Characterization of effects of chitooligosaccharide monomer addition on immunomodulatory activity in macrophages.

The present study aimed to investigate the effects of five chitooligosaccharide monomers of different molecular weights on immunomodulatory activity in macrophage-like RAW264.7 cells. The incubation of various chitooligosaccharide monomers enhanced phagocytosis and pinocytosis activity toward Staphylococcus aureus and Escherichia coli in RAW264.7 cells. The incorporation of chitooligosaccharide monomers significantly boosted the generation of reactive oxygen species and reactive nitrogen species, as well as the release of inflammatory cytokines. To further explore the mechanism of inflammation regulated by chitooligosaccharide, the activation inhibitors of NF-кB (CAPE) and TLR-4 (TAK-242) were utilized, the determination data demonstrated that chitobiose suppressed the expression of inflammatory cytokines and NF-кB p65. In addition, the investigation results revealed that the presence of the mannose receptor inhibitor (mannan) suppressed chitohexaose-induced phagocytic activity and inflammatory cytokines. These results suggested that the five distinct chitooligosaccharide monomers had inconsistent effects, the chitobiose and chitohexaose exhibiting the best biological activity in activating RAW264.7 cells, promoting cell proliferation, and increasing non-specific immunity.

The antibacterial activity of erythrocytes from Clarias fuscus associated with phagocytosis and respiratory burst generation.

It is widely known that red blood cells (RBCs) are responsible for respiration and the transport of gas. However, recent reports have also described the immune properties of RBCs, therefore creating new understanding for the functionality of RBCs. However, little is known about the immunological role of RBCs in bony fish. In this study, we used RBCs from Clarias fuscus as a model and demonstrate that these cells exhibited phagocytic ability with both latex beads and bacteria. Scanning electron microscopy and transmission electron microscopy provided visual confirmation of the phagocytotic process in RBCs. In addition, we used flow cytometry and fluorescence microscopy to analyse the rate of phagocytosis in RBCs. We found that RBCs exhibited stable phagocytotic ability with latex beads ranging from 0.5 to 1.0 µm in size. In response to bacterial stimulation, RBCs produced reactive oxygen species (ROS) and nitric oxide synthase (NOS), which are harmful to bacteria. RBCs also have an antioxidant system. Under conditions of oxidative stress, the expression levels of antioxidant enzymes, and particularly those of superoxide dismutase（SOD） increased significantly. Our results show that the erythrocytes of bony fish are phagocytic and also produce ROS which are toxic to bacteria. In addition, RBCs have an antioxidant system that removes excess ROS production to protect cells from oxidative damage.

Molecular and functional characterization of mitochondrial manganese superoxide dismutase from Macrobrachium rosenbergii during bacterial infection.

Superoxide dismutases (SODs) are the main antioxidant enzymes involved in alleviating oxidative stress. Although mitochondrial manganese SOD (mMnSOD) has been reported to be correlated with the immune response in crustaceans, its biological properties and role in the immune response remain unclear. Here, we cloned the Macrobrachium rosenbergii mMnSOD (MrmMnSOD), analyzed its activity and expression pattern under Staphylococcus aureus and Vibrio parahaemolyticus infection, and further explored its possible mechanism during antibacterial immune response. The results showed that both enzyme activity and the expression of MrmMnSOD were significantly up-regulated by bacterial infection. MrmMnSOD knockdown made the prawn susceptible to Vibrio infection, which increased the mortality rate and the number of bacteria in haemocytes. The bacterial agglutination assay confirmed that MrmMnSOD decreases bacterial abundance via agglutination. Overall, this work identified antibacterial function of MrmMnSOD in the immune response. In addition to contributing to immunological theory, these findings aid disease prevention and control in crustacean aquaculture.

Mitophagy in Cerebral Ischemia and Ischemia/Reperfusion Injury.

Ischemic stroke is a severe cerebrovascular disease with high mortality and morbidity. In recent years, reperfusion treatments based on thrombolytic and thrombectomy are major managements for ischemic stroke patients, and the recanalization time window has been extended to over 24 h. However, with the extension of the time window, the risk of ischemia/reperfusion (I/R) injury following reperfusion therapy becomes a big challenge for patient outcomes. I/R injury leads to neuronal death due to the imbalance in metabolic supply and demand, which is usually related to mitochondrial dysfunction. Mitophagy is a type of selective autophagy referring to the process of specific autophagic elimination of damaged or dysfunctional mitochondria to prevent the generation of excessive reactive oxygen species (ROS) and the subsequent cell death. Recent advances have implicated the protective role of mitophagy in cerebral ischemia is mainly associated with its neuroprotective effects in I/R injury. This review discusses the involvement of mitochondria dynamics and mitophagy in the pathophysiology of ischemic stroke and I/R injury in particular, focusing on the therapeutic potential of mitophagy regulation and the possibility of using mitophagy-related interventions as an adjunctive approach for neuroprotective time window extension after ischemic stroke.

Induction of apoptosis in SSN-1cells by Snakehead Fish Vesiculovirus (SHVV) via Matrix protein dependent intrinsic pathway.

An increasing important area in immunology is the process cell death mechanism, enabling the immune system triggered thru extrinsic or intrinsic signals to effectively remove unwanted or virus infected cells called apoptosis. A recently isolated infectious Snakehead fish vesiculovirus (SHVV), comprising negative strand RNA and encoded viral matrix (M) proteins, is responsible for causing cytopathic effects in infected fish cells. However, the mechanism by which viral M protein mediates apoptosis has not been elucidated. Therefore, in the present experiments, it was investigated the regulatory potential of apoptosis signals during SHVV infection. By employing the model of SHVV infection in SSN-1 cells, the accelerated apoptosis pathway involves an intrinsic pathway requiring the activation of caspase-9 but not caspase-3 or -8. In the groups of infection (SHVV) or treatment (hydrogen peroxide) were induced apoptotic morphological changes and indicated the activation of the main caspases, i.e.; executioner caspase-3, initiators caspase-8 and caspase-9 using colorimetric assays. Turning to the role of viral M protein when it was overexpressed in SSN-1 cells, it was indicated that the viral M gene alone has the ability to induce apoptosis. To elucidate the mechanism of apoptosis in SSN-1 cells, the activation inhibitors of main caspases were used showing that inhibiting of caspase-3 or caspase-8 activation did not seize induction of apoptosis in virus-infected SSN-1 cells. However, the inhibiting of caspase-9 activation reduced significantly the apoptosis initiation process and sharply the expression of viral M gene, suggesting that SHVV plays a major role in the early induction of apoptosis by caspase-9. Interestingly, there were also differences in the mitochondrial membrane potential after the apoptotic induction of caspases, which confirm that caspase-9 is primarily responsible for the cleavage of caspases during apoptosis. Taken together, these findings can therefore be assumed that viral M protein induces apoptosis via the intrinsic apoptotic pathway in SHVV infecting SSN-1 cells.

The Antibacterial Activity of Erythrocytes From Goose (Anser domesticus) Can Be Associated With Phagocytosis and Respiratory Burst Generation.

In the lumen of blood vessels, there are large numbers of erythrocytes, which are approximately 95% of the total blood cells. Although the function of erythrocytes is to transport oxygen in the organism, recent studies have shown that mammalian and teleost erythrocytes are involved in the immune response against bacterial infections. However, the immune mechanisms used by avian erythrocytes are not yet clear. Here, we demonstrated that erythrocytes from goose have the ability to phagocytose as well as conduct antimicrobial activity. Firstly, we revealed the phagocytosis or adhesion activity of goose erythrocytes for latex beads 0.1-1.0 µm in diameter by fluorescence microscopy, and scanning and transmission electron microscopy. The low cytometry results also proved that goose erythrocytes had a wide range of phagocytic or adhesion activity for different bacteria. Followed, the low cytometry analysis data further explored that the goose erythrocytes contain the ability to produce reactive oxygen species (ROS) and inducible nitric oxide synthase (iNOS) in response to bacterial stimulation, and also up-regulated the expression of NOX family includes NOX1 and NOX5. Finally, we also found that goose erythrocytes showed a powerful antibacterial activity against all the three bacteria, meanwhile the stimulation of three kinds of bacteria up-regulated the expression of inflammatory factors, and increased the production of antioxidant enzymes to protect the cells from oxidative damage. Herein, our results demonstrate that goose Erythrocytes possess a certain phagocytic capacity and antioxidant system, and that the antimicrobial activity of erythrocytes can occurred through the production of unique respiratory burst against foreign pathogenic bacteria, which provides new clues to the interaction between bacteria and avian erythrocytes.

Assessment of the safety and feasibility of 24-hour hospitalization after thyroidectomy.

This study assessed the safety and feasibility of 24-hour hospitalization after thyroid surgery. A randomized controlled trial study was performed for 432 patients scheduled for thyroidectomy in Guangdong General Hospital between January 2014 and January 2016. Group A cases (n = 216) were 24-hour hospital stay and group B cases (n = 216) were inpatient. Preoperative patient characteristics and operative characteristics as well surgical complications were evaluated. Two hundred and fourteen patients (99%) of group A were discharged after a 24-hour postoperative observation except 1 patient hospitalized 2 days for persistent nausea after surgery, and 1 patient who was hospitalized for 2 days for fear of the complication after the operation. The complication rates were similar between the 2 groups (9/216, 11/216; P > 0.05) and no one was readmitted for operation. The overall complication rate of 24-hour hospital stay procedure was low, and there were no differences in the rate of complications between these 2 groups. Thyroid surgery with 24-hour hospital stay is feasible and safe by experienced surgeon in a setting of appropriate facility and management protocol.

[Expression and significance of vascular cell adhesion molecule-1 in human oral squamous cell carcinoma].

OBJECTIVE: To study the expression and the location of vascular cell adhesion molecule-1 (VCAM-1) gene and its clinical significance in human oral squamous cell carcinoma (OSCC). METHODS: In situ hybridization, PV-9000 polymer detection system for immunohistochemical staining was used to detect the expression and the location of VCAM-1 mRNA and VCAM-1 protein in 48 cases of OSCC and 10 cases of normal controls. Statistical analysis was performed using chi-square test in SPSS 13.0. RESULTS: VCAM-1 protein was mainly expressed in tumor cell cytoplasm and membrane, VCAM-1 mRNA was mainly expressed in tumor cell cytoplasm. The expression rate of VCAM-1 mRNA and VCAM-1 protein was significantly higher in OSCC than that in normal oral mucosa (P<0.01). The expression of VCAM-1 mRNA was positively correlated with that of VCAM-1 protein (P<0.01). In the clinicopathologic factors, lymph node metastasis and depth of infiltration were closely correlated with VCAM-1 expression (P<0.01). The expression of VCAM-1 was significantly higher in tumor with lymph node metastasis than in tumor without lymph node metastasis (P<0.01). CONCLUSION: Overexpression of VCAM-1 gene in OSCC may play a potential role in the development of OSCC. The overexpression of VCAM-1 gene in OSCC may be related to the tumor infiltration and metastasis.

[Correlations between the expression of vascular cell adhesion molecule-1 gene and clinical pathological characteristics and angiogenesis in oral squamous cell carcinoma].

PURPOSE: To investigate the correlations between the expression of vascular cell adhesion molecule-1 (VCAM-1) gene and clinicopathologic characteristics and microvessel density (MVD) in oral squamous cell carcinoma (OSCC). METHODS: Expression and location of VCAM-1mRNA and protein in 48 OSCCs and 10 normal controls were detected by in situ hybridization and immunohistochemical stainingìMVD was also assessed. Statistical analysis was performed using SPSS13.0 software package for Student's t test and Chi-square test. RESULTS: VCAM-1mRNA was mainly detected in cytoplasm of OSCC.VCAM-1 protein was mainly detected in membrane and cytoplasm of OSCC. The expression of VCAM-1mRNA and protein were significantly higher in OSCC tissues than normal oral tissues (P<0.01). In the clinicopathologic factors, lymph node metastasis and depth of infiltration were closely correlated with VCAM-1 expression (P<0.01), but there was no significant correlation between the positively expression and patients' sex, age and tumor' differentiated degree (P>0.05). CONCLUSIONS: Overexpression of VCAM-1 gene in OSCC may play a potential role in the development of OSCC.It is closely associated with lymph node metastasis and the angiogenesis.

[Use of allogenic acellular dermal matrix combined with autologous epidermal cells for the repair of tissue defect].

OBJECTIVE: To investigate a method for the repair of tissue defect. METHODS: Allogenic acellular dermal matrixes (ADM) were implanted to full-thickness skin defects made on the dorsa of rats. Two weeks later, autologous suspended epidermal cells were transplanted on to the surface of vascularized ADM. Respectively, neoepidermis was macroscopically observed 2, 3, 5 weeks after grafting, and samples were taken to make routine paraffin sections for microscopical examination, and immunohistochemical staining for type IV collagen was also performed. RESULTS: The vascularized ADM could support proliferation and differentiation of epidermal cells, and also could promote the formation of dermal-epidermal junction. Suspended epidermal cells in an artificial culture system in vivo could develop into mature epidermis. The reconstructed skin not only looked like the normal one in appearance in which hair was removed, but also revealed a better function. CONCLUSIONS: Full-thickness skin defect can be repaired by transplanting autologous epidermal cell suspension on to vascularized ADM.