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Parasites & Vectors Mar 2024Toxoplasmosis is a zoonotic disease caused by the infection of the protozoa Toxoplasma gondii (T. gondii), and safe and effective therapeutic drugs are lacking....
BACKGROUND
Toxoplasmosis is a zoonotic disease caused by the infection of the protozoa Toxoplasma gondii (T. gondii), and safe and effective therapeutic drugs are lacking. Mitochondria, is an important organelle that maintains T. gondii survival, however, drugs targeting mitochondria are lacking.
METHODS
The cytotoxicity of BAM15 was detected by CCK-8 and the in vitro effects of BAM15 was detected by qPCR, plaque assay and flow cytometry. Furthermore, the ultrastructural changes of T. gondii after BAM15 treatment were observed by transmission electron microscopy, and further the mitochondrial membrane potential (ΔΨm), ATP level and reactive oxygen species (ROS) of T. gondii after BAM15 treatment were detected. The pharmacokinetic experiments and in vivo infection assays were performed in mice to determine the in vivo effect of BAM15.
RESULTS
BAM15 had excellent anti-T. gondii activity in vitro and in vivo with an EC50 value of 1.25 μM, while the IC50 of BAM15 in Vero cells was 27.07 μM. Notably, BAM15 significantly inhibited proliferation activity of T. gondii RH strain and Prugniaud strain (PRU), caused T. gondii death. Furthermore, BAM15 treatment induced T. gondii mitochondrial vacuolation and autolysis by TEM. Moreover, the decrease in ΔΨm and ATP level, as well as the increase in ROS production further confirmed the changes CONCLUSIONS: Our study identifies a useful T. gondii mitochondrial inhibitor, which may also serve as a leading molecule to develop therapeutic mitochondrial inhibitors in toxoplasmosis.'
Topics: Chlorocebus aethiops; Animals; Mice; Toxoplasma; Vero Cells; Reactive Oxygen Species; Toxoplasmosis; Mitochondria; Adenosine Triphosphate; Rodent Diseases
PubMed: 38424591
DOI: 10.1186/s13071-024-06187-8 -
Molecules (Basel, Switzerland) Feb 2024Lipoteichoic acid (LTA) plays an essential role in bacterial growth and resistance to antibiotics, and LTA synthetase (LtaS) was considered as an attractive target for...
Lipoteichoic acid (LTA) plays an essential role in bacterial growth and resistance to antibiotics, and LTA synthetase (LtaS) was considered as an attractive target for combating Gram-positive infections. Azalomycin F, a natural guanidyl-containing polyhydroxy macrolide, can target the LTA of . Using various technologies including enzyme-linked immunosorbent assay, transmission electron microscope, proteomics, and parallel reaction monitoring, here, the experimental results indicated that azalomycin F can accelerate the LTA release and disrupt the cell envelope, which would also lead to the feedback upregulation on the expressions of LtaS and other related enzymes. Simultaneously, the reconstituted enzyme activity evaluations showed that azalomycin F can significantly inhibit the extracellular catalytic domain of LtaS (eLtaS), while this was vague for LtaS embedded in the liposomes. Subsequently, the fluorescence analyses for five incubation systems containing azalomycin F and eLtaS or the LtaS-embedded liposome indicated that azalomcyin F can spontaneously bind to the active center of LtaS. Combining the mass spectroscopy analyses and the molecular dockings, the results further indicated that this interaction involves the binding sites of substrates and the LTA prolongation, especially the residues Lys299, Phe353, Trp354 and His416. All these suggested that azalomycin F has multiple antibacterial mechanisms against . It can not only inhibit LTA biosynthesis through the interactions of its guanidyl side chain with the active center of LtaS but also disrupt the cell envelope through the synergistic effect of accelerating the LTA release, damaging the cell membrane, and electrostatically interacting with LTA. Simultaneously, these antibacterial mechanisms exhibit a synergistic inhibition effect on cells, which would eventually cause the cellular autolysis.
Topics: Staphylococcus aureus; Lipopolysaccharides; Cell Membrane; Anti-Bacterial Agents; Teichoic Acids; Macrolides
PubMed: 38398608
DOI: 10.3390/molecules29040856 -
Nature Communications Feb 2024Traditional histochemical staining of post-mortem samples often confronts inferior staining quality due to autolysis caused by delayed fixation of cadaver tissue, and...
Traditional histochemical staining of post-mortem samples often confronts inferior staining quality due to autolysis caused by delayed fixation of cadaver tissue, and such chemical staining procedures covering large tissue areas demand substantial labor, cost and time. Here, we demonstrate virtual staining of autopsy tissue using a trained neural network to rapidly transform autofluorescence images of label-free autopsy tissue sections into brightfield equivalent images, matching hematoxylin and eosin (H&E) stained versions of the same samples. The trained model can effectively accentuate nuclear, cytoplasmic and extracellular features in new autopsy tissue samples that experienced severe autolysis, such as COVID-19 samples never seen before, where the traditional histochemical staining fails to provide consistent staining quality. This virtual autopsy staining technique provides a rapid and resource-efficient solution to generate artifact-free H&E stains despite severe autolysis and cell death, also reducing labor, cost and infrastructure requirements associated with the standard histochemical staining.
Topics: Hematoxylin; Eosine Yellowish-(YS); Staining and Labeling; Neural Networks, Computer
PubMed: 38396004
DOI: 10.1038/s41467-024-46077-2 -
Animal Nutrition (Zhongguo Xu Mu Shou... Mar 2024Phytin is the Ca-Mg-K salt of phytic acid that is created and deposited in the aleurone layer and/or germ of grains and legumes. Its high presence in feedstuffs for fowl... (Review)
Review
Phytin is the Ca-Mg-K salt of phytic acid that is created and deposited in the aleurone layer and/or germ of grains and legumes. Its high presence in feedstuffs for fowl and swine diets results in it being a universal and significant impediment to optimum performance. Phytin impairs gastrointestinal recovery of a wide array of nutrients, the effect varying with the nutrient concerned. On exposure to low pH during gastric digestion, phytin dissociates into phytic acid and solubilized Ca. Even at low gastric pH, phytic acid is negatively charged which forms the basis of its anti-nutritive behavior. Pepsinogen has extensive basic amino acids on its activation peptide that are presented as cations at low pH which are targeted by pepsin for activation. Partially crystalized Ca near the enzyme's active site further stabilizes its newly formed structure. Thus, phytic acid appears to interfere with gastric digestion by several mechanisms; interfering with pepsinogen activation by binding to the polypeptide's basic amino acids; coordinating free Ca, destabilizing pepsin; binding some dietary proteins directly, further compromising gastric proteolysis. Upon digesta attaining neutrality in the duodenum, Ca and other cations re-bind with accessible anions, phytic acid being a significant contender. Phytate not only binds free cations but can also strip them from enzymes (e.g. Ca, Zn) which reduces their structural resistance to autolysis and ability as co-factors (e.g. Zn) to increase enzyme activity. Goblet cells initially employ Ca as an electronic shield between mucin layers enabling granule formation and cell storage. After mucin granule release, Ca is progressively displaced by Na to free the viscous mucins enabling its translocation. Mucin entangles with the glycocalyx of adjacent enterocytes thereby constructing the unstirred water layer (USWL). Excessive removal of Ca from mucin by phytic acid increases its fluidity facilitating its loss from the USWL with its associated Na. This partly explains increased mucin and Na losses noted with high phytate diets. This review suggests that phytic acid binding of Ca and less so Zn is the basis for the diversity in nutrient losses encountered and that such losses are in proportion to dietary phytate content.
PubMed: 38379939
DOI: 10.1016/j.aninu.2023.11.010 -
Nature Communications Feb 2024Mechanical force contributes to perforin pore formation at immune synapses, thus facilitating the cytotoxic T lymphocytes (CTL)-mediated killing of tumor cells in a...
Mechanical force contributes to perforin pore formation at immune synapses, thus facilitating the cytotoxic T lymphocytes (CTL)-mediated killing of tumor cells in a unidirectional fashion. How such mechanical cues affect CTL evasion of perforin-mediated autolysis remains unclear. Here we show that activated CTLs use their softness to evade perforin-mediated autolysis, which, however, is shared by T leukemic cells to evade CTL killing. Downregulation of filamin A is identified to induce softness via ZAP70-mediated YAP Y357 phosphorylation and activation. Despite the requirements of YAP in both cell types for softness induction, CTLs are more resistant to YAP inhibitors than malignant T cells, potentially due to the higher expression of the drug-resistant transporter, MDR1, in CTLs. As a result, moderate inhibition of YAP stiffens malignant T cells but spares CTLs, thus allowing CTLs to cytolyze malignant cells without autolysis. Our findings thus hint a mechanical force-based immunotherapeutic strategy against T cell leukemia.
Topics: T-Lymphocytes, Cytotoxic; Perforin; Pore Forming Cytotoxic Proteins; Cytotoxicity, Immunologic
PubMed: 38360940
DOI: 10.1038/s41467-024-45750-w -
RSC Advances Feb 2024Determining asphyxia as the cause of death is crucial but is based on an exclusive strategy because it lacks sensitive and specific morphological characteristics in...
Determining asphyxia as the cause of death is crucial but is based on an exclusive strategy because it lacks sensitive and specific morphological characteristics in forensic practice. In some cases where the deceased has underlying heart disease, differentiation between asphyxia and sudden cardiac death (SCD) as the primary cause of death can be challenging. Herein, Raman spectroscopy was employed to detect pulmonary biochemical differences to discriminate asphyxia from SCD in rat models. Thirty-two rats were used to build asphyxia and SCD models, with lung samples collected immediately or 24 h after death. Twenty Raman spectra were collected for each lung sample, and 640 spectra were obtained for further data preprocessing and analysis. The results showed that different biochemical alterations existed in the lung tissues of the rats that died from asphyxia and SCD and could be used to distinguish between the two causes of death. Moreover, we screened and used 8 of the 11 main differential spectral features that maintained their significant differences at 24 h after death to successfully determine the cause of death, even with decomposition and autolysis. Eventually, seven prevalent machine learning classification algorithms were employed to establish classification models, among which the support vector machine exhibited the best performance, with an area under the curve value of 0.9851 in external validation. This study shows the promise of Raman spectroscopy combined with machine learning algorithms to investigate differential biochemical alterations originating from different deaths to aid determining the cause of death in forensic practice.
PubMed: 38357034
DOI: 10.1039/d3ra07684a -
Ultrasonics Sonochemistry Feb 2024This work aimed to explore low-intensity ultrasound-assisted adaptive laboratory evolution (US-ALE) of Bacillus velezensis and fermentation performance of mutant strains...
This work aimed to explore low-intensity ultrasound-assisted adaptive laboratory evolution (US-ALE) of Bacillus velezensis and fermentation performance of mutant strains were investigated by nitrogen transformation metabolism. Results showed ultrasound accelerated the process of adaptive evolution and enhanced cell dry weight, amylase and protease activity of mutant strains, accompanied with the improved transformation abilities of NO-N to NH-N. Compared with original strain, the total peptide-N, peptide-N (<3 kDa) and autolytic peptide-N of mutant strains increased by the maximum 23.17%, 66.07% and 30.30%, respectively, based on ideal fermentation medium. According to the actual liquid-state fermentation of soybean meal and corn gluten meal with mutant strains, the highest peptide yields of 50.63% and 23.67% were noticed in mutant strain US-ALE-BV3, accompanied with the improved amino acid composition by bacterial autolysis technology. Thus, this study showed that low-intensity ultrasound could accelerate the process of adaptive evolution and US-ALE will provide more possibilities for modifying fermentation strains.
Topics: Bacillus; Amino Acids; Peptides; Fermentation
PubMed: 38354424
DOI: 10.1016/j.ultsonch.2024.106805 -
The Canadian Veterinary Journal = La... Feb 2024Pregnancy loss after Day 40 in mares usually results in the expulsion (abortion) of the fetus and placental membranes. However, fetal retention within the uterus is also...
Pregnancy loss after Day 40 in mares usually results in the expulsion (abortion) of the fetus and placental membranes. However, fetal retention within the uterus is also a possible outcome, leading to either fetal mummification or maceration. Fetal maceration is septic decomposition of fetal tissues within the uterus following failure of expulsion. It requires the presence of bacteria and oxygen within the uterus, likely originating from an open cervix, and results in tissue autolysis, leaving only fetal bones remaining in the mare. Fetal maceration is a rare complication of pregnancy in mares that is usually associated with a recent history of abortion, a persistent vaginal discharge, and retention of numerous fetal bones. Here, we report 2 cases of fetal maceration with retention of only a few fetal bones in mares that were presented without noticeable clinical signs. Key clinical message: The unusual presentation of fetal maceration in these mares (only a few fetal bones and no noticeable clinical signs) brings attention to the potential insidious nature of fetal retention. It highlights the importance of a thorough reproductive examination before breeding, along with careful and ongoing monitoring after breeding and throughout pregnancy.
Topics: Pregnancy; Female; Horses; Animals; Placenta; Fetus; Uterus; Fetal Death; Horse Diseases
PubMed: 38304478
DOI: No ID Found -
Journal of Microbiology and... Apr 2024Microorganisms usually coexist as a multifaceted polymicrobial community in the natural habitats and at mucosal sites of the human body. Two opportunistic human...
Microorganisms usually coexist as a multifaceted polymicrobial community in the natural habitats and at mucosal sites of the human body. Two opportunistic human pathogens, and commonly coexist in the bacterial infections for hospitalized and/or immunocompromised patients. Here, we observed that autolysis of the quorum-sensing (QS) mutant () was suppressed by the presence of the cells in vitro. The QS mutant still displayed killing against cells, suggesting the link between the -killing activity and the autolysis suppression. Independent screens of the transposon mutants defective in the -killing and the transposon mutants devoid of the autolysis suppression revealed the genetic link between both phenotypes, suggesting that the iron-dependent metabolism involving exoproteins might be central to both phenotypes. The autolysis was suppressed by iron treatment as well. These results suggest that the interaction between and might be governed by mechanisms that necessitate the QS circuitry as well as the metabolism involving the extracellular iron resources during the polymicrobial infections in the human airway.
Topics: Pseudomonas aeruginosa; Quorum Sensing; Staphylococcus aureus; Iron; Mutation; Bacterial Proteins; Humans; Bacteriolysis; Microbial Interactions; DNA Transposable Elements
PubMed: 38303126
DOI: 10.4014/jmb.2312.12028