Cellular immunity after ethanol exposure and burn injury: dose and time dependence.

Acute ethanol exposure prior to burn injury increases the immune dysfunction seen with burn alone, which has been partially attributed to increased circulating and splenic macrophage production of interleukin-6 (IL-6). The current studies examined the effect dose and timing of ethanol exposure prior to burn on cellular immunity. Mice with high (300 mg/dl) circulating levels of ethanol at the time of burn demonstrated further suppression of the delayed type hypersensitivity (DTH) and splenocyte proliferative responses in comparison to mice with moderate (100 mg/dl) ethanol levels. Interestingly, the increase in macrophage IL-6 secretion seen at the moderate dose was not augmented at the high dose; however, the circulating IL-6 levels did reveal a further increase at the high ethanol dose. There were no alterations in splenocyte subset populations and/or apoptosis at the moderate vs. the high ethanol dose. Moderate ethanol exposure 24 h, in comparison to 30 min, before injury resulted in similar decreases in the DTH. These results suggest that the dose-dependent effects of ethanol on immunity following burn injury are not the result of splenic macrophage IL-6 production as shown at the moderate dose and that the immune suppressive effects of ethanol in this model persist after it is cleared from the circulation.     

Alcohol and immunology: introduction to and summary of the 2003 Alcohol and Immunology Research Interest Group (AIRIG) meeting.

The 8th Meeting of the Alcohol and Immunology Research Interest Group (AIRIG) was held at Loyola University Medical Center, Maywood, Illinois, USA, on November 21, 2003. Reports from multiple laboratories reveal that the functional integrity of the immune system is of paramount importance to the survival of the individual after infection or injury. Evidence supports the idea that exposure to alcohol causes dysregulation of both the innate and the adaptive arms of the immune system. Gaining a better understanding of how alcohol interferes with normal inflammatory and immunoregulatory processes will aid researchers in the design of therapeutic interventions that can be used to improve these responses to better fight infection and maintain the health of the individual. At this meeting, nine speakers presented a summary of their recent work on the combined effects of ethanol and injury, infection, or inflammatory challenge. Topics were (1) T-cell activation after chronic ethanol ingestion in mice, (2) effect of ethanol consumption on the severity of acute viral-mediated pancreatitis, (3) ethanol and alveolar macrophage dysfunction, (4) impaired intestinal immunity and barrier function: a cause for enhanced bacterial translocation in alcohol intoxication and burn injury, (5) immune consequences of the combined insult of acute ethanol exposure and burn injury, (6) consequences of alcohol-induced dysregulation of immediate hemodynamic and inflammatory responses to trauma/hemorrhage, (7) regulation of tumor necrosis factor-alpha production by Kupffer cells after chronic exposure to ethanol, (8) acute exposure to ethanol and suppression of cytokine responses induced through Toll-like receptors, and (9) inhibition of antigen-presenting cell functions by alcohol: implications for hepatitis C virus infection. We anticipate that the work presented at the 8th Meeting of AIRIG, summarized in this article, and presented in the nine articles to follow in this Special Issue of Alcohol will stimulate ideas that will develop into research projects in these topical areas.     

Ethanol and burn injury: estrogen modulation of immunity.

A good deal of clinical evidence supports the idea that ethanol exposure is a causative factor in the occurrence of burn or other traumatic injury. In addition, more recent evidence reveals that individuals who sustain injury while under the influence of ethanol suffer from increased morbidity and mortality compared with those with comparable injuries who did not consume ethanol. Many of the complications seen in ethanol-exposed, burn-injured subjects result from depressed immune responses, which render the host unable to fight off infectious organisms. Both injury and ethanol exposure independently affect cellular immune responses, including delayed-type hypersensitivity and splenocyte proliferative responses, and the combined insult of ethanol exposure and injury acts in conjunction to increase further the magnitude and duration of immunosuppression. It is interesting that these immune responses can be restored experimentally in male, but not in female, mice by administration of low, proestrous levels of estrogen. The complexity of the responses after injury in ethanol-exposed subjects is multiplied when the sex of the subjects is added to the equation. This is due, in part, to the effect of the combined insult of injury and ethanol on the production of gonadal steroid hormones in males and females and the direct effects of those hormones on cytokine gene expression in sensitive cell types such as the macrophage. Evidence seems to indicate that cellular immune responses after ethanol exposure and burn injury differ in kinetics and magnitude for male and female subjects, and, hence, the therapeutic interventions to treat burn-injured patients should take into account both sex and ethanol exposure.     

NLRP12对小鼠病毒性肝炎的保护作用及机制探讨

目的 探究NLRP12基因在MHV3（鼠三型肝炎病毒）诱导的小鼠病毒性肝炎中的作用及调控机制。方法 采用不同滴度MHV3病毒诱导野生型及NLRP12基因敲除C57BL/6J小鼠建立病毒性肝炎模型，观察小鼠生存情况，测定血清ALT、AST的表达，HE染色观察肝组织病理改变，TUNEL染色观察细胞凋亡情况，免疫组化染色检测FGL2蛋白表达，全自动生化仪进行小鼠血细胞分类计数，ELISA测定血清炎性细胞因子（IL - 6、TNF - α）及粒细胞集落刺激因子（G - CSF）的表达。结果 致死滴度（50、75和100 pfu）MHV3感染后，相比野生型小鼠，NLRP12基因敲除小鼠生存率明显降低。非致死滴度（25 pfu）MHV3感染情况下，NLRP12基因敲除小鼠呈现更严重的肝脏病理损伤，血清ALT、AST及炎性细胞因子水平更高，血液循环中性粒细胞数量未显著性上调，并伴随粒细胞分化相关标志物（Myadm）的表达降低，但不影响中性粒细胞趋化基因（CXCL1、CXCL2）及G - CSF的表达。结论 NLRP12基因可能通过调控中性粒细胞的发育分化，促进循环中性粒细胞的产生发挥抗病毒作用，从而保护小鼠免于MHV3病毒的感染，提示NLRP12可作为病毒性肝炎潜在的调控靶标。     

抑制活化素受体样激酶5对严重烧伤大鼠急性肺损伤的影响

目的研究TGF-β/Smads信号转导通路对烧伤大鼠急性肺损伤后促炎性细胞因子的表达和肺部炎性损伤程度的影响,以了解该信号转导通路在肺纤维化发生的早期过程中的作用。方法用SB431542抑制活化素受体样激酶5(ALK5)来抑制TGF-β/Smads通路。将24只雄性SD大鼠,随机分为对照组、烧伤组、早期处理组、后期处理组,每组6只。除对照组外,其他3组大鼠麻醉后以98℃水烫背部15 s,造成大鼠30%TBSAⅢ度烧伤,烧伤后腹腔注射40 ml/kg乳酸林格液进行液体复苏,对照组施行假烫,背部浸入37℃水中,未补液。早期处理组分别于烧伤后、1×24 h、2×24 h后腹腔注射SB431542,后期处理组分别于3×24 h、4×24 h、5×24 h后腹腔注射SB431542,7 d后取肺组织,采用Realtime PCR法检测TNF-α和IL-1β的mRNA转录水平,并行肺脏病理学检查及Szapiel评分。结果早期抑制ALK5可提高TNF-α和IL-1βmRNA的转录水平,病理学观察见早期抑制ALK5能加重肺泡炎,急性期后抑制不会加重肺泡炎。结论TGF-β/Smads信号转导通路参与了烧伤后的肺部炎症反应,早期抑制该通路可上调促炎性细胞因子TNF-α和IL-1βmRNA的转录水平,最终增加TNF-α和IL-1β的表达,加重烧伤后的肺损伤;而在炎症反应的急性期后抑制该通路不会加重肺损伤。     

荧蒽暴露致小鼠肺损伤及肺组织转录组分析

目的 本研究旨在评估苯并［b］荧蒽（Benzo［b］ fluoranthene, BbF）暴露导致小鼠肺组织的损伤,并运用转录组学（RNA-Seq）技术探讨潜在的相关基因及信号通路。 方法 对C57BL/6J 雄性小鼠采用非暴露式气管滴注不同剂量苯并［b］荧蒽14天,牺牲小鼠后提取肺组织进行H&E病理检测,提取肺组织总RNA制备cDNA文库,采用Illumina二代高通量测序平台检测小鼠肺组织差异表达基因,并进行GO富集分析和KEGG富集分析。 结果 H&E染色结果显示,与对照组比较,苯并［b］荧蒽暴露组表现为急、慢性炎症细胞浸润、泡沫细胞及组织细胞增生,残存肺泡腔可见炎性坏死物,并且随着暴露剂量增加炎性细胞浸润程度增强。转录组学分析共筛选到188个表达差异显著的基因,不同剂量苯并［b］荧蒽暴露组关键基因表达不相同,提示不同基因在肺部损伤中可能发挥着不同生物学功能。韦恩图显示有25个差异基因在不同剂量苯并［b］荧蒽暴露导致的肺损伤中共表达,Chil1、Retnla、Lcn2、Ccl6、Mmp12等基因可能参与了肺损伤的调控过程。GO富集分析显示差异表达基因主要与炎症和免疫反应相关。KEGG富集分析显示IL-17信号通路富集到的差异表达基因最多;随着暴露剂量增加,KEGG富集通路从细胞因子、炎症相关信号通路发展为疾病相关信号通路。 结论 苯并［b］荧蒽暴露会造成小鼠肺组织损伤和炎症反应,进而引起炎症、免疫及肺部疾病相关基因差异表达及信号通路的变化。     

Human pulmonary responses to experimental inhalation of high concentration fine and ultrafine magnesium oxide particles.

Exposure to air polluted with particles less than 2.5 micron in size is associated epidemiologically with adverse cardiopulmonary health consequences in humans. The goal of this study was to characterize human pulmonary responses to controlled experimental high-dose exposure to fine and ultrafine magnesium oxide particles. We quantified bronchoalveolar lavage (BAL) cell and cytokine concentrations, pulmonary function, and peripheral blood neutrophil concentrations in six healthy volunteers 18 to 20 hr after inhalation of fine and ultrafine magnesium oxide particles produced from a furnace system model. We compared postexposure studies with control studies from the same six subjects. Mean +/- standard deviation (SD) cumulative magnesium dose was 4,138 +/- 2,163 min x mg/m3. By weight, 28% of fume particles were ultrafine (<0.1 micron in diameter) and over 98% of fume particles were fine (<2.5 micron in diameter). There were no significant differences in BAL inflammatory cell concentrations, BAL interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor, pulmonary function, or peripheral blood neutrophil concentrations postexposure compared with control. Our findings suggest that high-dose fine and ultrafine magnesium oxide particle exposure does not produce a measurable pulmonary inflammatory response. These findings are in marked contrast with the well-described pulmonary inflammatory response following zinc oxide particle inhalation. We conclude that fine and ultrafine particle inhalation does not result in toxicity in a generic manner independent of particle composition. Our findings support the concept that particle chemical composition, in addition to particle size, is an important determinant of respiratory effects.     

Attenuated lung fibrosis in interleukin 6 knock-out mice after C-ion irradiation to lung

There is a great deal of evidence that a cyclic cascade of inflammatory cytokines, together with the activation of macrophages, is initiated very early after irradiation to develop lung fibrosis in a late phase. To understand the persistent effects of cytokines, the cytokine gene of knock out or transgenic mouse is one of the useful tools. In this study, we evaluated a role of a key molecule, interleukin-6 (IL-6), in the late-phase inflammatory response and subsequent fibrotic changes after irradiation using wild-type (WT) and IL-6 knock out (IL-6 KO) mice. The mice underwent thoracic irradiation with 10 Gy of C-ion beam or sham-irradiation and were examined by histology. Immunoreactivity for IL-6 was induced at the site of bronchiolar epithelium, in pneumocytes and in monocytes by C-ion irradiation. At 24 weeks after irradiation, the infiltration of macrophages, detected by positive immunohistological staining with Mac3 antibody, was observed in alveolar spaces both in WT and IL-6 KO mice. The thickening of bronchiolar and alveolar walls exhibited in WT mice, but not KO mice, and fibrotic changes detected by Masson-Trichrome staining, were observed only in the lungs of WT mice, while it was attenuated in IL-6 KO mice. These results indicated that IL-6 might not be essential for activating macrophages in the late phase, but plays an important role for fibrotic changes of the alveolar wall after irradiation.     

Ethanol exacerbates T cell dysfunction after thermal injury.

To understand the mechanism of suppressed immunity following alcohol consumption and thermal injury, we analyzed T cell functions in a mouse model of acute alcohol exposure and burn injury. Mice with blood alcohol levels at approximately 100 mg/dl were given a 15% scald or sham injury. Mice were sacrificed 48 h after injury. Our data demonstrated a 20-25% decrease in Con A-mediated splenic T cell proliferation (p<0.01) and 45-50% decrease in interleukin-2 (IL-2) production (p<0.01) following burn injury compared to the T cells from sham animals. A further decrease in the proliferation (25-30%) and IL-2 production (40-45%) was detected in T cells derived from burned animals receiving alcohol as compared to burn alone. No significant change in the proliferation and IL-2 production was observed in splenic T cells derived from sham-injured mice regardless of alcohol exposure. Additionally, there was no demonstrable difference in splenocyte apoptosis in any treatment group. These results suggest that alcohol consumption prior to burn injury causes a greater decrease in T cell proliferation and IL-2 production compared to either burn or alcohol injury alone that may further attenuate the cell-mediated immunity and thus enhance susceptibility to infection.     

Role of Fractalkine in promoting inflammation in sepsis-induced multiple organ dysfunction

ObjectiveFractalkine, CX3CL1, is involved in the directional movement of chemokine cells, immune response, inflammatory response, tissue repair, and other processes. However, its role in sepsis is not well known.MethodsWe measured circulating Fractalkine in adult patients with sepsis. Effects of Fractalkine on the survival, inflammation, tissue injury, and bacterial clearance were assessed using the WT or CX3CL^−/− murine model of cecal ligation and puncture (CLP)-induced sepsis.ResultsSerum Fractalkine concentrations were significantly elevated in adult patients with sepsis compared to healthy adults. Increased Fractalkine correlated positively with the number of blood leukocytes and the level of inflammatory cytokines, including IL-6, IL-1β, IL-17A, IFN-γ, and TNF-α, and correlated negatively with IL-10 in clinical sepsis. Recombinant Fractalkine impaired survival whereas Fractalkine gene knockout or anti-Fractalkine antibody improved survival in the murine model of CLP-induced sepsis. Fractalkine administration increased inflammatory response, evident by higher levels of cytokines (TNF-α, IL-1β, IL-17A, IFN-γ, and IL-6 but not IL-10), and tissue damage (lung, liver, and kidney) in CLP-induced sepsis. Fractalkine reduced bacterial clearance in CLP-induced polymicrobial sepsis by reducing macrophage or neutrophil phagocytosis and intracellular elimination of E. coli.ConclusionsFractalkine aggravates sepsis by increasing inflammation and decreasing bacterial clearance, and is a potential tool for anti-sepsis therapy.     

Effects of Inflammatory Factor Expression Regulated by 12/15 Lipoxygenase on Obesity-Related Nephropathy

Background: It has been demonstrated that 12/15-lipoxygenase (LO) contributes to insulin resistance by promoting beta cells’ exposure to inflammation. We investigate the mechanism by which 12/15-LO regulates the expression of inflammatory factors in obesity-related glomerular disease (ORG). Methods: Glomerular mesangial cells were treated with metabolite of 12/15-LO, and the expression of inflammatory factors was measured. Cell histones methylation in 12/15-LO related metabolic memory process were evaluated by chromatin immunoprecipitation (ChIP) assays. Wild-type (WT) and 12/15-LO knockout mice were fed a high-fat diet (HFD) to induce ORG. Results: 12(S)-HETE increased TNF-α, MCP-1, and IL-6 mRNA expression. Inhibition of 12/15-LO reduced the expression of inflammatory factors stimulated by PA or TNF-α. ChIP assays showed that 12(S)-HETE increased H3K4me modification in the TNF-α, IL-6, and MCP-1 gene promoters, and decreased H3K9me3 modification in the MCP-1 and IL-6 gene promoter. Urinary albumin excretion was greater in HFD-fed than in standard fat diet-fed mice, but both urinary protein and microalbumin amounts were lower in HFD-fed 12/15-LO knockout than in WT mice. The levels of TNF-α, IL-6, and MCP-1 in serum and renal cortex were higher in WT than in 12/15-LO knockout mice. Conclusions: 12/15-LO may regulate the expression of inflammatory factors in ORG by methylation of histones in the promoter regions of genes encoding inflammatory factors, sustaining the inflammatory phenotype of ORG.     

Low-dose ethanol aggravates allergic dermatitis in mice

Alcohol injures dendritic cells and suppresses cellular immunity, while some evidence indicates that drinking alcohol aggravates allergic asthma. This study investigated the effect of low doses of ethanol in enhancing allergic reactions in the skin of mice. Liquid food containing alcohol was administered to conventional NC/Nga mice to induce alcoholic hepatic steatosis, and spontaneous dermatitis was evaluated. BALB/c mice were administered approximately 1 g/kg body weight of ethanol by gavage, and contact hypersensitivity (CHS) or active cutaneous anaphylaxis (ACA) was induced. Spleens were collected 24 h after the elicitation of CHS and mRNA expressions of interferon (IFN)-γ, interleukin (IL)-4, IL-6, IL-10, and IL-18 were measured by quantitative RT-PCR. Alcohol-containing diet exaggerated spontaneous dermatitis in conventional NC/Nga mice and contact hypersensitivity in BALB/c mice. Ethanol administered by gavage for 5 days enhanced contact hypersensitivity in BALB/c mice. Ethanol administration with gavage also enhanced ACA of BALB/c mice. Ethanol did not affect mRNA expression of IFN-γ and IL-4, but did enhance IL-6, IL-10, and IL-18 mRNA expression. Histological evaluation revealed an absence of hepatic steatosis in mice administered ethanol by gavage for 5 days. In ethanol-administered mice, inflamed areas presented as lesions or a local extreme accumulation of mononuclear cells in the epidermis. These findings suggest that ethanol enhances the expression of inflammatory cytokines independently from T helper (Th)1/Th2 cytokine phenotypes, causing abnormalities in the epidermis resulting in exacerbated allergic reactivity.     

Profiling of cellular immune responses to Mycoplasma pulmonis infection in C57BL/6 and DBA/2 mice

Mycoplasma infections cause respiratory tract damages and atypical pneumonia, resulting in serious problems in humans and animals worldwide. It is well known that laboratory inbred mouse strains show various susceptibility to Mycoplasma pulmonis (M. pulmonis) infection, which causes murine respiratory mycoplasmosis. In this study, we aimed to demonstrate the difference in cellular immune responses between resistant strain, C57BL/6NCrSlc (B6) and susceptible strain, DBA/2CrSlc (D2) after challenging M. pulmonis infection. D2 mice showed higher amount of bacterial proliferation in lung, higher pulmonary infiltration of immune cells such as neutrophils, macrophages, and lymphocytes, and higher levels of interleukin (IL)-1β, IL-6, IL-17A, and tumor necrosis factor-α in bronchoalveolar lavage fluid than did B6 mice. The results of this study suggest that D2 mice are more susceptible than B6 mice to M. pulmonis infection due to a hyper-immune inflammatory response.     

Neutrophilic infiltration in alcoholic hepatitis.

Leukocyte infiltration in the liver is one of the most important features of alcoholic liver disease. However, in alcoholic hepatitis, the role of polymorphonuclear neutrophils (PMNs) in liver injury still remains to be fully elucidated. Furthermore, the migration of PMNs and their presence in the liver during alcoholic hepatitis have not been fully investigated. Up-regulation of chemokine secretion and adhesion molecule expression on effector cells (i.e., PMNs) and target cells (i.e., hepatocytes) are important factors in neutrophilic infiltration of the liver. The CXC chemokines--that is, interleukin (IL)-8 (in human beings), cytokine-induced neutrophil chemoattractant (CINC) (in rats), and KC (in mice)--are proneutrophilic agents. They are up-regulated during chronic--that is, several years of--alcohol use in human beings and in up to 30 weeks in experimental models of ethanol intoxication in mice and rats. Up-regulation of these chemokines in the circulation and tissues is also associated with enhanced neutrophilic infiltration in the liver. In the rat, the up-regulation of CXC chemokine production is time dependent. For example, after 16 weeks of feeding, up-regulation of CXC chemokine is observed, whereas after 32 weeks, CC chemokines are enhanced. Concomitantly, selective migration of PMNs and mononuclear cells is observed. In another model, in which both CXC and CC chemokines were enhanced after chronic ethanol use for 12 weeks in mice, neutrophilic and mononuclear/lymphocytic infiltrations were also seen. This model correlates closely with alcoholic hepatitis in human beings, characterized by increased IL-8, RANTES (regulated upon activation, normal T cell expressed and secreted), and macrophage inflammatory protein-1 (MIP-1) and profound increases in neutrophils and lymphocytes in the liver.     

CD44 and Bak expression in IL-6 or TNF-alpha gene knockout mice after whole lung irradiation

To understand the molecular mechanisms that underlie radiation pneumonitis, we examined whether knockout of the TNF or the IL-6 gene could give mice an inherent resistance to radiation in the acute phase of alveolar damage after thoracic irradiation. The temporal expression of inflammation (CD44) and apoptosis (Bak) markers in lung after thoracic irradiation was measured to determine the degree of alveolar damage. At 4 weeks post-irradiation (10 Gy), small inflammatory foci were observed in all mice, but there were no obvious histological differences between control (C57BL/6JSlc), TNF-alpha knockout (TNF KO), and IL-6 knockout (IL-6 KO) mice. However, immunohistochemical analysis of CD44 and Bak expression over a time course of 2 weeks highlighted significant differences between the three groups. C57BL/6JSlc and TNF KO mice had increased numbers of both CD44-positive and Bak-positive cells after irradiation, while the IL-6 KO mice showed stable levels of CD44 and Bak. In conclusion, the radioresistant status of IL-6 KO mice in the acute phase of alveolar damage after irradiation suggested an important role for IL-6 in radiation pneumonitis.     

Malondialdehyde-acetaldehyde-adducted protein inhalation causes lung injury

In addition to cigarette smoking, alcohol exposure is also associated with increased lung infections and decreased mucociliary clearance. However, little research has been conducted on the combination effects of alcohol and cigarette smoke on lungs. Previously, we have demonstrated in a mouse model that the combination of cigarette smoke and alcohol exposure results in the formation of a very stable hybrid malondialdehyde-acetaldehyde (MAA)-adducted protein in the lung. In in vitro studies, MAA-adducted protein stimulates bronchial epithelial cell interleukin-8 (IL-8) via the activation of protein kinase C epsilon (PKC?). We hypothesized that direct MAA-adducted protein exposure in the lungs would mimic such a combination of smoke and alcohol exposure leading to airway inflammation. To test this hypothesis, C57BL/6J female mice were intranasally instilled with either saline, 30 μL of 50 μg/mL bovine serum albumin (BSA)-MAA, or unadducted BSA for up to 3 weeks. Likewise, human lung surfactant proteins A and D (SPA and SPD) were purified from human pulmonary proteinosis lung lavage fluid and successfully MAA-adducted in vitro. Similar to BSA-MAA, SPD-MAA was instilled into mouse lungs. Lungs were necropsied and assayed for histopathology, PKC? activation, and lung lavage chemokines. In control mice instilled with saline, normal lungs had few inflammatory cells. No significant effects were observed in unadducted BSA- or SPD-instilled mice. However, when mice were instilled with BSA-MAA or SPD-MAA for 3 weeks, a significant peribronchiolar localization of inflammatory cells was observed. Both BSA-MAA and SPD-MAA stimulated increased lung lavage neutrophils and caused a significant elevation in the chemokine, keratinocyte chemokine, which is a functional homologue to human IL-8. Likewise, MAA-adducted protein stimulated the activation of airway and lung slice PKC?. These data support that the MAA-adducted protein induces a proinflammatory response in the lungs and that the lung surfactant protein is a biologically relevant target for malondialdehyde and acetaldehyde adduction. These data further implicate MAA-adduct formation as a potential mechanism for smoke- and alcohol-induced lung injury.     

Nicotine enhances ethanol-induced fat accumulation and collagen deposition but not inflammation in mouse liver

Introduction

Alcohol and tobacco are frequently co-abused. Tobacco smoke increases alcoholic steatosis in apoE(−/−) mice. Tobacco smoke contains more than 4000 chemicals, but it is unknown which compounds in tobacco smoke play a major role in increasing alcoholic steatosis.

Methods

C57BL/J6 mice were intraperitoneally injected with nicotine at 1 mg/kg every day or saline at the same volume as a control and the mice were fed dextrose-control or ethanol Lieber–DeCarli liquid diets. Three weeks later the mice were sacrificed after overnight fasting.

Results

Neither nicotine injection nor ethanol feeding alone increased serum levels of triglyceride, but the combination of nicotine and ethanol increased serum levels of triglyceride. Both nicotine injection alone and ethanol feeding alone increased hepatic collagen type I deposition, and nicotine injection and ethanol feeding combined further increased hepatic collagen type I deposition. The combination of nicotine and ethanol also activated hepatic stellate cells, a principal liver fibrogenic cell. Hepatic fat accumulation was induced by ethanol feeding, which was further enhanced by nicotine injection. Ethanol feeding caused an increase in serum ALT, but nicotine did not further increase serum ALT levels. Lipid droplets and inflammatory foci were observed in liver sections from ethanol-fed mice; nicotine treatment increased the number and size of lipid droplets, but not the number and size of inflammatory foci. Nicotine did not further increase ethanol-induced hepatic neutrophil infiltration.

Conclusions

These results suggest that nicotine enhances ethanol-induced steatosis and collagen deposition, but nicotine has no effect on ethanol-induced inflammation.     

骨髓间充质干细胞促小鼠皮肤烫伤修复研究

  目的  探讨骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)对小鼠皮肤烫伤的促修复作用,为临床采用BMSCs治疗烫伤提供依据。
  方法  以3周龄C57BL/6J小鼠的骨髓细胞悬液体外扩增培养BMSCs。将36只10周龄C57BL/6J小鼠随机分为局部细胞移植组、尾静脉细胞移植组和平行对照组(每组12只),建立皮肤烫伤模型。小鼠皮肤烫伤损伤模型建立成功1 h后,将BMSCs通过皮下和尾静脉分别注射到两个细胞移植组中,平行对照组注射生理盐水。观察动物创面变化,计算21 d后的创面愈合率、检测炎症因子变化和皮肤形态学变化。
  结果  分离培养的BMSCs增殖旺盛,能够多向分化为成骨细胞、成软骨细胞和成脂细胞。局部细胞移植组和尾静脉细胞移植组的创面愈合率在21 d后达到98.2%和99.0%,其差异无统计学意义(P > 0.05);而平行对照组愈合率在7 d后明显低于两个细胞移植组(P < 0.05)。BMSCs移植后,在第3天和第7天后,两个细胞移植组白细胞和白细胞介素-6(IL-6)水平明显低于平行对照组(P < 0.05);在3 d、7 d和14 d后,两个细胞移植组C反应蛋白和肿瘤坏死因子-α(TNF-α)水平明显低于平行对照组(P < 0.05);但21 d后各炎症因子水平在各组间差异无统计学意义(P > 0.05)。两个细胞移植组的皮肤形态学在21 d后胶原纤维丰富,皮肤组织结构清晰,而平行对照组可见炎性细胞浸润、胶原排列紊乱和充血现象。
  结论  皮肤烫伤模型移植BMSCs后,后者可提高宿主C57BL/6J小鼠的皮肤烫伤恢复能力。
     

大气颗粒物暴露对大鼠心肌组织氧化损伤研究

目的 探讨大气颗粒物暴露对大鼠心肌组织氧化损伤.方法 将48只SPF级SD雄性大鼠随机分为暴露组(3个月,6个月)和对照组,每组12只.对照组大鼠饲养在过滤大气颗粒物的独立通气笼盒(IVC)内,暴露组大鼠饲养在未过滤大气颗粒物的IVC内.HE染色观察6个月后大鼠心肌组织病理学改变.ELISA检测3个月和6个月大鼠心肌组...