The antiplasmodial activity of the carboxylic acid metabolite of piperaquine and its pharmacokinetic profiles in healthy volunteers.

BACKGROUND: The long-acting antimalarial drug piperaquine can be metabolized into the carboxylic acid metabolite (PQM). However, the clinical relevance of PQM remains unclear. OBJECTIVES: The pharmacodynamics/pharmacokinetics of PQM were studied. METHODS: The antimalarial activity of PQM was studied in vitro (Plasmodium strains Pf3D7 and PfDd2) and in vivo (murine Plasmodium yoelii). The toxicity of PQM was evaluated in mice, in terms of the general measures of animal well-being, serum biochemical examination and ECG monitoring. The pharmacokinetic profiles of piperaquine and its metabolite PQM were investigated in healthy subjects after recommended oral doses of piperaquine. RESULTS: PQM showed no relevant in vitro antimalarial activity (IC50 > 1.0 µM) with no significant toxicity. After recommended oral administration of piperaquine to healthy subjects, the maximum concentration of PQM was less than 30.0 nM, and it did not accumulate after repeated dosing. CONCLUSIONS: With a low antimalarial potency, PQM should not contribute to the efficacy of piperaquine with clinically acceptable doses.

LC-HRMS methods for the quantification of two artemisinin drugs and their metabolites in rat blood and plasma.

As first-line antimalarials used in the artemisinin combination therapy, artemisinin drugs exert their action inside red blood cells. However, the blood pharmacokinetic characteristics of artemisinin drugs have not been fully revealed owing to their built-in chemical instability initiated by Fe2+ released from hemoglobin, with limited information on their metabolites. In this study, liquid chromatography tandem high-resolution mass spectrometric (LC-HRMS) methods were developed for the quantification of two representative artemisinin drugs (artemisinin, ART; dihydroartemisinin, DHA) and their respective metabolite (deoxyartemisinin, D-ART; dihydroartemisinin glucuronide, DHA-Glu) in rat blood/plasma. The blood samples were pretreated with the stabilizer (0.4 m potassium dichromate and 3% EDTA-2Na). The methods displayed excellent specificity, linearity, accuracy and precision for ART (17.7-709.2 nm) and its metabolite D-ART (18.8-751.9 nm), and the linear range was 40.0-4,000.0 nm for both DHA and DHA-Glu. The methods were successfully applied to the pharmacokinetic studies of ART and DHA in rats. The blood-to-plasma ratio was 0.8-1.5 for ART, 1.0-1.5 for D-ART, 1.2-2.2 for DHA and 0.9-1.3 for DHA-Glu, which was time dependent. The results indicated that artemisinin drugs and their metabolites showed a high but different blood-to-plasma ratio, which should be considered when optimizating their dosing regimens or evaluating their clinical outcomes.

A scalable and reproducible preparation for the antitumor protein TLC, a human-derived telomerase inhibitor.

Telomerase, which is overexpressed in approximately 90% of liver cancer cells, is an ideal target for anti-liver cancer therapy. LPTS, a putative liver tumor suppressor, is the only human-derived protein that can bind telomerase directly and inhibit the extension of telomere activity. Our previous studies demonstrated that TAT-LPTS-LC (TLC), a recombinant protein fused by the C-terminal 133-328 fragment of LPTS and TAT peptides, could be delivered into cells to inhibit telomerase-positive hepatoma cell growth in vitro and in vivo with very low toxicity. In the present study, E. coli strains which expressed TLC in abundance were screened and cultured in a laboratory bioreactor. A reproducible protein separation process was built, and this process was suitable for industrial amplification. The yields of TLC protein were up to 184 mg in one batch with a purity of approximately 95%. The purified TLC protein had a similar inhibitory effect on telomerase activity in vitro compared with those purified by Ni-affinity chromatography. Furthermore, TLC protein could be delivered into the cell nucleus to increase the doubling time of the cell and suppress cell growth in telomerase-positive liver cancer cell lines. Cell growth inhibition was negatively correlated with telomere length, suggesting that TLC is a highly targeted telomerase-telomere anticancer agent. These results will contribute to future preclinical studies of the TLC protein.

Geniposide attenuates postischemic long-term potentiation via GluN2A.

N-Methyl-D-aspartate receptor (NMDAR)-induced antioxidation is a significant cause of neuronal injury after ischemic stroke. In a previous work, we verified the neuroprotective roles of geniposide during tMCAO in vivo. However, it remains unknown whether geniposide ameliorates injury to hippocampal neurons during Ischemic Long Term Potentiation (iLTP) induction in vitro. After induction of cells oxygen-glucose deprivation or hydrogen peroxide, the protection of geniposide evaluated by MTT assay and electrophysiological tests. In this study, we suggested neuronal cell apoptosis was attenuated by geniposide. Furthermore, field excitatory postsynaptic potentials (fEPSCs) following postischemic LTP were assessed by electrophysiological tests. Finally, we determined that medium and high doses of geniposide attenuated oxidative stress insult and improved iLTP. Importantly, these effects were abolished by cotreatment with geniposide and the GluN2A antagonist NVP. In contrast, the GluN2B inhibitor ifenprodil failed to have an effect. In conclusion, we suggest for the first time that treatment with geniposide can attenuate postischemic LTP induction in a concentration-dependent manner. We infer that GluN2A-containing NMDARs are involved in the neuroprotection induced by geniposide treatment in ischemia.

Identification of the association of CD28+ CD244+ Tc17/IFN-γ cells with chronic hepatitis C virus infection.

CD8+ T cells play multiple and complex immunological roles including antiviral, regulatory, and exhaustive effects in hepatitis C virus (HCV) infected patients. Some CD8+ T-cell subsets were confirmed to be closely related to HCV infection such as TCM , TEM , TEM RA, Tc17, and CD8+ Treg. Herein, we report a new subset of interleukin (IL)-17/interferon (IFN)-γ producing CD8+ T (Tc17/IFN-γ) cells that markedly correlate with CD28+ CD244+ cells, IL-17 levels, and HCV RNA in HCV patients. During early treatment with peg-IFN-a2a plus ribavirin, the imbalance of these Tc17/IFN-γ cells could be partially restored, together with normalized serum alanine aminotransferase but not aspartate transaminase. Also, we analyzed the dynamic change of the percentage of this T cells subset in patients with different outcome after 4-week course of treatment with peg-IFN-a2a plus ribavirin and found that the percentage of CD8+ CD28+ CD244+ T cells significantly decreased in recovered patients but not in nonrecovered patients. In vitro, CD28+ CD244+ T cells were the only CD8+ T-cell group that secreted both IL-17 and IFN-γ in this axis and blockade with anti-CD244 antibodies significantly reduced cytokine production. Taken together, this study demonstrates that the frequency and regulatory functions of CD28+ CD244+ Tc17/IFN-γ cells may play an important role in persistent HCV infection.

Decision-making among the substitute decision makers in intensive care units: An investigation of decision control preferences and decisional conflicts.

AIMS: To explore decision control preferences and decisional conflicts and to analyse their association among the surrogate decision makers in the intensive care unit. DESIGN: The study carried out a cross-sectional survey among the surrogates. METHODS: The participants were 115 surrogate decision makers of critical patients, from August to September 2019. A Chi-squared test and logistic regression were used to assess decision control preferences and decisional conflicts, and Spearman's rank correlation coefficient was employed to examine their association. RESULTS: Of the 115 surrogate decision makers, 51.3% preferred a collaborative role, and 63.48% were somewhat unsure about making decisions. Logistic regression analysis identified decision control preferences was associated with surrogates' age, education level, and personality traits, while decisional conflicts was associated with surrogates' age, education level, character, medical expense burden, and Acute Physiology and Chronic Health Evaluation-II score. Cohen's kappa statistics showed a bad concordance of decision-making expectations and actuality, with kappa values of 0.158 (p < .05). Wherein surrogates who experienced discordance between their preferred and actual roles, have relatively higher decisional conflicts. CONCLUSION: This study identified individual differences of surrogate decision makers in decision control preferences and decisional conflicts. These results imply that incorporation of the individual decision preferences and communication styles into care plans is an important first step to develop high quality decision support. IMPACT: This research is a contribution to the limited study on decision control preferences and decisional conflicts among surrogate decision makers of critically ill patients. Moreover based on the investigation of understanding the status and related factors of decision preferences and decisional conflicts set the stage for developing effective decision support interventions.

Metabolism of Piperaquine to Its Antiplasmodial Metabolites and Their Pharmacokinetic Profiles in Healthy Volunteers.

As a partner antimalarial for artemisinin drug-based combination therapy (ACT), piperaquine (PQ) can be metabolized into two major metabolites, including piperaquine N-oxide (M1) and piperaquine N,N-dioxide (M2). To better understand the antimalarial potency of PQ, the antimalarial activity of the PQ metabolites (M1 and M2) was studied in vitro (in Plasmodium falciparum strains Pf3D7 and PfDd2) and in vivo (in the murine species Plasmodium yoelii) in this study. The recrudescence and survival time of infected mice were also recorded after drug treatment. The pharmacokinetic profiles of PQ and its two metabolites (M1 and M2) were investigated in healthy subjects after oral doses of two widely used ACT regimens, i.e., dihydroartemisinin plus piperaquine phosphate (Duo-Cotecxin) and artemisinin plus piperaquine (Artequick). Remarkable antiplasmodial activity was found for PQ (50% growth-inhibitory concentration [IC50], 4.5 nM against Pf3D7 and 6.9 nM against PfDd2; 90% effective dose [ED90], 1.3 mg/kg of body weight), M1 (IC50, 25.5 nM against Pf3D7 and 38.7 nM against PfDd2; ED90, 1.3 mg/kg), and M2 (IC50, 31.2 nM against Pf3D7 and 33.8 nM against PfDd2; ED90, 2.9 mg/kg). Compared with PQ, M1 showed comparable efficacy in terms of recrudescence and survival time and M2 had relatively weaker antimalarial potency. PQ and its two metabolites displayed a long elimination half-life (∼11 days for PQ, ∼9 days for M1, and ∼4 days for M2), and they accumulated after repeated administrations. The contribution of the two PQ metabolites to the efficacy of piperaquine as a partner drug of ACT for the treatment of malaria should be considered for PQ dose optimization.

Synthesis, Design, and Structure⁻Activity Relationship of the Pyrimidone Derivatives as Novel Selective Inhibitors of Plasmodium falciparum Dihydroorotate Dehydrogenase.

The inhibition of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) potentially represents a new treatment option for malaria, as P. falciparum relies entirely on a de novo pyrimidine biosynthetic pathway for survival. Herein, we report a series of pyrimidone derivatives as novel inhibitors of PfDHODH. The most potent compound, 26, showed high inhibition activity against PfDHODH (IC50 = 23 nM), with >400-fold species selectivity over human dihydroorotate dehydrogenase (hDHODH). The brand-new inhibitor scaffold targeting PfDHODH reported in this work may lead to the discovery of new antimalarial agents.

MHC class II peptides induce CD8+CD44+Ly49+ regulatory T cells in C57BL/6 mice.

CD8+ regulatory T cells (Tregs) play an important role in regulating peripheral immune tolerance. However, difficulties in the characterization of CD8+ Tregs that lack suitable markers have a considerably limited research in this area. Moreover, the induction and effector mechanisms of CD8+ Tregs remain unclear. Herein, we demonstrate the suitability of Ly49 and CD44 as markers for CD8+ Tregs. Our data also show that MHC class II restricted peptides induce CD8+CD44+Ly49+ Tregs via CD4+ T cell activation. Furthermore, we also found cross-suppressive activity of these CD8+ Tregs on responding CD4+ T cells in a cytotoxicity dependent manner. Our data provide new insights into the induction and function of CD8+ Tregs.

Protein Dynamics Mediated by Cardiolipin in Bacteria.

Bacterial proteins targeting the appropriate subcellular sites are the base for their proper function. Several studies have shown that the anionic phospholipid cardiolipin (CL), a conical lipid preferring negative membrane curvature, modulates the lipid bilayers' structure, which impacts the activity of their resident proteins. Due to the favor of negative membrane curvature, CL is not randomly distributed in the bacterial plasma membrane. In contrast, it gathers in particular parts of the cell membrane to form microdomains, in which many functional membrane proteins are accumulated and carry out diverse physiological processes of bacteria, such as cell division, metabolism, infection, and antibiotic residence. In addition, CL has a unique structure that carries two negative charges, which makes it play a pivotal role in protein assembly, interaction, and location. These characteristics of CL make it closely related to many crucial physiological functions of bacteria. Here, we have reviewed the mechanism of protein dynamics mediated by CL initiated on the bacterial membrane. Furthermore, we studied the effect of CL on bacterial infection and antibiotic residence. Finally, the CL-targeting therapeutic agents for antibacterial therapy are also examined.

[Evaluation of transfection effectiveness using fluorescein-labelled oligonucleotides and entraster-R siRNA transfection into Plasmodium falciparum].

The cultured Plasmodium falciparum parasites were synchronized twice by 5% sorbitol treatment twice (8-hour window), and then incubated at 37 degrees C for 16 h. Parasites were transfected with fluorescein-labelled oligonucleotides (group A) or fluorescein-labelled oligonucleotides+Entranster-R siRNA transfection reagent (group B). After 5 h a part of parasites was evaluated by fluorescence microscopy and flow cytometry. The rest of parasites were washed with RPMI 1640 medium, and then incubated with 500 microl new medium containing 2% fresh erythrocytes for another 12 h, and detected by flow cytometry. The fluorescein-labelled oligonucleotides were localized in erythrocytes in group B, but nearly no fluorescence was observed for group A. Flow cytometry analysis indicated that the transfection efficiency of group B [(47.40 +/- 3.39)%] was higher than that of group A [(0.60 +/- 0.27)%]. In the second cell cycle, the transfection efficiency in group B was (26.85 +/- 2.90)%, while that of group A was nearly zero. The results indicated that Entranster-R siRNA transfection reagent may increase the oligonucleotides transfection efficiency.

The Effect of Retroconversion Metabolism of N-oxide Metabolites by Intestinal Microflora on Piperaquine Elimination in Mice, as well as in Humans Predicted Using a PBPK Model.

BACKGROUND: Piperaquine (PQ) and its pharmacologically active metabolite PQ N-oxide (PM1) can be metabolically interconverted via hepatic cytochrome P450 and FMO enzymes. OBJECTIVES: The reductive metabolism of PM1 and its further N-oxidation metabolite (PM2) by intestinal microflora was evaluated, and its role in PQ elimination was also investigated. METHODS: The hepatic and microbial reduction metabolism of PM1 and PM2 was studied in vitro. The reaction phenotyping experiments were performed using correlation analysis, selective chemical inhibition, and human recombinant CYP/FMO enzymes. The role of microbial reduction metabolism in PQ elimination was evaluated in mice pretreated with antibiotics. The effect of the reduction metabolism on PQ exposures in humans was predicted using a physiologically-based pharmacokinetic (PBPK) model. RESULTS: Both hepatic P450/FMOs enzymes and microbial nitroreductases (NTRs) contributed to the reduction metabolism of two PQ N-oxide metabolites. In vitro physiologic and enzyme kinetic studies of both N-oxides showed a comparable intrinsic clearance by the liver and intestinal microflora. Pretreatment with antibiotics did not lead to a significant (P > 0.05) change in PQ pharmacokinetics in mice after an oral dose. The predicted pharmacokinetic profiles of PQ in humans did not show an effect of metabolic recycling. CONCLUSION: Microbial NTRs and hepatic P450/FMO enzymes contributed to the reduction metabolism of PQ Noxide metabolites. The reduction metabolism by intestinal microflora did not affect PQ clearance, and the medical warning in patients with NTRs-related disease (e.g., hyperlipidemia) will not be clinically meaningful.

Ultrasound-assisted limited enzymatic hydrolysis of high concentrated soy protein isolate: Alterations on the functional properties and its relation with hydrophobicity and molecular weight.

The effects of power ultrasound (US) pretreatment on the preparation of soy protein isolate hydrolysate (SPIH) prepared at the same degree of hydrolysis (DH) of 12 % were measured. Cylindrical power ultrasound was modified into mono-frequency (20, 28, 35, 40, 50 kHz) ultrasonic cup coupled with an agitator to make it applicable for high density SPI (soy protein isolate) solutions (14 %, w/v). A comparative study of the alterations of the hydrolysates molecular weight, hydrophobics, antioxidants and functional properties change as well as their relation were explored. The results showed that under the same DH, ultrasound pretreatment decelerated the degradation of protein molecular mass and the decrease rate of the degradation lessened with the increase of ultrasonic frequency. Meanwhile, the pretreatments improved the hydrophobics and antioxidants properties of SPIH. Both surface hydrophobicity (H0) and relative hydrophobicity (RH) of the pretreated groups increased with the decrease of ultrasonic frequency. Lowest frequency (20 kHz) ultrasound pretreatment had the most improved emulsifying properties and water holding capacities, although decrease in the viscosity and solubility were found. Most of these alterations were correspondence toward the change in hydrophobics properties and molecular mass. In conclusion, the frequency selection of ultrasound pretreatment is essential for the alteration of SPIH functional qualities prepared at the same DH.

[Application of mind map in teaching of medical parasitology].

To improve the teaching quality of medical parasitology, mind map, a simple and effective learning method, was introduced. The mind map of each chapter was drawn by teacher and distributed to students before the class. It was helpful for teacher to straighten out the teaching idea, and for students to grasp the important learning points, perfect the class notes and improve learning efficiency. The divergent characteristics of mind map can also help to develop the students' innovation ability.

[Cloning and bioinformatics analysis of PFC0460w in Plasmodium falciparum].

The gene fragment of PFC0460w was amplified from RNA of Plasmodium falciparum 3D7 strain with RT-PCR, and cloned into pGEM-T easy vector. The recombinant plasmid was transformed into E. coli DH5alpha and the positive clones were selected, which were identified by PCR and sequencing. The results showed that there were three sequences of PFC0460w fragment, respectively with length of 618, 597 and 543 bp. The 618 bp fragment was completely consistent with the sequence published in PlasmoDB (GenBank No. XM_001351147), and the 597 bp and 543 bp fragments were submitted to GenBank with Accession No. of JF799872 and JF799873, respectively. 205 amino acids were encoded by the 618 bp fragment, and five kinds of protein structure were predicted by Robetta.

Corrigendum: Ultrasonic washing as an abiotic elicitor to induce the accumulation of phenolics of fresh-cut red cabbages: Effects on storage quality and microbial safety.

[This corrects the article DOI: 10.3389/fnut.2022.1006440.].

Ultrasonic washing as an abiotic elicitor to induce the accumulation of phenolics of fresh-cut red cabbages: Effects on storage quality and microbial safety.

Ultrasonic washing has been proved to be an abiotic elicitor to induce the accumulation of phenolics in some fruit and vegetables. However, the feasibility of ultrasonic washing on the accumulation of phenolics in fresh-cut red cabbages has not yet been reported. Therefore, the effects of ultrasonic washing on the phenolics and related phenolic metabolism enzymes of fresh-cut red cabbages, as well as quality and microbial safety during cold storage, were investigated. Firstly, the single-factor tests were used to optimize the ultrasonic processing parameters, including frequency mode, frequency amplitude, power density, frequency cycle time, and ultrasonic washing. Then the activities of the enzymes related to phenolic metabolisms after optimal ultrasound treatment were investigated, including phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD). Additionally, the quality and microbial safety of fresh-cut red cabbages stored at 4°C under the optimal ultrasound treatment were evaluated. The results showed that the content of soluble phenolics (SPs) in fresh-cut red cabbages increased significantly during storage under the optimal conditions (28 ± 2 kHz, 60 W/L, 400 ms, and 20 min) compared with the control (P < 0.05). The PAL activity was activated and the PPO and POD activities were inhibited after ultrasonic washing, which contributed to the increase in the content of SPs. Meanwhile, the storage quality and microbial safety of fresh-cut red cabbages were improved. Ultrasonic washing reduced the weight loss and respiration rate and improved the color and texture characteristics. Additionally, the fresh-cut red cabbages after ultrasonic washing showed more retention of ascorbic acid (AA), total soluble proteins (TSPs), total soluble sugars (TSSs), and total soluble solids (SSs) compared with the control. Finally, ultrasonic washing effectively inhibited the growth of bacteria, molds and yeasts, which is beneficial to the extension of the shelf-life of fresh-cut red cabbages. Therefore, ultrasonic washing can be used as a tool to increase the content of SPs in fresh-cut red cabbages while retaining quality attributes and microbial safety.

[Study of neutralization antibodie induced by DNA vaccine of HCV envelope protein 2 in mice].

OBJECTIVE: To explore the feasibility of induction of neutralization antibodies against hepatitis C virus (HCV) infection by HCV envelope 2 protein (E2) DNA vaccines immunization. METHODS: Two kinds of expression plasmids of HCV envelope 2 protein, plasmid pCI-1b661 Delta encoding hydrophobic carboxyl terminal truncated E2 and pCI-1b661 Delta encoding E2 with deletion of hypervariable region 1 (HVR1) and carboxyl terminal, were constructed and respectively transfeted 293T cells, and truncated E2 protein in whole cell lysate and supernatant of 293T cells were analyzed by Western blot. After BALB/c mouse were intramuscularly immunized by the plasmids, sera antibodies against HVR1 were detected by ELISA and the neutralization activity of the antibodies were assayed with HCV pseudotype particle (HCVpp). RESULTS: Both plasmids could express secretary truncated E2 protein. All the mice immunized with plasmid pCI-1b661 produced HVR1 antibodies,while no HVR1 antibodies were detected in pCI-1b661 Delta immunized mice. The sera neutralization percentages against HCVpp in pCI1lb661 Delta and pCI-lb661 Delta immunized mice were (78.5 +/- 13.8)% and (38.7 +/- 6.5)%, respectively (P <0.01). Sera neutralization activity against HCVpp was positive correlated with the level of HVR1 antibodies in pCI-1b661 immunized mice (r = 0.967, P<0.01). CONCLUSION: DNA vaccines expressing truncated E2 protein could induce neutralization antibodies against HCV, and neutralization antibodies mainly was consisted of the antibodies against HVR1.

The immunoenhancement effects of sea buckthorn pulp oil in cyclophosphamide-induced immunosuppressed mice.

In this study, the immunomodulatory effect of sea buckthorn (SBT) pulp oil was elucidated in immunosuppressed Balb/c mice induced by cyclophosphamide (CTX). The results showed that SBT pulp oil could reverse the decreasing trend of body weight, thymus/spleen index and hematological parameters induced by CTX. Compared with immunosuppressive mice induced by CTX, SBT pulp oil could enhance NK cytotoxicity, macrophage phagocytosis, and T lymphocyte proliferation, and regulate the proportion of T cell subsets in mesenteric lymph nodes (MLN), and promote the production of secretory immunoglobulin A (sIgA), IFN-γ, IL-2, IL-4, IL-12 and TNF-α in the intestines. In addition, SBT pulp oil can promote the production of short fatty acids (SCFAs), increase the diversity of gut microbiota, improve the composition of intestinal flora, increase the abundance of Alistipes, Bacteroides, Anaerotruncus, Lactobacillus, ASF356, and Roseburia, while decreasing the abundance of Mucispirillum, Anaeroplasma, Pelagibacterium, Brevundimonas, Ochrobactrum, Acinetobacter, Ruminiclostridium, Blautia, Ruminiclostridium, Oscillibacter, and Faecalibaculum. This study shows that SBT pulp oil can regulate the diversity and composition of intestinal microflora in CTX-induced immunosuppressive Balb/c mice, thus enhancing the intestinal mucosa and systemic immune response. The results can provide a basis for understanding the function of SBT pulp oil and its application as a new probiotic and immunomodulator.

Global survey of miRNAs and tRNA-derived small RNAs from the human parasitic protist Trichomonas vaginalis.

BACKGROUND: Small non-coding RNAs play critical regulatory roles in post-transcription. However, their characteristics in Trichomonas vaginalis, the causative agent of human sexually transmitted trichomoniasis, still remain to be determined. METHODS: Small RNA transcriptomes from Trichomonas trophozoites were deep sequenced using the Illumina NextSeq 500 system and comprehensively analyzed to identify Trichomonas microRNAs (miRNAs) and transfer RNA (tRNA)-derived small RNAs (tsRNAs). The tsRNA candidates were confirmed by stem-loop quantitative reverse transcription-PCR, and motifs to guide the cleavage of tsRNAs were predicted using the GLAM2 algorithm. RESULTS: The miRNAs were found to be present in T. vaginalis but at an extremely low abundance (0.0046%). Three categories of endogenous Trichomonas tsRNAs were identified, namely 5'tritsRNAs, mid-tritsRNAs and 3'tritsRNAs, with the 5'tritsRNAs constituting the dominant category (67.63%) of tsRNAs. Interestingly, the cleavage site analysis verified both conventional classes of tRNA-derived fragments (tRFs) and tRNA-halves in tritsRNAs, indicating the expression of tRNA-halves in the non-stress condition. A total of 25 tritsRNAs were experimentally confirmed, accounting for 78.1% of all tested candidates. Three motifs were predicted to guide the production of tritsRNAs. The results prove the expression of tRFs and tRNA-halves in the T. vaginalis transcriptome. CONCLUSIONS: This is the first report of genome-wide investigation of small RNAs, particularly tsRNAs and miRNAs, from Trichomonas parasites. Our findings demonstrate the expression profile of tsRNAs in T. vaginalis, while miRNA was barely detected. These results may promote further research aimed at gaining a better understanding of the evolution of small non-coding RNA in T. vaginalis and their functions in the pathogenesis of trichomoniasis.