Metabolomic and regular analysis reveal phytotoxic mechanisms of sterigmatocystin in Amaranthus retroflexus L.

Sterigmatocystin (STE) is a common hepatotoxic and nephrotoxic contaminant in cereals, however, its phytotoxicity and mechanisms are poorly understood. Here, the phytotoxic mechanisms of STE were investigated via the metabolomics of Amaranthus retroflexus L. A total of 140 and 113 differential metabolites were detected in the leaves and stems, respectively, among which amino acids, lipids, and phenolic compounds were significantly perturbed. Valine, leucine, isoleucine, and lysine biosynthesis were affected by STE. These metabolic responses revealed that STE might be toxic to plants by altering the plasma membrane and inducing oxidative damage, which was verified by measuring the relative electrical conductivity and quantification of reactive oxygen species. The elevated amino acids, as well as the decreased of D-sedoheptuiose-7-phosphate indicated increased proteolysis and carbohydrate metabolism restriction. Furthermore, the IAA level also decreased. This study provides a better understanding of the impacts of STE on the public health, environment and food security.

Efficacy and mechanism of anti-vascular endothelial growth factor drugs for diabetic macular edema patients.

BACKGROUND: Diabetes is a serious public health concern in China, with 30% of patients developing retinopathy, and diabetic macular edema (DME) having the biggest impact on vision. High blood glucose level can cause retinal cell hypoxia, thus promoting vascular endothelial growth factor (VEGF) formation and increasing vascular permeability, which induces DME. Moreover, cell hypoxia can accelerate the rate of apoptosis, which leads to the aging of patients. In severe cases, optic cell apoptosis or retinal fibrosis and permanent blindness may occur. AIM: To investigate and compare the efficacy, mechanism, and differences between two anti-VEGF drugs (Compaq and ranibizumab) in DME patients. METHODS: Ninety-six patients with DME who attended our hospital from April 2018 to February 2020 were included and randomly divided into two groups (Compaq group and ranibizumab group). The groups received vitreal cavity injections of 0.5 mg Compaq and 0.5 mg ranibizumab, respectively, once a month. The best corrected visual acuity (BCVA), intraocular pressure (IOP), macular retinal thickness (CMT), macular choroidal thickness (SFCT), foveal no perfusion area (FAZ), superficial capillary density, deep capillary density, treatment effect, and adverse reactions were compared before and after treatment and between the two groups. RESULTS: Before treatment and 1-mo post-treatment, there was no statistically significant difference in the estimated BCVA in both groups (P > 0.05). BCVA decreased in the Compaq group 3 mo after treatment, and the difference was statistically significant (P < 0.05). Before treatment, and 1 mo and 3 mo post-treatment, there was no statistically significant difference in the estimated IOP in either group (P > 0.05). Before treatment and 1-mo post-treatment, there was no statistically significant difference in the estimated CMT, SFCT, or FAZ in either group (P > 0.05). CMT and SFCT values decreased in the Compaq group 3 mo post-treatment, and the difference was statistically significant (P < 0.05). Before treatment, and 1 mo and 3 mo post-treatment, there were no statistically significant differences in vascular density in the shallow or deep capillary plexi of the fovea, parafovea, or overall macular area between the two groups (P > 0.05). Marked efficient, effective, and invalid rates were 70.83% and 52.08%, 27.08% and 39.58%, and 2.08% and 8.33% in the Compaq and ranibizumab groups, respectively. The differences between the two groups were statistically significant (P < 0.05). CONCLUSION: Anti-VEGF drugs can effectively improve CMT and SFCT, without affecting microcirculation, thus providing an effective and safe treatment for patients with DME.

Anti-CXCL10 monoclonal antibody therapy protects against the diabetic retinopathy in the mouse model induced by streptozotocin.

OBJECTIVE: To explore the effect of CXC chemokine CXCL10 in the mice with diabetic retinopathy (DR). METHODS: DR models were constructed on mice via injection of streptozotocin (STZ). At 3 weeks of STZ, mice were treated with anti-CXCL10 monoclonal antibodies (mAb)/control mAb, and a series of experiments were then conducted at 6 weeks of STZ, including HE staining, western blotting, retinal trypsin digestion, real-time qPCR and enzyme-linked immuno sorbent assay (ELISA). The corresponding kits were used to detect the activity of oxidative stress markers. RESULTS: Compared with nondiabetic eyes, DR mice both at 3 and 6 weeks presented the decreases in the total retinal thickness, the retinal outer nuclear layer (ONL) thickness, and the cells of ganglion cell layer (GCL), with the upregulated CXCL10, pro-inflammatory cytokines and malondialdehyde (MDA), as well as the downregulated levels of superoxide dismutase (SOD), glutathione peroxidase (GPx) and CAT, especially in those at 6 weeks, which were attenuated by the anti-CXCL10 mAb treatment. Moreover, in comparison with the DR mice, mice in the DR + anti-CXCL10 mAb group gained the significant decrease in the number of acellular capillaries of retina, with up-regulations of Claudin-5 and ZO-1 and down-regulations of VEGF and FGF-2. The DR mice injected with anti-CXCL10 mAb demonstrated alleviated retinal pathology as compared to mice at 3 weeks of STZ. CONCLUSION: Anti-CXCL10 mAb could mitigate the retinal pathology of DR mice, with the decreased inflammation and oxidative stress, thus mediating a delay in the development or disease improvement in patients of DR.

Repeated social defeat stress inhibits development of hippocampus neurons through mitophagy and autophagy.

The social defeat stress model is commonly used to study depression and anxiety disorder, which can significantly affect the structure and function of neurons in the hippocampus; however, the relevant mechanism in neuronal loss has not been clearly defined. In the present study, a social defeat stress model was established in mice to evaluate the impact of social defeat stress on the structure of neurons in the hippocampus using Western blotting, immunofluorescence, Nissl staining, Golgi staining and transmission electron microscopy. The results demonstrated that social defeat stress leads to disruption of homeostasis in the hippocampus and the integrity of mitochondria in hippocampal neurons was markedly affected by enhanced mitophagy and autophagy resulting in inhibition of development and growth. These findings provide new insights into the mechanisms of neuronal development and growth due to social defeat stress, which should help in the development of new strategies to combat the effects of depression and anxiety disorder.

Application of DNA barcoding and metabarcoding for species identification in salmon products.

Mislabelling is a significant manifestation of food fraud. Traditional Sanger sequencing technology is the gold standard for seafood species identification. However, this method is not suitable for analysing processed samples that may contain more than one species. This study tested the feasibility of next-generation sequencing in identifying mixed salmon products. Salmon samples containing up to eight species were amplified using 16S rRNA mini-barcode primers, and sequenced on an Illumina HiSeq2500 platform. All species were accurately identified, and mixtures as low as 1% (w/w) could be detected. Furthermore, this study conducted a market survey of 32 products labelled as salmon. For pure and mixed fish products, Sanger and next-generation sequencing techniques were respectively used for species identification, and for NGS results, we also used real-time PCR method to cross-validate the mixed products to further verify the accuracy of the DNA metabarcoding technology established in this study. DNA barcoding and metabarcoding of commercial salmon food products revealed the presence of mislabelling in 16 of 32 (50%) samples. The developed DNA barcoding and metabarcoding methods are useful for the identification of salmon species in food and can be used for quality control of various types of salmon products.

Clinical presentation and management of acquired thrombotic thrombocytopenic purpura: A case series of 55 patients.

The aim of this study was to explore the clinical characteristics and treatment of acquired thrombotic thrombocytopenic purpura (TTP). The clinical manifestations, laboratory findings, differential diagnoses, therapeutic methods, and prognosis of 55 patients with acquired TTP were retrospectively analyzed. Among the 55 TTP patients, 17 were males and 38 were females, with a mean age of 40 ± 15 years. Twenty-one patients had the Triad syndrome, which included neurological syndromes, microangiopathic hemolytic anemia, and thrombocytopenia. Twenty-three patients had the Quinary syndrome, which included fever, microangiopathic hemolytic anemia, thrombocytopenia, renal insufficiency, and neurological symptoms. Twenty-eight patients received the measurement for a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity and 23 patients had <10% of the normal range. ADAMTS13 inhibitor was tested in 20 patients and was positive in 18 patients. Both ADAMTS13 activity and ADAMTS13 inhibitor were examined in 20 patients and 90% of the patients showed double positive results. The treatment methods included plasma exchange, glucocorticoids, rituximab, immunosuppressants, and intravenous immunoglobulin. Thirty-three patients survived, and 22 patients died. Plasma exchange improved the remission rate from 16.7% to 65.3% (P = .022). The combined immunosuppressive therapy based on plasma exchange and glucocorticoids raised the remission rate from 43.8% to 75.8%. Most of acquired TTP patients had the Triad syndrome or the Quinary syndrome. A high proportion of TTP patients had ADAMTS13 activity reduction and ADAMTS13 inhibitor positivity. Plasma exchange and immunosuppressive therapy may improve the prognosis of this disease.

Gadd45α affects retinal ganglion cell injury in chronic ocular hypertension rats by regulating p38MAPK pathway.

OBJECTIVE: To investigate the impact and the mechanism of Gadd45α mediating p38MAPK pathway on the retinal ganglion cells (RGCs) injury in chronic ocular hypertension (COH) rats. METHODS: COH model in rats were established and intraocular pressure (IOP) was tested. Retrograde labeling was used for counting RGCs and TUNEL staining was performed for RGCs apoptosis. Western Blotting was conducted to examine the expression of Gadd45α and p38MAPK pathway. Besides, RGC-5 cells cultured in vitro were treated with H2O2. Cell viability was detected by CCK-8, ROS level tested by DCFH-DA assay, and cell apoptosis examined by flow cytometry. RESULTS: COH rats had increased expression of Gadd45α and p-p38/p38 protein 1-4 weeks after surgery. Rats in COH group enhanced obviously in IOP, RGC apoptosis rate and the protein expression of Gadd45α, p-p38/p38, Bax/Bcl-2 and cleaved caspase-3, but declined appreciably in RGC counting. However, the above indicators of COH rats were effectively improved by Gadd45α shRNA treatment. Additionally, RGC-5 cells in H2O2 group reduced in cell viability and went up in ROS level and apoptosis rate. The H2O2-induced RGC-5 cells treated with Gadd45α shRNA were improved apparently in those indicators, and cells treated with pcDNA Gadd45α showed an opposite trend. Moreover, p38 MAPK inhibitor SB203580 can effectively reverse the damage of pcDNA Gadd45α from H2O2-induced RGC-5 cells. CONCLUSION: Silencing Gadd45α can reduce the RGC damage in COH rats by inhibiting p38MAPK pathway and such a protective role may be associated with the suppression of RGC apoptosis and the mitigation of oxidative stress.

Morbidity and mortality risk factors in emergency department patients with Acinetobacter baumannii bacteremia.

BACKGROUND: Acinetobacter baumannii (AB) bacteremia is an increasingly common and often fatal nosocomial infection. Identification of morbidity and mortality risk factors for AB bacteremia in emergency department (ED) patients may provide ways to improve the clinical outcomes of these patients. METHODS: The records for 51 patients with AB bacteremia and 51 patients without AB infection were collected and matched in a retrospective case-control study between 2013 and 2015 in a single-center ED. Risk factors were analyzed by Chi-square and multivariate logistic regression statistical models. RESULTS: A significant risk factor for morbidity was the presence of a central venous catheter (CVC) (P<0.001). The mortality rate for the 51 patients with AB bacteremia was 68.6%. Risk factors for mortality were the presence of a CVC (P=0.021) and an ED stay longer than two weeks (P=0.015). CONCLUSION: AB infections lead to high morbidity and mortality. The presence of a CVC was associated with higher morbidity and mortality in patients with AB bacteremia. Avoiding CVC insertions may improve outcomes in ED patients with AB bacteremia.

The effect of spleen tyrosine kinase inhibitor R406 on diabetic retinopathy in experimental diabetic rats.

PURPOSE: To investigate the effect of spleen tyrosine kinase (Syk) inhibitor R406 on diabetic retinopathy (DR) in diabetic mellitus (DM) rats. METHODS: Rats were randomized into Normal, DM, DM + 5 mg/kg R406 and DM + 10 mg/kg R406 groups. DM rats were established via injection of streptozotocin (STZ). One week after model establishment, rats in treatment groups received 5 mg/kg or 10 mg/kg R406 by gavage administration for 12 weeks consecutively, followed by the detection with hematoxylin-eosin (HE) staining, Evans blue angiography, retinal trypsin digestion assay, Western blotting, immunohistochemistry, TUNEL assay, immunofluorescence assay and quantitative reverse transcriptase real-time polymerase chain reaction (qRT-PCR). RESULTS: The retina of DM rats presented different degree of edema, disordered and loose structure, swollen cells with enlarged intercellular space, and dilated and congested capillaries. Besides, the retinal vessels of DM rats showed high fluorescence leakage. However, R406 alleviated the above-mentioned conditions, which was much better with high concentration of R406 (10 mg/kg). R406 also reversed the down-regulations of occludin, claudin-5, ZO-1 and the up-regulation of and VEGF in retinal tissues of DM rats; inhibited retinal cell apoptosis; strengthened retinal cell proliferation; and reduced expressions of IL-1ß, IL-6, TNF-α and nuclear p65 NF-κB in retinal tissues. The improvement in all these indexes was much more significant in rats of DM + 10 mg/kg R406 group than in rats of DM + 5 mg/kg R406 group. CONCLUSION: Syk inhibitor R406 could attenuate retinal inflammation in DR rats via the repression of NF-κB activation.

[Role of Pim1 Gene Overexpression in Pathogenesis of Acute Myeloid Leukemia].

OBJECTIVE: To investigate the effect of Pim1 expression up-regulation on cell proliferation, apoptosis, chemotaxis and angiogenesis in acute myeloid leukemia (AML) cell line U937, and to explore the possible molecular mechanism involved, finally to estimate the Pim1 expression in primary AML cells. METHODS: GFP-tagged plasmid for Pim1 overexpression and an empty vector plasmid were constructed, and then a stable Pim1 expressed U937 cell line and a control virus-infected U937 cell line were established by a lentiviral vector system. After confirming Pim1 overexpression in U937 cells, proliferation and apoptosis are determined by CCK-8 Kit and flow cytometry respectively. Transwell chemotaxis assay was used to measure the effect of Pim1 overexpression on AML cells. Flow cytometry and confocal microscopy were applied to detect the influence of Pim1 overexpression on phosphorylated CXCR4 (pCXCR4) and its location. Real-time fluorescence quantitative PCR (qPCR) was used to detect the expression of angiogenesis and adhesion related genes in AML primary cells. RESULTS: The lentivirus-infected AML cell line with Pim1 overex-pression and the control virusinfected AML cell line were established successfully. The Pim1 overexpression could enhance the proliferation and inhibit the cell apoptosis, moreover accompnied with the increasing expression of cyclin D1, phosphorylated BAD (pBAD) and pCXCR4. After SDF-1 α stimuli, Pim1 overexpression induced AML cell chemotaxis accompanied with p-CXCR4 expression and calcium influx increment. Pim1 overexpression has no effect on angiogenesis. Pim1 mRNA expression was significantly higher in AML patients than the healthy people. CONCLUSION: Pim1 plays an important role in the pathogenesis of AML, which not only promotes AML cell proliferation and inhibition of apoptosis, but also enhances the chemotactic ability of leukemia cells, which closely relates with Pim1 phosphorylation of CXCR4 and the increase of intracellular calcium ion influx signals.

Rapid detection and identification of infectious pathogens based on high-throughput sequencing.

BACKGROUND: The dilemma of pathogens identification in patients with unidentified clinical symptoms such as fever of unknown origin exists, which not only poses a challenge to both the diagnostic and therapeutic process by itself, but also to expert physicians. METHODS: In this report, we have attempted to increase the awareness of unidentified pathogens by developing a method to investigate hitherto unidentified infectious pathogens based on unbiased high-throughput sequencing. RESULTS: Our observations show that this method supplements current diagnostic technology that predominantly relies on information derived five cases from the intensive care unit. This methodological approach detects viruses and corrects the incidence of false positive detection rates of pathogens in a much shorter period. Through our method is followed by polymerase chain reaction validation, we could identify infection with Epstein-Barr virus, and in another case, we could identify infection with Streptococcus viridians based on the culture, which was false positive. CONCLUSIONS: This technology is a promising approach to revolutionize rapid diagnosis of infectious pathogens and to guide therapy that might result in the improvement of personalized medicine.