[Analysis of the Development Mechanism of Cytokine Storm in Severe Burn Patients Complicated with Infection].

In the early stage of infection in severe burn patients, the killing function of the natural immune cells is continuously low, which causes the immune system to continuously and compensatorily secrete a large amount of cytokines to improve the ability to resist bacterial infection. Once the cytokine secretion is out of control, a cytokine storm will form. In the late stage of severe burn infection, the bone marrow mobilization caused by continuous acute myelodysplasia will be exhausted, the level of immune response will be low, and the secretion of anti-inflammatory factors promoting repair will be increased, which will lead to immune suppression. Cytokine storm after burn infection is caused by excessive proinflammatory stimulation, inadequate inflammatory regulation, or a combination of the two. From the perspective of immunology, this review will briefly summarize the changing process of immune response against pathogenic bacteria after severe burn infection, cytokine storm in the early stage of severe burn infection and the mechanism of occurrence and transformation of immunosuppression in the late stage of severe burn infection. We suggest that future research direction from the following aspects: Mechanism of low bacterial killing function of innate immune cells after severe burns; The mechanism by which acute myeloid hyperplasia leads to myeloid inhibitory cells (MDSC) and nucleated erythrocytosis during the development of cytokine storms; The key regulatory mechanism between macrophage phagocytic dysfunction and cytokine hyperactivity; The role and key regulatory mechanism of destruction of the dynamic balance of M1/M2 macrophages and effector/regulatory T cells in triggering immune suppression.

LncRNA SNHG1 promotes EMT process in gastric cancer cells through regulation of the miR-15b/DCLK1/Notch1 axis.

BACKGROUND: Gastric cancer (GC) is a malignant tumour originating from the gastric mucosa epithelium that seriously threatens human health. DCLK1, miR-15b and lncRNA SNHG1 play potential roles in the occurrence of GC, but the mechanism remains unclear. METHODS: Gene expression of DCLK1, miR-15b and lncRNA SNHG1 was investigated by qRT-PCR. Protein expression was detected by Western blotting. Migration and invasion of gastric cancer cells was tested by a Transwell assay and wound healing assay. Cell proliferation was measured by an MTT assay. Finally, the correctness of the prediction results was confirmed by a dual-luciferase reporter assay. RESULTS: The expression of DCLK1, Notch1, and SNHG1 was increased in GC tissues, while the expression of miR-15b was decreased. Overexpression of lncRNA SNHG1 promoted the expression of DCLK1 and Nothc1 in GC cells. Moreover, miR-15b targeted DCLK1 to regulate Notch1 expression and inhibited the EMT process in GC cells. SNHG1 enhanced the effects of DCLK1/Notch1 on the EMT process through regulating miR-15b expression. CONCLUSION: SNHG1 enhances the EMT process in GC cells through DCLK1-mediated Notch1 pathway, which can be a potential target for treating GC.

Eukaryotic initiation factor 6 modulates myofibroblast differentiation at transforming growth factor-ß1 transcription level via H2A.Z occupancy and Sp1 recruitment.

Eukaryotic initiation factor 6 (eIF6) is a pivotal regulator of ribosomal function, participating in translational control. Previously our data suggested that eIF6 acts as a key binding protein of P311 (a hypertrophic scar-related protein; also known as NREP). However, a comprehensive investigation of its functional role and the underlying mechanisms in modulation of myofibroblast (a key effector of hypertrophic scar formation) differentiation remains unclear. Here, we identified that eIF6 is a novel regulator of transforming growth factor-ß1 (TGF-ß1) expression at transcription level, which plays a key role in myofibroblast differentiation. Mechanistically, this effect is associated with eIF6 altering the occupancy of the TGF-ß1 promoter by H2A.Z (Swiss-Prot P0C0S6) and Sp1. Accordingly, modulation of eIF6 expression in myofibroblasts significantly affects their differentiation via the TGF-ß/Smad signaling pathway, which was verified in vivo by the observation that heterozygote eIF6(+/-) mice exhibited enhanced TGF-ß1 production coupled with increased α-smooth muscle actin (α-SMA)(+) myofibroblasts after skin injury. Overall, our data reveal a novel transcriptional regulatory mechanism of eIF6 that acts on facilitating Sp1 recruitment to TGF-ß1 promoter via H2A.Z depletion and thus results in increased TGF-ß1 transcription, which contributes to myofibroblast differentiation.

MiR-185-3p regulates epithelial mesenchymal transition via PI3K/Akt signaling pathway by targeting cathepsin D in gastric cancer cells.

BACKGROUND: Recently research reported that miR-185-3p could serve as an independent prognosis factor in gastric cancer (GC). However, the functional role and underlying mechanism of miR-185-3p in GC and epithelial-mesenchymal transition (EMT) progression remains largely elusive. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to analyze the expression of miR-185-3p and cathepsin D in patient-derived GC samples and various GC cell lines. Scratch assay and Transwell assay were used to evaluate the migration ability. The influence of miR-185-3p on the cell cycle distribution and cell apoptosis was evaluated using flow cytometry. Western blotting assay was performed to detect the expression of EMT associated proteins and the activity of PI3K/Akt signaling pathway. Furthermore, the interaction between miR-185-3p and cathepsin D was explored by dual-luciferase reporter assay. RESULTS: Our data revealed that miR-185-3p was down-regulated, while cathepsin D was up-regulated in both patient-derived GC samples and GC cells. Apart from inducing apoptosis, overexpression of miR-185-3p also inhibited EMT process and migration of GC cells. Mechanically, we firstly verified that miR-185-3p directly targeted the cathepsin D. Furthermore, miR-185-3p exerted its function on EMT process and migration via inhibiting cathepsin D to mediated PI3K/Akt signaling pathway. CONCLUSIONS: Our findings suggested that miR-185-3p targeted cathepsin D inhibiting EMT process via PI3K/Akt signaling, which may serve as a potential prognosis factor and therapeutic target to reduce the malignancy of GCs.

Process of Hypertrophic Scar Formation: Expression of Eukaryotic Initiation Factor 6.

BACKGROUND: Hypertrophic scar is one of the most common complications and often causes the disfigurement or deformity in burn or trauma patients. Therapeutic methods on hypertrophic scar treatment have limitations due to the poor understanding of mechanisms of hypertrophic scar formation. To throw light on the molecular mechanism of hypertrophic scar formation will definitely improve the outcome of the treatment. This study aimed to illustrate the negative role of eukaryotic initiation factor 6 (eIF6) in the process of human hypertrophic scar formation, and provide a possible indicator of hypertrophic scar treatment and a potential target molecule for hypertrophic scar. METHODS: In the present study, we investigated the protein expression of eIF6 in the human hypertrophic scar of different periods by immunohistochemistry and Western blot analysis. RESULTS: In the hypertrophic scar tissue, eIF6 expression was significantly decreased and absent in the basal layer of epidermis in the early period, and increased slowly and began to appear in the basal layer of epidermis by the scar formation time. CONCLUSIONS: This study confirmed that eIF6 expression was significantly related to the development of hypertrophic scar, and the eIF6 may be a target molecule for hypertrophic scar control or could be an indicator of the outcomes for other treatment modalities.

[Effects of antisense p38 α mitogen-activated protein kinase on myocardial cells exposed to hypoxia and burn serum].

OBJECTIVE: To study the effects of antisense p38α mitogen-activated protein kinase (hereinafter referred to as p38α) on myocardial cells exposed to hypoxia and burn serum. METHODS: Thirty adult SD rats were inflicted with 40% TBSA full-thickness burn on the back to obtain burn serum. The myocardial cells were isolated from 80 neonatal SD rats and cultured, then they were divided into 4 groups according to the random number table: normal control group (N, ordinary culture without any treatment), hypoxia+burn serum group (HB, exposed to hypoxia after being treated with 10% burn rat serum), hypoxia+burn serum+infection group (HBI, exposed to hypoxia and 10% burn rat serum after being infected with antisense p38α gene-carrying adenovirus), hypoxia+burn serum+empty vector infection group (exposed to hypoxia and 10% burn rat serum after being infected with adenovirus empty vector). At post hypoxia hour (PHH) 1, 3, 6, and 12, mRNA and protein expression levels of p38α in the latter 3 groups were determined by RT-PCR and Western blotting, cell viability was determined by methylthianolyldiphenyl-tetrazolium bromide assay, and lactate dehydrogenase (LDH) activity was assayed at the same time point. At PHH 1, 6, and 12, apoptosis rate of myocardial cells was assessed by annexin V staining method. The indexes of group N were determined with the methods mentioned-above. Three wells were set at each time point in each group. Data were processed with one-way analysis of variance and LSD- t test. RESULTS: (1) At PHH 1, 3, and 6, the p38α mRNA level was higher in group HB than in group N and group HBI (with t values from 2.725 to 4.375, P values all below 0.05). (2) At PHH 1, 3, and 6, the p38α protein level was higher in group HB than those in group N and group HBI (with t values from 5.351 to 7.981, P values all below 0.01). (3) At PHH 3, 6, and 12, the cell viability in group HB (0.115 ± 0.007, 0.104 ± 0.006, 0.094 ± 0.005) was lower than that in group N (0.141 ± 0.014) and group HBI (0.136 ± 0.009, 0.124 ± 0.010, 0.112 ± 0.007, with t values from 2.357 to 6.812, P values all below 0.05). (4) The LDH activity was up-regulated in group HB as compared with that in group N and group HBI at each time point (with t values from 22.753 to 201.273, P values all below 0.01). (5) At PHH 1, 6, and 12, the apoptosis rate of myocardial cells in group HB [(5.4 ± 0.7)%, (8.7 ± 1.1)%, (13.6 ± 1.7)%] was higher than that of group N [(3.1 ± 0.3)%] and group HBI [(4.3 ± 0.5)%, (5.1 ± 0.7)%, (7.2 ± 0.9)%, with t values from 2.345 to 9.700, P < 0.05 or P < 0.01]. CONCLUSIONS: Antisense p38α can protect the myocardial cells from the injury of hypoxia and burn serum.

Analyses of differential proteome of human synovial fibroblasts obtained from arthritis.

There is mounting evidence indicating that the synovial fibroblasts (SFs) contribute to the pathogenesis of rheumatoid arthritis (RA). The present study showed the differential proteins expression pattern of SFs from patients with RA or osteoarthritis (OA) and healthy control. Cellular proteins of cultured SFs were subjected to 2-DE and visualized by silver nitrate staining. A total of 49 spots that were statistically and differentially overexpressed in RA or OA in comparison to healthy ones were identified by MALDI-TOF-MS, and 25 proteins were successfully identified. Western blot was used to further verify some of the differential proteins. These proteins included enzymatic and structural proteins, signal transduction proteins, calcium binding protein, etc. From all of the identified proteins, a number of proteins have been implicated that involved in the healthy or pathological SFs function (e.g., S100A4, S100A10, cathepsin D) or that have potential diagnostic and prognostic value for RA (alpha-enolase and TPI) or that may be the new therapeutic targets (Annexin, SOD, PRX).

[Study of xenotransplantation of fetal pig skin precursor tissue].

OBJECTIVE: To select the optimal pregnancy time window of embryonic pig skin precursor tissue for xenotransplantation and study its ability in wound repair. METHODS: Skin precursor tissues were obtained from pig fetus of fetal age of 35, 42, 56, 70 days, and were minced into microskin and transplanted to dorsal wounds of BALB/c nude mice, then they were covered with residual skin after plastic surgery of patients or adult pig skin (white). The characteristics of growth and development were observed after transplantation. Pathological examination was performed on 6 and 12 post operation weeks respectively to observe the tissue structure and tumorigenicity. RESULTS: Skin precursor tissues from fetal pig survived and developed after transplantation, and the microskin fused. New tissue area from skin precursor tissues with fetal age of 42 days was (47 +/- 6) mm2, which was higher than that of 35 days (18 +/- 8 mm2), 56 days (31 +/- 12 mm2), 70 days (20 +/- 8 mm2, P < 0.05). The skin precursor developed into "intact skin" with hair, sebaceous glands and sweat glands, and melanocytes were also detected in epidermis. The newly-grown skin tissue included epidermal and dermal layer, and obvious dermal papillae. Teratoma was not found after transplantation in skin precursor tissue with fetal age of 56, 70 days. CONCLUSION: Fetal pig skin precursor tissue with fetal age of 56 days can be used to repair wound as xenotransplantation.

[Blockage of allergic rhinitis in mice with recombinant protein of cytotoxic T lymphocyte associated antigen-4 extracellular domain].

OBJECTIVE: To explore a new immunotherapy against allergic rhinitis. METHODS: The recombinant protein of CTLA4 extracellular domain was obtained through construction of CTLA4-yeast expression system. The allergic rhinitis in mice was induced by sensitizing and challenging with ovalbumin (OVA). The allergic rhinitis related symptoms and the morphological changes in nasal mucosa were compared between the allergic rhinitis group and the CTLA4 extracellular domain group treated with CTLA4 extracellular domain before each challenge by ways of intraperitoneal injection. RESULTS: CTLA4 extracellular domain with a molecular weight of 28 000, which was confirmed by Western blot, could be generated through CTLA4-yeast expression system. The purified CTLA4 extracellular domain could inhibit T cells proliferation in mixed lymphocyte reaction with a inhibitory rate of 95.4%. The mice in allergic rhinitis group appeared typical allergic rhinitis symptoms after OVA challenge, such as rhinorrhea and sneeze. Meanwhile the nasal pathological studies showed edema and congestion in mucosa tissue and local influx of inflammatory cells. Whereas in CTLA4 extracellular domain group, the nasal symptoms were rarely observed, and the pathological change in nasal mucosa was significantly abated. CONCLUSIONS: The protein of CTLA4 extracellular domain could prevent the allergic rhinitis in mice. The underlying mechanism of which might be the inhibition of the T cell activation.

[An experimental study on the role of indirect antigen presentation pathway on the immunogenetic of epidermal cells].

OBJECTIVE: To explore the role of indirect antigen presentation pathway on the immunogenecity of epidermal cells. METHODS: Human epidermal cells (HEC), allogeneic human peripheral blood lymphocytes (PBL) and mononuclear cells (PBM, including monocytes) were isolated and cultured in vitro. HECs were transfected by human-originated CTLA4Ig-adenovirus vector. The CTLA4Ig expression was observed. Allogeneic PBLs or PBMs were added to the transfected and non-transfected HECs with simple cultured PBLs and PBMs as the control. The proliferation of PBL and PBM was determined by (3)H-TdR incooperation. RESULTS: HECs could be successfully transfected by CTLA4Ig-adenovirus vector and expressed corresponding proteins. The non-transfected HECs could stimulate slight proliferation of allogeneic PBLs (P < 0.05) and stimulate remarkable proliferation of PBMs (including monocytes) (P < 0.05). The proliferation reaction of PBLs and PBMs decreased significantly (P < 0.05) after being stimulated by HEC which was modulated by CTLA4Ig genes. CONCLUSION: Indirect antigen presentation pathway might play important roles in the HEC immunogenicity which could be evidently inhibited by CTLA4Ig.