Significance: Older age at the time of hepatitis virus infection and age of liver donors are major determinants of liver fibrosis progression and disease severity. Our study demonstrates that aging is accompanied by significant changes in gene expression and identifies a gene, chitinase 3-like 1 ( CHI3L1 ), as having the greatest age-dependent increase in expression and as being overexpressed in cirrhotic livers. Our in vivo and in vitro results provide evidence that CHI3L1 plays a central role in liver fibrogenesis and support a role for CHI3L1 in the increased susceptibility of aging livers to fibrosis progression. This study may open avenues for specific antifibrotic or microRNA therapy to reduce or prevent hepatic fibrosis and its ominous complications.

Mononuclear cell activity was monitored in vivo after the temporary inhibition of colony-stimulating factor-1 receptor by using multispectral fluorine MRI with the administration of two fluorine probes at early and late stages of cell renewal. BackgroundMRI with fluorine 19 (19F) probes has shown an ability to track immune cell activity with a specific, stable, and quantitative signal. In addition, the chemical shift differences of selected 19F probes make dual-probe imaging possible. To improve 19F MRI sensitivity for dual-probe imaging, optimal fluorine probes are needed.PurposeTo develop multispectral 19F MRI to image immune cell activity in vivo using 19F nanoparticles of two distinct fluorocarbons.Materials and MethodsBoth 19F nanoparticles formulated with two fluorocarbons with distinct resonance frequencies and a high fluorine payload were characterized in terms of size, stability, MR profile, and relaxation times at 7 T. 19F MRI sensitivity was tested on labeling cells both in vitro and in vivo in C57BL/6 mice after conditional ablation of myeloid cells through the inhibition of colony-stimulating factor-1 receptor (CSF1Ri) to monitor the change of immune cells phagocytosis. Fluorine MRI data were acquired at the resonance frequency of ...

HBV is the most common risk factor for HCC development, accounting for almost 50% of cases worldwide. Despite significant advances in immunotherapy, there is limited information on the HBV-HCC tumor microenvironment (TME), which may influence the response to checkpoint inhibitors. Here, we characterize the TME in a unique series of liver specimens from HBV-HCC patients to identify who might benefit from immunotherapy. By combining an extensive immunohistochemistry analysis with the transcriptomic profile of paired liver samples (tumor vs. nontumorous tissue) from 12 well-characterized Caucasian patients with HBV-HCC, we identified two distinct tumor subtypes that we defined immune-high and immune-low. The immune-high subtype, seen in half of the patients, is characterized by a high number of infiltrating B and T cells in association with stromal activation and a transcriptomic profile featuring inhibition of antigen presentation and CTL activation. All the immune-high tumors expressed high levels of CTLA-4 and low levels of PD-1, while PD-L1 was present only in four of six cases. In contrast, the immune-low subtype shows significantly lower lymphocyte infiltration and stromal activation. By whole exome sequencing, we documented that four out of six individuals with the immune-low subtype had missense mutations in the CTNNB1 gene, while only one patient had mutations in this gene in the immune-high subtype. Outside the tumor, there were no differences between the two subtypes. This study identifies two distinctive immune subtypes in HBV-associated HCC, regardless of the microenvironment observed in the surrounding nontumorous tissue, providing new insights into pathogenesis. These findings may be instrumental in the identification of patients who might benefit from immunotherapy.