Synthetic augmentation of bilirubin metabolism in human pluripotent stem cell-derived liver organoids

UGT1A1 (UDP glucuronosyltransferase family 1 member A1) is the primary enzyme required for bilirubin conjugation, which is essential for preventing hyperbilirubinemia. Animal models lack key human organic anion transporting polypeptides with distinct epigenetic control over bilirubin metabolism, necessitating a human model to interrogate the regulatory mechanism behind UGT1A1 function. Here, we use induced pluripotent stem cells to develop human liver organoids that can emulate conjugation failure phenotype. Bilirubin conjugation assays, chromatin immunoprecipitation, and transcriptome analysis elucidated the role of glucocorticoid antagonism in UGT1A1 activation. This antagonism prevents the binding of transcriptional repressor MECP2 at the expense of NRF2 with associated off-target effects. Therefore, we introduced functional GULO (L-gulonolactone oxidase) in human organoids to augment intracellular ascorbate for NRF2 reactivation. This engineered organoid conjugated more bilirubin and protected against hyperbilirubinemia when transplanted in immunosuppressed Crigler-Najjar syndrome rat model. Collectively, we demonstrate that our organoid system serves as a manipulatable model for interrogating hyperbilirubinemia and potential therapeutic development.

Demonstration of Safety in Wild Type Mice of npFOXF1, a Novel Nanoparticle-Based Gene Therapy for Alveolar Capillary Dysplasia with Misaligned Pulmonary Veins

Introduction

Alveolar Capillary Dysplasia with Misaligned Pulmonary Veins (ACDMPV) is a fatal congenital disease resulting from a pulmonary vascular endothelial deficiency of FOXF1, producing abnormal morphogenesis of alveolar capillaries, malpositioned pulmonary veins and disordered development of lung lobes. Affected neonates suffer from cyanosis, severe breathing insufficiency, pulmonary hypertension, and death typically within days to weeks after birth. Currently, no treatment exists for ACDMPV, although recent murine research in the Kalinichenko lab demonstrates nanoparticle delivery improves survival and reconstitutes normal alveolar-capillary architecture. The aim of the present study is to investigate the safety of intravenous administration of FOXF1-expressing PEI-PEG nanoparticles (npFOXF1), our pioneering treatment for ACDMPV.

Methods

npFOXF1 was constructed, validated, and subsequently administered in a single dose to postnatal day 14 (P14) mice via retro-orbital injection. Biochemical, serologic, and histologic safety were monitored at postnatal day 16 (P16) and postnatal day 21 (P21).

Results

With treatment we observed no lethality, and the general condition of mice revealed no obvious abnormalities. Serum chemistry, whole blood, and histologic toxicity was assayed on P16 and P21 and revealed no abnormality.

Discussion

In conclusion, npFOXF1 has a very good safety profile and combined with preceding studies showing therapeutic efficacy, npFOXF1 can be considered as a good candidate therapy for ACDMPV in human neonates.

Diagnostic, treatment, and follow-up of osteoporosis-position statement of the Latin American Federation of Endocrinology

The Latin American Federation of Endocrinology position statement on osteoporosis was developed by endocrinologists from 9 countries. It encompasses the definition, diagnosis, treatment, and follow-up of the disease, the identification of barriers to healthcare, and proposals to improve the disease care in the region.

INTRODUCTION

There is a gap in the understanding of osteoporosis in Latin America. The objective of this work is to state the position of the Latin American Federation of Endocrinology on osteoporosis care in postmenopausal women to better bridge this gap.

METHODS

An experts' panel was formed comprising of 11 endocrinologists from 9 countries. A data search was conducted with a conceptual approach and data selection was based on the hierarchy of the EBHC pyramid. Unpublished data was considered for local epidemiological data and expert opinion for the identification of barriers to healthcare. An expert consensus based on the Delphi methodology was carried out. Experts were asked to respond on a 5-point Likert Scale to two provided answers to guiding questions.

RESULTS

Consensus was agreed on the answer for the questions with the higher median on the Likert scale and synthetized on 16 statements covering the definition of osteoporosis, diagnostic approach, treatment options, and follow-up. Besides clinical topics, unmet needs in osteoporosis were identified in relation to local epidemiological data, barriers to treatment, and misclassification of programs within health systems.

CONCLUSIONS

Through a process based on recognized methodological tools, FELAEN's position on osteoporosis was developed. This made it possible to state an optimum scenario for the care of the disease and helped to identify knowledge gaps. There is great variability in the approach to osteoporosis in Latin America and barriers in all the stages of healthcare persist.