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Publications (42)
Background
Infection by coronavirus SARS-CoV2 is a severe and often deadly disease that has implications for the respiratory system and multiple organs across the human body. While the effects in the lung have been extensively studied, less is known about the impact COVID-19 has across other organs.
Methods
Here, we contribute a single-nuclei RNA-...
Description
The acute hepatic porphyrias (AHP) are rare, inborn errors of heme-metabolism and include acute intermittent porphyria, hereditary coproporphyria, variegate porphyria, and porphyria due to severe deficiency of 5-aminolevulinic acid dehydratase. Acute intermittent porphyria is the most common type of AHP, with an estimated prevalence of...
The use of iron supplementation for anemia in erythropoietic protoporphyria (EPP) is controversial with both benefit and deterioration reported in single case reports. There is no systematic study to evaluate the benefits or risks of iron supplementation in these patients. We assessed the potential efficacy of oral iron therapy in decreasing erythr...
Background
Acute hepatic porphyria (AHP) is a family of four rare genetic diseases, each involving deficiency in a hepatic heme biosynthetic enzyme. Resultant overproduction of the neurotoxic intermediates δ-aminolevulinic acid (ALA) and porphobilinogen (PBG) leads to disabling acute neurovisceral attacks and progressive neuropathy. We evaluated th...
Pediatric hepatoblastoma is the most common primary liver cancer in infants and children. Studies of hepatoblastoma that focus exclusively on tumor cells demonstrate sparse somatic mutations and a common cell of origin, the hepatoblast, across patients. In contrast to the homogeneity these studies would suggest, hepatoblastoma tumors have a high de...
Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are rare genetic photodermatoses. Limited expertise with these disorders among physicians leads to diagnostic delays. Here, we present evidence-based consensus guidelines for the diagnosis, monitoring, and management of EPP and XLP. A systematic literature review was conducted, a...
Background: Acute Intermittent Porphyria (AIP) is a rare inborn error of heme biosynthesis characterized clinically by life-threatening acute neurovisceral attacks. Few studies have assessed quality of life (QoL) tools in the AIP population, and none are validated for use in AIP. In this study, the Patient Reported Outcomes Measurement Information...
Background & aims
Gain of function (GOF) mutation of CTNNB1 gene is one of the most frequent genetic events in hepatocellular carcinoma (HCC). T-box transcription factor 3 (TBX3) is a liver-specific target of the Wnt/β-Catenin pathway and thought to be an oncogene mediating activated β-Catenin driven HCC formation.
Methods
We evaluated TBX3 expres...
Introduction
Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP) are inborn errors of heme biosynthesis caused by the abnormal accumulation of erythrocyte protoporphyrin IX (ePPIX). These protoporphyrias are characterized by excruciating painful attacks on prolonged sunlight exposure. Before the onset of phototoxic pain, patients e...
Purpose:
Erythropoietic protoporphyria (EPP), characterized by painful cutaneous photosensitivity, results from pathogenic variants in ferrochelatase (FECH). For 96% of patients, EPP results from coinheriting a rare pathogenic variant in trans of a common hypomorphic variant c.315-48T>C (minor allele frequency 0.05). The estimated prevalence of EP...
Background and aim:
The risk for hepatocellular carcinoma (HCC) is increased in the acute hepatic porphyrias (AHP). The aim of this study was to explore the clinicopathologic characteristics, outcomes, and frequency of HCC in patients with AHP in the United States.
Methods:
Cross-sectional analysis evaluating patients with HCC in a multi-center,...
Background
Up-regulation of hepatic delta-aminolevulinic acid synthase 1 (ALAS1), with resultant accumulation of delta-aminolevulinic acid (ALA) and porphobilinogen, is central to the pathogenesis of acute attacks and chronic symptoms in acute hepatic porphyria. Givosiran, an RNA interference therapy, inhibits ALAS1 expression.
Methods
In this dou...
Liver regeneration is a fundamental biological process required for sustaining body homeostasis and restoring liver function after injury. Emerging evidence demonstrates that cytokines, growth factors and multiple signaling pathways contribute to liver regeneration. Mammalian target of rapamycin complex 2 (mTORC2) was identified to regulate cell me...
Acute intermittent porphyria (AIP) is a rare inborn error of heme biosynthesis characterized by life-threatening acute attacks. Few studies have assessed quality of life (QoL) in AIP and those that have had small sample sizes and used tools that may not have captured important domains.
Baseline data from the Porphyrias Consortium’s Longitudinal Stu...
INTRODUCTION
Acute Hepatic Porphyria (AHP) is a family of rare genetic diseases due to enzyme deficiencies in heme biosynthesis in the liver that can lead to neurovisceral attacks and chronic symptoms. (1, 2) AHP is also associated with multiple long-term complications, including neuropathy (3,4), hypertension (5,6), chronic kidney disease (7), and...
Background:
Erythropoietic protoporphyria (EPP) and X-linked Protoporphyria (XLP) are rare photodermatoses presenting with severe phototoxicity. Although anecdotally, providers who treat EPP patients acknowledge their life-altering effects, tools that fully capture their impact on quality of life (QoL) are lacking.
Methods:
Adult patients with E...
In the liver, Wnt/β‐catenin signaling is involved in regulating zonation and hepatocyte proliferation during homeostasis. We have examined Wnt gene expression and signaling after injury and we show by in situ hybridization that Wnts are activated by acute carbon tetrachloride (CCl4) toxicity. Following injury, peri‐injury hepatocytes become Wnt‐res...
Inactivating mutations of AXIN1, a negative regulator of the Wnt/β‐Catenin cascade, are among the common genetic events in human hepatocellular carcinoma (HCC), affecting around 10% of cases. In the present manuscript, we sought to define the genetic crosstalk between Axin1 mutants and Wnt/β‐catenin as well as Notch signaling cascades along hepatoc...
In the liver, Wnt/β-catenin signaling is involved in regulating zonation and hepatocyte proliferation during homeostasis. We have examined Wnt gene expression and signaling after injury and we show by in situ hybridization that Wnts are activated by acute carbon tetrachloride (CCl4) toxicity. Following injury, peri-injury hepatocytes become Wnt-res...
The acute hepatic porphyrias (AHPs) are a group of four inherited diseases of heme biosynthesis that present with episodic, acute neurovisceral symptoms. The four types are 5‐aminolevulinic acid (ALA) dehydratase deficiency porphyria, acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria. Their diagnoses are often missed...
In the healthy adult liver, most hepatocytes proliferate minimally. However, upon physical or chemical injury to the liver, hepatocytes proliferate extensively in vivo under the direction of multiple extracellular cues, including Wnt and pro-inflammatory signals. Currently, liver organoids can be generated readily in vitro from bile-duct epithelial...
Importance
Autosomal recessive erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are rare photodermatoses presenting with variable degrees of painful phototoxicity that markedly affects quality of life. The clinical variability, determinants of severity, and genotype/phenotype correlations of these diseases are not well characte...
The acute hepatic porphyrias (AHPs) are a group of four inherited disorders, each resulting from the deficient activity of a specific enzyme in the heme biosynthetic pathway. They present clinically with acute neurovisceral symptoms which may be sporadic or recurrent, and which, when severe, can be life-threatening. The diagnosis is often missed or...
Background:
Laboratory diagnosis of erythropoietic protoporphyria (EPP) requires a marked increase in total erythrocyte protoporphyrin (300-5000 μ g/dL erythrocytes, reference interval <80 μ g/dL) and a predominance (85%-100%) of metal-free protoporphyrin (normal, mostly zinc protoporphyrin); plasma porphyrins are not always increased. X-linked pr...
The source of new hepatocytes in the uninjured liver has remained an open question. By lineage tracing using the Wnt-responsive gene Axin2 in mice, we identify a population of proliferating and self-renewing cells adjacent to the central vein in the liver lobule. These pericentral cells express the early liver progenitor marker Tbx3, are diploid, a...
The porphyrias comprise a set of diseases, each representing an individual defect in one of the eight enzymes mediating the pathway of heme synthesis. The diseases are genetically distinct but have in common the overproduction of heme precursors. In the case of the acute (neurologic) porphyrias, the cause of symptoms appears to be overproduction of...
Objective:
We describe a young woman with previously undiagnosed thyrotoxicosis who presented with acute liver failure (ALF).
Methods:
We present a case report and review the relevant literature.
Results:
An extensive evaluation excluded possible causes of ALF other than thyrotoxicosis. The management of thyrotoxicosis posed several unique cha...
Recent evidence has contradicted the prevailing view that homeostasis and regeneration of the adult liver are mediated by self duplication of lineage-restricted hepatocytes and biliary epithelial cells. These new data suggest that liver progenitor cells do not function solely as a backup system in chronic liver injury; rather, they also produce hep...
Unlabelled:
Acute biliary obstruction leads to periductal myofibroblasts and fibrosis, the origin of which is uncertain. Our study provides new information on this question in mice and humans. We show that bile duct obstruction induces a striking increase in cholangiocyte alphavbeta6 integrin and that expression of this integrin is directly linked...
Progenitor ("oval") cell expansion accompanies many forms of liver injury, including alcohol toxicity and submassive parenchymal necrosis as well as experimental injury models featuring blocked hepatocyte replication. Oval cells can potentially become either hepatocytes or biliary epithelial cells and may be critical to liver regeneration, particul...
Frizzled (Fz) and Dishevelled (Dsh) are components of an evolutionarily conserved signaling pathway that regulates planar cell polarity. How this signaling pathway directs asymmetric cytoskeletal reorganization and polarized cell morphology remains unknown. Here, we show that Drosophila Rho-associated kinase (Drok) works downstream of Fz/Dsh to med...
Hereditary coproporphyria (HCP) is an acute (hepatic) porphyria in which the acute symptoms are neurovisceral and occur in discrete episodes. Attacks typically start in the abdomen with low-grade pain that slowly increases over a period of days (not hours) with nausea progressing to vomiting. In some individuals, the pain is predominantly in the ba...
