LABRESEARCH

Learn about our pioneering efforts to unravel
the complexities of chronic liver diseases

The liver is a marvel of functional complexity, structured into specialized units known as liver lobules delineated by a remarkable spatial compartmentalization orchestrated by a unique vascular architecture. Blood, coursing through both the hepatic artery and portal vein, converges within the liver’s capillary network before exiting through the centrilobular vein. Beyond their architectural and circulatory role, these blood vessels wield significant influence, extending an instructive hand to neighbouring cells and establishing distinct peri-central and periportal areas. Indeed, vascular endothelial cells orchestrate a symphony of diverse gene expressions along the lobular axis, shaping what we term “lobular zonation.” This intricate process involves a substantial portion of the genome expressed by hepatocytes and parenchymal cells. At InversoLab our current focus lies in deciphering the complexities of vascular control within liver lobules and its pivotal role in chronic disease progression.

Vascular Control of NASH Progression

Delving into the intricacies of liver lobules, our research explores the dynamic interplay of blood vessels in chronic disease progression. Within the microcosm of lobular zonation, vascular endothelial cells orchestrate a symphony of gene expressions, shaping the liver’s functional units. Beyond anatomical structuring, blood vessels instruct neighboring cells, contributing to chronic diseases. Our current projects aim to unravel the comprehensive vascular control mechanisms of metabolically driven liver disease such as NAFLD and NASH, providing insights into chronic disease progression.

Non-alcoholic steato-hepatitis (NASH) stands as a distinct yet integral part of a spectrum of liver diseases, encompassing a range from initial steatosis to irreversible stages like fibrosis and cirrhosis. This spectrum collectively arises from a complex metabolic dysfunction and impacts nearly 25% of the global population, posing one of the most significant health challenge of our time.

The progression of the disease is strongly linked to the lobular structure of the liver. Specifically, the liver is organized in functional unit named lobules in which the hepatocytes are arranged around a vasculature system, extending from the portal area to the central-lobular vein. Today we know that a large part of the hepatocyte’s genome has a strong expression gradient along this axis, and the consequent functional compartmentalization is what we define as liver lobular zonation.

The role of blood vessels, particularly vascular endothelial cells, transcends mere anatomical support within the liver lobules. These cells play a crucial instructive role by emitting signals (angiocrine function) that orchestrate neighboring cell zonation, thereby shaping both the anatomical and functional compartments of the liver lobule. The progressive disruption of this delicate lobular structure during NASH marks a critical transition between reversible and irreversible lesions, signifying a key pathological moment in the disease progression.

Despite the endothelium’s pivotal role in maintaining liver structure and zonation, much remains unclear regarding the vascular determinants of NASH progression. Key questions persist: How does dysregulated hepatic zonation correlate with NASH progression? Are specific signalling events or zonation patterns indicative of prognostic value? Can targeting endothelial cells rescue liver zonation and impact disease progression?

 

Our overarching hypothesis posits that vascular zonation exerts significant control over NASH progression, suggesting potential therapeutic avenues that extend beyond conventional strategies focused solely on hepatocytes or metabolic pathways.

This project integrates murine models of dietary-induced NASH and human samples with advanced imaging and spatially resolved multi-omics. By characterizing liver vasculature dynamics during NASH, we aim to correlate pathological zonation patterns with disease stages—an aspect often overlooked in current diagnostic and prognostic approaches.  Ultimately, our research endeavors could redefine treatment paradigms for NASH, promising better patient outcomes and transforming the landscape of managing metabolic-related liver diseases.

Vascular determinants of leukocytes migration along the gut-liver route

Within the intricate landscape of non-alcoholic steato-hepatitis (NASH), our project unravels the fascinating journey of leukocytes migrating from the gut to the liver. Focusing on the liver zonation dynamics and disruptions in the gut-vascular-barrier (GVB), our study explores the heightened influx of damaging patterns into specific liver zones during NASH. This investigative focus sheds light on the early activation of B- and T-cells in the gut, their subsequent migration to distinct liver zones, and their pivotal role in driving NASH and liver fibrosis progression. Utilizing advanced imaging and multi-omics, our goal is to identify novel trafficking molecules, providing crucial insights into the interplay between gut-derived immune cells, liver zonation, and endothelial cells.

The liver and gut possess a unique vascular connection critical for their mutual function and communication. The hepatic portal vein channels metabolite-rich blood, including bacterial products, from the intestines to the liver, forming a specialized dual blood supply in conjunction with the hepatic artery.  Within this framework, vascular endothelial cells play a pivotal role in governing the organ function of both the gut and liver.

For instance, The gut and liver’s functional connection is governed by specialized vascular architecture. The gut-vascular-barrier (GVB), comprising unique cell-cell junctions, pericytes, and glial cells, regulates metabolite and toxin flux from the gut to the liver. In NASH, GVB disruption intensifies the influx of damage-associated molecular patterns (DAMPs) and metabolite-associated patterns (MAMPs), exacerbating hepatic damage. We previously show that the liver sinusoidal endothelial cells (LSEC) play a multifaceted role beyond facilitating cell trafficking: They act as antigen-presenting cells, presenting hepatocyte antigens to CD8 T-cells; LSEC’s peculiar structure allows circulating T-cells to execute effector functions within vessel lumens, altering conventional immune response paradigms. Moreover, LSEC support an unconventional intravascular platelet aggregation instrumental in immune cell recruitment during viral hepatitis, NASH, and HCC.

 

This project centers on understanding leukocyte trafficking and activation along the gut-liver axis within dietary-induced metabolic dysfunctions like fatty liver disease and NASH. Our observations reveal early activation of B- and T-cells in the intestinal mucosa and lamina propria, later migrating to the liver and significantly contributing to NASH and liver fibrosis. Preliminary data underscore a distinct compartmentalization of intestinal inflammatory cells, clustering B and T cells in the lamina propria and atypical migratory cells in the intestinal lymphatic.

Building on these observations, we will focus on the following questions:

  1. i) Is there a preferential route (lymphatic vs vascular) for T-cell migration to the liver?
  2. ii) Where do gut-activated T-cells localize within the liver

iii) What specific interaction signature exists between gut-derived T-cells and liver endothelial cells?

 

To address these questions, we’ll employ intravital multi-photon microscopy and advanced cell tracking techniques, tracing immune cell dynamics during their migration from the gut to the liver in the context NASH and fibrosis progression.Enhanced by spatially resolved transcriptomic and proteomic analyses, this approach aims to uncover novel trafficking molecules governing metabolic-driven cell accumulation in the liver.

 

This research endeavors to illuminate the intricate interplay between gut-derived immune cells and liver endothelial cells during NASH, potentially revealing promising therapeutic targets for managing metabolic-related liver pathologies.

IN2SIGHT: A breakthrough for in-vivo optical imaging.

IN2SIGHT, a pioneering consortium funded by the European Innovation Council, converges the expertise of 9 partners across 5 countries. This collaborative initiative merge expertise in material science, laser polymerization printing, nanostructured surfaces, intravital microscopy, and vascular and immune biology, with the collective mission to create a revolutionary in-vivo optical imaging platform. This breakthrough technology enables long-term intravital imaging, enhancing biocompatibility screening and studying complex biological processes like neo-angiogenesis and inflammatory reactions.

IN2SIGHT stands as a pioneering endeavor within the realm of in-vivo optical imaging, propelled by a collaborative consortium funded by the European Innovation Council (EIC) established the  European Commission. This multidisciplinary consortium comprises 9 partners hailing from academic, research, and industrial domains across Italy, Israel, Spain, Germany, and Greece.

The IN2SIGHT consortium amalgamates unique expertise in material science, laser polymerization printing, nanostructured surfaces, intravital microscopy, vascular and immune-biology. The overarching goal is to engineer a transformative in-vivo optical imaging platform dedicated to biological studies and biocompatibility tests.

Specifically, The focal point of this collaborative effort is the development of an “all-in-one” biocompatible and implantable optical device, compactly housed within a few micrometers. This innovative device seamlessly integrates optical components and a spatial tracing system, enabling prolonged and longitudinal intravital imaging. The paramount objective is to achieve an unprecedented level of reliability for biocompatibility screening while investigating intricate biological processes such as neo-angiogenesis and inflammatory reactions triggered by diverse materials.

 

For additional insights into the IN2SIGHT consortium and its groundbreaking work in advancing in-vivo optical imaging, please visit our consortium web page.

PARTNER