Biology subjects

Karbiener, M.

Publications and source records attributed to Karbiener, M..

4 recordsLinked to original sources

bioRxiv2022

Host-directed therapy with 2-Deoxy-D-glucose inhibits human rhinoviruses, endemic coronaviruses, and SARS-CoV-2

Rhinoviruses (RVs) and coronaviruses (CoVs) upregulate host cell metabolic pathways such as glycolysis to meet their bioenergetic demands for rapid multiplication. Using the glycolysis inhibitor 2-deoxy-D-glucose (2-DG), we assessed the dose-dependent inhibition of viral replication of minor- and major-receptor group RVs in epithelial cells. 2-DG disrupted RV infection cycle by inhibiting template negative-strand as well as genomic positive-strand RNA synthesis, resulting in less progeny virus and RV-mediated cell death. Assessment of 2-DGs intracellular kinetics revealed that after a short-exposure to 2-DG, the active intermediate, 2-DG6P, is stored intracellularly for several hours. Finally, we confirmed the antiviral effect of 2-DG on pandemic SARS-CoV-2 and showed for the first time that 2-DG also reduces replication of endemic human coronaviruses (HCoVs). These results provide further evidence that 2-DG could be utilized as a broad-spectrum antiviral. HIGHLIGHTSO_LI2-DG inhibits replication of minor- and major-group rhinoviruses in epithelial cells including human nasal epithelial cell. C_LIO_LI2-DG disrupts rhinovirus infection cycle and reduces rhinovirus-mediated cell death in vitro. C_LIO_LI2-DG treatment attenuates viral load of endemic coronaviruses in vitro. C_LI

microbiology↗

bioRxiv2021

The obesity-linked human lncRNA AATBC regulates adipocyte plasticity by stimulating mitochondrial dynamics and respiration

Adipocytes are critical regulators of metabolism and energy balance. While white adipocyte dysfunction is a hallmark of obesity-associated disorders, the activation of thermogenic brown and beige adipocytes is linked to improved cardiometabolic health. As adipocytes dynamically adapt to environmental cues by functionally switching between white and thermogenic phenotypes, a molecular understanding of this adipocyte plasticity could help improving energy balance and weight loss. Here, we show that the long non-coding RNA (lncRNA) Apoptosis associated transcript in bladder cancer (AATBC) is a human-specific regulator of adipocyte plasticity. Searching for new human lncRNAs implicated in adipocyte biology we compared transcriptional profiles of human adipose tissues and cultured adipocytes and discovered that AATBC was enriched in thermogenic conditions. Using primary human adipocytes and immortalized human adipocytes we found that gain-of-function of AATBC enhanced the thermogenic phenotype whereas loss-of-function diminished this effect. The AATBC-mediated increase in mitochondrial respiration was linked to a more fragmented mitochondrial network and vice versa. While we found that AATBC is predominantly located in the nucleus, its effect on global transcription was only marginal. As AATBC is specific to humans, we expressed AATBC in adipose tissue of mice to study its systemic impact, which led to lower plasma leptin levels. Interestingly, this association was also present in human subjects, as AATBC in adipose tissue was inversely correlated with plasma leptin levels, body mass index and other measures of metabolic health. In conclusion, AATBC is a novel obesity-linked regulator of adipocyte plasticity and mitochondrial function in humans.

molecular biology↗

bioRxiv2021

Rapidly Increasing SARS-CoV-2 Neutralization by Intravenous Immunoglobulins Produced from Plasma Collected During the 2020 Pandemic

Immunoglobulin (IG) lots (N=176) released since March 2020 were tested for SARS-CoV-2 neutralizing antibodies, with first positive results for September 2020 lots, mean = 1.8 IU/ml, 46% of lots positive. From there, values steadily increased, in correlation with the cumulative COVID-19 incidence, to reach a mean of 36.7 IU/ml and 93% of lots positive by January 2021. Extrapolating the correlation, IGs could reach an anti-SARS-CoV-2 potency of ~400 IU/ml by July 2021. At that stage, prophylactic IG treatment for primary/secondary immunodeficiency could contain similar doses of anti-SARS-CoV-2 as convalescent plasma which is used for treatment of COVID-19.

immunology↗

bioRxiv2020

No SARS-CoV-2 cross-neutralization by intravenous immunoglobulins produced from plasma collected before the 2020 pandemic

The 2020 SARS-CoV-2 pandemic is caused by a zoonotic coronavirus transmitted to humans, similar to earlier events. Whether the other, seasonally circulating coronaviruses induce cross-reactive, potentially even cross-neutralizing antibodies to the new species in humans is unclear. The question is of particular relevance for people with immune deficiencies, as their health depends on treatment with immunoglobulin preparations that need to contain neutralizing antibodies against the pathogens in their environment. Testing 54 IVIG preparations, produced from plasma collected in Europe and the US, highly potent neutralization of a seasonal coronavirus was confirmed, yet no cross-neutralization of the new SARS-CoV-2 was seen. SUMMARYIVIG products manufactured from pre-pandemic plasma do not neutralize SARS-CoV-2 but contain high neutralizing titers for seasonal coronavirus hCoV-229E.

immunology↗