A novel 4E-interacting protein in Leishmania is involved in stage-specific translation pathways

In eukaryotes, exposure to stress conditions causes a shift from cap-dependent to cap-independent translation. In trypanosomatids, environmental switches are the driving force of a developmental program of gene expression, but it is yet unclear how their translation machinery copes with their constantly changing environment. Trypanosomatids have a unique cap structure (cap-4) and encode four highly diverged paralogs of the cap-binding protein, eIF4E; none were found to genetically complement a yeast mutant failing to express eIF4E. Here we show that in promastigotes, a typical cap-binding complex is anchored through LeishIF4E-4, which associates with components of the cap-binding pre-initiation complex. In axenic amastigotes, expression of LeishIF4E-4 decreases and the protein does not bind the cap, whereas LeishIF4E-1 maintains its expression level and associates with the cap structure and with translation initiation factors. However, LeishIF4E-1 does not interact with eIF4G-like proteins in both life stages, excluding its involvement in cap-dependent translation. Using pull-down assays and mass-spectrometry, we identified a novel, non-conserved 4E-Interacting Protein (Leish4E-IP), which binds to LeishIF4E-1 in promastigotes, but not in amastigotes. Yeast two-hybrid and NMR spectroscopy confirmed the specificity of this interaction. We propose that Leish4E-IP is a translation regulator that is involved in switching between cap-dependent and alternative translation pathways

PhosTryp: a phosphorylation site predictor specific for parasitic protozoa of the family trypanosomatidae

<p>Abstract</p> <p>Background</p> <p>Protein phosphorylation modulates protein function in organisms at all levels of complexity. Parasites of the <it>Leishmania </it>genus undergo various developmental transitions in their life cycle triggered by changes in the environment. The molecular mechanisms that these organisms use to process and integrate these external cues are largely unknown. However <it>Leishmania </it>lacks transcription factors, therefore most regulatory processes may occur at a post-translational level and phosphorylation has recently been demonstrated to be an important player in this process. Experimental identification of phosphorylation sites is a time-consuming task. Moreover some sites could be missed due to the highly dynamic nature of this process or to difficulties in phospho-peptide enrichment.</p> <p>Results</p> <p>Here we present PhosTryp, a phosphorylation site predictor specific for trypansomatids. This method uses an SVM-based approach and has been trained with recent <it>Leishmania </it>phosphosproteomics data. PhosTryp achieved a 17% improvement in prediction performance compared with Netphos, a non organism-specific predictor. The analysis of the peptides correctly predicted by our method but missed by Netphos demonstrates that PhosTryp captures <it>Leishmania</it>-specific phosphorylation features. More specifically our results show that <it>Leishmania </it>kinases have sequence specificities which are different from their counterparts in higher eukaryotes. Consequently we were able to propose two possible <it>Leishmania</it>-specific phosphorylation motifs.</p> <p>We further demonstrate that this improvement in performance extends to the related trypanosomatids <it>Trypanosoma brucei </it>and <it>Trypanosoma cruzi</it>. Finally, in order to maximize the usefulness of PhosTryp, we trained a predictor combining all the peptides from <it>L. infantum, T. brucei and T. cruzi</it>.</p> <p>Conclusions</p> <p>Our work demonstrates that training on organism-specific data results in an improvement that extends to related species. PhosTryp is freely available at <url>http://phostryp.bio.uniroma2.it</url></p

Translational Control through eIF2alpha Phosphorylation during the Leishmania Differentiation Process

The parasitic protozoan Leishmania alternates between an invertebrate and a mammalian host. Upon their entry to mammalian macrophages, Leishmania promastigotes differentiate into amastigote forms within the harsh environment of the phagolysosomal compartment. Here, we provide evidence for the importance of translational control during the Leishmania differentiation process. We find that exposure of promastigotes to a combined elevated temperature and acidic pH stress, a key signal triggering amastigote differentiation, leads to a marked decrease in global translation initiation, which is associated with eIF2α phosphorylation. Interestingly, we show that amastigotes adapted to grow in a cell-free medium exhibit lower levels of protein synthesis in comparison to promastigotes, suggesting that amastigotes have to enter a slow growth state to adapt to the stressful conditions encountered inside macrophages. Reconversion of amastigotes back to promastigote growth results in upregulation of global translation and a decrease in eIF2α phosphorylation. In addition, we show that while general translation is reduced during amastigote differentiation, translation of amastigote-specific transcripts such as A2 is preferentially upregulated. We find that A2 developmental gene regulation is triggered by temperature changes in the environment and that occurs mainly at the level of translation. Upon elevated temperature, the A2 transcript is stabilized through its association with polyribosomes leading to high levels of translation. When temperature decreases during amastigote to promastigote differentiation, the A2 transcript is not longer associated with translating polyribosomes and is being gradually degraded. Overall, these findings contribute to our better understanding of the adaptive responses of Leishmania to stress during its development and highlight the importance of translational control in promastigote to amastigote differentiation and vice-versa

Monoaminergic and histaminergic strategies and treatments in brain diseases

The monoaminergic systems are the target of several drugs for the treatment of mood, motor and cognitive disorders as well as neurological conditions. In most cases, advances have occurred through serendipity, except for Parkinson's disease where the pathophysiology led almost immediately to the introduction of dopamine restoring agents. Extensive neuropharmacological studies first showed that the primary target of antipsychotics, antidepressants, and anxiolytic drugs were specific components of the monoaminergic systems. Later, some dramatic side effects associated with older medicines were shown to disappear with new chemical compounds targeting the origin of the therapeutic benefit more specifically. The increased knowledge regarding the function and interaction of the monoaminergic systems in the brain resulting from in vivo neurochemical and neurophysiological studies indicated new monoaminergic targets that could achieve the efficacy of the older medicines with fewer side-effects. Yet, this accumulated knowledge regarding monoamines did not produce valuable strategies for diseases where no monoaminergic drug has been shown to be effective. Here, we emphasize the new therapeutic and monoaminergic-based strategies for the treatment of psychiatric diseases. We will consider three main groups of diseases, based on the evidence of monoamines involvement (schizophrenia, depression, obesity), the identification of monoamines in the diseases processes (Parkinson's disease, addiction) and the prospect of the involvement of monoaminergic mechanisms (epilepsy, Alzheimer's disease, stroke). In most cases, the clinically available monoaminergic drugs induce widespread modifications of amine tone or excitability through neurobiological networks and exemplify the overlap between therapeutic approaches to psychiatric and neurological conditions. More recent developments that have resulted in improved drug specificity and responses will be discussed in this review.peer-reviewe

Laparoscopic Versus Robot-Assisted Pyeloplasty in Adults&mdash;A Single-Center Experience

Background: Laparoscopic (LP) and robot-assisted pyeloplasty (RAP) are minimally invasive techniques for correcting uretero-pelvic junction obstruction (UPJO). We retrospectively compared the clinical outcomes of all adults who underwent RAP (n = 41) to those who underwent LP (n = 24) for UPJO at our institution between 2003&ndash;2022. Methods: Age, sex, body mass index, surgical side, past abdominal/endoscopic surgeries, pre- and postoperative renal scans, pre- and postoperative serum creatinine levels, operative time (OT), presence of crossing vessels, estimated blood loss, postoperative complications, length of hospital stay, time to JJ stent removal, follow-up length, and postoperative hydronephrosis were analyzed. Results: The groups were demographically comparable. The mean total and skin-to-skin OTs (minutes) were significantly longer in the RAP group than in the LP group (242.4 &plusmn; 55 vs. 161.4 &plusmn; 40 p &lt; 0.001; 163.7 &plusmn; 41.8 vs. 124.3 &plusmn; 30.3 p = 0.006, respectively). Hospital stay (days) was shorter in the RAP group (3.3 &plusmn; 2.1 vs. 7.3 &plusmn; 2.5 p &lt; 0.001). Postoperative complication rates were identical for both groups. The LP group had a significantly longer follow-up period (85.2 &plusmn; 73 vs. 19 &plusmn; 14 months p &lt; 0.001). The success rates for the LP and RAP groups were 87.5% and 90.6% (p = 0.708). Conclusions: RAP achieves equivalent results to LP, in adult patients. A longer OT may be expected with the robotic system since it can handle more complicated cases

Systemic Changes in Endocannabinoids and Endocannabinoid-like Molecules in Response to Partial Nephrectomy-Induced Ischemia in Humans

Renal ischemia–reperfusion (IR), a routine feature of partial nephrectomy (PN), can contribute to the development of acute kidney injury (AKI). Rodent studies show that the endocannabinoid system (ECS) is a major regulator of renal hemodynamics and IR injury; however, its clinical relevance remains to be established. Here, we assessed the clinical changes in systemic endocannabinoid (eCB) levels induced by surgical renal IR. Sixteen patients undergoing on-clamp PN were included, with blood samples taken before renal ischemia, after 10 min of ischemia time, and 10 min following blood reperfusion. Kidney function parameters (serum creatinine (sCr), blood urea nitrogen (BUN), and serum glucose) and eCB levels were measured. Baseline levels and individual changes in response to IR were analyzed and correlation analyses were performed. The baseline levels of eCB 2-arachidonoylglycerol (2-AG) were positively correlated with kidney dysfunction biomarkers. Unilateral renal ischemia increased BUN, sCr, and glucose, which remained elevated following renal reperfusion. Renal ischemia did not induce changes in eCB levels for all patients pooled together. Nevertheless, stratifying patients according to their body mass index (BMI) revealed a significant increase in N-acylethanolamines (anandamide, AEA; N-oleoylethanolamine, OEA; and N-palmitoylethanolamine, PEA) in the non-obese patients. No significant changes were found in obese patients who had higher N-acylethanolamines baseline levels, positively correlated with BMI, and more cases of post-surgery AKI. With the inefficiency of ‘traditional’ IR-injury ‘preventive drugs’, our data support future research on the role of the ECS and its manipulation in renal IR

The Added Value of Systematic Sampling in In-Bore Magnetic Resonance Imaging-Guided Prostate Biopsy

We sought to quantify the additive value of systematic biopsy (SB) using in-bore magnetic resonance (MR)-guided prostate biopsy (IBMRGpB) by retrospectively reviewing the records of 189 patients who underwent IBMRGpB for suspected prostate cancer or as part of the surveillance protocol for previously diagnosed prostate cancer. The endpoints included clinically significant and non-clinically significant cancer diagnosis. SB detected clinically significant disease in 67 (35.5%) patients. Five (2.65%) patients whose targeted biopsies indicated benign or non-clinically significant disease had clinically significant disease based on SB. SB from the lobe contralateral to the lesion detected clinically significant disease in 15 (12%) patients. The size of the prostate was larger and the percentage of lesions located in the peripheral zone of the prostate was higher in patients with SB-detected clinically significant disease. The location of the main lesion in the peripheral zone of the prostate was a predictor for clinically significant disease in the multivariate analysis (OR = 8.26, p = 0.04), a finding supported by a subgroup analysis of biopsy-naïve patients (OR = 10.52, p = 0.034). The addition of SB during IBMRGpB increased the diagnosis of clinically significant as well as non-clinically significant prostate cancer. The location of the main lesion in the peripheral zone emerged as a positive predictive factor for clinically significant disease based on SB. These findings may enhance patient-tailored management

Tunable microsecond dynamics of an allosteric switch regulate the activity of a AAA+ disaggregation machine.

Large protein machines are tightly regulated through allosteric communication channels. Here we demonstrate the involvement of ultrafast conformational dynamics in allosteric regulation of ClpB, a hexameric AAA+ machine that rescues aggregated proteins. Each subunit of ClpB contains a unique coiled-coil structure, the middle domain (M domain), proposed as a control element that binds the co-chaperone DnaK. Using single-molecule FRET spectroscopy, we probe the M domain during the chaperone cycle and find it to jump on the microsecond time scale between two states, whose structures are determined. The M-domain jumps are much faster than the overall activity of ClpB, making it an effectively continuous, tunable switch. Indeed, a series of allosteric interactions are found to modulate the dynamics, including binding of nucleotides, DnaK and protein substrates. This mode of dynamic control enables fast cellular adaptation and may be a general mechanism for the regulation of cellular machineries

6-Br-5methylindirubin-3′oxime (5-Me-6-BIO) targeting the leishmanial glycogen synthase kinase-3 (GSK-3) short form affects cell-cycle progression and induces apoptosis-like death: Exploitation of GSK-3 for treating leishmaniasis

Indirubins known to target mammalian cyclin-dependent kinases (CDKs) and glycogen synthase kinase (GSK-3) were tested for their antileishmanial activity. 6-Br-indirubin-3'-oxime (6-BIO), 6-Br-indirubin-3'acetoxime and 6-Br-5methylindirubin-3'oxime (5-Me-6-BIO) were the most potent inhibitors of L. donovani promastigote and amastigote growth (IC50 values ≤ 1.2 μM). Since the 6-Br substitution on the indirubin backbone greatly enhances the selectivity for mammalian GSK-3 over CDKs, we identified the leishmanial GSK-3 homologues, a short (LdGSK-3s) and a long one, focusing on LdGSK-3s which is closer to human GSK-3β for further studies. Kinase assays showed that 5-Me-6-BIO inhibited LdGSK-3s more potently than CRK3 (the CDK1 homologue in Leishmania), while 6-BIO was more selective for CRK3. Promastigotes treated with 5-Me-6-BIO accumulated in the S and G2/M cell-cycle phases and underwent apoptosis-like death. Interestingly, these phenotypes were completely reversed in parasites over-expressing LdGSK-3s. This finding strongly supports that LdGSK-3s is a) the intracellular target of 5-Me-6-BIO and b) involved in cell-cycle control and in pathways leading to apoptosis-like death. 6-BIO treatment induced a G2/M arrest, consistent with inhibition of CRK3, and apoptosis-like death. These effects were partially reversed in parasites over-expressing LdGSK-3s suggesting that in vivo 6-BIO may also target LdGSK-3s. Molecular docking of 5-Me-6-BIO in CRK3 and 6-BIO in human GSK-3β and LdGSK-3s active sites predict the existence of functional/structural differences that are sufficient to explain the observed difference in their affinity. In conclusion, LdGSK-3s is validated as a potential drug target in Leishmania and could be exploited for the development of selective indirubin-based leishmanicidals

Trends in urologic oncology clinical practice and medical education under COVID-19 pandemic: An international survey of senior clinical and academic urologists

Objective: Ad-hoc guidelines for managing the COVID-19 pandemic are published worldwide. We investigated international applications of such policies in the urologic-oncology community. Methods: A 20-item survey was e-mailed via SurveyMonkey to 100 international senior urologic-oncology surgeons. Leaders’ policies regarding clinical/surgical management and medical education were surveyed probing demographics, affiliations, urologic-oncologic areas of interest, and current transportation restrictions. Data on COVID-19 burden were retrieved from the ECDC. Statistical analyses employed non-parametric tests (SPSS v.25.0, IBM). Results: Of 100 leaders from 17 countries, 63 responded to our survey, with 58 (92%) reporting university and/or cancer-center affiliations. Policies on new-patient visits remained mostly unchanged, while follow-up visits for low-risk diseases were mostly postponed, for example, 83.3% for small renal mass (SRM). Radical prostatectomy was delayed in 76.2% of cases, while maintaining scheduled timing for radical cystectomy (71.7%). Delays were longer in Europe than in the Americas for kidney cancer (SRM follow-up, P = 0.014), prostate cancer (new visits, P = 0.003), and intravesical therapy for intermediate-risk bladder cancer (P = 0.043). In Europe, COVID-19 burden correlated with policy adaptation, for example, nephrectomy delays for T2 disease (r = 0.5, P =0.005). Regarding education policies, trainees’ medical education was mainly unchanged, whereas senior urologists' planned attendance at professional meetings dropped from 6 (IQR 1−11) to 2 (IQR 0−5) (P < 0.0001). Conclusion: Under COVID-19, senior urologic-oncology surgeons worldwide apply risk-stratified approaches to timing of clinical and surgical schedules. Policies regarding trainee education were not significantly affected. We suggest establishment of an international consortium to create a directive for coping with such future challenges to global healthcare.SCOPUS: re.jDecretOANoAutActifinfo:eu-repo/semantics/publishe