MSC-derived exosomes attenuate hepatic fibrosis in primary sclerosing cholangitis through inhibition of Th17 differentiation

Primary sclerosing cholangitis(PSC)is an autoimmune cholangiopathy characterized by chronic inflammation of the biliary epithelium and periductal fibrosis,with no curative treatment available,and liver transplantation is inevitable for end-stage patients.Human placentalmesenchymal stem cell(hpMSC)-derived exosomes have demonstrated the ability to prevent fibrosis,inhibit collagen production and possess immunomodulatory properties in autoimmune liver disease.Here,we prepared hpMSC-derived exosomes(Exo^(MSC))and further investigated the anti-fibrotic effects and detailed mechanism on PSC based on Mdr2^(−/−)mice and multicellular organoids established from PSC patients.The results showed that Exo^(MSC) ameliorated liver fibrosis in Mdr2^(−/−)mice with significant collagen reduction in the preductal area where Th17 differentiation was inhibited as demonstrated by RNAseq analysis,and the percentage of CD4+IL-17A+T cells was reduced both in Exo^(MSC)-treated Mdr2^(−/−)mice(Mdr2^(−/−)-Exo)in vivo and Exo^(MSC)-treated Th17 differentiation progressed in vitro.Furthermore,Exo^(MSC) improved the hypersecretory phenotype and intercellular interactions in the hepatic Th17 microenvironment by regulating PERK/CHOP signaling as supported by multicellular organoids.Thus,our data demonstrate the antifibrosis effect of Exo^(MSC) in PSC disease by inhibiting Th17 differentiation,and ameliorating the Th17-induced microenvironment,indicating the promising potential therapeutic role of Exo^(MSC) in liver fibrosis of PSC or Th17-related diseases.

Genome-wide CRISPR screening identifies critical role of phosphatase and tensin homologous (PTEN) in sensitivity of acute myeloid leukemia to chemotherapy

Although significant progress has been made in the development of novel targeted drugs for the treatment of acute myeloid leukemia(AML)in recent years,chemotherapy still remains the mainstay of treatment and the overall survival is poor in most patients.Here,we demonstrated the antileukemia activity of a novel small molecular compound NL101,which is formed through the modification on bendamustine with a suberanilohydroxamic acid(SAHA)radical.NL101 suppresses the proliferation of myeloid malignancy cells and primary AML cells.It induces DNA damage and caspase 3-mediated apoptosis.A genome-wide clustered regularly interspaced short palindromic repeats(CRISPR)library screen revealed that phosphatase and tensin homologous(PTEN)gene is critical for the regulation of cell survival upon NL101 treatment.The knockout or inhibition of PTEN significantly reduced NL101-induced apoptosis in AML and myelodysplastic syndrome(MDS)cells,accompanied by the activation of protein kinase B(AKT)signaling pathway.The inhibition of mammalian target of rapamycin(mTOR)by rapamycin enhanced the sensitivity of AML cells to NL101-induced cell death.These findings uncover PTEN protein expression as a major determinant of chemosensitivity to NL101 and provide a novel strategy to treat AML with the combination of NL101 and rapamycin.

Human Placental Mesenchymal Stem Cells Relieve Primary Sclerosing Cholangitis via Upregulation of TGR5 in Mdr2^(-/-)Mice and Human Intrahepatic Cholangiocyte Organoid Models

Primary sclerosing cholangitis(PSC)is a biliary disease accompanied by chronic inflammation of the liver and biliary stricture.Mesenchymal stem cells(MSCs)are used to treat liver diseases because of their immune regulation and regeneration-promoting functions.This study was performed to explore the therapeutic potential of human placental MSCs(hP-MSCs)in PSC through the Takeda G protein-coupled receptor 5(TGR5)receptor pathway.Liver tissues were collected from patients with PSC and healthy donors(n=4)for RNA sequencing and intrahepatic cholangiocyte organoid construction.hP-MSCs were injected via the tail vein into Mdr2^(-/-),bile duct ligation(BDL),and 3,5-diethoxycarbonyl-1,4-dihydrocollidine(DDC)mouse models or co-cultured with organoids to confirm their therapeutic effect on biliary cholangitis.Changes in bile acid metabolic profile were analyzed by liquid chromatography/tandem mass spectrometry(LC-MS/MS).Compared with healthy controls,liver tissues and intrahepatic cholangiocyte organoids from PSC patients were characterized by inflammation and cholestasis,and marked downregulation of bile acid receptor TGR5 expression.hP-MSC treatment apparently reduced the inflammation,cholestasis,and fibrosis in Mdr2^(-/-),BDL,and DDC model mice.By activating the phosphatidylinositol 3 kinase/extracellular signal-regulated protein kinase pathway,hP-MSC treatment promoted the proliferation of cholangiocytes,and affected the transcription of downstream nuclear factorκB through regulation of the binding of TGR5 and Pellino3,thereby affecting the cholangiocyte inflammatory phenotype.