Mechanistically based blood proteomic markers in the TGF-β pathway stratify risk of hepatocellular cancer in patients with cirrhosis

Hepatocellular carcinoma (HCC) is the third leading cause of death from cancer worldwide but is often diagnosed at an advanced incurable stage. Yet, despite the urgent need for blood-based biomarkers for early detection, few studies capture ongoing biology to identify risk-stratifying biomarkers. We address this gap using the TGF-β pathway because of its biological role in liver disease and cancer, established through rigorous animal models and human studies. Using machine learning methods with blood levels of 108 proteomic markers in the TGF-β family, we found a pattern that differentiates HCC from non-HCC in a cohort of 216 patients with cirrhosis, which we refer to as TGF-β based Protein Markers for Early Detection of HCC (TPEARLE) comprising 31 markers. Notably, 20 of the patients with cirrhosis alone presented an HCC-like pattern, suggesting that they may be a group with as yet undetected HCC or at high risk for developing HCC. In addition, we found two other biologically relevant markers, Myostatin and Pyruvate Kinase M2 (PKM2), which were significantly associated with HCC. We tested these for risk stratification of HCC in multivariable models adjusted for demographic and clinical variables, as well as batch and site. These markers reflect ongoing biology in the liver. They potentially indicate the presence of HCC early in its evolution and before it is manifest as a detectable lesion, thereby providing a set of markers that may be able to stratify risk for HCC.

Effects of rIL2/anti-IL2 antibody complex on chikungunya virus-induced chronic arthritis in a mouse model

Chikungunya virus (CHIKV) is characterized by disabling joint pain that can cause persistent arthritis in approximately one-fourth of patients. Currently, no standard treatments are available for chronic CHIKV arthritis. Our preliminary data suggest that decreases in interleukin-2 (IL2) levels and regulatory T cell (Treg) function may play a role in CHIKV arthritis pathogenesis. Low-dose IL2-based therapies for autoimmune diseases have been shown to up-regulate Tregs, and complexing IL2 with anti-IL2 antibodies can prolong the half-life of IL2. A mouse model for post-CHIKV arthritis was used to test the effects of recombinant IL2 (rIL2), an anti-IL2 monoclonal antibody (mAb), and the complex on tarsal joint inflammation, peripheral IL2 levels, Tregs, CD4 + effector T cells (Teff), and histological disease scoring. The complex treatment resulted in the highest levels of IL2 and Tregs, but also increased Teffs, and therefore did not significantly reduce inflammation or disease scores. However, the antibody group, which had moderately increased levels of IL2 and activated Tregs, resulted in a decreased average disease score. These results suggest the rIL2/anti-IL2 complex stimulates both Tregs and Teffs in post-CHIKV arthritis, while the anti-IL2 mAb increases IL2 availability enough to shift the immune environment towards a tolerogenic one.

Effects of IL2/anti-IL2 antibody complex on chikungunya virus-induced arthritis in a mouse model

Chikungunya virus (CHIKV) is characterized by disabling joint pain that can cause persistent arthritis in approximately one-fourth of patients. Currently, no standard treatments are available for chronic CHIKV arthritis. Our preliminary data suggest that decreases in interleukin-2 (IL2) levels and regulatory T cell (Treg) function may play a role in CHIKV arthritis pathogenesis. Low-dose IL2-based therapies for autoimmune diseases have been shown to up-regulate Tregs, and complexing IL2 with anti-IL2 antibodies can prolong the half-life of IL2. A mouse model for post-CHIKV arthritis was used to test the effects of IL-2, an anti-IL2 monoclonal antibody (mAb), and the complex on tarsal joint inflammation, peripheral IL2 levels, Tregs, effector (Teff) T cells, and histological disease scoring. The complex treatment resulted in the highest levels of IL2 and Tregs, but also increased Teffs, and therefore did not significantly reduce inflammation or disease scores. However, the antibody group, which had moderately increased levels of IL2 and activated Tregs, resulted in a decreased average disease score. These results suggest the IL2/anti-IL2 complex stimulates both Tregs and Teffs in post-CHIKV arthritis, while the anti-IL2 mAb increases IL2 availability enough to shift the immune environment towards a tolerogenic one.

Abstract 1463: Impaired reciprocal regulation between SIRT6 and TGF-β signaling as a potential mechanism for development and progression of fatty liver

Background: Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of fibrotic liver disease and hepatocellular carcinoma (HCC). Dysregulated TGF-β signaling and loss of SIRT6 activity are implicated in fatty liver disease. SIRT6 limits fibrosis by inhibiting SMAD3 activity and limits de novo lipogenesis by inhibiting SREBP1 and SREBP2 activity. We hypothesized that altered reciprocal regulation between TGF-β signaling and SIRT6 contributes to NAFLD and its progression. The goal of this study was to identify regulatory crosstalk between SIRT6 and SMAD3 and SPTBN1, a regulator of SMAD3 activity.

Methods: We used bioinformatics and chromatin immunoprecipitation (ChIP) with HepG2 cells to examine the binding of SMAD3 or CTCF to the SIRT6 gene in the presence or absence of TGF-β. Using cultured cells, we examined the effect of altering SPTBN1 or SMAD3 on SIRT6 abundance, and of altering SIRT6 on SPTBN1 and SMAD3 abundance. We examined liver phenotypes of SPTBN1+/- mice fed either a normal chow diet or a high-fat diet (HFD) and monitored body weight and serum total cholesterol and triglyceride concentrations, as well as analyzed liver tissue for SIRT6 abundance.

Results: We identified two consensus SMAD-binding elements and two consensus CTCF binding sites in the SIRT6 promoter and showed by ChIP that TGF-β stimulated SMAD3 and CTCF binding to the promoter region of SIRT6. We found that deficiency in SMAD3 or SPTBN1 reduced SIRT6 mRNA and protein abundance. Overexpression of SIRT6 reduced expression of selected TGF-β-induced genes. Knockdown of SIRT6 increased SPTBN1 but not SMAD3 abundance and overexpression of SIRT6 reduced only SPTBN1 abundance. We found that fatty liver and associated metabolic changes induced by HFD is worse in SPTBN1+/- mice than in control mice. Furthermore, this condition was associated with reduced SIRT6 protein abundance in the liver.

Conclusions: We found a reciprocal regulatory mechanism involving SPTBN1 through which SIRT6 can influence TGF-β signaling and identified SIRT6 as a target of TGF-β-SMAD3 signaling. The development of liver steatosis with reduced SIRT6 in SPTBN1+/- mice suggested that impaired induction of SIRT6 contributes to the severe liver phenotype, which resembles nonalcoholic steatohepatitis (NASH). Future investigation may yield opportunities to intervene and prevent NAFLD from progressing to NASH and thus reduce the risk of HCC.

Citation Format: Kazufumi Ohshiro, Xiyan Xiang, David Bernstein, James M. Crawford, Bibhuti Mishra, Patricia S. Latham, Nancy R. Gough, Shuyun Rao, Lopa Mishra. Impaired reciprocal regulation between SIRT6 and TGF-β signaling as a potential mechanism for development and progression of fatty liver [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1463.

Abstract 3378: Targeted serum proteomics identifies a signature for use in multivariable logistic regression modeling to predict HCC

Background: Hepatocellular carcinoma (HCC) is curable in its early stages. However, early stage HCC is difficult to detect without invasive surgical procedures. Additionally, current blood-based biomarkers have low sensitivity and specificity in detecting HCC. Human data and animal models support a functional role for the TGF-β pathway in HCC initiation and progression. The goal of this study is to determine whether TGF-β pathway markers can predict HCC in cirrhotic patients that are at high risk for HCC.

Methods: We used an aptamer-based high-throughput proteomics assay to detect a selected set of proteins associated with fibrosis or TGF-β signaling in serum samples from 101 patients with only cirrhosis and 33 patients with cirrhosis and HCC. We applied multivariable logistic regression modeling to identify a biomarker panel predictive of HCC and then integrated this model with clinical variables to develop and a final predictive HCC model. The predictive power, sensitivity, and specificity of the final model were determined.

Results: We identified a protein signature in patient serum that differentiated patients with only cirrhosis from those with HCC. We also identified a potential high-risk cirrhosis patient group (n = 14) with a similar signature to that of HCC patients. The logistic regression model identified that a panel of 15 proteins was independently predictive of HCC. By adding clinical predictors into the model, we developed a model that required only 5 of the proteins to achieve high predictive power. Analysis of the receiver operating characteristic (ROC) curve of the final model showed an area under the curve (AUC) of 0.96. The mean predicted probability of having HCC was 8.3% in the non-HCC group [95% confidence interval (CI) 5.6 - 11.1%] and 75% in the HCC group (95% CI 63 - 86%). At a threshold of 0.30, sensitivity was 0.88, specificity was 0.88, and positive predictive value (PPV) was 0.71. At a threshold of 0.04, the sensitivity increased to 1.0 at the expense of specificity (0.64) and PPV (0.48).

Conclusions: The final 5-protein model that includes clinical variables represents a potential non-invasive method to detect early HCC. Furthermore, follow up studies of patients with the 15-protein signature that resembles the signature of HCC patients is warranted to determine if this signature represents patients in the earliest stages of HCC or who subsequently are diagnosed with HCC.

Citation Format: Shuyun Rao, Richard Amdur, Xiyan Xiyan, Kirti Shetty, Herbert Yu, Linda L. Wong, Wilma Jogunoori, Karan Amin, Patricia S. Latham, Lopa Mishra. Targeted serum proteomics identifies a signature for use in multivariable logistic regression modeling to predict HCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3378.

Abstract 3379: Multi-cohort study shows HCC is associated with a relative regional reduction in TGFBR2 in liver biopsies from patients with cirrhosis

Background: Early detection of hepatocellular carcinoma (HCC) is challenging partly because most patients also have cirrhosis. Furthermore, patients with cirrhosis are at high risk of developing HCC. Loss of function of the transforming growth factor β (TGF-β) pathway is associated with HCC. The goal of this study was to determine if a reduction in TGF-β receptors (TGFBR1, TGFBR2) was able to reliably and reproducibly predict HCC in cirrhotic tissue.

Methods: We performed quantitative immunohistochemical (IHC) analysis of biopsy tissue from patients with cirrhosis with or without HCC using 3 separate sets of samples. We developed an automated image analysis pipeline to quantify IHC of TGFBR1 and TGFRB2 in liver biopsies. Using logistic regression modeling, we evaluated the predictive power of staining intensity of TGFBR1, TGFBR2, or the combination in differentiating HCC from cirrhosis.

Results: We found a consistently significant reduction in TGFBR2 in HCC (p < 0.02) among independent patient cohorts from 3 separate institutions. With the data, we developed an artificial intelligence-based image analysis pipeline that confirmed the significant reduction in TGFBR2 staining intensity in HCC compared to cirrhotic tissue (p < 0.002). Unfortunately, logistic regression modeling of the quantitative data showed that there is not a simple threshold of TGFBR2 staining intensity that is diagnostic of HCC. Instead, in 84% of samples with HCC, HCC was associated with a relative regional reduction in TGFBR2 compared to tumor-adjacent cirrhotic tissue.

Conclusions: The qualitative and quantitative analyses indicate that evaluating biopsy samples for a reduction in TGFBR2 abundance relative to the surrounding cirrhotic tissue could be an early indicator of the development of HCC in high-risk groups undergoing surveillance for HCC. Furthermore, an automated image analysis pipeline for quantitative IHC of TGFBR staining could improve the reliability of image analysis across institutions participating in clinical trials. 

Citation Format: Krishanu Bhowmick, Richard Amdur, Xiyan Xiang, Herbert Yu, Linda L. Wong, Shuyun Rao, Aiwu R. He, Karan Amin, Daewa Zaheer, Raj K. Narayan, Sanjaya K. Satapathy, Chandan Guha, Patricia S. Latham, Kirti Shetty, Nancy R. Gough, Lopa Mishra. Multi-cohort study shows HCC is associated with a relative regional reduction in TGFBR2 in liver biopsies from patients with cirrhosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3379.

Using quantitative immunohistochemistry in patients at high risk for hepatocellular cancer

Hepatocellular carcinoma (HCC) is the primary form of liver cancer and a major cause of cancer death worldwide. Early detection is key to effective treatment. Yet, early diagnosis is challenging, especially in patients with cirrhosis, who are at high risk of developing HCC. Dysfunction or loss of function of the transforming growth factor β (TGF-β) pathway is associated with HCC. Here, using quantitative immunohistochemistry analysis of samples from a multi-institutional repository, we evaluated if differences in TGF-β receptor abundance were present in tissue from patients with only cirrhosis compared with those with HCC in the context of cirrhosis. We determined that TGFBR2, not TGFBR1, was significantly reduced in HCC tissue compared with cirrhotic tissue. We developed an artificial intelligence (AI)-based process that correctly identified cirrhotic and HCC tissue and confirmed the significant reduction in TGFBR2 in HCC tissue compared with cirrhotic tissue. Thus, we propose that a reduction in TGFBR2 abundance represents a useful biomarker for detecting HCC in the context of cirrhosis and that incorporating this biomarker into an AI-based automated imaging pipeline could reduce variability in diagnosing HCC from biopsy tissue.

Impaired reciprocal regulation between SIRT6 and TGF-β signaling in fatty liver

Dysregulated transforming growth factor-beta (TGF-β) signaling contributes to fibrotic liver disease and hepatocellular cancer (HCC), both of which are associated with fatty liver disease. SIRT6 limits fibrosis by inhibiting TGF-β signaling through deacetylating SMAD2 and SMAD3 and limits lipogenesis by inhibiting SREBP1 and SREBP2 activity. Here, we showed that, compared to wild-type mice, high-fat diet-induced fatty liver is worse in TGF-β signaling-deficient mice (SPTBN1^+/- ) and the mutant mice had reduced SIRT6 abundance in the liver. Therefore, we hypothesized that altered reciprocal regulation between TGF-β signaling and SIRT6 contributes to these liver pathologies. We found that deficiency in SMAD3 or SPTBN1 reduced SIRT6 mRNA and protein abundance and impaired TGF-β induction of SIRT6 transcripts, and that SMAD3 bound to the SIRT6 promoter, suggesting that an SMAD3-SPTBN1 pathway mediated the induction of SIRT6 in response to TGF-β. Overexpression of SIRT6 in HCC cells reduced the expression of TGF-β-induced genes, consistent with the suppressive role of SIRT6 on TGF-β signaling. Manipulation of SIRT6 abundance in HCC cells altered sterol regulatory element-binding protein (SREBP) activity and overexpression of SIRT6 reduced the amount of acetylated SPTBN1 and the abundance of both SMAD3 and SPTBN1. Furthermore, induction of SREBP target genes in response to SIRT6 overexpression was impaired in SPTBN1 heterozygous cells. Thus, we identified a regulatory loop between SIRT6 and SPTBN1 that represents a potential mechanism for susceptibility to fatty liver in the presence of dysfunctional TGF-β signaling.

CD137 agonist potentiates the abscopal efficacy of nanoparticle-based photothermal therapy for melanoma

Despite the promise of immunotherapy such as the immune checkpoint inhibitors (ICIs) anti-PD-1 and anti-CTLA-4 for advanced melanoma, only 26%-52% of patients respond, and many experience grade III/IV immune-related adverse events. Motivated by the need for an effective therapy for patients non-responsive to clinically approved ICIs, we have developed a novel nanoimmunotherapy that combines locally administered Prussian blue nanoparticle-based photothermal therapy (PBNP-PTT) with systemically administered agonistic anti-CD137 monoclonal antibody therapy (aCD137). PBNP-PTT was administered at various thermal doses to melanoma cells in vitro, and was combined with aCD137 in vivo to test treatment effects on melanoma tumor progression, animal survival, immunological protection against tumor rechallenge, and hepatotoxicity. When administered at a melanoma-specific thermal dose, PBNP-PTT elicits immunogenic cell death (ICD) in melanoma cells and upregulates markers associated with antigen presentation and immune cell co-stimulation in vitro. Consequently, PBNP-PTT eliminates primary melanoma tumors in vivo, yielding long-term tumor-free survival. However, the antitumor immune effects generated by PBNP-PTT cannot eliminate secondary tumors, despite significantly slowing their growth. The addition of aCD137 enables significant abscopal efficacy and improvement of survival, functioning through activated dendritic cells and tumor-infiltrating CD8⁺ T cells, and generates CD4⁺ and CD8⁺ T cell memory that manifests in the rejection of tumor rechallenge, with no long-term hepatotoxicity. This study describes for the first time a novel and effective nanoimmunotherapy combination of PBNP-PTT with aCD137 mAb therapy for melanoma.

β2-spectrin (SPTBN1) as a therapeutic target for diet-induced liver disease and preventing cancer development

[Figure: see text].

Tumour DDR1 promotes collagen fibre alignment to instigate immune exclusion

Immune exclusion predicts poor patient outcomes in multiple malignancies, including triple-negative breast cancer (TNBC)¹. The extracellular matrix (ECM) contributes to immune exclusion². However, strategies to reduce ECM abundance are largely ineffective or generate undesired outcomes^3,4. Here we show that discoidin domain receptor 1 (DDR1), a collagen receptor with tyrosine kinase activity⁵, instigates immune exclusion by promoting collagen fibre alignment. Ablation of Ddr1 in tumours promotes the intratumoral penetration of T cells and obliterates tumour growth in mouse models of TNBC. Supporting this finding, in human TNBC the expression of DDR1 negatively correlates with the intratumoral abundance of anti-tumour T cells. The DDR1 extracellular domain (DDR1-ECD), but not its intracellular kinase domain, is required for immune exclusion. Membrane-untethered DDR1-ECD is sufficient to rescue the growth of Ddr1-knockout tumours in immunocompetent hosts. Mechanistically, the binding of DDR1-ECD to collagen enforces aligned collagen fibres and obstructs immune infiltration. ECD-neutralizing antibodies disrupt collagen fibre alignment, mitigate immune exclusion and inhibit tumour growth in immunocompetent hosts. Together, our findings identify a mechanism for immune exclusion and suggest an immunotherapeutic target for increasing immune accessibility through reconfiguration of the tumour ECM.

Downregulation of miR-375 contributes to ERBB2-mediated VEGFA overexpression in esophageal cancer

Esophageal cancer (EC) is a lethal cancer with an extremely aggressive nature and poor survival rate. However, the molecular mechanisms driving the occurrence and progression of EC are not well understood. MicroRNAs (miRNAs) are small RNA molecules that regulate the expression of protein-coding genes. miRNA-mediated gene regulation plays an important role in EC. By cross-referencing studies from NCBI, we found that microRNA-375 (miR-375) is one of the most frequently downregulated miRNAs in EC. We assessed expression of miR-375 in EC cell lines and primary EC tissues and their matched normal tissues. We found significant downregulation of miR-375 in both cell lines and EC tissues. Forced expression of miR-375 attenuated EC cell proliferation and invasion. Human epidermal growth factor receptor 2 (HER2, ERBB2), a known proto-oncogene, was identified here as one of the potential target genes of miR-375. Ectopic expression of miR-375 significantly suppressed the expression of ERBB2 and subsequently downregulated one of its target genes, vascular endothelial growth factor A (VEGFA), which is related to cancer invasion and metastasis. These findings suggest that miR-375 acts as a tumor suppressor by blocking the ERBB2/VEGFA pathway with the potential to modulate the occurrence and/ or progression of EC.

microRNA-196b promotes esophageal squamous cell carcinogenesis and chemoradioresistance by inhibiting EPHA7, thereby restoring EPHA2 activity

Esophageal cancer (EC) is extremely aggressive and has a very poor survival rate. Esophageal squamous cell carcinoma (ESCC) accounts for 80% of all ECs worldwide, with the majority of the remaining 20% being esophageal adenocarcinoma (EAC). Due to its occult and insidious presentation, ESCC is typically diagnosed and treated in its advanced stages, thereby limiting the success of present therapeutic modalities. microRNAs (miRNAs) can function as tumor suppressors or oncogenes, playing critical roles in cancer initiation and progression by regulating target genes in oncogenic pathways. In the current study, we demonstrated that microRNA-196b (miR-196b) is one of the most upregulated miRNAs in both ESCC and EAC. miR-196b was overexpressed in ESCC and EAC cell lines, cellular exosomal RNAs, and ESCC tissue samples. Functional studies revealed that miR-196b acted as an oncomiR by directly targeting a tumor suppressor, ephrin type-A receptor 7 (EPHA7). EPHA7 abrogates the activity of ephrin type-A receptor 2 (EPHA2), a key molecule involved in the epithelial-to-mesenchymal transition (EMT) and MAPK/ERK pathways, mediating resistance to UV and chemoradiotherapy in both ESCC and EAC. Taken together, these findings suggest that miR-196b is a strong candidate molecular target for EC treatment.

Abstract 2910: A TGF-β-ALDH2 axis controls liver- brain-gut microbiome driven obesity, metabolic syndrome and cancer

Background/Aims: ALDH2 (Aldehyde dehydrogenase 2) is associated with multiple human diseases including cancers, Asian flush syndrome (deficiencies affect 35%-40% of East Asians), and alcoholic liver disease. Yet, oncogenic mechanisms and pathways that ALDH2 interacts with remain unclear. Previously we have demonstrated that TGF-β-deficient mutants derived from the loss of Smad3 and its adaptor Sptbn1 are exquisitely sensitive to alcohol, with impaired DNA damage repair. ALDH2 levels are altered in the liver tissues of the mouse mutants, and the Sptbn1-/- phenotype is similar to ALDH2-FancD2 mutants. We, therefore, hypothesized that disruption of TGF-β signaling combined with ALDH2 deficiency would increase the susceptibility of liver diseases and cancer.

Methods: Aldh2-/- mice were intercrossed with Sptbn1+/-, Smad3+/- mice. Control mice and intercrosses were fed with high-fat diet (HFD) or chow diet or alcohol diet, or hepatic vagotomy followed by phenotypic and mechanistic analyses through RNA-seq, lipidomics, metabolomics, western blot analyses, RTPCR, structure modeling, cell fractionation, and immunohistochemistry. Fecal samples from these mice underwent shotgun metagenomic sequencing.

Results: Strikingly, compared to WT, Aldh2-/-Sptbn1+/- (ASKO) mice on a normal diet develop metabolic syndromes with truncal obesity, insulin resistance, with increased blood glucose (272.3±28.6mg/dl vs 189.9 ±7.0mg/dl, p<0.05), serum triglyceride (185.2±40.0 mg/dl vs 83.7 ±7.8 mg/dl, p<0.05). Nonalcoholic steatohepatitis (NASH), and cancer, with raised ALT and AST levels, also develop in the mutant mice. HFD exacerbated obesity and NASH in Aldh2-/-Sptbn1+/- on HFD with substantial additional visceral fat accumulation and hyperglycemia with Zone 3 hepatic macro-steatosis and inflammation, which correlated with increased fatty acid metabolism and gluconeogenesis. ASKO mice had significantly altered neurotransmitter receptors in the liver including cholinergic receptors (e.g., Chrnb1, and Chrna2) and altered gut microbiome composition with increased abundance of S. pseudoporcinus (Aldh2-/-Smad3+/- vs WT: 85.6±29 vs 2.71 ±1.44, p<0.05) and decreased A. propionicum (ASKO vs WT: 65±21 vs 168±31, p<0.05).

Conclusions: Aldh2-/-Sptbn1+/- mice develop metabolic syndrome with alterations in the cholinergic pathway and microbiome species, suggesting a disruption in afferent vagal activity. ALDH2/SPTBN1 is therefore potentially a major liver-brain-gut vagal regulator of obesity. Aldh2 and TGF-β signaling are important in maintaining normal gut microbiome composition. These studies highlight the potential role of the gut-liver axis in regulating obesity and liver disease. With > 35% Asian population harboring ALDH2 alterations, our studies potentially have a high impact on these patient populations with a high risk of metabolic syndrome.

Citation Format: Shuyun Rao, Xiaochun Yang, Zhanhuai Wang, Kazufumi Ohshiro, Sobia Zaidi, Wilma Jogunoori, Bryan Nguyen, Keith A. Crandall, Patricia S. Latham, Kirti Shetty, Lopa Mishra. A TGF-β-ALDH2 axis controls liver- brain-gut microbiome driven obesity, metabolic syndrome and cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2910.

ND-13, a DJ-1-Derived Peptide, Attenuates the Renal Expression of Fibrotic and Inflammatory Markers Associated with Unilateral Ureter Obstruction

DJ-1 is a redox-sensitive chaperone with reported antioxidant and anti-inflammatory properties in the kidney. The 20 amino acid (aa) peptide ND-13 consists of 13 highly conserved aas from the DJ-1 sequence and a TAT-derived 7 aa sequence that helps in cell penetration. This study aimed to determine if ND-13 treatment prevents the renal damage and inflammation associated with unilateral ureter obstruction (UUO). Male C57Bl/6 and DJ-1^-/- mice underwent UUO and were treated with ND-13 or vehicle for 14 days. ND-13 attenuated the renal expression of fibrotic markers TGF-β and collagen1a1 (Col1a1) and inflammatory markers TNF-α and IL-6 in C57Bl/6 mice. DJ-1^-/- mice treated with ND-13 presented similar decreased expression of TNF-α, IL-6 and TGF-β. However, in contrast to C57Bl/6 mice, ND-13 failed to prevent renal fibrosis or to ameliorate the expression of Col1a1 in this genotype. Further, UUO led to elevated urinary levels of the proximal tubular injury marker neutrophil gelatinase-associated lipocalin (NGAL) in DJ-1^-/- mice, which were blunted by ND-13. Our results suggest that ND-13 protects against UUO-induced renal injury, inflammation and fibrosis. These are all crucial mechanisms in the pathogenesis of kidney injury. Thus, ND-13 may be a new therapeutic approach to prevent renal diseases.

Targeting the E3 Ubiquitin Ligase PJA1 Enhances Tumor-Suppressing TGFβ Signaling

RING-finger E3 ligases are instrumental in the regulation of inflammatory cascades, apoptosis, and cancer. However, their roles are relatively unknown in TGFβ/SMAD signaling. SMAD3 and its adaptors, such as β2SP, are important mediators of TGFβ signaling and regulate gene expression to suppress stem cell-like phenotypes in diverse cancers, including hepatocellular carcinoma (HCC). Here, PJA1, an E3 ligase, promoted ubiquitination and degradation of phosphorylated SMAD3 and impaired a SMAD3/β2SP-dependent tumor-suppressing pathway in multiple HCC cell lines. In mice deficient for SMAD3 (Smad3 ^+/-), PJA1 overexpression promoted the transformation of liver stem cells. Analysis of genes regulated by PJA1 knockdown and TGFβ1 signaling revealed 1,584 co-upregulated genes and 1,280 co-downregulated genes, including many implicated in cancer. The E3 ligase inhibitor RTA405 enhanced SMAD3-regulated gene expression and reduced growth of HCC cells in culture and xenografts of HCC tumors, suggesting that inhibition of PJA1 may be beneficial in treating HCC or preventing HCC development in at-risk patients.Significance: These findings provide a novel mechanism regulating the tumor suppressor function of TGFβ in liver carcinogenesis.

Gut Colonization with Methanogenic Archaea Lowers Plasma Trimethylamine N-oxide Concentrations in Apolipoprotein e-/- Mice

A mechanistic link between trimethylamine N-oxide (TMAO) and atherogenesis has been reported. TMAO is generated enzymatically in the liver by the oxidation of trimethylamine (TMA), which is produced from dietary choline, carnitine and betaine by gut bacteria. It is known that certain members of methanogenic archaea (MA) could use methylated amines such as trimethylamine as growth substrates in culture. Therefore, we investigated the efficacy of gut colonization with MA on lowering plasma TMAO concentrations. Initially, we screened for the colonization potential and TMAO lowering efficacy of five MA species in C57BL/6 mice fed with high choline/TMA supplemented diet, and found out that all five species could colonize and lover plasma TMAO levels, although with different efficacies. The top performing MA, Methanobrevibacter smithii, Methanosarcina mazei, and Methanomicrococcus blatticola, were transplanted into Apoe^−/− mice fed with high choline/TMA supplemented diet. Similar to C57BL/6 mice, following initial provision of the MA, there was progressive attrition of MA within fecal microbial communities post-transplantation during the initial 3 weeks of the study. In general, plasma TMAO concentrations decreased significantly in proportion to the level of MA colonization. In a subsequent experiment, use of antibiotics and repeated transplantation of Apoe^−/− mice with M. smithii, led to high engraftment levels during the 9 weeks of the study, resulting in a sustained and significantly lower average plasma TMAO concentrations (18.2 ± 19.6 μM) compared to that in mock-transplanted control mice (120.8 ± 13.0 μM, p < 0.001). Compared to control Apoe^−/− mice, M. smithii-colonized mice also had a 44% decrease in aortic plaque area (8,570 μm [95% CI 19587–151821] vs. 15,369 μm [95% CI [70058–237321], p = 0.34), and 52% reduction in the fat content in the atherosclerotic plaques (14,283 μm [95% CI 4,957–23,608] vs. 29,870 μm [95% CI 18,074–41,666], p = 0.10), although these differences did not reach significance. Gut colonization with M. smithii leads to a significant reduction in plasma TMAO levels, with a tendency for attenuation of atherosclerosis burden in Apoe^−/− mice. The anti-atherogenic potential of MA should be further tested in adequately powered experiments.

Abstract 055: ND-13, a DJ-1-Derived Peptide, Protects Against the Renal Fibrosis and Inflammation Associated With Unilateral Ureter Obstruction

Oxidative stress and inflammation are important players in the pathogenesis of cardiovascular and renal diseases. DJ-1 is a redox-sensitive chaperone that regulates the expression of several antioxidant genes. Activation of the DJ-1/Nrf2 pathway in the kidney inhibits the development and progression of several renal diseases. The 20 aa peptide ND-13 consists of 13 highly conserved aa from the DJ-1 sequence and a TAT- derived 7 aa sequence to help in cell penetration. ND-13 prevents neuronal degeneration in mice; however, its effects on kidney damage remain unknown. We hypothesized that treatment with ND-13 would prevent the renal damage and inflammation associated with unilateral ureter obstruction (UUO). C57Bl/6 mice and DJ1 -/- mice underwent UUO and were divided in 3 groups: control (no UUO), UUO+scrambled peptide (SP) or UUO+ND-13 (3 mg/kg, s.c. daily). After 14 days of treatment, urine and kidneys were collected for analysis of renal damage. ND-13 treatment prevented the development of fibrosis in C57Bl/6 mice (UUO+SP: 702±189% of control, UUO+ND-13: 264±8% of control, n=2-4/group, p<0.05), suggesting that ND-13 is protective against connective tissue deposition in the kidney. Treatment with ND-13 decreased renal mRNA expression of TNF- α ( fold change from control: 101±46 in UUO+SP; 18±7 in UUO+ND-13, n=4-5/group, p<0.05), IL-6 (6.7±2 in UUO+SP; 1.54±0.3 in UUO+ND-13, p<0.05), TGF- β ( 3.3±1.12 UUO+SP; 1.4±0.03 UUO+ND-13, p<0.05) and Colagen1 α 1 (79±16 UUO+SP; 33±3.8 in UUO +ND-13, p<0.05) in C57Bl/6 mice. In DJ1 -/- mice, treatment with ND-13 similarly decreased expression of TNF-α, IL-6 and TGF-β, but, in contrast, failed to prevent renal fibrosis or kidney expression of col1 α 1 . UUO also led to elevated urinary NGAL, marker of proximal tubular injury, in DJ-1 -/- mice and ND-13 treatment prevented that increase (71±17% UUO vs control: -18±21% UUO+ND-13 vs control, n=5/group). Our results suggest that ND-13 has protective effects on renal injury, fibrosis and inflammation, crucial mechanisms in the pathogenesis of renal disease. Thus, ND-13 treatment may be a new therapeutic approach for the prevention of renal injury, fibrosis and inflammation in renal diseases. Funded by T32DK007545 to CDM and 5P01 HL074940-10, 7R01 DK039308-31 to PAJ.

The effect of HIV infection and HCV viremia on inflammatory mediators and hepatic injury-The Women's Interagency HIV Study

Hepatitis C virus infection induces inflammation and while it is believed that HIV co-infection enhances this response, HIV control may reduce inflammation and liver fibrosis in resolved or viremic HCV infection. Measurement of systemic biomarkers in co-infection could help define the mechanism of inflammation on fibrosis and determine if HIV control reduces liver pathology. A nested case-control study was performed to explore the relationship of systemic biomarkers of inflammation with liver fibrosis in HCV viremic and/or seropositive women with and without HIV infection. Serum cytokines, chemokines, growth factors and cell adhesion molecules were measured in HIV uninfected (HIV-, n = 18), ART-treated HIV-controlled (ARTc, n = 20), uncontrolled on anti-retroviral therapy (ARTuc, n = 21) and elite HIV controllers (Elite, n = 20). All were HCV seroreactive and had either resolved (HCV RNA-; <50IU/mL) or had chronic HCV infection (HCV RNA+). In HCV and HIV groups, aspartate aminotransferase to platelet ratio (APRI) was measured and compared to serum cytokines, chemokines, growth factors and cell adhesion molecules. APRI correlated with sVCAM, sICAM, IL-10, and IP-10 levels and inversely correlated with EGF, IL-17, TGF-α and MMP-9 levels. Collectively, all HCV RNA+ subjects had higher sVCAM, sICAM and IP-10 compared to HCV RNA-. In the ART-treated HCV RNA+ groups, TNF-α, GRO, IP-10, MCP-1 and MDC were higher than HIV-, Elite or both. In ARTuc, FGF-2, MPO, soluble E-selectin, MMP-9, IL-17, GM-CSF and TGF-α are lower than HIV-, Elite or both. Differential expression of soluble markers may reveal mechanisms of pathogenesis or possibly reduction of fibrosis in HCV/HIV co-infection.

Genomes of Fasciola hepatica from the Americas Reveal Colonization with Neorickettsia Endobacteria Related to the Agents of Potomac Horse and Human Sennetsu Fevers

Food borne trematodes (FBTs) are an assemblage of platyhelminth parasites transmitted through the food chain, four of which are recognized as neglected tropical diseases (NTDs). Fascioliasis stands out among the other NTDs due to its broad and significant impact on both human and animal health, as Fasciola sp., are also considered major pathogens of domesticated ruminants. Here we present a reference genome sequence of the common liver fluke, Fasciola hepatica isolated from sheep, complementing previously reported isolate from cattle. A total of 14,642 genes were predicted from the 1.14 GB genome of the liver fluke. Comparative genomics indicated that F. hepatica Oregon and related food-borne trematodes are metabolically less constrained than schistosomes and cestodes, taking advantage of the richer millieux offered by the hepatobiliary organs. Protease families differentially expanded between diverse trematodes may facilitate migration and survival within the heterogeneous environments and niches within the mammalian host. Surprisingly, the sequencing of Oregon and Uruguay F. hepatica isolates led to the first discovery of an endobacteria in this species. Two contigs from the F. hepatica Oregon assembly were joined to complete the 859,205 bp genome of a novel Neorickettsia endobacterium (nFh) closely related to the etiological agents of human Sennetsu and Potomac horse fevers. Immunohistochemical studies targeting a Neorickettsia surface protein found nFh in specific organs and tissues of the adult trematode including the female reproductive tract, eggs, the Mehlis' gland, seminal vesicle, and oral suckers, suggesting putative routes for fluke-to-fluke and fluke-to-host transmission. The genomes of F. hepatica and nFh will serve as a resource for further exploration of the biology of F. hepatica, and specifically its newly discovered trans-kingdom interaction with nFh and the impact of both species on disease in ruminants and humans.

Hepatic fibrosis and immune phenotype vary by HCV viremia in HCV/HIV co-infected subjects: A Women's interagency HIV study

HCV and HIV independently lead to immune dysregulation. The mechanisms leading to advanced liver disease progression in HCV/HIV coinfected subjects remain unclear.In this cross-sectional study, we assessed the association of HCV viremia, liver fibrosis, and immune response patterns in well-characterized HIV phenotypes: Elite controllers (Elites), HIV controlled (ARTc), and HIV uncontrolled (ARTuc) matched by age and race. Groups were stratified by HCV RNA status. Regulatory T-cell frequencies, T-cell activation (HLADR+CD38+), apoptosis (Caspase-3+), and intracellular cytokines (interferon-γ, IL-2, IL-17) were assessed using multiparametric flow-cytometry. Liver fibrosis was scored by AST to platelet ratio index (APRI).We found liver fibrosis (APRI) was 50% lower in Elites and ARTc compared to ARTuc. Higher liver fibrosis was associated with significantly low CD4+ T cell counts (P < 0.001, coefficient r = -0.463). Immune activation varied by HIV phenotype but was not modified by HCV viremia. HCV viremia was associated with elevated CD8 T-cell Caspase-3 in Elites, ARTuc, and HIV- except ARTc. CD8 T-cell Caspase-3 levels were significantly higher in HCV RNA+ Elites (P = 0.04) and ARTuc (P = 0.001) and HIV- groups (P = 0.02) than ARTc. Importantly, ARTuc HCV RNA+ had significantly higher CD4 T-cell interleukin-17 levels than ARTuc HCV RNA- (P = 0.005).HIV control was associated with lower liver fibrosis in HCV/HIV co-infected women. HCV viremia is associated with an inflammatory CD4 TH-17 phenotype in absence of HIV control and higher frequency of pro-apoptosis CD8 T-cells critical to avert progression of HIV and HCV disease that is attenuated in ART controllers. Elite controllers with HCV viremia are more prone to CD8 T-cell apoptosis than ART controllers, which could have negative consequences over time, highlighting the importance of ART control in HCV/HIV coinfected individuals.

Resistin expression correlates with steatohepatitis in morbidly obese patients

BACKGROUND

Morbidly obese patients are at risk for nonalcoholic steatohepatitis (NASH) even in the absence of risk factors for liver disease. Unfortunately, NASH is usually not clinically evident, and a definitive, noninvasive test for NASH does not exist. Resistin, a cytokine originating from adipose tissue, is involved in insulin resistance and also initiates proinflammatory signaling from hepatic stellate cells. This study explores the relationship between resistin expression and liver pathology in bariatric surgery patients.

METHODS

Blood samples from 30 patients undergoing bariatric surgery were collected. Total RNA was extracted and cDNA was synthesized. Quantitative RT-PCR was used to quantify relative gene expression using 18s rRNA gene as an internal control. Wedge liver biopsies from these patients were sectioned and stained. Based on a previously published scoring method, biopsies were assigned an overall NASH severity score and subscores for steatosis, inflammation, and fibrosis. Results were analyzed by using Student's t test.

RESULTS

Resistin mRNA levels ranged from 0.5 to 9.7. A group of five patients with very high resistin expression (>4) was identified. These patients had a significantly higher average NASH score compared with the rest of the group (7.9 vs. 4.48, p = 0.019). Steatosis and inflammation scores were significantly higher in the high-resistin group (p < 0.05 for both comparisons). There also was a trend toward higher fibrosis score in this group, which approached statistical significance (p = 0.051).

CONCLUSIONS

In morbidly obese patients, high resistin expression in serum is associated with hepatic steatosis, inflammation, and fibrosis. The development of elevated resistin expression may represent a link between obesity and the onset of steatohepatitis.

Interactions between hepatic iron and lipid metabolism with possible relevance to steatohepatitis

The liver is an important site for iron and lipid metabolism and the main site for the interactions between these two metabolic pathways. Although conflicting results have been obtained, most studies support the hypothesis that iron plays a role in hepatic lipogenesis. Iron is an integral part of some enzymes and transporters involved in lipid metabolism and, as such, may exert a direct effect on hepatic lipid load, intrahepatic metabolic pathways and hepatic lipid secretion. On the other hand, iron in its ferrous form may indirectly affect lipid metabolism through its ability to induce oxidative stress and inflammation, a hypothesis which is currently the focus of much research in the field of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH). The present review will first discuss how iron might directly interact with the metabolism of hepatic lipids and then consider a new perspective on the way in which iron may have a role in the two hit hypothesis for the progression of NAFLD via ferroportin and the iron regulatory molecule hepcidin. The review concludes that iron has important interactions with lipid metabolism in the liver that can impact on the development of NAFLD/NASH. More defined studies are required to improve our understanding of these effects.

The effects of opiate use and hepatitis C virus infection on risk of diabetes mellitus in the Women's Interagency HIV Study

BACKGROUND

Opiate use is common in HIV-infected and hepatitis C virus (HCV)-infected individuals, however, its contribution to the risk of diabetes mellitus is not well understood.

METHODS

Prospective study of 1713 HIV-infected and 652 HIV-uninfected participants from the Women's Interagency HIV Study between October 2000 and March 2006. Diabetes defined as fasting glucose > or =126 mg/dL, self report of diabetes medication use, or confirmed diabetes diagnosis. Opiate use determined using an interviewer-administered questionnaire. Detectable plasma HCV RNA confirmed HCV infection.

RESULTS

Current opiate users had a higher prevalence of diabetes (15%) than nonusers (10%, P = 0.03), and a higher risk of incident diabetes (adjusted relative hazard: 1.58, 95% confidence interval: 1.01 to 2.46), after controlling for HCV infection, HIV/antiretroviral therapy status, and diabetes risk factors including age, race/ethnicity, family history of diabetes, and body mass index. HCV infection was also an independent risk factor for diabetes (adjusted relative hazard: 1.61, 95% confidence interval: 1.02 to 2.52). HCV-infected women reporting current opiate use had the highest diabetes incidence (4.83 cases per 100 person-years).

CONCLUSIONS

Among women with or at-risk for HIV, opiate use is associated with increased diabetes risk independently of HCV infection. Diabetic screening should be part of care for opiate users and those infected with HCV.

AIDS-associated infections in salivary glands: autopsy survey of 60 cases

We reviewed the autopsy findings for the submandibular glands of 60 patients with AIDS who were autopsied at the George Washington University Medical Center (Washington, DC) from 1982 to 1992. AIDS-associated infections in the submandibular glands were compared with those in the pancreas and lung. Cytomegalovirus intranuclear inclusions were found in 10 cases, and Pneumocystis carinii infection was found in one case. Disseminated mycobacterial and fungal infections were not identified in the submandibular gland, even in the presence of documented pancreatic and pulmonary infection (P < .05). Overall, the major salivary glands of patients with AIDS are less frequently involved with disseminated opportunistic infections than is either the lung or the pancreas (P < .01 and P < .001, respectively).

Antibody-facilitated macrophage killing of Trypanosoma musculi is an extracellular process as studied in several variations of an in vitro analytical system

Antibody-facilitated macrophage (MP) destruction of Trypanosoma musculi involves ingestion and intracellular degradation of the parasites. It is likely, however, as we show here, that death of the trypanosomes is extracellular and it is the corpses that are ingested by MPs. We have utilized both peritoneal MPs and a cloned line (WLG 5) of mouse MPs to analyze the killing of T. musculi. Both types of MP were more effective when activated by interferon-gamma (IFN-gamma) rather than lipopolysaccharide (LPS). When activated by both, LPS diminished the killing activity stimulated by IFN-gamma, perhaps by changing the spectrum of lysins/toxins released by the MPs. Nitric oxide (NO) was found to be toxic for T. musculi and to be responsible, in part, for MP killing of the parasites. Although antibody and complement in concert caused lysis of T musculi, complement was not required for MP killing of the parasites. In the course of this investigation, we developed an in vitro system, involving line 5 MPs and plasma from infected mice containing resident parasites, that should prove satisfactory for detailed analyses of the mechanisms of the antibody-dependent, cell-mediated cure of T. musculi infection.

Studies with 1,1'-ethylidenebis(tryptophan), a contaminant associated with L-tryptophan implicated in the eosinophilia-myalgia syndrome

L-Tryptophan binds to a rat liver nuclear envelope protein, and this binding is saturable, stereospecific, and of high affinity. Utilizing an in vitro assay of [3H]tryptophan binding to rat hepatic nuclear envelopes, we have previously determined that the L-tryptophan obtained from Showa Denko and which was implicated in cases of the eosinophilia-myalgia syndrome (EMS) inhibited [3H]tryptophan binding differently than did control L-tryptophan (not implicated in EMS). Therefore, in this study we investigated whether the addition of 1,1'-ethylidenebis(tryptophan) (EBT), a contaminant or impurity in L-tryptophan implicated in EMS, would have an effect. Our results indicate that EBT alone has little inhibitory binding effect compared with that of control L-tryptophan and that when EBT was added to control L-tryptophan the inhibitory binding effort was similar to that of control L-tryptophan alone. On the other hand, in vitro addition of EBT plus L-tryptophan to nuclei of cultured murine macrophages (WLG5) results in less inhibition of [3H]-tryptophan binding than does addition of L-tryptophan alone. Similar in vitro additions to nuclei of rat brain reveal little effect on binding, as was also the case for hepatic nuclear envelopes. Adding EBT to an in vitro hepatic protein synthesis system and measuring [3H]tryptophan incorporation into acid-precipitable proteins reveal that it competes similarly to that found with equimolar concentrations of unlabeled L-tryptophan. It does not affect [14C]leucine incorporation into proteins. [14C]EBT becomes incorporated in vitro into proteins (acid-precipitable), and this incorporation is diminished in the presence of equimolar concentrations of unlabeled EBT or L-tryptophan. This suggests that EBT or possibly a breakdown product becomes incorporated into proteins. Speculation as to how EBT may affect tissues in experimental animals is presented.

Effect of 3-phenylamino-L-alanine on tryptophan binding to rat hepatic nuclear envelopes

We have determined that the addition of 3-phenylamino-L-alanine (PAA), a recently reported contaminant in L-tryptophan implicated in the eosinophilia-myalgia syndrome, affects tryptophan binding by utilizing an in vitro measurement of 3H-tryptophan binding to hepatic nuclei or nuclear envelopes. PAA (10(-10) to 10(-4) M) diminishes the inhibitory effect of binding due to excess unlabeled L-tryptophan (10(-4) M). PAA alone has no inhibitory effect on binding. The effect of PAA on in vitro tryptophan binding is in contrast to that of another contaminant, 1,1'-ethylidenebis(tryptophan), which together with excess unlabeled L-tryptophan does not appreciably affect the binding. In vitro addition of PAA and L-tryptophan to nuclei of rat brain or of cultured murine macrophages does not affect [3H]tryptophan binding in comparison to L-tryptophan alone as is the case with hepatic nuclear envelopes. Adding PAA to an in vitro protein synthesis system and measuring [3H]tryptophan or [3H]alanine incorporation into acid-precipitable proteins reveals that it competes similarly, but somewhat less, than does equimolar concentrations of unlabeled L-tryptophan or L-alanine, respectively. This suggests that PAA or a breakdown compound becomes incorporated into proteins. Speculation as to how PAA may affect tissues in experimental animals is presented.

Effect of macrophage source and activation on susceptibility in an age-dependent model of murine hepatitis caused by a phlebovirus, Punta Toro

The Adames strain of a bunyavirus, Punta Toro virus (PTV), is an hepatotrophic virus that has been described to produce an age-dependent lethal hepatic necrosis in 3-4 week old C57BL/6 mice, but 8 week old mice survive with minimal necrosis. The course of PTV infection in vitro in macrophages derived from these mice served as a model to study the pathogenesis of phlebovirus infection. Peripheral blood monocytes, resident or elicited peritoneal macrophages, and Kupffer cell liver macrophages, as well as hepatocytes, were able to support replication of PTV in vitro to a variable extent. Kupffer cells were the only population of macrophages, however, that expressed an age-related ability to affect viral infection and replication in vitro, suggesting that liver macrophages may have a unique modulatory effect on the occurrence and severity of PTV-induced hepatitis in mice. Whereas PTV showed minimal replication in resident peritoneal macrophages, the virus could replicate effectively in peritoneal macrophages elicited by thioglycolate. Activation of peritoneal macrophages with endotoxin resulted in a significant inhibition of intrinsic PTV replication (p less than 0.001), and a modest extrinsic inhibitory effect on PTV replication in cocultured hepatocytes. Both effects persisted in the presence of anti-interferon. These results indicate that the source and state of activation of macrophage/monocyte populations can influence the course of infection in vitro by the phlebovirus, Punta Toro, and can modulate infection in cocultured target cells.

Herpes simplex virus hepatitis in pregnancy. Two patients successfully treated with acyclovir

Two cases of herpes simplex virus hepatitis in pregnancy are presented. Each case was characterized by extremely high serum aminotransferase levels with minimal bilirubin elevation. In both cases, liver biopsy was instrumental in arriving at the diagnosis. In addition, computed tomography showed a radiographic appearance of the liver not characteristically seen in other hepatic disorders of pregnancy. A high index of suspicion in the second case led to early recognition and treatment. Despite the presence of fulminant liver failure and evidence of herpes encephalitis in the other case, institution of therapy with acyclovir was associated with complete recovery in both patients. The present cases are compared and contrasted with the literature. The incidence of two cases within a 6-month period suggests that herpes simplex virus hepatitis in pregnancy may occur more frequently than previously reported.

Role of hepatocytes and Kupffer cells in age-dependent murine hepatitis caused by a phlebovirus, Punta Toro

Punta Toro virus (PTV) infection of C57BL/6 mice results in fulminant hepatic necrosis and death in 3-week-old susceptible mice, but survival with minimal hepatocellular necrosis in 8-week-old resistant mice. Susceptibility in 3-week-old mice is associated with an earlier rise of viral titers in liver and serum than that occurring in 8-week-old resistant mice. There is also an earlier and more rapid accumulation of infectious progeny in serum vs. liver after PTV infection in both age groups, suggesting that the virus may replicate in extrahepatic sites as well as the liver. PTV infection of isolated hepatocytes and Kupffer cells from 3- and 8-week-old mice demonstrates a significant age-related difference in the ability of these cells to support replication of PTV in vitro (P less than 0.05). The age-related difference in liver cell-PTV interaction appears to be an inherent difference in the liver cells themselves, since there are no age-related differences in viral adsorption, morphogenesis, cytopathic effect, or interferon action within these cells. Thus, age-related differences in PTV replication or dissemination at extrahepatic sites, and the ability of the virus to replicate in intrahepatic sites, may be additive factors in the expression of age-related susceptibility to PTV in C57BL/6 mice.

Expression of human immunodeficiency virus long terminal repeat in the human promonocyte cell line U937: effect of endotoxin and cytokines

Phagocytic macrophages are known to support noncytopathic, chronic infections of human immunodeficiency virus (HIV). Regulation of viral replication in such cells with either chronic low-grade or latent HIV infection is probably influenced by both viral and cellular factors acting on the viral long terminal repeat (LTR). This study identifies naturally occurring biological response modifiers which are able to affect the HIV-LTR linked to the chloramphenicol acetyl transferase (LTR-CAT) gene in a stable transfection of the human promonocyte cell line, U937, in the absence of other viral proteins. In this model system, endotoxin lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha) are able to independently stimulate expression of LTR-CAT. Granulocyte/macrophage-colony-stimulating factor can enhance the effect of TNF-alpha or LPS, but other cytokines tested had minimal or no effect on LTR-CAT. In addition to effects on cellular susceptibility and immune function, the ability of naturally occurring factors to affect HIV-LTR in its integrated state may have particular relevance to progression of active disease from latent infection.

Characterization of tumor binding by the IC-21 macrophage cell line

The purpose of this study was to determine if the SV40-transformed murine macrophage cell line IC-21 is a suitable model to study the selective high avidity binding of tumor cells by subpopulations of activated macrophages. IC-21 macrophages bound P815, RBL5, and EL-4 murine tumor cells with high avidity, as measured by the inverted centrifugation method. Tumor binding by IC-21 macrophages was competitively inhibited by crude membrane vesicles prepared from tumor cells but not by cell membranes prepared from nontransformed splenic leukocytes, suggesting that this process was mediated by tumor-specific binding sites. IC-21 macrophages and primary cultures of pyran copolymer-elicited peritoneal macrophages demonstrated similar tumor binding avidity, kinetics, saturability, and metabolic requirements for optimal high avidity tumor binding. However, compared with primary cultures of pyran copolymer-elicited peritoneal macrophages, IC-21 macrophages bound 4-fold more tumor cells and were more homogeneous for tumor binding capability. Finally, one third of maximal tumor cell binding by IC-21 macrophages was completed within 5 min of contact with tumor, suggesting that IC-21 macrophages constitutively expressed some high avidity tumor binding sites. Their stable and homogeneous capability for binding tumor cells and their ease of growth make the IC-21 macrophage cell line a potentially valuable model for elucidating the molecular mechanisms responsible for selective high avidity tumor binding by subpopulations of activated macrophages.

Functional and structural changes in parotid glands of alcoholic cirrhotic patients

The parotid gland function and structure was studied in 30 patients with biopsy-proven alcoholic cirrhosis and in 43 age- and sex-matched alcoholic and nonalcoholic control subjects. Mean simulated parotid saliva flow rate was significantly (p less than 0.05) lower in patients with alcoholic cirrhosis as compared with alcoholic and nonalcoholic control subjects. A similar reduction was observed in mean basal parotid saliva flow rate in patients with alcoholic cirrhosis that reached statistical significance (p less than 0.05) in comparison with nonalcoholic control subjects. In addition, the concentration of sodium, bicarbonate, and total proteins in stimulated parotid saliva was significantly (p less than 0.005) lower in patients with alcoholic cirrhosis as compared with the two groups of control subjects. Sialograms in 6 patients with alcoholic cirrhosis did not reveal any obstructive lesion in the primary parotid duct or its branches. Histology of salivary tissue revealed an increase in the interstromal fatty infiltration, edema, and fibrosis without evidence of inflammatory reaction in 5 patients as compared with the control subjects. These data provide evidence for marked parotid gland dysfunction in patients with alcoholic cirrhosis presumably due to metabolic derangement and altered parotid gland structure.

Acute fatty liver of pregnancy. A reassessment based on observations in nine patients

Acute fatty liver of pregnancy was diagnosed in nine patients over a 10-year period. Eight patients had severe hepatic dysfunction typical for this syndrome and one had subclinical disease but typical hepatic histologic findings. All patients survived with little fetal wastage; all had preeclampsia. Histologic findings included cholestasis, hepatocellular necrosis, and inflammation, as well as microvesicular fat. Histologic findings from biopsy specimens of four of seven patients were initially misinterpreted as hepatitis. This disorder may have both a broad clinical and histologic spectrum; it is probably not rare but often misdiagnosed, perhaps as viral hepatitis. The concurrence of this disorder with toxemia of pregnancy suggests that these entities may be pathophysiologically related.

Chronic liver disease following community-acquired non-A, non-B hepatitis

Chronic non-A, non-B hepatitis occurring in an urban American population was identified in 23 patients followed for more than six months after the onset of acute hepatitis. Eight of the 23 patients subsequently developed normal aminotransferase levels a mean of 12.3 months after the onset of hepatitis. Liver biopsies were obtained from 9 of the remaining 15 patients. Eight biopsies revealed abnormalities consistent with chronic persistent hepatitis. One revealed chronic active hepatitis. The probable source of hepatitis included blood transfusions in 4%, intravenous drugs in 43%, personal contact in 4%, and no known source in 48%. Normalization of aminotransferase activity could not be predicted by initial symptoms, physical findings, or laboratory values. This study suggests that the chronic liver disease following community-acquired non-A, non-B hepatitis is frequent and may have a benign course.

Achalasia associated with squamous cell carcinoma of the esophagus: a case report

A case of achalasia associated with squamous cell carcinoma of the esophagus is presented. Microscopic examination of the resected esophagus demonstrated abundant nerve fibers but absent ganglion cells throughout the tumor-involved segment. This finding is believed to be the cause of achalasia in this patient.

Hyperalimentation-associated jaundice: an example of a serum factor inducing cholestasis in rats

A patient receiving total parenteral nutrition (TPN) at home following emergency resection of the small intestine was studied over a two year interval. Cholestatic jaundice developed after 6 months. A factor in serum was found to produce cholestatic changes in the bile flow of rats on intravenous infusion. Normal human serum and saline infusion did not produce this cholestasis. Endotoxin infusion in the rat produced a similar impairment in bile flow. The hypothesis was proposed that endotoxin might be an occult factor contributing to cholestasis in this case. An antiserum prepared to an endotoxin isolated from a sequestered E. coli infection in this patient, ameliorated the cholestatic effects of the patients' serum in rats. The possible role of endotoxin in the cholestasis of the TPN-induced jaundice in this patient is presented and discussed.

Prevalence and natural history of distal common bile duct stenosis in alcoholic pancreatitis

Distal common bile duct stenosis was observed in 16 (9%) of 170 alcoholic patients admitted to a Veterans Administration Medical Center in the last five years. The following clinical and biochemical features were significantly more common (P less than 0.05) among the 16 patients with common bile duct stenosis than in 154 without: jaundice, cholangitis, hyperbilirubinemia, alkaline phosphatasemia, pancreatic calcification, and malabsorption. Surgical decompression of biliary tree was necessitated in 13 of 16 cases due to obstructive jaundice in seven, cholangitis in four, portal fibrosis in one, and persistent abdominal pain in one. The mean (+/- SE) time interval between initial serum alkaline phosphatase elevation and surgical intervention was 308 +/- 108 days. Liver histology in eight cases was remarkable for portal fibrosis in seven and biliary cirrhosis in one. These data suggest that distal common bile duct stenosis is a progressive lesion which is quite prevalent in patients with advanced pancreatic disease of alcoholic etiology.

Liver ultrastructure in mitochondrial urea cycle enzyme deficiencies and comparison with Reye's syndrome

The liver ultrastructural findings in two girls with partial carbamyl phosphate synthetase I (CPS) deficiency and their heterozygote parents and two siblings with ornithine transcarbamylase (OTC) deficiency are described. Liver ultrastructure in the four patients with inherited deficiencies of urea cycle enzymes showed minimal alterations with essentially normal mitochondria when biopsy was performed during periods of good control of their hyperammonemia. Mitochondrial ultrastructure was also essentially normal in the heterozygotes for carbamyl phosphate synthetase I deficiency. These findings are in contrast to the marked alterations in mitochondrial ultrastructure found in the study of two cases of Reye's syndrome in which severe depression of ornithine transcarbamylase and carbamyl phosphate synthetase I activities was noted.

The ultrastructural localization of transport ATPase in the rat liver at non-bile canalicular plasma membranes

Na,K-ATPase in rat livers was localized cytochemically at the ultrastructural level. The Ernst technique, a method using p-nitrophenylphosphate (pNPP) substrate, was used to demonstrate ouabain-sensitive, K-dependent phosphatase, an enzyme of the Na,K-ATPase reaction sequence. Reaction product was localized predominantly on the sinusoidal and non-bile canalicular (intercellular) surfaces. This localization contrasts with previous histo-chemical studies using ATP substrate and with models that have considered the transport enzyme to be localized at the canalicular surface. If Na,K-ATPase is of importance in bile salt independent flow, a significant presence of the enzyme at sites other than the canalicular membrane suggests that a paracellular movement of sodium and water into the canaliculus must be considered.