Small
extracellular vesicles (sEVs) derived from the plasma have
been increasingly recognized as important vehicles of intercellular
communication and potential sources of new biomarkers for multiple
diseases. In this study, proteomic profiles of plasma sEVs from normal
subjects and diabetic patients with or without diabetic retinopathy
(DR) were systematically compared using iTRAQ-based quantitative proteomics.
Among a total of 901 identified proteins in plasma sEVs (false discovery
rate (FDR) < 1%), 90 proteins were found to have significantly
changed levels in DR. Based on the findings from the proteomic analysis,
the role of tumor necrosis factor-α-induced protein 8 (TNFAIP8)
in promoting human retinal microvascular endothelial cell (HRMEC)
proliferation was investigated. The enzyme-linked immunosorbent assay
(ELISA) showed that TNFAIP8 levels in plasma sEVs and vitreous are
elevated in DR, whereas not statistically different in large EVs (lEVs)
and plasma. In addition, in vitro experiments demonstrated
that 4-hydroxynonenal (4-HNE) increased the expression of TNFAIP8
in HRMECs. TNFAIP8 significantly increased HRMECs cell viability and
promote cell migration and tube formation, and the depletion of TNFAIP8
impaired HRMEC proliferation. We demonstrated that TNFAIP8 in plasma
sEVs could be used as a potential biomarker of DR. Functional studies
suggested that TNFAIP8 might be an important mediator of angiogenesis
in DR.
Background: Angiostrongylus cantonensis can cause severe symptoms of central nervous system infections. In the host, this parasite localizes in the blood and cerebrospinal fluid, and its secreted components can impact immune responses. Our previous study demonstrated that immune responses were inhibited in A. cantonensis-infected mice immunized with Ac-Galectin-1 (AcGal-1). However, the mechanisms by which AcGal-1 regulates the immune responses remain unclear. Macrophages are innate immune cells that rapidly respond to infection. The direct impact of AcGal-1 on macrophages may affect the immune responses.Methods: AcGal-1 protein was purified by nickel ion affinity chromatography. The effect of AcGal-1 on the apoptosis of macrophages was detected using CCK-8 assay, flow cytometry and western blot. Macrophage membrane proteins bound to AcGal-1 were obtained using the His-tag-based pull-down assay and identified via mass spectrometry. Co-localization of AcGal-1 and the macrophage membrane protein Annexin A2 was observed by immunofluorescence microscopy, and their interaction was validated by co-immunoprecipitation experiments. SiRNA-mediated knockdown of Annexin A2 was used to determine if AcGal-1-induced macrophage apoptosis required interaction with Annexin A2. The phosphorylation level of apoptotic signal pathway protein was detected by phospho-antibody microarray and western blot.
Results:Our study showed that AcGal-1 caused apoptosis of the macrophages. AcGal-1 increased the expression of apoptosis proteins caspase-3, caspase-9, Bax, but reduced the expression of anti-apoptosis protein Bcl-2. AcGal-1 interacted with the membrane protein Annexin A2, and knockdown of Annexin A2 expression increased Bcl-2 but decreased Bax levels in AcGal-1-treated cells. Moreover, AcGal-1 increased JNK phosphorylation and the inhibition of JNK phosphorylation in AcGal-1-treated cells decreased the expression of caspase-3, -9, Bax and almost restored Bcl-2 to the level observed in control cells.
Conclusions:AcGal-1 can induce the apoptosis of macrophages by binding to Annexin A2 and activating JNK downstream the apoptotic signaling pathway.
Cryptosporidiosis is a major public health problem in humans and animals. Information on the prevalence and molecular diversity of Cryptosporidium in farmed deer in northeastern China is limited. In this study, the prevalence of these parasites was investigated in four farmed deer species, including 125 reindeer, 109 red deer, 86 sika deer, and 18 Siberian roe deer by nested PCR amplification of the partial small subunit of ribosomal RNA (SSU rRNA) gene. C. ubiquitum isolates were subtyped using nested PCR and sequence analysis of the 60-kDa glycoprotein (gp60) gene. The overall prevalence of Cryptosporidium was 7.1%, with 15.1% for sika deer, 4.0% for reindeer, 4.6% for red deer, and 5.6% for roe deer. C. ubiquitum (n = 4), C. xiaoi (n = 2), and Cryptosporidium deer genotype (n = 18) were identified. All four C. ubiquitum isolates belonged to the XIIa subtype (n = 4). This study confirms that Cryptosporidium deer genotype is widely occurring in deer in the investigated areas. Presence of zoonotic C. ubiquitum XIIa subtype indicates that farmed deer represent potential source of zoonotic cryptosporidia and might pose a threat to human health.
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