2] and by stereospecific synthesis [(+)-R-1]. Their analgesic and cognition-enhancing activities were tested in mice and their ACh-releasing properties determined on rat parietal cortex. These compounds show enantioselectivity in analgesic and cognition-enhancing tests on mice, the eutomers being the isomers which possess the same spatial arrangement of the groups on the chiral atom as (+)-R hyoscyamine [(+)-R-SM₂₁, (+)-S-PG₉]. The ACh-releasing effect of the enantiomers of SM₂₁ in rats is in agreement with the results in mice, while PG₉ enantiomers do not show any appreciable enantioselectivity in this test. On the basis of the different effects of the 5-HT₄ antagonist SDZ 205557 on analgesia induced by the enantiomers of 1 and 2 and by (+)-R-hyoscyamine and the α-tropanyl ester of 2-phenylpropionic acid 3, a mechanism of action is proposed for this class of compounds. © 1996 Wiley-Liss, Inc.