Rifaat Safadi

Prof. Rifaat Safadi


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2014 in Clinical Gastroenterology and Hepatology
Verified
Journal Article
Open access
RSRifaat Safadi
Rifaat Safadi
FKFred M. Konikoff
Fred M. Konikoff
MMMahmud Mahamid
Mahmud Mahamid
SZShira Zelber-Sagi
Shira Zelber-Sagi
MHMaya Halpern
Maya Halpern
MMMeir Mizrahi
Meir Mizrahi
We investigated the effects of the fatty acid-bile acid conjugate 3β-arachidyl-amido, 7α-12α-dihydroxy, 5β-cholan-24-oic acid (Aramchol; Trima Israel Pharmaceutical Products Ltd, Maabarot, Israel) in a phase 2 trial of patients with nonalcoholic fatty liver disease (NAFLD). We performed a randomized, double-blind, placebo-controlled trial of 60 patients with biopsy-confirmed NAFLD (6 with nonalcoholic steatohepatitis) at 10 centers in Israel. Patients were given Aramchol (100 or 300 mg) or placebo once daily for 3 months (n = 20/group). The main end point was the difference between groups in the change in liver fat content according to magnetic resonance spectroscopy. The secondary end points focused on the differences between groups in alterations of liver enzyme levels, levels of adiponectin, homeostasis model assessment scores, and endothelial function. No serious or drug-related adverse events were observed in the 58 patients who completed the study. Over 3 months, liver fat content decreased by 12.57% ± 22.14% in patients given 300 mg/day Aramchol, but increased by 6.39% ± 36.27% in the placebo group (P = .02 for the difference between groups, adjusted for age, sex, and body mass index). Liver fat content decreased in the 100-mg Aramchol group, by 2.89% ± 28.22%, but this change was nonsignificant (P = .35), indicating a dose-response relationship (P for trend = .01). Groups given Aramchol had nonsignificant improvements over time in endothelial function and levels of alanine aminotransferase and adiponectin, but homeostasis model assessment scores did not change. The appropriateness of a single daily dose was confirmed by pharmacokinetic analysis. Three months' administration of the fatty acid-bile acid conjugate Aramchol is safe, tolerable, and significantly reduces liver fat content in patients with NAFLD. The reduction in liver fat content occurred in a dose-dependent manner and was associated with a trend of metabolic improvements, indicating that Aramchol might be used for the treatment of fatty liver disease. ClinicalTrials.gov number: NCT01094158.

1 July 2006 in Journal of Hepatology
Verified
Journal Article
Closed access
AMAlaa Melhem
Alaa Melhem
NMNidal Muhanna
Nidal Muhanna
ABAmal Bishara
Amal Bishara
CACarlos E. Alvarez
Carlos E. Alvarez
YIYaron Ilan
Yaron Ilan
RSRifaat Safadi
Rifaat Safadi

16 May 2008 in Hepatology
Verified
Journal Article
Open access
PDF file
NMNidal Muhanna
Nidal Muhanna
SDSarit Doron
Sarit Doron
OWOri Wald
Ori Wald
AHAmjad Horani
Amjad Horani
AEAhmed Eid
Ahmed Eid
RSRifaat Safadi
Rifaat Safadi
Increased CD8-T lymphocytes and reduced natural killer (NK) cells contribute to hepatic fibrosis. We have characterized pathways regulating the interactions of human hepatic stellate cells (HSCs) with specific lymphocyte subsets in vivo and in vitro . Fluorescence-activated cell sorting (FACS) was used to characterize human peripheral blood lymphocytes (PBLs) and intrahepatic lymphocytes (IHLs) obtained from healthy controls and from patients with either hepatitis B virus (HBV) or hepatitis C virus (HCV) with advanced fibrosis. Liver sections were analyzed by immunohistochemistry and confocal microscopy. To investigate in vitro interactions, PBLs from healthy controls or patients with HCV cirrhosis were co-cultured with an immortalized human HSC line (LX2 cells) or with primary HSCs. Significant alterations in lymphocyte distribution were identified in IHLs but not PBLs. The hepatic CD4/CD8 ratio and NK cells were significantly reduced in HBV/HCV patients. Expression of alpha-smooth muscle actin and infiltration of CD4, CD8, and NK cells were readily apparent in liver sections from patients with cirrhosis but not in healthy controls. Lymphocytes from each subset were in proximity to HSCs primarily within the periportal regions, and some were directly attached or engulfed. In culture, HSC activation was stimulated by HCV-derived CD8-subsets but attenuated by NK cells. Confocal microscopy identified lymphocyte phagocytosis within HSCs that was completely prevented by blocking intracellular adhesion molecule 1 (ICAM-1) and integrin molecules, or by irradiation of HSCs. LX2 knockdown of either Cdc42 or Rac1 [members of the Rho-guanosine triphosphatase (GTPase) family] prevented both phagocytosis and the activation of HSC by HCV-derived lymphocytes. Conclusion: The CD4/CD8 ratio and NK cells are significantly decreased in livers with advanced human fibrosis. Moreover, disease-associated but not healthy lymphocytes are engulfed by cultured HSCs, which is mediated by the Rac1 and Cdc42 pathways. Ingestion of lymphocytes by HSCs in hepatic fibrosis is a novel and potentially important pathway regulating the impact of lymphocytes on the course of hepatic fibrosis. (Hepatology 2008.)

15 July 2002
Verified
Journal Article
Closed access
RSRifaat Safadi
Rifaat Safadi
SFScott Laurence Friedman
Scott Laurence Friedman

7 March 2007 in Clinical and Experimental Immunology
Verified
Journal Article
Open access
PDF file
NMN. Muhanna
N. Muhanna
AHA. Horani
A. Horani
SDS. Doron
S. Doron
RSRifaat Safadi
Rifaat Safadi
Recent functional research studies suggest an anti-fibrotic role for natural killer (NK) cells coupled with a profibrotic role for CD8 cells. However, the morphological cellular interplay between the different cell types is less clear. To investigate lymphocyte/hepatic stellate cell (HSC) interactions, hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) intraperitoneally (i.p.) for 4 weeks in C57Bl/6 mice. Animals were killed at 0, 1, 2, 3 and 4 weeks. Liver sections were stained for Sirius red. Confocal microscopy was used to evaluate alpha smooth-muscle actin (αSMA) and lymphocyte subsets in liver sections. At weeks 0 and 4, liver protein extracts were assessed for αSMA by Western blotting and isolated liver lymphocytes as well as HSC were analysed by fluorescence activated cell sorter (FACS). Similar to the results obtained from classical Sirius red staining and αSMA blotting, analysis of liver sections by confocal microscopy revealed a marked and continuous accumulation of αSMA staining along sequential experimental check-points after administering CCl4. Although the number of all liver lymphocyte subsets increased following fibrosis induction, FACS analysis revealed an increase in the distribution of liver CD8 subsets and a decrease of CD4 T cells. Confocal microscopy showed a significant early appearance of CD8 and NK cells, and to a lesser extent CD4 T cells, appearing only from week 2. Lymphocytes were seen in proximity only to HSC, mainly in the periportal area and along fibrotic septa, suggesting a direct interaction. Notably, lymphocyte subsets were undetectable in naive liver sections. Freshly isolated HCS show high expression of major histocompatibility complex (MHC) class II and CD11c. In the animal model of hepatic fibrosis, lymphocytes infiltrate into the liver parenchyma and it is thought that they attach directly to activated HSC. Because HSCs express CD11c/class II molecules, interactions involving them might reflect that HSCs have an antigen-presenting capacity.

22 June 2023 in JCI Insight
Verified
Journal Article
Open access
PDF file
RGRaanan Greenman
Raanan Greenman
MSMichal Segal-Salto
Michal Segal-Salto
NBNeta Barashi
Neta Barashi
OHOphir Hay
Ophir Hay
AKAvi Katav
Avi Katav
AMAdi Mor
Adi Mor
ˆCCL24 is a pro-fibrotic, pro-inflammatory chemokine expressed in several chronic fibrotic diseases. In the liver, CCL24 plays a role in fibrosis and inflammation, and blocking CCL24 led to reduced liver injury in experimental models. We studied the role of CCL24 in primary sclerosing cholangitis (PSC) and evaluated the potential therapeutic effect of blocking CCL24 in this disease. Multidrug resistance gene 2–knockout (Mdr2 –/– ) mice demonstrated CCL24 expression in liver macrophages and were used as a relevant experimental PSC model. CCL24-neutralizing monoclonal antibody, CM-101, significantly improved inflammation, fibrosis, and cholestasis-related markers in the biliary area. Moreover, using spatial transcriptomics, we observed reduced proliferation and senescence of cholangiocytes following CCL24 neutralization. Next, we demonstrated that CCL24 expression was elevated under pro-fibrotic conditions in primary human cholangiocytes and macrophages, and it induced proliferation of primary human hepatic stellate cells and cholangiocytes, which was attenuated following CCL24 inhibition. Correspondingly, CCL24 was found to be highly expressed in liver biopsies of patients with PSC. CCL24 serum levels correlated with Enhanced Liver Fibrosis score, most notably in patients with high alkaline phosphatase levels. These results suggest that blocking CCL24 may have a therapeutic effect in patients with PSC by reducing liver inflammation, fibrosis, and cholestasis.