Biology subjects

Giordano, T.

Publications and source records attributed to Giordano, T..

3 recordsLinked to original sources

bioRxiv2024

Somatic Mutations in MCOLN3 in Aldosterone-Producing Adenomas cause Primary Aldosteronism.

Primary aldosteronism is characterized by renin-independent hyperaldosteronism that originates from aldosterone-producing lesions in the adrenal glands. Under physiological conditions, aldosterone synthase (CYP11B2) expression is confined to the adrenal zona glomerulosa where it catalyzes the final reaction yielding aldosterone. The regulation of CYP11B2 transcription depends on the control of cellular membrane potential and cytosolic calcium activity. In primary aldosteronism, aldosterone-producing adenomas (APAs) are characterized by disrupted regulation of CYP11B2 expression resulting in autonomous biosynthesis of aldosterone. These lesions often harbor aldosterone-driver somatic mutations in genes encoding ion transporters/channels/pumps that increase cytosolic calcium activity causing increased CYP11B2 expression and aldosterone biosynthesis. We investigated APAs devoid of known somatic mutations and detected a missense mutation and a deletion-insertion variant in MCOLN3 which encodes for mucolipin-3 (TRPML3) -- a highly conserved inwardly-rectifying, cation-permeable channel. These MCOLN3 mutations were identified in three APAs derived from male patients with primary aldosteronism: p. Y391D and p.N411_V412delinsI. Both mutations are located near the ion pore and selectivity filter of TRPML3. This is the first report of disease-causing MCOLN3 mutations in humans. Functional studies suggest MCOLN3Y391D might directly or indirectly via membrane depolarization alter calcium influx of transfected adrenocortical cells, resulting in increased CYP11B2 transcription and aldosterone production. This study implicates mutated MCOLN3 as a driver of aldosterone excess in primary aldosteronism. Significance StatementPrimary aldosteronism is a common but under-diagnosed endocrine disease that contributes to global hypertension burden and cardiovascular mortality and morbidity. Hyperaldosteronism in primary aldosteronism is mainly caused by adrenal lesions harboring somatic mutations that disrupt intracellular calcium levels and consequently aldosterone synthase expression and aldosterone production. Majority of these mutations have been identified in genes encoding ion transporters/channels/pumps. Herein, we report the first disease-causing somatic mutations in human MCOLN3 in aldosterone-producing adenomas (APAs) devoid of known mutations. In vitro investigations showed the MCOLN3 variant (p.Y391D) caused an influx of cytosolic calcium in adrenocortical cells and the subsequent increase in aldosterone synthase and aldosterone biosynthesis.

genetics↗

bioRxiv2023

Discovery of Novel Small Molecule CB2 Agonist for the Treatment of Glioblastoma Tumors

Malignant brain tumors cause over 15,000 deaths per year in the United States. Survival for over five years is only 36%. Nearly 49% of malignant brain tumors are glioblastomas (GBM), and 30% of them have the ability to diffuse and infiltrate. Treatment frequently includes surgery, radiotherapy and chemotherapy. In case of GBM patients, combining temozolomide (TMZ) chemotherapy with radiation improved survival over radiotherapy alone (survival by 2 years: 17% vs. 11%; 5 years: 10% vs. 2%). Most primary GBM tumors from pediatric and adult patients express high levels of cannabinoid type II (CB2) receptors, and that expression correlated with tumor grade. Cannabinoids like (-)-trans-{Delta}9-tetrahydrocannabinol ({Delta}9-THC) were shown to suppress GBM tumor growth, trigger apoptosis in GBM stem cells, and slow down angiogenesis, thus cutting GBM cells off of blood supply. These data led to local administration of {Delta}9-THC in clinical trials in patients with recurrent glioblastomas, although the well-known psychotropic effects of {Delta}9 -THC and related compounds mediated via the CB1 receptors have raised some concerns among clinicians. Thus, the medicinal usage of cannabinoids has been limited. One leading strategy to avoid the side effects is administration of CB2-selective non-psychotic drugs. To create an effective solution, we designed a preclinical study to develop a novel GBM therapy, using NeuroTherapias lead molecule, the CB2 agonist NTRX-07. We have already demonstrated that NTRX-07 ameliorates Amyloid {beta} production and deposition in the hippocampus, and thus restored Long-Term Potentiation - the cellular mechanism for learning and memory formation. Consequently, we showed that NTRX-07 has a highly competitive target compound profile, and that is safe in murine models, dogs and humans. NTRX-07 has entered clinical trials for the management of AD as the first orally available CB2 agonist designed to be centrally active. The phase I single ascending dose study in normal volunteers demonstrated targeted plasma levels of the drug after oral administration with no serious adverse events or clinically significant changes in safety examinations or laboratory tests. In this pilot mouse GBM survival study, we found breakthrough evidence that our compound can exert potent anti-cancer activity and significantly extend the survival of GBM animals; even without previously exposing them to radiotherapy or TMZ. Our goal is to bring NTRX-07 into the clinic as a new therapeutic for patients with GBM.

neuroscience↗

bioRxiv2022

Human cartilage progenitor cells from ear, nose, rib, and joint have a robust, stable phenotype for cartilage repair

BackgroundCartilage progenitor cells (CPCs) are a small but highly proliferative cell population that resides within cartilage. Joint cartilage CPCs have a high chondrogenic potential and superior cartilage formation characteristics; however, CPCs from other cartilage sources more accessible for translation such as ear, nose, and rib are broadly unexplored. Our study illuminates the differences between CPCs from these four cartilages, their corresponding tissue chondrocyte (CC), and bone marrow-derived mesenchymal stem cell (MSC). MethodsCPCs subtypes were isolated from pediatric cartilage via fibronectin selection, immunophenotyped by flow cytometry and compared to MSCs. Trilineage differentiation capacity was assessed via histology and qRT-PCR. Next, triiodothyronine was used to hypertrophically challenge each CPC subset and their corresponding chondrocyte population. After 28 days cartilage pellets were assessed via histology, immunohistochemistry, and qRT-PCR. FindingsEach CPC subset possessed a specific immunophenotypic signature with CD56 as a potential common marker. All CPC subsets proliferated 2-fold faster than MSCs and 4-fold faster than CCs. Additionally, CPCs had a substantially reduced propensity for osteogenic differentiation and very limited adipogenic capacity by histology and gene expression. Finally, all CPC subsets resisted the hypertrophic challenge more than the corresponding chondrocyte population marked by less collagen X secretion and downregulation of hypertrophy associated genes. InterpretationCPCs represent a promising cell type for cartilage regeneration. The ease of accessibility of the ear and nose CPCs present opportunities for new translational approaches and reduced clinical timelines. FundingCHOP Research Institute, Frontier Program in Airway Disorders of CHOP, NIH (R21HL159521), NSF-GRFP (DGE-1845298)

bioengineering↗