co-transplantation-human-ovarian-tissue-with-engineered-endothelial

Co-transplantation of Human Ovarian Tissue with Engineered Endothelial Cells: A Cell-based Strategy Combining Accelerated Perfusion with Direct Paracrine Delivery

Infertility is a frequent side effect of chemotherapy and/or radiotherapy and for some patients, cryopreservation of oocytes or embryos is not an option. ...

Weill Cornell Medical College

Hepatitis B virus (HBV) chronically infects 400 million people worldwide and is a leading driver of end-stage liver disease and liver cancer. Research into the biology and treatment of HBV requires an in vitro cell-culture system that supports the infection of human hepatocytes, and accurately recapitulates virus-host interactions. Here, we report that micropatterned cocultures of primary human hepatocytes with stromal cells (MPCCs) reliably support productive HBV infection, and infection can be enhanced by blocking elements of the hepatocyte innate immune response associated with the induction of IFN-stimulated genes. MPCCs maintain prolonged, productive infection and represent a facile platform for studying virus-host interactions and for developing antiviral interventions. Hepatocytes obtained from different human donors vary dramatically in their permissiveness to HBV infection, suggesting that factors--such as divergence in genetic susceptibility to infection--may influence infection in vitro. To establish a complementary, renewable system on an isogenic background in which candidate genetics can be interrogated, we show that inducible pluripotent stem cells differentiated into hepatocyte-like cells (iHeps) support HBV infection that can also be enhanced by blocking interferon-stimulated gene induction. Notably, the emergence of the capacity to support HBV transcriptional activity and initial permissiveness for infection are marked by distinct stages of iHep differentiation, suggesting that infection of iHeps can be used both to study HBV, and conversely to assess the degree of iHep differentiation. Our work demonstrates the utility of these infectious systems for studying HBV biology and the virus' interactions with host hepatocyte genetics and physiology.

Modeling host interactions with hepatitis B virus using primary and induced pluripotent stem cell-derived hepatocellular systems.

Pancreatic ductal adenocarcinomas (PDACs) are highly metastatic with poor prognosis, mainly due to delayed detection. We hypothesized that intercellular communication is critical for metastatic progression. Here, we show that PDAC-derived exosomes induce liver pre-metastatic niche formation in naive mice and consequently increase liver metastatic burden. Uptake of PDAC-derived exosomes by Kupffer cells caused transforming growth factor β secretion and upregulation of fibronectin production by hepatic stellate cells. This fibrotic microenvironment enhanced recruitment of bone marrow-derived macrophages. We found that macrophage migration inhibitory factor (MIF) was highly expressed in PDAC-derived exosomes, and its blockade prevented liver pre-metastatic niche formation and metastasis. Compared with patients whose pancreatic tumours did not progress, MIF was markedly higher in exosomes from stage I PDAC patients who later developed liver metastasis. These findings suggest that exosomal MIF primes the liver for metastasis and may be a prognostic marker for the development of PDAC liver metastasis.

Pancreatic cancer exosomes initiate pre-metastatic niche formation in the liver.

Chronic hepatitis B virus (HBV) infection is prevalent, deadly, and seldom cured due to the persistence of viral episomal DNA (cccDNA) in infected cells. Newly developed genome engineering tools may offer the ability to directly cleave viral DNA, thereby promoting viral clearance. Here, we show that the CRISPR/Cas9 system can specifically target and cleave conserved regions in the HBV genome, resulting in robust suppression of viral gene expression and replication. Upon sustained expression of Cas9 and appropriately chosen guide RNAs, we demonstrate cleavage of cccDNA by Cas9 and a dramatic reduction in both cccDNA and other parameters of viral gene expression and replication. Thus, we show that directly targeting viral episomal DNA is a novel therapeutic approach to control the virus and possibly cure patients. 

CRISPR/Cas9 cleavage of viral DNA efficiently suppresses hepatitis B virus.

Although patients infected by genotype 1b hepatitis C virus (HCV) with Q(70) and/or M(91)core gene mutations have an almost five-fold increased risk of developing hepatocellular carcinoma (HCC) and increased insulin resistance, the absence of a suitable experimental system has precluded direct experimentation on the effects of these mutations on cellular gene expression.

A cell culture system for distinguishing hepatitis C viruses with and without liver cancer-related mutations in the viral core gene.

Zika virus (ZIKV) infects fetal and adult human brain and is associated with serious neurological complications. To date, no therapeutic treatment is available to treat ZIKV-infected patients. We performed a high-content chemical screen using human pluripotent stem cell-derived cortical neural progenitor cells (hNPCs) and found that hippeastrine hydrobromide (HH) and amodiaquine dihydrochloride dihydrate (AQ) can inhibit ZIKV infection in hNPCs. Further validation showed that HH also rescues ZIKV-induced growth and differentiation defects in hNPCs and human fetal-like forebrain organoids. Finally, HH and AQ inhibit ZIKV infection in adult mouse brain in vivo. Strikingly, HH suppresses viral propagation when administered to adult mice with active ZIKV infection, highlighting its therapeutic potential. Our approach highlights the power of stem cell-based screens and validation in human forebrain organoids and mouse models in identifying drug candidates for treating ZIKV infection and related neurological complications in fetal and adult patients.

High-Content Screening in hPSC-Neural Progenitors Identifies Drug Candidates that Inhibit Zika Virus Infection in Fetal-like Organoids and Adult Brain.

Article	Year
Modeling host interactions with hepatitis B virus using primary and induced pluripotent stem cell-derived hepatocellular systems. Proceedings of the National Academy of Sciences of the United States of America\| PubMed ID: 25092305	2014
Pancreatic cancer exosomes initiate pre-metastatic niche formation in the liver. Nature cell biology\| PubMed ID: 25985394	2015
CRISPR/Cas9 cleavage of viral DNA efficiently suppresses hepatitis B virus. Scientific reports\| PubMed ID: 26035283	2015
A cell culture system for distinguishing hepatitis C viruses with and without liver cancer-related mutations in the viral core gene. Journal of hepatology\| PubMed ID: 26220749	2015
High-Content Screening in hPSC-Neural Progenitors Identifies Drug Candidates that Inhibit Zika Virus Infection in Fetal-like Organoids and Adult Brain. Cell stem cell\| PubMed ID: 28736217	2017
Hepatology Highlights. Hepatology (Baltimore, Md.)\| PubMed ID: 29480971	2018
Hepatology Highlights. Hepatology (Baltimore, Md.)\| PubMed ID: 29574955	2018
Hepatology Highlights. Hepatology (Baltimore, Md.)\| PubMed ID: 29669400	2018

Robert E. Schwartz

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