Research on the biological mechanism and potential application of CEMIP

Cell migration-inducing protein (CEMIP), also known as KIAA1199 and hyaluronan-binding protein involved in hyaluronan depolymerization, is a new member of the hyaluronidase family that degrades hyaluronic acid (HA) and remodels the extracellular matrix. In recent years, some studies have reported that CEMIP can promote the proliferation, invasion, and adhesion of various tumor cells and can play an important role in bacterial infection and arthritis. This review focuses on the pathological mechanism of CEMIP in a variety of diseases and expounds the function of CEMIP from the aspects of inhibiting cell apoptosis, promoting HA degradation, inducing inflammatory responses and related phosphorylation, adjusting cellular microenvironment, and regulating tissue fibrosis. The diagnosis and treatment strategies targeting CEMIP are also summarized. The various functions of CEMIP show its great potential application value.

Cyclophilin A as a Pro-Inflammatory Factor Exhibits Embryotoxic and Teratogenic Effects during Fetal Organogenesis

The precise balance of Th1, Th2, and Th17 cytokines is a key factor in successful pregnancy and normal embryonic development. However, to date, not all humoral factors that regulate and influence physiological pregnancy have been completely studied. Our data here pointed out cyclophilin A (CypA) as the adverse pro-inflammatory factor negatively affecting fetal development and associated with pregnancy complications. In different mouse models in vivo, we demonstrated dramatic embryotoxicity and teratogenicity of increased CypA levels during pregnancy. Using generated transgenic models, we showed that CypA overexpression in fetal tissues induced the death of all transgenic fetuses and complete miscarriage. Administration of recombinant human CypA in a high dose to pregnant females during fetal organogenesis (6.5-11.5 dpc) exhibited teratogenic effects, causing severe defects in the brain and bone development that could lead to malformations and postnatal behavioral and cognitive disorders in the offspring. Embryotoxic and teratogenic effects could be mediated by CypA-induced up-regulation of M1 macrophage polarization via activation of the STAT1/3 signaling pathways. Here, we propose secreted CypA as a novel marker of complicated pregnancy and a therapeutic target for the correction of pregnancy complications.

Soluble TREM-1, as a new ligand for the membrane receptor Robo2, promotes hepatic stellate cells activation and liver fibrosis

Triggering receptor expressed on myeloid cells‐1 (TREM‐1) exists in two forms: a transmembrane form and a soluble form (sTREM‐1). The levels of sTREM‐1 are elevated in supernatants of activated HSCs. However, the role of sTREM‐1 in HSC activation and liver fibrosis remains undefined. Previous studies have primarily focused on the transmembrane form of TREM‐1; we innovatively observed the function of sTREM‐1 as a ligand in liver fibrosis and screened its receptor. Here, recombinant sTREM‐1 was used as a stimulator which induced HSC activation and further aggravated liver fibrosis. Then, screening for sTREM‐1 interacting membrane receptors was performed using pull‐down assay followed by mass spectrometry, and the membrane receptor roundabout guidance receptor 2 (Robo2) was identified as a candidate receptor for sTREM‐1. The interaction between sTREM‐1 and Robo2 was verified by pull‐down and immunofluorescence. The role of Robo2 on sTREM‐1‐induced HSC activation and its downstream signal pathways was assessed by knockdown of Robo2 in LX‐2 cells. Furthermore, HSC‐specific knockdown of Robo2 was achieved in a mouse model of liver fibrosis by using a recombinant adeno‐associated virus (AAV) vector to confirm the role of the receptor, and we proved that Robo2 knockdown inhibited the activation of HSC and liver fibrosis, which also led to the inactivation of Smad2/3 and PI3K/Akt pathways in sTREM‐1‐induced HSC activation and liver fibrosis. In conclusion, sTREM‐1 acts as a new ligand of Robo2; the binding of sTREM‐1 to Robo2 initiates the activation of the downstream Smad2/3 and PI3K/Akt signalling pathways, thereby promoting HSC activation and liver fibrosis.

Wild-Type p53-Induced Phosphatase 1 Plays a Positive Role in Hematopoiesis in the Mouse Embryonic Head

The first adult repopulating hematopoietic stem cells (HSCs) are found in the aorta-gonad-mesonephros (AGM) region, which are produced from hemogenic endothelial cells. Embryonic head is the other site for HSC development. Wild-type p53-induced phosphatase 1 (Wip1) is a type-2Cδ family serine/threonine phosphatase involved in various cellular processes such as lymphoid development and differentiation of adult HSCs. Most recently, we have shown that Wip1 modulates the pre-HSC maturation in the AGM region. However, it is not clear whether Wip1 regulates hematopoiesis in the embryonic head. Here we reported that disruption of Wip1 resulted in a decrease of hematopoietic progenitor cell number in the embryonic head. In vivo transplantation assays showed a reduction of HSC function after Wip1 ablation. We established that Wip1 deletion reduced the frequency and cell number of microglia in the embryonic head. Further observations revealed that Wip1 absence enhanced the gene expression of microglia-derived pro-inflammatory factors. Thus, it is likely that Wip1 functions as a positive regulator in HSC development by regulating the function of microglia in the embryonic head.

Genome-Wide Screen and Validation of Microglia Pro-Inflammatory Mediators in Stroke

Stroke activates microglia pro-inflammatory response that not only induces the early neuronal injuries but also causes the secondary brain infarction. Yet, the underlying mechanisms for how microglia become activated in stroke are still unknown. Here, using the next-generation of RNA sequencing we find a total of 778 genes increasingly expressed in brain of stroke mice. Of these, we identified Hmgb2 as a microglia pro-inflammatory mediator by promoting the transcription of Ctss. Inhibition of either Hmgb2 or Ctss blocks microglia pro-inflammatory response and protects against brain damages and improves the neurological functions of stroke mice. This study uncovers Hmgb2 and Ctss as the major microglia inflammatory response mediators in stroke and hence warrants the promising targets for stroke therapies.

Effects of Dexmedetomidine on Postoperative Delirium and Expression of IL-1β, IL-6, and TNF-α in Elderly Patients After Hip Fracture Operation

Objective

Postoperative delirium (POD) is a common surgical complication in elderly patients. This study investigated the effects of dexmedetomidine on POD and pro-inflammatory markers in elderly patients with hip fracture.

Methods

This randomized, double-blind, controlled trial enrolled patients ≥65 years of age who underwent an operation for hip fracture at Beijing JiShuiTan Hospital from October 2016 to January 2017. The patients were divided into the DEX group (injected with dexmedetomidine 0.5 µg/kg/h) and the NS group (injected with normal saline). After surgery, the incidence of delirium at postoperative day 1 (T1), 2 (T2), and 3 (T3) was assessed using the Confusion Assessment Method delirium scale. Interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α blood levels were detected at T0 (before surgery), T1, and T3.

Results

Data from 240 patients were analyzed, with 120/group (intent-to-treat analysis). Dexmedetomidine decreased POD incidence (18.2 vs. 30.6%, P = 0.033). Compared to T0, all three pro-inflammatory markers were higher at T1 and then decreased at T3 (time interaction, all P < 0.001). IL-6 (P < 0.001) levels were lower in the DEX group at T1, and TNF-α (P = 0.003) levels were lower in the DEX group at T1 and T3, but IL-1β levels were similar between the two groups. The rate of adverse events was similar in the two groups.

Conclusion

Dexmedetomidine reduced the incidence of POD in elderly patients on the first day after hip fracture surgery, and reduced IL-6 and TNF-α levels over the first 3 days after surgery.

Ginsenoside Rg1 Suppresses Type 2 PRRSV Infection via NF-κB Signaling Pathway In Vitro, and Provides Partial Protection against HP-PRRSV in Piglet

Porcine reproductive and respiratory syndrome virus (PRRSV) is a huge threat to the modern pig industry, and current vaccine prevention strategies could not provide full protection against it. Therefore, exploring new anti-PRRSV strategies is urgently needed. Ginsenoside Rg1, derived from ginseng and notoginseng, is shown to exert anti-inflammatory, neuronal apoptosis-suppressing and anti-oxidant effects. Here we demonstrate Rg1-inhibited PRRSV infection both in Marc-145 cells and porcine alveolar macrophages (PAMs) in a dose-dependent manner. Rg1 treatment affected multiple steps of the PRRSV lifecycle, including virus attachment, replication and release at concentrations of 10 or 50 µM. Meanwhile, Rg1 exhibited broad inhibitory activities against Type 2 PRRSV, including highly pathogenic PRRSV (HP-PRRSV) XH-GD and JXA1, NADC-30-like strain HNLY and classical strain VR2332. Mechanistically, Rg1 reduced mRNA levels of the pro-inflammatory cytokines, including IL-1β, IL-8, IL-6 and TNF-α, and decreased NF-κB signaling activation triggered by PRRSV infection. Furthermore, 4-week old piglets intramuscularly treated with Rg1 after being challenged with the HP-PRRSV JXA1 strain display moderate lung injury, decreased viral load in serum and tissues, and an improved survival rate. Collectively, our study provides research basis and supportive clinical data for using Ginsenoside Rg1 in PRRSV therapies in swine.

The Role of Recombinant Human Cyclophilin A in the Antitumor Immune Response

Cyclophilin A (CypA) is a multifunctional protein that exhibits an isomerase activity and exists in the intracellular and secretory forms. Secretory CypA promotes regeneration of the hematopoietic and the immune systems of an organism by stimulating stem cell migration from the bone marrow. New approaches based on CypA are currently being developed for the treatment of limb ischemia, neutralization of the side effects of Cyclosporine A (CsA) therapy, etc. However, the role of CypA in the antitumor immune response is still unexplored. In this work, we used the model experimental system of lymphoma EL-4 rejection in B10.D2(R101) mice and showed that recombinant human CypA (rhCypA) stimulates the antitumor immune response via early recruitment of granulocytes to the tumor cell localization site and rapid accumulation of effector T-killers.

The effect of rfaD and rfaF of Haemophilus parasuis on lipooligosaccharide induced inflammation by NF-κB/MAPKs signaling in porcine alveolar macrophages

In Haemophilus parasuis, the rfa cluster has been identified as a virulence-associated factor that is involved in lipooligosaccharide (LOS) biosynthesis. In this study, we assessed the roles of rfaD and rfaF genes in H. parasuis SC096 on LOS-induced pro-inflammatory factors and the related signaling pathways in porcine alveolar macrophages (PAMs) by real-time PCR and western blotting. The results showed that the LOSs of both rfaD and rfaF mutants (ΔrfaD-LOS and ΔrfaF-LOS) significantly decreased the mRNA expression of pro-inflammatory factors (IL-1α, IL-1β, IL-6, IL-8 and TNF-α) in PAMs compared with H. parasuis SC096 LOS (WT-LOS). Furthermore, in ΔrfaD-LOS- and ΔrfaF-LOS-treated cells, IκBα degradation was significantly inhibited and levels of phospho-p65 and phospho-p38 were significantly reduced in PAMs. These findings suggested that the rfaD and rfaF genes mediated LOS induction of pro-inflammatory cytokines in PAMs by regulating the NF-κB and MAPKs signaling pathways during H. parasuis infection.