DARS expression in BCR/ABL1-negative myeloproliferative neoplasms and its association with the immune microenvironment.

DARS, encoding for aspartyl-tRNA synthetase, is implicated in the pathogenesis of various cancers, including renal cell carcinoma, glioblastoma, colon cancer, and gastric cancer. Its role in BCR/ABL1-negative myeloproliferative neoplasms (MPNs), however, remains unexplored. This study aimed to elucidate the expression of DARS in patients with MPNs (PV 23, ET 19, PMF 16) through immunohistochemical analysis and to examine the profiles of circulating immune cells and cytokines using flow cytometry. Our findings indicate a significant overexpression of DARS in all MPNs subtypes at the protein level compared to controls (P < 0.05). Notably, elevated DARS expression was linked to splenomegaly in MPNs patients. The expression of DARS showed a negative correlation with CD4+ T cells (R = - 0.451, P = 0.0004) and CD4+ T/CD8+ T cell ratio (R = - 0.3758, P = 0.0040), as well as with CD68+ tumor-associated macrophages (R = 0.4037, P = 0.0017). Conversely, it was positively correlated with IL-2 (R = 0.5419, P < 0.001), IL-5 (R = 0.3161, P = 0.0166), IL-6 (R = 0.2992, P = 0.0238), and IFN-γ (R = 0.3873, P = 0.0029). These findings underscore a significant association between DARS expression in MPNs patients and specific clinical characteristics, as well as immune cell composition. Further investigation into the interplay between DARS and the immune microenvironment in MPNs could shed light on the underlying mechanisms of MPNs pathogenesis and immune dysregulation.

Effects of immune cells in mediating the relationship between gut microbiota and myelodysplastic syndrome: a bidirectional two-sample, two-step Mendelian randomization study.

BACKGROUND: The definitive establishment of a causal relationship between gut microbiota and myelodysplastic syndrome (MDS) has not been achieved. Furthermore, the involvement of immune cells in mediating the connection between gut microbiota and MDS is presently unclear. METHODS: To elucidate the bidirectional correlation between gut microbiota and MDS, as well as to investigate the mediating role of immune cells, a bidirectional two-sample, two-step Mendelian randomization (MR) study was conducted. Summary statistics were obtained from genome-wide association studies (GWAS), including MDS (456,348 individuals), gut microbiota (18,340 individuals), and 731 immune cells signatures (3757 individuals). RESULTS: Genetically predicted eight gut microbiota traits were significantly associated with MDS risk, but not vice versa. Through biological annotation of host-microbiome shared genes, we found that immune regulation may mediate the impact of gut microbiota on MDS. Subsequently, twenty-three immunophenotypes that exhibited significant associations with MDS risk and five of these immunophenotypes were under the causal influence of gut microbiota. Importantly, the causal effects of gut microbiota on MDS were significantly mediated by five immunophenotypes, including CD4 +T cell %leukocyte, CD127 on CD45RA - CD4 not regulatory T cell, CD45 on CD33 + HLA DR + WHR, CD33 on basophil, and Monocyte AC. CONCLUSIONS: Gut microbiota was causally associated with MDS risk, and five specific immunophenotypes served as potential causal mediators of the effect of gut microbiota on MDS. Understanding the causality among gut microbiota, immune cells and MDS is critical in identifying potential targets for diagnosis and treatment.

Exploring the causal relationship between gut microbiota and multiple myeloma risk based on Mendelian randomization and biological annotation.

Introduction: The microbial genome-wide association studies (mbGWAS) have highlighted significant host-microbiome interactions based on microbiome heritability. However, establishing causal relationships between particular microbiota and multiple myeloma (MM) remains challenging due to limited sample sizes. Methods: Gut microbiota data from a GWAS with 18,340 participants and MM summary statistics from 456,348 individuals. The inverse variance-weighted (IVW) method was used as the main bidirectional Mendelian randomization (MR) analysis. To assess the robustness of our results, we further performed supplementary analyses, including MR pleiotropy residual sum and outlier (MR-PRESSO) test, MR-Egger, Weighted median, Simple mode, and Weighted mode. Moreover, a backward MR analysis was conducted to investigate the potential for reverse causation. Finally, gene and gene-set-based analyses were then conducted to explore the common biological factors connecting gut microbiota and MM. Results: We discovered that 10 gut microbial taxa were causally related to MM risk. Among them, family Acidaminococcaceae, Bacteroidales family S24-7, family Porphyromonadaceae, genus Eubacterium ruminantium group, genus Parabacteroides, and genus Turicibacter were positively correlated with MM. Conversely, class Verrucomicrobia, family Verrucomicrobiaceae, genus Akkermansia, and order Verrucomicrobiales were negatively correlated with MM. The heterogeneity test revealed no Heterogeneity. MR-Egger and MR-PRESSO tests showed no significant horizontal pleiotropy. Importantly, leave-one-out analysis confirmed the robustness of MR results. In the backward MR analysis, no statistically significant associations were discovered between MM and 10 gut microbiota taxa. Lastly, we identified novel host-microbiome shared genes (AUTS2, CDK2, ERBB3, IKZF4, PMEL, SUOX, and RAB5B) that are associated with immunoregulation and prognosis in MM through biological annotation. Discussion: Overall, this study provides evidence supporting a potential causal relationship between gut microbiota and MM risk, while also revealing novel host-microbiome shared genes relevant to MM immunoregulation and clinical prognosis.

Supplementing a specific synbiotic suppressed the incidence of AOM/DSS-induced colorectal cancer in mice.

In this study, we evaluated the effect of a specific synbiotic on CAC (AOM/DSS-induced colitis-associated cancer). We confirmed that the synbiotic intervention was able to protect the intestinal barrier and inhibit CAC occurrence via upregulating tight junction proteins and anti-inflammatory cytokines, and downregulating pro-inflammatory cytokines. Moreover, the synbiotic significantly improved the disorder of the colonic microbiota of CAC mice, promoted the formation of SCFAs and the production of secondary bile acids, and alleviated the accumulation of primary bile acids in the CAC mice. Meanwhile, the synbiotic could significantly inhibit the abnormal activation of the intestinal Wnt/ß-catenin signaling pathway significantly related to IL-23. In a word, the synbiotic can inhibit the occurrence and development of colorectal tumors and it may be a functional food to prevent inflammation-related colon tumors, and the research also provided a theoretical basis for improving the intestinal microecological environment through diet therapy.

Development of magnetic particle-based chemiluminescence immunoassay for measurement of SARS-CoV-2 nucleocapsid protein.

BACKGROUND: Recently, the Coronavirus Disease 2019 (COVID-19) caused by SARS-CoV-2 infection has spread rapidly around the world, becoming a new global pandemic disease. Nucleic acid detection is the primary method for clinical diagnosis of SARS-CoV-2 infection, with the addition of antibody and antigen detection. Nucleocapsid protein (NP) is a kind of conservative structural protein with abundant expression during SARS-CoV-2 infection, which makes it an ideal target for immunoassay. METHODS: The coding sequence for SARS-CoV-2-NP was obtained by chemical synthesis, and then inserted into pET28a(+). The soluble recombinant NP (rNP) with an estimated molecular weight of 49.4 kDa was expressed in E. coli cells after IPTG induction. Six-week-old BALB/c mice were immunized with rNP, and then their spleen cells were fused with SP2/0 cells, to develop hybridoma cell lines that stably secreted monoclonal antibodies (mAbs) against NP. The mAbs were preliminarily evaluated by enzyme-linked immunosorbent assay (ELISA), and then used to develop a magnetic particle-based chemiluminescence enzyme immunoassay (CLEIA) for measurement of SARS-CoV-2-NP. RESULTS: mAb 15B1 and mAb 18G10 were selected as capture and detection antibody respectively to develop CLEIA, due to the highest sensitivity for rNP detection. The proposed CLEIA presented a good linearity for rNP detection at a working range from 0.1 to 160 µg/L, with a precision coefficient of variance below 10 %. CONCLUSION: The newly developed mAbs and CLEIA can serve as potential diagnostic tools for clinical measurement of SARS-CoV-2-NP.

Fructooligosaccharide supplementation alleviated the pathological immune response and prevented the impairment of intestinal barrier in DSS-induced acute colitis mice.

The dysbiosis of gut microbiota is closely related to the occurrence and development of inflammatory bowel disease (IBD). The manipulation of intestinal flora through prebiotics or probiotics is expected to induce and maintain the remission of IBD symptoms. 6-week-old C57BL/J mice were daily gavaged with fructooligosaccharides (FOS) or the synbiotic two weeks before the administration of dextran sulfate sodium (DSS). The supplementation of FOS or synbiotic could significantly ameliorate the body weight loss and colon histological damage in DSS-induced acute colitis mice. The altered composition of gut microbiota in acute colitis mice was reversed by FOS or Synbiotic supplementation, with a characteristic of decreased abundance of Mucispirillum. Both FOS and synbiotic mitigated DSS-induced loss of mucus protein (MUC2) and epithelium tight junction proteins (ZO-1, Occluding, Claudin1) in colon mucosa. The expression of pro-inflammatory cytokines (IL-6 and TNF-α) was decreased by FOS or synbiotic treatment, while the expression of Tbx21 and IL-10 was increased. The results suggested that the modulation of gut microbiota by FOS or synbiotic supplementation could decrease the inflammation potential of colonized commensals, which prevented the impairment of the intestinal barrier and induced a regulation of immune response in DSS-induced acute colitis mice.

Development of magnetic particle-based chemiluminescence immunoassay for measurement of human procalcitonin in serum.

BACKGROUND: Serum procalcitonin (PCT) has been recognized as a primary biomarker in bacterial infections, and monitoring its concentration could help to evaluate the prognosis of sepsis and guide the antibiotic administration. We aimed to establish a fast and accurate immunoassay for PCT quantitation. METHODS: Our newly developed monoclonal antibodies (mAbs) against human PCT were preliminarily evaluated by enzyme-linked immunosorbent assay and then used to develop a chemiluminescence enzyme immunoassay (CLEIA). The proposed CLEIA was assessed in analytical performance and applied to measurement of serum PCT. RESULTS: mAb 2D3 and mAb 8F6 were selected as capture and detection antibody respectively, due to the highest sensitivity for PCT detection with no cross reaction to calcitonin gene-related peptides. The proposed CLEIA based on mAb pair of 2D3/8F6-AP was characterized for a working range from 0.03 to 100 µg/L. An excellent correlation was observed between our proposed assay and the VIDAS BRAHMS PCT assay (r: 0.9825). CONCLUSION: Our newly developed mAbs and CLEIA can serve as important diagnostic tools for measurement of human PCT in serum.

Combination of Aß clearance and neurotrophic factors as a potential treatment for Alzheimer's disease.

There is no effective drug to treat Alzheimer's disease (AD), a neurodegenerative disease affecting an estimated 30 million people around the world. Strongly supported by preclinical and clinical studies, amyloid-beta (Aß) may be a target for developing drugs against AD. Meanwhile, the fact that localized neuronal death/loss and synaptic impairment occur in AD should also be considered. Neuronal regeneration, which does not occur normally in the mammalian central nervous system, can be promoted by neurotrophic factors (NTFs). Evidence from clinical trials has shown that both Aß clearance and NTFs are potentially effective in treating AD, thus a new approach combining Aß clearance and administration of NTFs may be an effective therapeutic strategy.

Daphnetin prevents chronic unpredictable stress-induced cognitive deficits.

Chronic exposure to stress hormones might impair cognitive functions such as learning and memory, which were associated with many mood disorders and neurodegenerative diseases. In this study, we aimed to screen for effective compounds to prevent cognitive deficits induced by chronic stress. Daphnetin was found to protect the cortical neurons against dexamethasone-induced reduction of cell viability in a dose-dependent manner in vitro. We further evaluated its effects on chronic unpredictable stress (CUS) mice in vivo. Two and 8 mg/kg administration of daphnetin could improve the performance of stress mice in Morris water maze tests and forced swimming tests. The results suggested that daphnetin might be a potent compound to treat cognitive deficits induced by CUS.

Schizandrin prevents dexamethasone-induced cognitive deficits.

OBJECTIVE: To model glucocorticoid-induced cognitive impairment and evaluate the neuroprotection by schizandrin (Sch) against dexamethasone (Dex)-induced neurotoxicity in vivo and in vitro. METHODS: Cerebral cortical cells from neonatal Sprague-Dawley rats (within 24 hours after birth) were cultured for 9 days, and then treated with Dex (10(-4), 10(-5), 10(-6) or 10(-7) mol/L) for 24 h or pretreated with 10(-4) mol/L Dex for 24 h followed by 10, 20, 40, or 80 µmol/L Sch for 48 h. Cell viability was assessed using the MTT assay. Immunofluorescence and real-time PCR for MAP2 were performed to confirm the effects of Dex on neurite outgrowth. In vivo, kunming mice were randomly divided into six groups: control [(intragastric (i.g.) vehicle for 42 days]; Dex group I (5 mg/kg · d(-1) Dex i.g. treatment for 28 days followed by i.g. vehicle for 14 days); Dex group II (Dex i.g. for 42 days); Dex + Sch (Dex i.g. for 28 days followed by 5, 15, or 45 mg/kg · d(-1) Sch i.g. for 14 days). Learning and memory were assessed by Morris water maze test. Histological examination was used to assess pathology and apoptosis in neurons. RESULTS: Compared to the Dex groups, Sch increased cell viability in a dose-dependent manner, improved performance in the Morris water maze and ameliorated the morphological changes. CONCLUSION: Sch has neuroprotective effects against insults induced by glucocorticoid.

Phosphorylation of Akt is involved in protocatechuic acid-induced neurotrophic activity.

OBJECTIVE: To investigate the mechanisms underlying protocatechuic acid (PCA)-induced neurotrophic effects on cultured cortical neurons. METHODS: The mRNA expression of microtubule-associated protein 2 (MAP2) and brain-derived neurotrophic factor (BDNF) were measured by real-time quantitative PCR (qPCR). Subsequently, antagonists were used to study the signaling pathways activated by PCA and western blotting was used to detect the phosphorylation level of kinase-related protein. RESULTS: The mRNA expression of MAP2 and BDNF were upregulated in neurons treated with PCA compared with vehicle control. PCA-induced neurite outgrowth and neuronal survival in cultured cortical neurons were significantly inhibited by ZM241385 (an A(2A) receptor antagonist) and LY294002 (a PI3K inhibitor), but not by K252a (a TrkA receptor antagonist), GÖ6976 (a protein kinase C inhibitor) and PD98059 (a MEK inhibitor). PCA enhanced the phosphorylation of Akt, which could be blocked by LY294002. CONCLUSION: The PI3K/Akt signaling pathway might play an important role in the neurotrophic activity of PCA.

Neurotrophic effects of magnesium fructose 1, 6-diphosphate on cortical neurons.

In this study, we evaluated the neurotrophic effects of magnesium fructose 1, 6-diphosphate (FDP-Mg) on cortical neurons. The results demonstrated that FDP-Mg promoted dendrite outgrowth and neuronal survival in a dose-dependent manner. In order to investigate the associated mechanisms, we determined adenosine triphosphate (ATP) levels and brain-derived neurotrophic factor (BDNF) mRNA expression in cortical neurons. Treatment with FDP-Mg significantly increased ATP levels and BDNF mRNA expression in cortical neurons. These data suggest that FDP-Mg can exert neurotrophic effects on cortical neurons. The increases in BDNF mRNA expression and cellular ATP levels are involved in the neurotrophic effects produced by FDP-Mg.

Methyl 3,4-dihydroxybenzoate promotes neurite outgrowth of cortical neurons cultured in vitro.

Cerebral cortical neurons from neonatal rats were cultured in the presence of methyl 3,4-dihydroxybenzoate (MDHB; 2, 4, and 8 µM). Results showed that MDHB significantly promoted neurite outgrowth and microtubule-associated protein 2 mRNA expression, and increased neuronal survival in a dose-dependent manner. Moreover, MDHB induced brain-derived neurotrophic factor expression. These findings suggest that MDHB has a neurotrophic effect, which may be due to its ability to increase brain-derived neurotrophic factor expression.