Laser captured hepatocytes show association of butyrylcholinesterase gene loss and fibrosis progression in hepatitis C-infected drug users

The immune niche of the liver

The liver is an essential organ that is critical for the removal of toxins, the production of proteins, and the maintenance of metabolic homeostasis. Behind each liver functional unit, termed lobules, hides a heterogeneous, complex, and well-orchestrated system. Despite parenchymal cells being most commonly associated with the liver's primary functionality, it has become clear that it is the immune niche of the liver that plays a central role in maintaining both local and systemic homeostasis by propagating hepatic inflammation and orchestrating its resolution. As such, the immunological processes that are at play in healthy and diseased livers are being investigated thoroughly in order to understand the underpinnings of inflammation and the potential avenues for restoring homeostasis. This review highlights recent advances in our understanding of the immune niche of the liver and provides perspectives for how the implementation of new transcriptomic, multimodal, and spatial technologies can uncover the heterogeneity, plasticity, and location of hepatic immune populations. Findings from these technologies will further our understanding of liver biology and create a new framework for the identification of therapeutic targets.

Intrahepatic Viral Kinetics During Direct-Acting Antivirals for Hepatitis C in Human Immunodeficiency Virus Coinfection: The AIDS Clinical Trials Group A5335S Substudy

BACKGROUND

Direct-acting antivirals (DAAs) targeting hepatitis C virus (HCV) have revolutionized outcomes in human immunodeficiency virus (HIV) coinfection.

METHODS

We examined early events in liver and plasma through A5335S, a substudy of trial A5329 (paritaprevir/ritonavir, ombitasvir, dasabuvir, with ribavirin) that enrolled chronic genotype 1a HCV-infected persons coinfected with suppressed HIV: 5 of 6 treatment-naive enrollees completed A5335S.

RESULTS

Mean baseline plasma HCV ribonucleic acid (RNA) = 6.7 log10 IU/mL and changed by -4.1 log10 IU/mL by Day 7. In liver, laser capture microdissection was used to quantify HCV. At liver biopsy 1, mean %HCV-infected cells = 25.2% (95% confidence interval [CI], 7.4%-42.9%), correlating with plasma HCV RNA (Spearman rank correlation r = 0.9); at biopsy 2 (Day 7 in 4 of 5 participants), mean %HCV-infected cells = 1.0% (95% CI, 0.2%-1.7%) (P < .05 for change), and DAAs were detectable in liver. Plasma C-X-C motif chemokine 10 (CXCL10) concentrations changed by mean = -160 pg/mL per day at 24 hours, but no further after Day 4.

CONCLUSIONS

We conclude that HCV infection is rapidly cleared from liver with DAA leaving <2% HCV-infected hepatocytes at Day 7. We extrapolate that HCV eradication could occur in these participants by 63 days, although immune activation might persist. Single-cell longitudinal estimates of HCV clearance from liver have never been reported previously and could be applied to estimating the minimum treatment duration required for HCV infection.

Graphene Oxide Causes Disordered Zonation Due to Differential Intralobular Localization in the Liver

The liver is the primary organ to sequester nanodrugs, representing a substantial hurdle for drug delivery and raising toxicity concerns. However, the mechanistic details underlying the liver sequestration and effects on the liver are still elusive. The difficulty in studying the liver lies in its complexity, which is structured with stringently organized anatomical units called lobules. Graphene oxide (GO) has attracted attention for its applications in biomedicine, especially as a nanocarrier; however, its sequestration and effects in the liver, the major enrichment and metabolic organ, are less understood. Herein, we unveiled the differential distribution of GO in lobules in the liver, with a higher amount surrounding portal triad zones than the central vein zones. Strikingly, liver zonation patterns also changed, as reflected by changes in vital zonated genes involved in hepatocyte integrity and metabolism, leading to compromised hepatic functions. RNA-Seq and DNA methylation sequencing analyses unraveled that GO-induced changes in liver functional zonation could be ascribed to dysregulation of key signaling pathways governing liver zonation at not only mRNA transcriptions but also DNA methylation imprinting patterns, partially through TET-dependent signaling. Together, this study reveals the differential GO distribution pattern in liver lobules and pinpoints the genetic and epigenetic mechanisms in GO-induced liver zonation alterations.

Type 3 cytokines IL-17A and IL-22 drive TGF-β-dependent liver fibrosis

Inflammatory immune cells can modulate activation of hepatic stellate cells (HSCs) and progression of liver fibrosis. Type 3 inflammation characterized by production of interleukin-17A (IL-17) and IL-22 by innate and adaptive immune cells is implicated in many inflammatory conditions of the gut and can be counteracted by regulatory T cells (Tregs), but its contribution to liver fibrosis is still poorly understood. Here, we evaluated the contribution of type 3 inflammation in liver fibrosis using clinical liver biopsies, in vitro stimulation of primary HSCs, and in vivo mouse models. We report dysregulated type 3 responses in fibrotic lesions with increased IL-17+CD4+/FOXP3hiCD4+ ratio and increased IL-17 and IL-22 production in advanced liver fibrosis. Neutrophils and mast cells were the main sources of IL-17 in situ in humans. In addition, we demonstrate a new profibrotic function of IL-22 through enhancement of transforming growth factor-β signaling in HSCs in a p38 mitogen-activated protein kinase-dependent manner. In vivo, IL-22RA1 knockout mice exhibited reduced fibrosis in response to thioacetamide and carbon tetrachloride. Blocking either IL-22 or IL-17 production using aryl hydrocarbon receptor or RAR-related orphan receptor gamma-t antagonists resulted in reduced fibrosis. Together, these data have identified a pathogenic role for type 3 immune response mediated by IL-22 in driving liver fibrosis during chronic liver injury.

Human hepatic gene expression signature of non-alcoholic fatty liver disease progression, a meta-analysis

Non-alcoholic fatty liver disease (NAFLD) is a wide-spread chronic liver condition that places patients at risk of developing cardiovascular diseases and may progress to cirrhosis or hepatocellular carcinoma if untreated. Challenges in clinical and basic research are caused by poor understanding of NAFLD mechanisms. The purpose of current study is to describe molecular changes occurring in human liver during NAFLD progression by defining a reproducible gene expression signature. We conduct a systematic meta-analysis of published human gene expression studies on liver biopsies and bariatric surgery samples of NAFLD patients. We relate gene expression levels with histology scores using regression models and identify a set of genes showing consistent-sign associations with NAFLD progression that are replicated in at least three independent studies. The analysis reveals genes that have not been previously characterized in the context of NAFLD such as HORMAD2 and LINC01554. In addition, we highlight biomarker opportunities for risk stratification and known drugs that could be used as tool compounds to study NAFLD in model systems. We identify gaps in current knowledge of molecular mechanisms of NAFLD progression and discuss ways to address them. Finally, we provide an extensive data supplement containing meta-analysis results in a computer-readable format.

Environmental exposures as a risk factor for fibrolamellar carcinoma

Fibrolamellar carcinoma was first described in 1956. Subsequent large studies failed to identify cases before 1939 (the start of the World War II). This finding, combined with the presence of aryl hydrocarbon receptors on the tumor cells, have suggested that fibrolamellar carcinomas may be caused by environmental exposures that are new since World War II. To investigate this possibility, the surgical pathology files before 1939 were reviewed for hepatocellular carcinomas resected in young individuals. Two cases of fibrolamellar carcinoma were identified, from 1915 to 1924. The diagnosis of fibrolamellar carcinoma was confirmed at the histologic, ultrastructural and proteomic levels. These two fibrolamellar carcinoma cases clarify a key aspect of fibrolamellar carcinoma biology, reducing the likelihood that these tumors result exclusively from post World War II environmental exposures.

Chromosomal and Genetic Analysis of a Human Lung Adenocarcinoma Cell Line OM

Background:

Lung cancer has become the leading cause of death in many regions. Carcinogenesis is caused by the stepwise accumulation of genetic and chromosomal changes. The aim of this study was to investigate the chromosome and gene alterations in the human lung adenocarcinoma cell line OM.

Methods:

We used Giemsa banding and multiplex fluorescence in situ hybridization focusing on the human lung adenocarcinoma cell line OM to analyze its chromosome alterations. In addition, the gains and losses in the specific chromosome regions were identified by comparative genomic hybridization (CGH) and the amplifications of cancer-related genes were also detected by polymerase chain reaction (PCR).

Results:

We identified a large number of chromosomal numerical alterations on all chromosomes except chromosome X and 19. Chromosome 10 is the most frequently involved in translocations with six different interchromosomal translocations. CGH revealed the gains on chromosome regions of 3q25.3-28, 5p13, 12q22-23.24, and the losses on 3p25-26, 6p25, 6q26-27, 7q34-36, 8p22-23, 9p21-24, 10q25-26.3, 12p13.31-13.33 and 17p13.1-13.3. And PCR showed the amplification of genes: Membrane metalloendopeptidase (MME), sucrase-isomaltase (SI), butyrylcholinesterase (BCHE), and kininogen (KNG).

Conclusions:

The lung adenocarcinoma cell line OM exhibited multiple complex karyotypes, and chromosome 10 was frequently involved in chromosomal translocation, which may play key roles in tumorigenesis. We speculated that the oncogenes may be located at 3q25.3-28, 5p13, 12q22-23.24, while tumor suppressor genes may exist in 3p25-26, 6p25, 6q26-27, 7q34-36, 8p22-23, 9p21-24, 10q25-26.3, 12p13.31-13.33, and 17p13.1-13.3. Moreover, at least four genes (MME, SI, BCHE, and KNG) may be involved in the human lung adenocarcinoma cell line OM.

Strong correlation between ASPM gene expression and HCV cirrhosis progression identified by co-expression analysis

Hepatitis C virus (HCV) cirrhosis is at a high risk of hepatocellular carcinoma (HCC), and its progression is influenced by a complex network of gene interactions. A weighted gene co-expression network was constructed to identify gene modules associated with the seven-stage disease progression from HCV cirrhosis to HCV-related HCC (n=65). In the significant module (R²=0.86), a total of 25 network hub genes were identified, half of which were also hub nodes in the protein-protein interaction network of the module genes. In validation, most hub genes showed a moderate correlation with the disease progression, and only ASPM was highly correlated (R²=0.801). In the test set (n=63), ASPM was also more highly expressed in HCV cirrhosis with concomitant HCC than in those without HCC (P=0.0054). Gene set enrichment analysis (GSEA) demonstrated that the gene set of "regulation of protein amino acid phosphorylation" (n=20) was enriched in HCV cirrhosis samples with ASPM highly expressed (false discovery rate (FDR)=0.049). In gene ontology (GO) analysis, genes in the enriched set were associated with liver neoplasms and other neoplastic diseases. In conclusion, through co-expression analysis, ASPM was identified and validated in association with the progression of HCV cirrhosis probably by regulating tumor-related phosphorylation.

Altered Peripheral Blood Monocyte Phenotype and Function in Chronic Liver Disease: Implications for Hepatic Recruitment and Systemic Inflammation

BACKGROUND AND AIMS

Liver and systemic inflammatory factors influence monocyte phenotype and function, which has implications for hepatic recruitment and subsequent inflammatory and fibrogenic responses, as well as host defence.

METHODS

Peripheral blood monocyte surface marker (CD14, CD16, CD163, CSF1R, CCR2, CCR4, CCR5, CXCR3, CXCR4, CX3CR1, HLA-DR, CD62L, SIGLEC-1) expression and capacity for phagocytosis, oxidative burst and LPS-stimulated TNF production were assessed in patients with hepatitis C (HCV) (n = 39) or non-alcoholic fatty liver disease (NAFLD) (n = 34) (classified as non-advanced disease, compensated cirrhosis and decompensated cirrhosis) and healthy controls (n = 11) by flow cytometry.

RESULTS

The selected markers exhibited similar monocyte-subset-specific expression patterns between patients and controls. Monocyte phenotypic signatures differed between NAFLD and HCV patients, with an increased proportion of CD16+ non-classical monocytes in NAFLD, but increased expression of CXCR3 and CXCR4 in HCV. In both cohorts, monocyte CCR2 expression was reduced and CCR4 elevated over controls. CD62L expression was specifically elevated in patients with decompensated cirrhosis and positively correlated with the model-for-end-stage-liver-disease score. Functionally, monocytes from patients with decompensated cirrhosis had equal phagocytic capacity, but displayed features of dysfunction, characterised by lower HLA-DR expression and blunted oxidative responses. Lower monocyte TNF production in response to LPS stimulation correlated with time to death in 7 (46%) of the decompensated patients who died within 8 months of recruitment.

CONCLUSIONS

Chronic HCV and NAFLD differentially affect circulating monocyte phenotype, suggesting specific injury-induced signals may contribute to hepatic monocyte recruitment and systemic activation state. Monocyte function, however, was similarly impaired in patients with both HCV and NAFLD, particularly in advanced disease, which likely contributes to the increased susceptibility to infection in these patients.

Application of Laser Capture Microdissection and 16S rRNA Gene Polymerase Chain Reaction in the Analysis of Bacteria Colonizing the Intestinal Tissue of Neonates With Necrotizing Enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in newborns. However, the pathogenesis of NEC remains unclear because most bacterial characterizations of alleged pathogens have been performed via the analysis of human fecal samples and experimental animal studies. The objective is to investigate the microbial composition of NEC using inflamed intestinal tissue surgically removed from neonates diagnosed with NEC (n = 18).

METHODS

We obtained intestinal tissues via a combination of laser capture microdissection and Gram staining, which was used to mark individual bacteria. Tissues with congenital intestinal atresia (n = 7) served as control specimens. An analysis of the 16S rRNA of each sample was performed via polymerase chain reaction-denaturing gradient gel electrophoresis.

RESULTS

Numerous bacteria were observed in the inflamed intestinal wall tissue samples obtained from neonates with NEC following Gram staining and examination under an optical microscope. The total number of types detected by polymerase chain reaction-denaturing gradient gel electrophoresis was 12.17 ± 2.83 per infant with NEC, whereas only 2.57 ± 1.81 types were detected in each infant with congenital intestinal atresia. Proteobacteria had the highest constituent ratio (188 of 285) of all detected clone sequences in the NEC group. Additionally, Pseudomonas sp., Acinetobacter sp., Klebsiella sp., Clostridium sp., Ochrobactrum sp. and Arcobacter sp. were detected only in the NEC group.

CONCLUSIONS

The combination of Gram staining and laser capture microdissection was a reliable method to obtain and prepare tissue samples for processing. NEC was associated with multiple species of bacteria, and microflora within the disease-affected sites may be relatively specific and stable. Proteobacteria demonstrated the highest constituent ratio. Our observations warrant closer examination of the 6 bacterial genera that were only detected in NEC, particularly Clostridium sp., which may be closely correlated with pneumatosis intestinalis.

Use of laser capture microdissection for the assessment of equine lamellar basal epithelial cell signalling in the early stages of laminitis

REASONS FOR PERFORMING STUDY

Dysadhesion of laminar basal epithelial cells (LBECs) from the underlying dermis is the central event leading to structural failure in equine laminitis. Although many studies of sepsis-related laminitis have reported multiple events occurring throughout the lamellar tissue, there is minimal information regarding signalling events occurring specifically in LBECs.

OBJECTIVES

To determine signalling events in the LBECs during the early stages of carbohydrate-induced laminitis.

STUDY DESIGN

Experimental study.

METHODS

Eight horses were given an overload of carbohydrate (CHO) consisting of corn starch mixture via nasogastric tube. Prior to administration of CHO, lamellar biopsies were taken from the left forefoot (control [CON]). Biopsies were taken from the left hind foot at the onset of fever (developmental [DEV]) and from the right forefoot at the onset of Obel grade 1 lameness (OG1). Laminar basal epithelial cells were isolated from cryosections using a laser capture microdissection (LCM) microscope. Next generation sequencing (RNA-seq) was used to identify transcripts expressed in the LBECs for each time point and bioinformatic analysis was performed with thresholds for between group comparisons set at a greater than 2-fold change and P value ≤0.05.

RESULTS

Forty genes (22 increased/18 decreased) were significantly different from DEV time vs. CON and 107 genes (57 increased/50 decreased) were significantly different from OG1 time vs. CON. Significant increases in inflammatory genes were present in addition to significantly altered expression of genes related to extracellular matrix composition, stability and turnover.

CONCLUSIONS

Signalling related to inflammatory response and extracellular matrix regulation was strongly represented at the DEV and OG1 times. These results indicate that the LBEC is not only a casualty but also an active participant in lamellar events leading to structural failure of the digital lamellae in equine laminitis.

Use of laser capture microdissection to map hepatitis C virus-positive hepatocytes in human liver

BACKGROUND & AIMS

Hepatitis C virus (HCV) predominantly infects hepatocytes, but many hepatocytes are not infected; studies have shown that HCV antigens cluster within the liver. We investigated spatial distribution and determinants of HCV replication in human liver samples.

METHODS

We analyzed liver samples from 4 patients with chronic HCV infection (genotype 1, Metavir scores 0-1) to estimate the proportion of infected hepatocytes and the amount of HCV viral RNA (vRNA) per cell. Single-cell laser capture microdissection was used to capture more than 1000 hepatocytes in grids, to preserve geometric relationships. HCV vRNA and interferon-induced transmembrane protein 3 (IFITM3) messenger RNA (the transcript of an interferon-stimulated gene) were measured in the same hepatocytes by quantitative polymerase chain reaction and assembled in maps to identify areas of high and low HCV replication.

RESULTS

Patients' serum levels of HCV RNA ranged from 6.87 to 7.40 log10 IU/mL; the proportion of HCV-infected hepatocytes per person ranged from 21% to 45%, and the level of vRNA ranged from 1 to 50 IU/hepatocyte. Infection was not random; we identified clustering of HCV-positive hepatocytes using infected-neighbor analysis (P < .0005) and distance to the kth nearest neighbor compared with random distributions, obtained by bootstrap simulations (P < .02). Hepatocytes that expressed IFITM3 did not appear to cluster and were largely HCV negative.

CONCLUSIONS

We used single-cell laser capture and high-resolution analysis to show that in human liver HCV infects hepatocytes in nonrandom clusters, whereas expression of antiviral molecules is scattered among hepatocytes. These findings show that quantitative single-cell RNA measurements can be used to estimate the abundance of HCV vRNA per infected human hepatocyte and are consistent with cell-cell propagation of infection in the absence of clustered IFITM3.

Homogeneous phenomenon of the graft when using different genotype characteristic of recipients/donors in living donor liver transplantation

AIM: To investigate the evidence of homogeneous phenomenon on CYP3A5*3 MDR1-3435 and CYP3A4*18 of the liver graft after living donor liver transplantation (LDLT).

METHODS: We identified the proportional change of the CYP3A5*3, MDR1-3435 and CYP3A4*18 from the peripheral blood mononuclear cell of 41 pairs recipient/donor with different genotype polymorphisms and 119 liver graft biopsy samples used with the pyrosequencing technique after LDLT. Polymerase chain reaction/ligase detection reaction assay and restriction fragment length polymorphism was employed for genotyping the CYP3A5*3 and CYP3A4*18 single nucleotide polymorphisms (SNPs). All of the recipients and donors expressed with the similar SNP genotype of CYP3A5*3, MDR1-3435 or CYP3A4*18 were excluded.

RESULTS: The final genetic polymorphisms of the liver graft biopsy samples of CYP3A5*3, MDR1-3435 and CYP3A4*18 was predominated depends on the donor with restriction fragment length polymorphism and seems to be less related to the recipient. The proportional changes of G to A alleles of the 119 samples of CYP3A5*3 (included A > A/G, A/G > A, A/G > G, G > A, G > A/G and A > G), C to T alleles of the 108 samples of MDR1-3435 (included C > C/T, C/T > C, C/T > T, T > C/T and T > C), and T to C alleles of 15 samples of CYP3A4*18 (included T/C > T and T > C/T) were significant different between the recipients and the liver graft biopsy samples (P < 0.0001) and less difference when compared with the donors in the pyrosequencing analysis after LDLT.

CONCLUSION: The CYP3A5*3, MDR1-3435 and CYP3A4*18 of the recipient could be modified by the donor so-called homogenous phenomenon when the recipient’s blood drained into the liver graft.