CRISPR-Cas systems have transformed functional genomics in protozoan parasites; however, their genome engineering outcomes are strongly influenced by parasite-specific biological and genetic contexts. This review focuses on experimentally established CRISPR applications in representative protozoan parasite systems and examines how DNA repair pathways, delivery architectures, the biological consequences of DNA double-strand breaks (DSBs), and the cellular burden associated with Cas expression collectively shape genome-editing outcomes. We summarize recent advances in Cas9- and Cas12a-mediated genome editing, as well as dCas-based transcriptional regulation (CRISPRi/a), in protozoan parasites. Available evidence indicates that no universally optimal CRISPR platform exists across protozoan systems. Instead, CRISPR strategy selection should be guided by experimental objectives, target-gene properties, and species-specific biological characteristics. Cas9- and Cas12a-based systems remain advantageous for targeted gene disruption and endogenous tagging, whereas DSB-independent regulatory approaches such as dCas-mediated CRISPRi/a may provide biologically less disruptive alternatives in parasites with high sensitivity to DNA damage. Emerging RNA-targeting, precision-editing, and compact RNA-guided effectors may further expand the protozoan genetic engineering toolbox, although most remain at an early stage of development. Overall, CRISPR applications in protozoan parasites are transitioning from a tool-centered paradigm toward a biologically informed and decision-oriented framework for protozoan genome engineering.
Orientobilharzia turkestanicum (O. turkestanicum) is a water-associated schistosome parasite widely distributed in pastoral regions of Asia and Europe, where freshwater systems act as key interfaces linking livestock hosts, snail intermediate hosts, and environmental transmission pathways. Despite its strong environmental dependency, effective surveillance of O. turkestanicum in water-related settings remains limited by conventional diagnostic approaches that are time-consuming, equipment-dependent, and poorly suited for field-based monitoring. In this study, a rapid and sensitive detection assay based on clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 12a (RPA-CRISPR/Cas12a) was developed for on-site identification of O. turkestanicum. The ITS1-5.8S region was selected as the molecular target to enable reliable species discrimination from closely related schistosomes, particularly Schistosoma japonicum (S. japonicum). The assay operates under isothermal conditions at 37 °C and allows result interpretation through visual fluorescence and lateral flow strip (LFS) readouts without the need for sophisticated instrumentation. The established RPA-CRISPR/Cas12a assay exhibited high analytical specificity, showing no cross-reactivity with a range of non-target parasites and bacterial species. Sensitivity evaluation using serially diluted standard plasmids demonstrated analytical limit of detection of 0.16 copies/μL by visual fluorescence and 160 copies/μL by LFS. Field applicability was validated using snail samples, cattle feces, liver, intestinal tissues and simulated infected water samples, yielding an overall concordance rate of 97.55 % compared with qPCR. Collectively, these results indicate that the proposed RPA-CRISPR/Cas12a assay provides a practical and field-deployable tool for livestock and water-associated transmission environment of O. turkestanicum and offers a useful framework for improving field surveillance and risk assessment of livestock schistosomiasis in endemic regions.
Babesiosis, a globally significant tick-borne disease, poses substantial threats to livestock production and public health. Reported cases of human babesiosis in the United States increased from 1742 in 2014 to 3586 in 2023. In livestock, cattle babesiosis causes mortality, reduced meat and milk production, reproductive losses, and substantial control costs, with annual economic losses estimated at hundreds of millions of US dollars in several endemic countries. Rapid and sensitive detection methods are essential for early warning, surveillance, and control of this disease. In this study, we developed a closed-tube, one-pot assay for genus-level detection of Babesia spp. associated with cattle and sheep, based on recombinase polymerase amplification (RPA) coupled with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a. This format effectively minimizes cross-contamination risks associated with repeated tube opening in conventional assays. A three-channel signal readout system, including blue-light fluorescence visualization, ultraviolet (UV) fluorescence visualization, and lateral flow strip (LFS) readout, was integrated to enable flexible endpoint detection under different laboratory and field conditions. The assay targets a conserved region of the Babesia 18S rRNA gene and enables genus-level detection of Babesia spp. within 40 min at 37°C. The established RPA-CRISPR/Cas12a platform exhibited high analytical sensitivity, with a limit of detection of 5 copies/μL for recombinant plasmid templates, high analytical specificity against the tested nontarget pathogens, and low equipment dependency. The detection limit of the LFS format reached 50 copies/μL. Field validation using 71 pooled tick samples and 53 clinical blood samples collected from cattle and sheep yielded positive rates of 15.49% and 9.43%, respectively, with 100% concordance between this assay and conventional polymerase chain reaction (PCR) for both specimen types. In conclusion, this one-pot RPA-CRISPR/Cas12a detection platform provides a rapid, sensitive, and field-applicable molecular screening tool for genus-level detection of Babesia spp. This assay may support early warning and preliminary field monitoring of babesiosis, particularly in resource-limited settings. However, species-level confirmation should be performed by sequencing or other species-specific methods when epidemiological tracing or precise species identification is required.
Trichomonas vaginalis (T. vaginalis) is an infectious protozoan parasite responsible for trichomoniasis, which is one of the world's most pervasive non-viral sexually transmitted infections globally. This parasite primarily causes vaginitis and urethritis and is also linked to complications in premature delivery. Autophagy, a cellular process that regulates epithelial cell permeability by modulating tight junctions, plays an essential role in maintaining optimal cell health. However, whether T. vaginalis infection affects vaginal epithelial cell autophagy and the specific signaling pathways involved, remain poorly understood. Here, we found that the expression of p62 in VK2/E6E7 cells infected with T. vaginalis significantly decreased by 50% at 4 h (P < 0.000 1), and the LC3II/LC3I ratios were reduced by approximately 20% at 8 h post-infection (P < 0.05). Indirect immunofluorescence and transmission electron microscopy showed that T. vaginalis stimulation significantly decreased the fluorescence intensity of the LC3 protein (P < 0.01) and the number of autophagolysosomes in VK2/E6E7 cells. These preliminary results showed that autophagy was significantly inhibited. LC3II levels continued to decrease following infection with T. vaginalis (P < 0.000 1), even when autophagosome degradation was inhibited by chloroquine (CQ). This suggests that the decrease in LC3II expression in T. vaginalis-infected VK2/E6E7 cells resulted from reduced autophagosome production rather than excessive autophagosome degradation. Further analysis indicated that T. vaginalis infection might disrupt autophagy through specific signaling pathways. T. vaginalis infection can significantly reduce the ratio of LC3II/LC3I in rapamycin (Rapa) pretreated cells (P < 0.001), reduce the fluorescence intensity of LC3 and reduce the red fluorescence spots of LC3 (P < 0.000 1), suggesting that mTOR may be involved in the inhibition of autophagy of VK2/E6E7 cells by T. vaginalis. After T. vaginalis infected VK2/E6E7 cells 4 h, Western blotting detection showed that PI3K expression increased by 7-fold compared to controls (P < 0.000 1), while the protein levels of p-AKT, p-AMPK, p-ULK1 levels were reduced by 25%, 70%, and 80% (P < 0.01), respectively. p-mTOR and mTOR were all down-regulated (P < 0.05), indicating that the inhibition of autophagy of VK2/E6E7 cells by T. vaginalis may be mediated by the AMPK-ULK1 signal pathway rather than the classical PI3K-AKT-mTOR pathway. Following the activation of autophagy using the AMPK agonist GSK621, T. vaginalis infection significantly decreased the expression of LC3II, p-AMPK, and p-ULK1 in cells treated with GSK621 (P < 0.001). It is further confirmed that the AMPK-ULK1 signaling pathway plays an integral role in T. vaginalis inhibiting VK2/E6E7 cells autophagy. In conclusion, T. vaginalis infection inhibits the autophagy of VK2/E6E7 cells through AMPK-ULK1 signaling pathways involved in mTOR.
BackgroundGiardia duodenalis is a prevalent intestinal pathogen causing giardiasis, a condition characterized by diarrhea and frequently linked to malnutrition and growth impairments in children. The virulence of Giardiavirus (GLV) may efficiently clear Giardia parasites from infected patients. However, we have a limited understanding of GLV transmission among Giardia species and GLV-infected Giardia's impact on pathogenicity.MethodsThis study investigated extracellular vesicles (EVs) isolated via ultracentrifugation or exosome assay kit to detect the presence of GLV in EVs, the results were detected using ultrastructure and molecular methods, including transmission electron microscopy, scanning electron microscopy, quantitative polymerase chain reaction (qPCR), and dot blot. Transwell migration assays confirmed the spread of GLV-enveloped EVs among Giardia species using inhibitor experiments and immunofluorescence. Mice gavaged with Giardia, with or without GLV infection, were assessed for disease progression, including growth parameters (weight and size gains), intestinal permeability, and pathology.ResultsParts of GLV exploit the Giardia EVs pathway to reach the extracellular environment, allowing GLV to spread among Giardia species via these EVs. The uptake of GLV-containing EVs by Giardia results in rapid trophozoite infection, and GLV wrapped in EVs also offers protection against external interference. Importantly, EV-coated GLV-infected Giardia leads to divergent clinical symptoms in mice, posing less risk to mice and reducing symptoms, such as emaciation, stunted growth, and lesion damage, compared with GLV-free Giardia-infected mice.ConclusionsOur studies show that GLV wrapped in EVs can spread among Giardia species, and GLV infection alleviates the lesions caused by Giardia. These findings reveal that GLV could be a target for the development of novel intervention strategies against Giardia.
Haemonchus contortus (H. contortus), a highly pathogenic and blood-feeding nematode, could cause haemonchosis,resulting in tens of billions of dollars in production losses and significantly impacting the development of sheep husbandry. Rapid and accurate detection methods were particularly important for the prevention and control of haemonchosis. In this study, we developed a one-pot effective detection method that integrating recombinase polymerase amplification (RPA) with CRISPR/Cas12a technology based on the conserved region of ITS2 of H. contortus, with readout through fluorescence signals visualized by lateral flow strips (LFS) and observable under UV or blue light. The detection procedure was successfully finished in within 1 h and demonstrated high specificity and sensitivity, with no cross-reactivity detected with nine other common ovine pathogens and a detection limit as low as 0.1 copies/μL for fluorescence and 100 copies/μL for LFS. Validation with 89 sheep fecal samples revealed a 46.07 % positivity rate, fully consistent with quantitative PCR results. In summary, the RPA-CRISPR/Cas12a method for H. contortus detection exhibited the advantages of high specificity, high sensitivity, and low device dependence, portable and visible results. The technique presented significant potential for large-scale clinical application and provided novel point-of-care testing for clinical use in remote rural and resource-constrained areas.
Giardiasis is a common intestinal infection caused by Giardia duodenalis, which is a major economic and health burden for humans and livestock. Currently, a convenient and effective detection method is urgently needed. CRISPR/Cas12a-based diagnostic methods have been widely used for nucleic acid-based detection of pathogens due to their high efficiency and sensitivity. In this study, a technique combining CRISPR/Cas12a and RPA was established that allows the detection of G. duodenalis in faecal samples by the naked eye with high sensitivity (10−1 copies/μL) and specificity (no cross-reactivity with nine common pathogens). In clinical evaluations, the RPA-CRISPR/Cas12a-based detection assay detected Giardia positivity in 2
Fasciola hepatica is a foodborne zoonotic parasite causing significant economic losses and impacting human and livestock health in resource-limited regions. We developed a rapid, reliable, and sensitive detection method combining recombinase polymerase amplification (RPA) with CRISPR/Cas12a, allowing visualization with the naked eye or a fluorescence reader. Multiple visual methods were used to analyze the assay results. Fluorescence signals were collected using a fluorescence reader or observed under UV or blue light. Lateral flow strips (LFS) were used for visual detection. Among seven primer pairs and three CRISPR RNA (crRNA) screened, F1/R1 and crRNA3 were optimal. The Cas12a reaction buffer was optimized with 50 mM Tris-HCl and 80 mM NaCl, with an RPA reaction time of 20 min. The assay showed high specificity and excellent sensitivity for F. hepatica, detecting 0.122 copies/μL with fluorescence and 8.6 copies/μL with LFS. Testing of 143 sheep and 43 human fecal samples showed 98.39 % consistency with qPCR and nested PCR, with prevalence rates of 52.45 % and 18.6 % in sheep and humans, respectively. Our assay offers substantial potential for point-of-care testing in resource-limited areas, addressing the need for rapid and accurate diagnosis of F. hepatica.
The present study aims to investigate the role of liensinine in life-threatened sepsis-associated encephalopathy (SAE) mice and the underlying mechanism. Here, seventy-two mice were divided into six groups, including the control group, SAE group, liensinine-treated group, and three doses of liensinine-treated SAE groups. Lipopolysaccharide triggered cerebrum necrosis and disrupted the integrity and permeability of blood-brain barrier (BBB). While liensinine restored cerebrum structure and improved BBB integrity with upregulated tight junction proteins, decreased evans blue leakage and fibrinogen expression with decreased matrix metalloproteinases 2/9 in serum, thereby reducing BBB permeability. Moreover, lipopolysaccharide triggered cerebrum oxidative stress and inflammation, whereas liensinine enhanced antioxidant enzymes activities and weakened malondialdehyde through nuclear factor erythroid 2-related factor. Meanwhile, liensinine inhibited inflammation by activating inducible nitric oxide synthase. Tunel staining combined with transmission electron microscope indicated that lipopolysaccharide induced cerebrum apoptosis, whereas liensinine blocked apoptosis through decreasing B-cell lymphoma-2 associated X (Bax) expression and cytochrome C (Cyto-c) release, increasing B-cell lymphoma-2 (Bcl-2) expression, blocking apoptosome assembly, inhibiting caspase-3 activation, thereby suppressing intrinsic mitochondria apoptosis. Recovering of inflammatory homeostasis and inhibition of mitochondria apoptosis by liensinine ultimately restored cognitive function in SAE mice. Altogether, liensinine attenuated lipopolysaccharide-induced SAE via modulation of Nrf2-mediated inflammatory biomarkers and mitochondria apoptosis.
This study aimed to explore the protective roles of malvidin in life-threatened sepsis-associated encephalopathy (SAE) and illustrate the underlying mechanism. SAE mice models were developed and treated with malvidin for subsequently protective effects evaluation. Malvidin restored neurobehavioral retardation, declined serum S100β and NSE levels, sustained cerebrum morphological structure, improved blood-brain barrier integrity with elevated tight junction proteins, and decreased evans blue leakage, and finally protect SAE mice from brain injury. Mechanistically, malvidin prevented cerebrum from mitochondrial dysfunction with enhanced JC-1 aggregates and ATP levels, and ROS accumulation with decreased lipid peroxidation and increased antioxidant enzymes. UCP2 protein levels were found to be decreased after LPS stimulation in the cerebrum and BV-2 cells, and malvidin recovered its levels in a ROS dependent manner. In vivo inhibition of UCP2 with genipin or in vitro interference with siRNA UCP2 both disrupted the mitochondrial membrane potential, decreased ATP levels and intensified DCF signals, being a key target for malvidin. Moreover, dorsomorphin block assays verified that malvidin upregulated UCP2 expression through phosphorylating AMPK in SAE models. Also, malvidin alleviated SAE progression through inhibition of ROS-dependent NLRP3 inflammasome activation mediated serum pro-inflammatory cytokines secretion and mitochondrial pathway mediated apoptosis with weakened apoptosis body formation and tunel positive signals, and decreased Bax, cytochrome C, caspase-3 and increased Bcl-2 protein levels. Overall, this study illustrated that malvidin targeted AMPK-α/UCP2 axis to restore LPS-induced mitochondrial dysfunction and alleviate ROS accumulation, which further inhibits NLRP3 inflammasome activation and mitochondrial apoptosis in a ROS dependent way, and ultimately protected SAE mice, providing a reference for the targeted development of SAE prophylactic approach.
Alcoholic liver disease (ALD) is the most frequent liver disease worldwide, resulting in severe harm to personal health and posing a serious burden to public health. Based on the reported antioxidant and anti-inflammatory capacities of scutellarin (SCU), this study investigated its protective role in male BALB/c mice with acute alcoholic liver injury after oral administration (10, 25, and 50 mg/kg). The results indicated that SCU could lessen serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and improve the histopathological changes in acute alcoholic liver; it reduced alcohol-induced malondialdehyde (MDA) content and increased glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) activity. Furthermore, SCU decreased tumor necrosis factor-α ( TNF-α ), interleukin-6 ( IL-6 ), and IL-Iβ messenger RNA (mRNA) expression levels, weakened inducible nitric oxide synthase (iNOS) activity, and inhibited nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome activation. Mechanistically, SCU suppressed cytochrome P450 family 2 subfamily E member 1 (CYP2E1) upregulation triggered by alcohol, increased the expression of oxidative stress-related nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) pathways, and suppressed the inflammation-related degradation of inhibitor of nuclear factor-κB (NF-κB)-α (IκBα) as well as activation of NF-κB by mediating the protein kinase B (AKT) and p38 mitogen-activated protein kinase (MAPK) pathways. These findings demonstrate that SCU protects against acute alcoholic liver injury via inhibiting oxidative stress by regulating the Nrf2/HO-1 pathway and suppressing inflammation by regulating the AKT, p38 MAPK/NF-κB pathways.
This study aims to investigate the effects of environmentally relevant concentrations of abamectin on the cardiac function of carp and the potential mechanisms. Here, male carp were exposed to abamectin, and cardiac function-related enzymatic markers were examined. Cardiac histopathology, redox equilibrium, inflammation, and cell death were evaluated. Abamectin exposure caused cardiac dysfunction by upregulating lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK), creatine Kinase MB isoenzyme (CK-MB) and white blood cells (WBCs), and decreasing red blood cells (RBCs) and hemoglobin (Hb). DHE staining and biochemical assays revealed that abamectin caused ROS release and oxidative stress by inhibiting Nrf2-ARE pathway. Histopathological and real-time fluorescence quantitative PCR (RT-qPCR) assays revealed that abamectin caused myocardial fiber swelling and inflammatory cell infiltration, enhanced pro-inflammatory cytokines tumor necrosis factor-α (Tnf-α), interleukin-1 beta (Il-1β), and Il-6 levels and attenuated anti-inflammatory cytokines Il-10 and transforming growth factor beta 1 (Tgf-β1) through activating NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and nuclear factor kappa-B (NF-κB) pathway. Tunel staining showed that abamectin triggered cardiac apoptosis via activating p53-mediated mitochondrial apoptosis with elevated bcl2-associated X (Bax), reduced B-cell lymphoma-2 (Bcl-2), and activated Caspase-9 and Caspase-3. Immunoblot analysis revealed that abamectin activated autophagic flow by inhibiting mammalian target of rapamycin (mTOR), resulting in the conversion of LC3B from LC3-I to LC3-II, elevation of autophagy protein 5 (Atg5), and reduction of p62. Overall, abamectin caused cardiac dysfunction in carp via inhibiting redox equilibrium and resulting in immune inflammatory response and programmed cell death.
Oncorhynchus mykiss,a kind of freshwater fish,belongs to the Salmonidae family and Oncorhynchus genus[1].O.mykiss is farmed in more than 20 cities in China,being one of the most common cold-water farming fish.The wide range of O.mykiss may attribute to its rapid growth and tolerance of different environ-mental conditions.Salmo salar attracts customers'interest for its delicious taste and high nutrient contents.However,wild S.salar supply is far less than high demands,and artificial breeding faces difficulties in yield and cost.External morphological characteristics can distinguish full-fledged fish,but it is difficult to distinguish after processing with pigments for the white and blue O.mykiss meat displaying orange color and texture[2].The food industry provides cheaper O.mykiss adulteration in S.salar,infringing consumers'rights and interests.Moreover,farmed O.mykiss in fresh water may risk parasite infection,and customers who eat raw food face food safety concerns[3].
Aeromonas caviae, an important food-borne pathogen, induces serious invasive infections and inflammation. The pro-inflammatory IL-1β functions against pathogenic infections and is elevated in various Aeromonas infection cases. However, the molecular mechanism of A. caviae-mediated IL-1β secretion remains unknown. In this study, mouse macrophages (PMs) were used to establish A. caviae infection model and multiple strategies were utilized to explore the mechanism of IL-1β secretion. IL-1β was elevated in A. caviae infected murine serum, PMs lysates or supernatants. This process triggered NLRP3 levels upregulation, ASC oligomerization, as well as dot gathering of NLRP3 and speck-like signals of ASC in the cytoplasm. MCC950 blocked A. caviae mediated IL-1β release. Meanwhile, NLRP3 inflammasome mediated the release of IL-1β in dose- and time-dependent manners, and the release of IL-1β was dependent on active caspase-1, as well as NLRP3 inflammasome was activated by potassium efflux and cathepsin B release ways. A. caviae also enhanced TLR2 levels, and deletion of TLR2 obviously decreased IL-1β secretion. What's more, A. caviae resulted in NF-κB p65 nuclear translocation partly in a TLR2-dependent manner. Blocking NF-κB using BAY 11-7082 almost completely inhibited NLRP3 inflammasome first signal pro-IL-1β expression. Blocking TLR2, NF-κB, NLRP3 inflammasome significantly downregulated IL-1β release and TNF-α and IL-6 levels. These data illustrate that A. caviae caused IL-1β secretion in PMs is controlled by NLRP3 inflammasome, of which is mediated by NF-κB pathway and is partially dependent on TLR2, providing basis for drugs against A. caviae.
• SIN protects from alcohol-induced ALI. • SIN reduced oxidative stress by enhancing antioxidant enzyme levels and Nrf2/HO-1. • SIN decreased inflammation by inhibiting NLRP3 inflammasome and Akt/NF-κB pathway. • SIN inhibited apoptotic protein levels and down-regulated MAPK expressions.
Acute alcohol consumption has adverse effects in the kidney, resulting in kidney damage and disease, which are typically accompanied by oxidation and inflammation. Scutellarin (SCU) is the major effective ingredient of breviscapine and its anti-inflammation and antioxidant efficacy has been previously reported. The present study revealed the protective effective of SCU as therapeutic medicine against alcohol-induced inflammation and oxidative stress, leading to acute kidney injury (AKI). The AKI model was established by giving 50 % ethanol (12 mL/kg) via lavage. Kidney tissues were collected and used for histopathology analysis, biochemical assays and qRT-PCR analysis. The therapeutic effects of SCU were evaluated by observing pathological changes from HE-stained kidney tissues. Additionally, the anti-inflammation activity of SCU was evaluated by measuring the relative mRNA expression levels of Tnf-α, Il-1β, Il-6 and the activity of iNOS. The antioxidant capacity was assessed by measuring the lipid peroxidation marker 'MDA' and antioxidant enzymes activity of SOD, CAT and GSH-Px. The results showed that serious swelling and damage occurred in the renal tubular epithelium of alcohol intake group, accompanying with glomerular atrophy, necrosis and increase of inflammatory infiltration. SCU treatment significantly reduced the damage of diseased renal tubular epithelium and glomerular, and less inflammatory cell emerged. The inflammation cytokines expression levels were elevated and oxidative stress index decreased after alcohol intake compared to the control group. In conclusion, inflammation and oxidative stress occur in the kidney after acute and excessive alcohol intake, SCU exhibited protective roles via its anti-inflammation and antioxidant activity in AKI.
Vibrio harveyi is a zoonotic pathogen that can infect humans through wounds and cause severe inflammatory responses. Previous studies have reported that the Toll like receptors (TLR) mediated MAPK, AKT and NF-κB signaling pathways are involved in innate immune system resistance to pathogen invasion. However, the molecular mechanism of these pathways, as well as their involvement in V. harveyi infection remains elusive. This study established a V. harveyi infection model using murine peritoneal macrophages (PMs). Various techniques, including western blotting, ELISA, RT-qPCR, immunofluorescence, inhibition assays, were used to explore the roles of TLRs, MAPK, AKT and NF-κB signaling pathways in V. harveyi-induced inflammatory responses. ELISA assays showed that V. harveyi infection triggered proinflammatory cytokines secretion in PMs. RT-qPCR and inhibition assays showed that TLR2 participated in V. harveyi infection and up-regulated the proinflammatory cytokines secretion in murine PMs. Western blotting data showed that the phosphorylation of p38, JNK, AKT, and NF-κB p65 were significantly increased partly mediated by TLR2. In addition, immunofluorescence assays revealed that the NF-κB p65 translocated into nucleus in response to V. harveyi infection. The secretion of IL-1β, IL-6, IL-12, and TNF-α were considerably reduced when the p38 MAPK and NF-κB signaling pathways were blocked, whereas blocking of AKT significantly increased the expression of IL-1β, IL-6, IL-12, and TNF-α. These findings indicate that V. harveyi infection induces inflammatory responses in murine PMs via activation of p38 MAPK and NF-κB pathways, which are partly mediated by TLR2, but are inhibited by PI3K/AKT pathways.
Vibrio alginolyticus is an important zoonotic marine pathogenic bacterium. Previous studies on the mechanism of innate immune against V. alginolyticus infection have been limited to aquatic animals, however, how V. alginolyticus activates mammalian immune cells has not been fully clarified. Here, ELISA combined RT-qPCR assays were used to detect the secretion and transcription level of pro-inflammatory cytokines and TLRs during V. alginolyticus infection of mice peritoneal macrophages (PMϕs). Western blotting was used to explore the phosphorylation levels of p38, JNK, ERK, AKT and NF-κB protein. Immunofluorescence assay was used to determine the location of NF-κB protein. Inhibition assay was used to study the role of up-regulated TLR in activated signaling pathways and the role of these pathways in the release of pro-inflammatory cytokines. Our data showed that V. alginolyticus can up-regulate the expression levels of IL-1β, IL-6, IL-12 and TNF-α in PMϕs. In addition, V. alginolyticus stimulation activated the phosphorylation of p38, JNK and ERK were TLR2 heterodimers-dependent, whereas inhibitors of SB203580 (p38), SCH772984 (ERK) and SP600125 (JNK) significantly reduced IL-1β, IL-6, IL-12 and TNF-α production. We further revealed that V. alginolyticus activated the signaling pathways of AKT via TLR2 heterodimers. The inhibitor of MK-2206 2HCl (AKT) negatively regulated the IL-1β, IL-6 and TNF-α release levels. Moreover, V. alginolyticus infection of PMϕs resulted in TLR2 heterodimers-mediated activation of NF-κB and induced translocation of phosphorylated NF-κB protein from the cytoplasm into the nucleus via IκBα degradation. V. alginolyticus induced IL-1β, IL-6, IL-12 and TNF-α release were blocked by the specific NF-κB inhibitor, BAY 11-7082. Taken together, our results suggested that activation of the TLR2 heterodimers-mediated downstream signaling pathways NF-κB, MAPK and AKT is responsible for inflammatory response during Vibrio alginolyticus infection in vitro.
Drinking culture has high significance in both China and the world, whether in the entertainment sector or in social occasions; according to the World Health Organization's 2018 Global Alcohol and Health Report, about 3 million people died from excessive drinking in 2016, accounting for 5.3% of the total global deaths that year. Oxidative stress and inflammation are the most common pathological phenomena caused by alcohol abuse (Snyder et al., 2017). Scutellarin, a kind of flavonoid, is one of the main active ingredients extracted from breviscapine. It exerts anti-inflammatory, antioxidant, and vasodilation effects, and has been used to treat cardiovascular diseases and alcoholic liver injury. Although scutellarin can effectively alleviate multi-target organ injury induced by different forms of stimulation, its protective effect on alcoholic brain injury has not been well-defined. Therefore, the present study established an acute alcohol mice brain injury model to explore the effect of scutellarin on acute alcoholic brain injury. The study was carried out based on the targets of oxidative stress and inflammation, which is of great significance for the targeted therapy of clinical alcohol diseases.
Neospora caninum, an obligate intracellular protozoan, is the major cause for neosporosis and brings serious economic losses to cattle breeding industries worldwide. After invasion, dense granules proteins are abundantly secreted and being important components of parasitophorous vacuole and intravacuolar network where N. caninum survives and replicates. The aim of the present study was to evaluate the protective immunity induced by DNA vaccines with genes encoding dense granules proteins 1 (GRA1), GRA4, GRA9, GRA14, GRA17, and GRA23 against N. caninum tachyzoites in BALB/C mice. Eukaryotic expressing plasmids of pcNcGRAs were constructed and the mice were intramuscularly immunized with pcNcGRAs followed by challenging infection with lethal doses of N. caninum. Immune responses were evaluated through monitoring the levels of serum antibodies, measurement of lymphocyte proliferation, and secretion of cytokines. Immune protection assays were carried out through monitoring survival time, body weight, and parasite burden in the brains. Results showed that all the pcNcGRA DNA vaccines could trigger remarkably specific humoral and cellular responses, with higher levels of IgG and IgG2a antibodies as well as obviously increased secretion of Th1-type IFN-γ cytokines. The immune protective efficacy revealed that pcNcGRA4, pcNcGRA14, and pcNcGRA17 DNA vaccines could individually increase the survival rate to 50, 37.5, and 25% in comparison with 0% in the control group; prolong the survival time more than 20.88 ± 11.12, 18.88 ± 10.83, and 16.63 ± 10.66 days compared with the control group of 4 ± 1.31 days; and decrease parasite burden in the brains to 297.63 ± 83.77, 471.5 ± 110.74, and 592.13 ± 102.2 parasites/100 ng comparing with 1221.36 ± 269.59 parasites/100 ng in the control group. These findings indicated that NcGRA4, NcGRA14, and NcGRA17 are potential vaccine candidates; NcGRA4 displayed better performance in immune protective efficacy and could be further combined with other advantageous antigens applied to the development of safe and effective DNA vaccines against N. caninum.