CD24+LCN2+ liver progenitor cells in ductular reaction contributed to macrophage inflammatory responses in chronic liver injury.

BACKGROUND: CD24+CK19+/CD24+SOX9+ resident liver cells are activated and expanded after chronic liver injury in a ductular reaction. However, the sources and functions of these cells in liver damage remain disputed. RESULTS: The current study combined genetic lineage tracing with in vitro small-molecule-based reprogramming to define liver progenitor cells (LPCs) derived from hepatic parenchymal and non-parenchymal tissues. tdTom+ hepatocytes were isolated from ROSA26tdTomato mice following AAV8-Tbg-Cre-mediated recombination, EpCAM+ biliary epithelial cells (BECs) from wild-type intrahepatic bile ducts and ALB/GFP-EpCAM- cells were isolated from AlbCreERT/R26GFP mice. A cocktail of small molecules was used to convert the isolated cells into LPCs. These in vitro cultured LPCs with CD24 and SOX9 expression regained the ability to proliferate. Transcriptional profiling showed that the in-vitro cultured LPCs derived from the resident LPCs in non-parenchymal tissues expressed Lipocalin-2 (Lcn2) at high levels. Accordingly, endogenous Cd24a+Lcn2+ LPCs were identified by integration of sc-RNA-sequencing and pathological datasets of liver dysfunction which indicates that LPCs produced by ductular reactions might also originate from the resident LPCs. Transplantation of in-vitro cultured Cd24a+Lcn2+ LPCs into CCl4-induced fibrotic livers exacerbated liver damage and dysfunction, possibly due to LCN2-dependent macrophage inflammatory response. CONCLUSIONS: CD24+LCN2+ LPCs constituted the expanding ductular reaction and contributed to macrophage-mediated inflammation in chronic liver damage. The current findings highlight the roles of LPCs from distinct origins and expose the possibility of targeting LPCs in the treatment of chronic hepatic diseases.

[Progress in metabolism and function of myelin lipids].

Myelin is a highly specialized membrane structure, wrapping around the axons. It is essential for the protection of axons, insulation and maintenance of the saltatory conduction of the action potential. Myelin membrane is rich in lipids, however, the lipid composition varies significantly from other biological membranes. Since myelination requires extraordinarily high level of lipid synthesis, the integrity of myelin is susceptible to numerous lipid metabolism disorders. Studies on transgenic mice targeting key molecules of various lipid biosynthesis pathways have elucidated the lipid metabolism and functions of myelin. Besides, myelinating glial cells have a remarkable capacity to take up extracellular lipids, which also contributes to myelination. Therefore, understanding the metabolism and functions of myelin lipids will help us to understand the role of lipids in myelin damage-related diseases and provide novel strategies for the treatment of demyelinating diseases. In this paper, some progresses in metabolism and functions of myelin lipids are reviewed.

Spirometric prediction equations and the relationship between metabolic syndrome and spirometric parameters from an island in Fujian, China.

BACKGROUND: We investigated risk factors for decreased lung function among Chinese island residents (≥30 years) to determine the relationship between metabolic syndrome (MS) and decreased lung function. METHODS: From October 17, 2011 to November 1, 2011, 2607 residents aged ≥30 years who lived on the Huangqi Peninsula of Fujian were enlisted by random cluster sampling. They completed a questionnaire designed according to the Burden of Obstructive Lung Disease (BOLD) questionnaire, and underwent physical examination, blood test, and lung function evaluation. We constructed spirometric prediction equations for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), determined the lower limits of normal for FVC, FEV1 and FEV1/FVC, and examined the relationship between lung function and MS. RESULTS: Prediction equations for normal island residents were as follows: FVC (L) = -0.023 × age (years) + 0.042 × height (cm) + 0.641 × weight (kg) - 3.607 (males); FVC (L) = -0.017 × age (years) + 0.030 × height (cm) + 0.009 × weight (kg) - 1.741 (females); FEV1 (L) = -0.023 × age (years) + 0.040 × height (cm) + 0.010 × weight (kg) - 2.999 (males); FEV1 (L) = -0.017 × age (years) + 0.026 × height (cm) + 0.007 × weight (kg) -1.135 (females). The odds ratio for MS for increased risk of decreased FVC was 4.623 (95%CI =3.626-5.894, P<0.001), and for increased risk of decreased FEV1 was 3.043 (95%CI =2.447-3.785, P<0.001). CONCLUSIONS: MS is a risk factor for decreased lung function in island residents ≥30 years old.

Risk factors for small airway obstruction among Chinese island residents: a case-control study.

BACKGROUND: We investigated the prevalence of and risk factors for small airway obstruction (SAO) among Chinese island residents to establish means to prevent and treat SAO. METHODS: From October 17, 2011 to November 1, 2011, a total of 2,873 residents aged >20 years who lived on the Huangqi Peninsula of Fujian were recruited by random cluster sampling. They were asked to complete a Burden of Obstructive Lung Disease (BOLD) questionnaire and underwent physical examinations and lung function evaluations. SAO was defined as a forced expiratory flow at 50% of vital capacity, Vmax50%, of less than 70% of predicted. Risk factors for SAO were assessed from among demographic and anthropometric variables, blood chemistry results, and questionnaire response items. RESULTS: A total of 216 (7.52%) Chinese island residents were identified as having SAO (95 males; 121 females). Their survey and test results were compared with 432 age and sex-matched healthy controls (192 males; 240 females) for SAO risk factors. Among numerous factors investigated, only diabetes mellitus (p = 0.039), smoking index (SI, p<0.001 for SI>600), second hand smoke (p = 0.002), and lack of regular exercise (p<0.001) were significant risk factors for SAO. CONCLUSIONS: The risk factors for SAO among Chinese island residents appeared to be similar to those among people who live in high-density urban environments and impoverished rural areas. Public health policies and medical practices directed toward improving respiratory health for island residents should be comparable to those used for urban and rural dwellers.

[Immunization with 2nd extracellular loop peptide of muscarinic acetylcholine 3 receptor induces the secretion of IL-17 and IFN-γ in NOD-scid mice].

AIM: To evaluate whether or not the changes in the secretions of IL-17 and IFN-γ can be induced by the immunization with 2nd extracellular loop peptide of muscarinic acetylcholine 3 receptor (M3R) in NOD-scid (nonobese diabetic-severe combined immunodeficiency) mice. METHODS: We synthesized the 2nd extracellular loop peptide of M3R and immunized NOD-scid mice subcutaneously with the 1:1 mixture of the peptide and the incomplete Freund's adjuvant (IFA). At day 1, 7, 14, 21 after immunization, tail blood samples were taken to determine the antibody titer and evaluate the secretions of IL-17 and IFN-γ in sera. Meanwhile, we recorded the fluid intake amount per mouse every week. At day 21, all of the NOD-scid mice were killed to measure the concentrations of IL-17 and IFN-γ in cell supernatants. Immunofluorescence staining of lacrimal glands was performed to observe the changes in the secretions of IL-17 and IFN-γ. RESULTS: Compared with the control group, the sera titers of anti-2nd extracellular loop peptide antibodies were significantly higher in 2nd extracellular loop peptide immunized NOD-scid mice at day 14 (P<0.05). The concentrations of IL-17 and IFN-γ increased significantly in sera of the 2nd extracellular loop peptide immunized NOD-scid mice at day 7 and 14 (P<0.01). The concentration of IL-17 maintained at a certain level in the supernatants of spleen cells co-cultured with 2nd extracellular loop peptide, while it decreased significantly in the control groups (P<0.01). Immunofluorescence staining demonstrated that the production of IL-17 and IFN-γ increased in the lacrimal glands of NOD-scid mice immunized with the 2nd extracellular loop peptide. However, no changes in fluid intake was observed in NOD-scid mice immunized with the 2nd extracellular loop peptide(P>0.05). CONCLUSION: Immunization with 2nd extracellular loop peptide of M3R can induce the production of anti-2nd extracellular loop peptide antibodies and the secretions of IL-17 and IFN-γ in NOD-scid mice.