Isoform Switch of TET1 Regulates DNA Demethylation and Mouse Development.

The methylcytosine oxidase TET proteins play important roles in DNA demethylation and development. However, it remains elusive how exactly they target substrates and execute oxidation. Interestingly, we found that, in mice, the full-length TET1 isoform (TET1e) is restricted to early embryos, embryonic stem cells (ESCs), and primordial germ cells (PGCs). By contrast, a short isoform (TET1s) is preferentially expressed in somatic cells, which lacks the N terminus including the CXXC domain, a DNA-binding module that often recognizes CpG islands (CGIs) where TET1 predominantly occupies. Unexpectedly, TET1s can still bind CGIs despite the fact that its global chromatin binding is significantly reduced. Interestingly, global chromatin binding, but not targeted binding at CGIs, is correlated with TET1-mediated demethylation. Finally, mice with exclusive expression of Tet1s failed to erase imprints in PGCs and displayed developmental defects in progeny. These data show that isoform switch of TET1 regulates epigenetic memory erasure and mouse development.

Deep medullary veins: a promising neuroimaging marker for mild cognitive impairment in outpatients.

BACKGROUND AND PURPOSE: Mild cognitive impairment is an age-dependent pre-dementia state caused by varied reasons. Early detection of MCI helps handle dementia. Vascular factors are vital for the occurrence of MCI. This study investigates the correlation between deep medullary veins and multi-dimensional cognitive outcomes. MATERIALS AND METHODS: A total of 73 participants with MCI and 32 controls were enrolled. Minimum Mental State Examination and Montreal Cognitive Assessment were used to examine the global cognitive function, and different cognitive domains were measured by specific neuropsychological tests. MRI was used to assess the visibility of the DMV and other neuroimage markers. RESULTS: DMV score was statistically significantly higher in the MCI group compared with the control group (P = 0.009) and independently related to MCI (P = 0.007). Linear regression analysis verified that DMV score was linearly related to global cognition, memory, attention, and executive function after adjusting for cerebrovascular risk factors. CONCLUSION: DMV score was independently related to the onset of MCI, and correlates with overall cognition, memory, attention, and executive function in outpatients.

Co-translational folding of nascent polypeptides: Multi-layered mechanisms for the efficient biogenesis of functional proteins.

The coupling of protein synthesis and folding is a crucial yet poorly understood aspect of cellular protein folding. Over the past few years, it has become possible to experimentally follow and define protein folding on the ribosome, revealing principles that shape co-translational folding and distinguish it from refolding in solution. Here, we highlight some of these recent findings from biochemical and biophysical studies and their potential significance for cellular protein biogenesis. In particular, we focus on nascent chain interactions with the ribosome, interactions within the nascent protein, modulation of translation elongation rates, and the role of mechanical force that accompanies nascent protein folding. The ability to obtain mechanistic insight in molecular detail has set the stage for exploring the intricate process of nascent protein folding. We believe that the aspects discussed here will be generally important for understanding how protein synthesis and folding are coupled and regulated.

Energetic dependencies dictate folding mechanism in a complex protein.

Large proteins with multiple domains are thought to fold cotranslationally to minimize interdomain misfolding. Once folded, domains interact with each other through the formation of extensive interfaces that are important for protein stability and function. However, multidomain protein folding and the energetics of domain interactions remain poorly understood. In elongation factor G (EF-G), a highly conserved protein composed of 5 domains, the 2 N-terminal domains form a stably structured unit cotranslationally. Using single-molecule optical tweezers, we have defined the steps leading to fully folded EF-G. We find that the central domain III of EF-G is highly dynamic and does not fold upon emerging from the ribosome. Surprisingly, a large interface with the N-terminal domains does not contribute to the stability of domain III. Instead, it requires interactions with its folded C-terminal neighbors to be stably structured. Because of the directionality of protein synthesis, this energetic dependency of domain III on its C-terminal neighbors disrupts cotranslational folding and imposes a posttranslational mechanism on the folding of the C-terminal part of EF-G. As a consequence, unfolded domains accumulate during synthesis, leading to the extensive population of misfolded species that interfere with productive folding. Domain III flexibility enables large-scale conformational transitions that are part of the EF-G functional cycle during ribosome translocation. Our results suggest that energetic tuning of domain stabilities, which is likely crucial for EF-G function, complicates the folding of this large multidomain protein.

Rosiglitazone attenuates hypoxia-induced renal cell apoptosis by inhibiting NF-κB signaling pathway in a PPARγ-dependent manner.

BACKGROUND: In recent years, peroxisome proliferator-activated receptor γ (PPARγ) has been found to be closely associated with hypoxia renal disease. The aim of this study was to investigate the relationship between rosiglitazone and mitochondrial apoptosis in renal tissue and its associated mechanisms. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into three groups (n = 8 in each): normal control group, hypoxia injury group (equal volume of 0.9% saline), and PPARγ agonist group (Rosiglitazone, 10 mg/kg · d, intraperitoneally). The hypoxia injury group and PPARγ agonist group were placed in a hypoxia chamber and the simulated altitude was set at 7,000 m for 7 days. Blood and kidney samples were collected after 7 days. The quantitative real-time polymerase chain reaction and Western blot methods were used to determine the expression of PPARγ, nuclear factor kappa-B (NF-κB), B-cell lymphoma-2 (Bcl-2), and Bax. RESULTS: The results showed that compared with the normal control group, the renal tissue of rats after hypoxia was severely damaged, as shown by massive renal tubular epithelial cell degeneration and detachment, and renal tubular dilation. The NF-κB protein expression significantly increased, the Bcl-2 protein and mRNA expression significantly decreased, and Bax protein and mRNA expression significantly increased (p < .05 for all). Renal injury was much less severe in the PPARγ agonist group compared to the hypoxia injury group. CONCLUSIONS: Rosiglitazone can alleviate hypoxia renal injury, with the possible mechanism involving attenuation of apoptosis by inhibiting the activation of the NF-κB signaling pathway in a PPARγ-dependent manner and increasing Bcl-2 and decreasing Bax expression.

Bloody Diarrhea Caused by Intestinal Myiasis in an Infant: A Case Report and Review of Pediatric Literature.

Intestinal myiasis caused by fly larvae parasitic in gastrointestinal tract was rare reported in children. We reported an infant with bloody diarrhea caused by intestinal myiasis. A 1 year and 7 months old boy presented with the only symptom of bloody diarrhea of unknown origin. In the second week of onset, numerous moving worms were observed in the bloody stool after bowel preparation with polyethylene glycol for colonoscopy. The bloody diarrhea disappeared after 1 week of combined therapy with albendazole and metronidazole. On follow-up after 6 months, the patient remained well without bloody diarrhea. In conclusion, intestinal myiasis being a rare disease that is very challenging to diagnose, physicians should remember it when they receive cases of bloody diarrhea with non-specific symptoms without any apparent cause.

Effects on applying micro-film case-based learning model in pediatrics education.

BACKGROUND: In view of the harsh reality Chinese paediatricians face, the challenge of paediatric education is about instilling not only knowledge and clinical skills but also resilience and beliefs. The aim of the study is to explore a more effective method than the traditional lecture-based learning (LBL) model for optimizing educational outcomes by establishing an innovative, comprehensive, case-based learning (CBL) model combined with the micro-film technique (MF + CBL). This approach has four important components: interests (attraction), knowledge application, competency, and scenario coping skills. METHODS: Experimental research was conducted via a controlled parallel group study. The total sample of 104 senior-year students (Chinese) majoring in clinical medicine was randomly divided into two groups. The experimental group was exposed to the MF + CBL model and the control group to the LBL model. Overall, the results were assessed after an 8-week course via a student self-assessment questionnaire, a satisfaction survey and the final examination. RESULTS: The experimental group generally performed better than the control group on the student self-assessment (P<0.05), satisfaction survey (P<0.05), and final examination (80.02 ± 3.77 vs 73.65 ± 3.69, P = 0.000). The open question at the end of the questionnaire revealed that a small number of students did not favour the MF + CBL model due to its time- and energy-consuming features. CONCLUSIONS: Compared with LBL, the MF + CBL model was an innovative teaching method that promoted more comprehensive quality development. It represents an alternative model for optimizing the capacity of future paediatric doctors.

Effects of Zinc Combined with Probiotics on Antibiotic-associated Diarrhea Secondary to Childhood Pneumonia.

AIM: The aim of this study was to evaluate the impact of zinc combined with probiotics (Bifico) on antibiotic-associated diarrhea (AAD) secondary to pneumonia. METHODS: A total of 50 patients with AAD secondary to pneumonia were randomly divided into a probiotics group (Bifico) and a combined group (zinc combined with Bifico) and 25 pneumonia patients without AAD as the control group. Serum levels of zinc, diamine oxidase (DAO) activity, D-lactate and intestinal flora [Bifidobacterium, Escherichia coli and Bifidobacterium/E. coli (B/E) ratio] were detected before and after intervention. RESULTS: The results showed that zinc combined with Bifico had significantly higher overall efficiency than Bifico alone for treatment of AAD secondary to pneumonia. Notably, the combined treatment increased the population of Bifidobacterium, while the number of E. coli was reduced, the B/E value was improved and DAO activity and D-lactate levels were markedly reduced. CONCLUSION: Patients with AAD secondary to pneumonia benefit from zinc supplementation of probiotic treatment.

Artificial Protein Scaffold System (AProSS): An efficient method to optimize exogenous metabolic pathways in Saccharomyces cerevisiae.

Scaffold proteins influence cellular signaling by orchestrating multiple enzymes, receptors or ion channels, and could be tailored to enhance the efficiency of biochemical reactions by positioning related enzymes physically together. However, the number of applicable domains remains small, and the construction of scaffold proteins with optimal domain ratio could be tedious and time-consuming. In this study, we outlined a modular design to quickly assemble scaffold proteins using protein interaction domains, which have been constructed into a standardized vector. We generated multiple protein interaction domains and ligands for making artificial scaffold proteins. At the same time, we developed a robust Golden-Gate-based molecular toolkit for the construction of artificial scaffold proteins, allowing a variance of domain types, number, and positions. The synthesized domain-ligand interaction was verified by yeast two-hybrid and split-GFP assays. Using synthetic scaffolds, we demonstrated an increase in the yield of two target products by 29% and 63% respectively. Moreover, we demonstrated that the synthetic scaffold could be applied to rewire the metabolic flux. Our system could be a useful tool for metabolic engineering and beyond.

[A clinical analysis of children with invasive pulmonary fungal infections after biliary atresia surgery].

OBJECTIVE: To investigate the clinical features of invasive pulmonary fungal infections (IPFIs) after biliary atresia (BA) surgery and related risk factors. METHODS: A retrospective analysis was performed for the clinical data of 49 children with IPFIs after BA surgery, including clinical features, lung imaging findings, and pathogenic features. The risk factors for IPFIs after BA surgery were also analyzed. RESULTS: The most common pathogens of IPFIs after BA surgery was Candida albicans (17 strains, 45%), followed by Candida tropicalis (7 strains, 18%), Aspergillus (6 strains, 16%), Candida krusei (3 strains, 8%), Candida glabrata (3 strains, 8%), and Candida parapsilosis (2 strains, 5%). Major clinical manifestations included pyrexia, cough, and shortness of breath, as well as dyspnea in severe cases; the incidence rate of shortness of breath reached 78%, and 35% of all children had no obvious rale. The multivariate logistic regression analysis showed that age at the time of surgery, time of glucocorticoid application, cumulative time of the application of broad-spectrum antibiotics, and recurrent cholangitis were major risk factors for IPFIs after BA surgery. CONCLUSIONS: The three most common pathogens of IPFIs after BA surgery are Candida albicans, Candida tropicalis, and Aspergillus. It is important to perform surgery as early as possible, avoid recurrent cholangitis, and shorten the course of the treatment with broad-spectrum antibiotics and glucocorticoids for decreasing the risk of IPFIs.

Visual effect of air pollution on the need for arousal and variety-seeking behavior.

Research on air pollution, one of the most common environmental factors, has primarily focused on its effects on physical, mental, and cognitive health. However, air pollution-induced achromatic color of an environment, which is a prominent feature of air pollution, has received little attention. This study explored the visual effects of air pollution on the variety-seeking purchase behavior of consumers through two scenario-based experiments and primed manipulation (Study 1 and Study 2) and one natural experiment using data from a local fruit chain store (Study 3). Study 1 tested the main effect of air pollution on the variety-seeking behavior and found that primed air pollution increased variety-seeking when consumers purchased beverages. Study 2 broadened the category and tested the mechanism, and the results indicated that primed air pollution increased the variety of purchased chocolates and demonstrated the mediating effect of the need for arousal. Study 3 tested the boundary condition and extended the external validity with actual purchases. The results revealed that severe air pollution increased the purchased SKUs by 22.9% and visibility reduced the moderation effect. This research extended the literature on the visual effect of air pollution by providing evidence of the effects of air pollution on variety-seeking behavior through the need for arousal. And, product managers could leverage the results by offering a greater variety of goods on days with air pollution to increase sales.

Cumulative Exposure to Oxidized Low-density Lipoprotein is a Potential Predictor for Prognosis in Acute Ischemic Stroke: A Cohort Study.

BACKGROUND: Oxidized Low-Density Lipoprotein (ox-LDL) is crucial in the recrudescence and prognosis of acute ischemic stroke (AIS). We aimed to probe into the influence of cumulative ox-LDL exposure on the 90-day prognosis of AIS. METHODS: Patients with AIS were recruited in this research. AIS severity at admission was estimated with infarct volumes and National Institute of Health Stroke Scale (NIHSS) scores. AIS prognosis was assessed using Modified Rankin Scale (mRS) scores at 90 days and the change in NIHSS scores from admission to discharge. Cumulative ox-LDL exposure was defined as ox-LDL level (pg/mL) multiplied by age(y). Multivariate logistic regression analysis was employed to reveal the correlation between exposure factors and the prognosis of AIS. The prognostic prediction ability of cumulative ox-LDL exposure was compared with cumulative LDL exposure by the receiver operating characteristic curve (ROC). RESULTS: Higher cumulative ox-LDL exposure was related to worse prognosis, including neurological worsening at discharge (NIHSS increasing more than 2 points) (OR = 3.02, 95% CI, 1.30-6.98, P = 0.01) and poor functional prognosis at 90 days (mRS ≥ 3) (OR = 21.21, 95% CI, 4.72-95.36, P < 0.001). As multivariate regression analysis showed, significantly increased cumulative ox-LDL exposure was relevant to poor functional prognosis at 90 days (OR = 9.92, 95% CI, 1.23-79.76, P = 0.031), but not with neurological worsening at discharge (P = 0.414). ROC curve revealed that cumulative ox-LDL exposure had a higher predictive value (AUC = 0.843, P < 0.001) for functional prognosis of AIS than cumulative LDL exposure (AUC = 0.629, P = 0.023). CONCLUSION: Cumulative ox-LDL exposure has a positive correlation with poor prognosis at 90 days of AIS, and has a more accurate predictive ability than cumulative LDL exposure.

Protective effect of zinc gluconate on intestinal mucosal barrier injury in antibiotics and LPS-induced mice.

Objective: The aim of the study is to investigate the function and mechanism of Zinc Gluconate (ZG) on intestinal mucosal barrier damage in antibiotics and Lipopolysaccharide (LPS)-induced mice. Methods: We established a composite mouse model by inducing intestinal mucosal barrier damage using antibiotics and LPS. The animals were divided into five groups: Control (normal and model) and experimental (low, medium, and high-dose ZG treatments). We evaluated the intestinal mucosal barrier using various methods, including monitoring body weight and fecal changes, assessing pathological damage and ultrastructure of the mouse ileum, analyzing expression levels of tight junction (TJ)-related proteins and genes, confirming the TLR4/NF-κB signaling pathway, and examining the structure of the intestinal flora. Results: In mice, the dual induction of antibiotics and LPS led to weight loss, fecal abnormalities, disruption of ileocecal mucosal structure, increased intestinal barrier permeability, and disorganization of the microbiota structure. ZG restored body weight, alleviated diarrheal symptoms and pathological damage, and maintained the structural integrity of intestinal epithelial cells (IECs). Additionally, ZG reduced intestinal mucosal permeability by upregulating TJ-associated proteins (ZO-1, Occludin, Claudin-1, and JAM-A) and downregulating MLCK, thereby repairing intestinal mucosal barrier damage induced by dual induction of antibiotics and LPS. Moreover, ZG suppressed the TLR4/NF-κB signaling pathway, demonstrating anti-inflammatory properties and preserving barrier integrity. Furthermore, ZG restored gut microbiota diversity and richness, evidenced by increased Shannon and Observed features indices, and decreased Simpson's index. ZG also modulated the relative abundance of beneficial human gut bacteria (Bacteroidetes, Firmicutes, Verrucomicrobia, Parabacteroides, Lactobacillus, and Akkermansia) and harmful bacteria (Proteobacteria and Enterobacter), repairing the damage induced by dual administration of antibiotics and LPS. Conclusion: ZG attenuates the dual induction of antibiotics and LPS-induced intestinal barrier damage and also protects the intestinal barrier function in mice.

Resolving sulfation PTMs on a plant peptide hormone using nanopore sequencing.

Peptide phytohormones are decorated with post-translational modifications (PTMs) that are crucial for receptor recognition. Tyrosine sulfation on these hormones is essential for plant growth and development1. Measuring the occurrence and position of sulfotyrosine is, however, compromised by major technical challenges during isolation and detection2. We recently introduced a nanopore peptide sequencing method that sensitively detects PTMs at the single-molecule level3. By translocating PTM variants of the plant pentapeptide hormone phytosulfokine (PSK) through a nanopore, we here demonstrate accurate identification of sulfation and phosphorylation on the two tyrosine residues of PSK. Sulfation can be clearly detected and distinguished (>90%) from phosphorylation on the same residue. Moreover, the presence or absence of PTMs on the two close-by tyrosine residues can be accurately determined (>96% accuracy). Our findings demonstrate the extraordinary sensitivity of nanopore protein measurements, providing a new tool for identifying sulfation on peptide phytohormones and promising wider applications to identify protein PTMs.

Determination of the median lethal dose of zinc gluconate in mice and safety evaluation.

BACKGROUND: Zinc Gluconate (ZG) is a safe and effective supplement for zinc. However, there is limited research on the optimal dosage for intravenous injection and the safety evaluation of animal models for ZG. This study aims to determine the safe dose range of ZG for intravenous injection in C57BL/6J mice. METHODS: A Dose titration experiment was conducted to determine the LD50 and 95% confidence interval (95%CI) of ZG in mice. Based on the LD50, four sub-lethal doses (SLD) of ZG were evaluated. Following three injections of each SLD and monitoring for seven days, serum zinc levels were measured, and pathological changes in the liver, kidney, and spleen tissues of mice were determined by histological staining. RESULTS: The dose titration experiment determined the LD50 of ZG in mice to be 39.6 mg/kg, with a 95%CI of 31.8-49.3 mg/kg. There was a statistically significant difference in the overall serum zinc levels (H = 36.912, P < 0.001) following SLD administration. Pairwise comparisons showed that the serum zinc levels of the 1/2 LD50 and 3/4 LD50 groups were significantly higher than those of the control group (P < 0.001); the serum zinc level of the 3/4 LD50 group was significantly higher than those of the 1/8 LD50 and 1/4 LD50 groups (P < 0.05). There was a positive correlation between the different SLDs of ZG and the serum zinc levels in mice (rs = 0.973, P < 0.001). H&E staining showed no significant histological abnormalities or lesions in the liver, kidney, and spleen tissues of mice in all experimental groups. CONCLUSION: The appropriate dose range of ZG for intravenous injection in C57BL/6J mice was clarified, providing a reference for future experimental research.

Taurine Regulates the Expression of Interleukin -17/10 and Intestinal Flora and Protects the Liver and Intestinal Mucosa in a Nonalcoholic Fatty Liver Disease Rat Model.

Purpose: To investigate the intestinal inflammatory response and the abundance of intestinal bacteria in rats with high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) and assess the intervention effects of taurine (TAU). Methods: Forty male Sprague-Dawley rats were randomly divided into five groups: group I, normal diet and normal saline gavage; group II, normal diet and TAU gavage; group III, HFD and normal saline gavage; group IV, HFD and TAU gavage (from the 1st week); group V, HFD and TAU gavage (from the 10th week). At the end of the 16th week, all the animals were sacrificed. Body weight, liver weight, liver function, and serum lipid levels were measured. The histopathologies of the liver and ileum were observed. The mRNA and protein expression levels of interleukin 17 (IL-17) and IL-10 in the ileum were detected by reverse transcription quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Three types of bacteria were detected in intestinal feces using the 16S rDNA qPCR method. Results: The ileal IL-17 level in group III was significantly higher than those in the other four groups (P < 0.01). The ileal IL-10 mRNA levels in group IV was significantly higher than those in groups III and V (P < 0.05), and IL-10 protein MOD levels in group III was significantly lower than those in the other four groups (P < 0.01). The numbers of Lactobacillus in group III were significantly lower than those in the other four groups (P < 0.01 or P < 0.05). The numbers of Bifidobacteria in groups IV and V were significantly increased compared with that in group III (P < 0.05). Conclusion: TAU may down-regulate the expression of IL-17, up-regulate the expression of IL-10 and regulate the intestinal flora, and alleviate the liver and intestinal damage in rats with HFD-induced NAFLD.

[Effects of ursodeoxycholic acid on mRNA expression of MDR3 and FXR in infants with cholestatic hepatitis].

OBJECTIVE: To analyze the effects of ursodeoxycholic acid (UDCA) on the mRNA expression of multidrug resistance protein 3 (MDR3) and farnesoid X receptor (FXR) in infants with cholestatic hepatitis. METHODS: Twenty-eight infants who were diagnosed with cholestatic hepatitis between July 2008 and July 2010 were included in the study. These patients received treatment with UDCA. The mRNA expression levels of MDR3 and FXR were measured by real-time quantitative RT-PCR with SYBR Green I, before and after treatment with UDCA. RESULTS: After treatment with UDCA, the infants with cholestatic hepatitis had significantly decreased serum levels of total bilirubin, direct bilirubin, alanine aminotransferase, and gamma-glutamyltransferase (P<0.05) and significantly increased mRNA expression of MDR3 (P<0.05). No significant change in mRNA expression of FXR was observed, however (P>0.05). CONCLUSIONS: UDCA improves liver function indices in infants with cholestatic hepatitis, which may be related to up-regulated mRNA expression of MDR3.

AP profiling resolves co-translational folding pathway and chaperone interactions in vivo.

Natural proteins have evolved to fold robustly along specific pathways. Folding begins during synthesis, guided by interactions of the nascent protein with the ribosome and molecular chaperones. However, the timing and progression of co-translational folding remain largely elusive, in part because the process is difficult to measure in the natural environment of the cytosol. We developed a high-throughput method to quantify co-translational folding in live cells that we term Arrest Peptide profiling (AP profiling). We employed AP profiling to delineate co-translational folding for a set of GTPase domains with very similar structures, defining how topology shapes folding pathways. Genetic ablation of major nascent chain-binding chaperones resulted in localized folding changes that suggest how functional redundancies among chaperones are achieved by distinct interactions with the nascent protein. Collectively, our studies provide a window into cellular folding pathways of complex proteins and pave the way for systematic studies on nascent protein folding at unprecedented resolution and throughput.

Neutrophil extracellular traps involved in the pathogenesis of IgA vasculitis: Confirmed in two IgAV rat models.

BACKGROUND: Neutrophil extracellular traps (NETs) have been found to play a role in the development of autoimmune diseases. In the past two years, studies have demonstrated a significantly increase of NETs in skin tissues during the early stages of IgAV, indicating their involvement in disease activity among children with IgAV. However, the presence of NETs in IgAV animal models has not yet been reported. The objective of this study is to investigate whether NETs are involved in the pathogenesis of IgA vasculitis (IgAV) rats. METHODS: Twenty-four SD rats were randomly divided into three groups: the ovalbumin group, the gliadin group, and the control group. The IgAV rat models were established administering Indian ink with ovalbumin (ovalbumin group) or gliadin (gliadin group) with Freund's complete adjuvant. The cell-free DNA (cf-DNA) was quantified by using dsDNA quantification kit, while the levels of Immunoglobulins, complement C3 and myeloperoxidase-DNA (MPO-DNA) in serum were tested using enzyme linked immunosorbent assay (ELISA). The IgA, complement C3 and NETs in tissues were detected through multiple immunofluorescences. RESULTS: Both the ovalbumin group and gliadin group showed IgA and C3 deposition in various tissues, including the glomerular mesangial region, skin, and digestive tract, while the control group showed no such deposition. The levels of circulatory cf-DNA and MPO-DNA, which are components of NETs, were significantly elevated in both ovalbumin and gliadin groups compared with the control group. Furthermore, the presence of NETs were found in gastrointestinal and renal tissues of the ovalbumin and gliadin groups, but not in the control group. CONCLUSIONS: IgAV model rat can be established through the combination of ovalbumin and gliadin with Indian ink and Freund's complete adjuvant. This study provides the first confirmation that NETs are involved in the pathogenesis of IgAV rat.

DNase I targeted degradation of neutrophil extracellular traps to reduce the damage on IgAV rat.

BACKGROUND: In the past two years, studies have found a significant increase in neutrophil extracellular traps (NETs) in patients with IgA vasculitis (IgAV), which is correlated with the severity of the disease. NETs have been reported as an intervention target in inflammatory and autoimmune diseases. This study aimed to investigate the effect of targeted degradation of NETs using DNase I in IgAV rat model. METHODS: Twenty-four Sprague-Dawley rats were randomly divided into three groups: the IgAV model group, the DNase I intervention group and the normal control group, with an average of 8 rats in each group. The model group was established by using Indian ink, ovalbumin, and Freund's complete adjuvant. In the intervention group, DNase I was injected through tail vein 3 days before the end of established model. The circulating cell free-DNA (cf-DNA) and myeloperoxidase-DNA (MPO-DNA) were analyzed. The presence of NETs in the kidney, gastric antrum and descending duodenum were detected using multiple fluorescences immunohistochemistry and Western blots. Morphological changes of the tissues were observed. RESULTS: After the intervention of DNase I, there was a significant reduction in cf-DNA and MPO-DNA levels in the intervention group compared to the IgAV model group (all P<0.001). The presence of NETs in renal, gastric, and duodenal tissues of the intervention group exhibited a significant decrease compared to the IgAV model group (P < 0.01). Moreover, the intervention group demonstrated significantly lower levels of renal MPO and citrullinated histone H3 (citH3) protein expression when compared to the IgAV model group (all P < 0.05). The HE staining results of intervention group demonstrated a significant reduction in congestion within glomerular and interstitial capillaries. Moreover, there was a notable improvement in gastric and intestinal mucosa necrosis, congestion and bleeding. Additionally, there was a substantial decrease in inflammatory cells infiltration. CONCLUSION: The degradation of NETs can be targeted by DNase I to mitigate tissue damage in IgAV rat models. Targeted regulation of NETs holds potential as a therapeutic approach for IgAV.