Heavy Metal Exposure-Mediated Dysregulation of Sphingolipid Metabolism.

Exposure to heavy metals (HMs) is often associated with inflammation and cell death, exacerbating respiratory diseases including asthma. Most inhaled particulate HM exposures result in the deposition of HM-bound fine particulate matter, PM, in pulmonary cell populations. While localized high concentrations of HMs may be a causative factor, existing studies have mostly evaluated the effects of systemic or low-dose chronic HM exposures.

Altered sphingolipid pathway in SARS-CoV-2 infected human lung tissue.

Introduction: The SARS-CoV-2 mediated COVID-19 pandemic has impacted millions worldwide. Hyper-inflammatory processes, including cytokine storm, contribute to long-standing tissue injury and damage in COVID-19. The metabolism of sphingolipids as regulators of cell survival, differentiation, and proliferation has been implicated in inflammatory signaling and cytokine responses.

Different mechanisms of calcium entry within different dendritic compartments.

From our experiments combining in vivo calcium imaging and electrophysiology on fly vertical motion-sensitive cells (VS-cells) during visual stimulation, we infer different mechanisms of calcium entry within different dendritic compartments; while in the main dendritic branches calcium influx from extracellular space takes place only via voltage-activated calcium channels (VACCs), calcium enters the dendritic tips through VACCs as well as nicotinic acetylcholine receptors (nAChRs). Consequently, neuronal nACHRs of insects have to be assumed to be permeable to some extent for calcium under in vivo conditions.

Local current spread in electrically compact neurons of the fly.

Analyses of active and passive membrane properties predict an asymmetry in the spread of electrical current through a neuron. Simulated current injection into a large-diameter compartment of a biophysically realistic model neuron causes a local potential shift that can spread throughout the cell. In contrast, causing the same local potential shift in the dendritic tip of the same neuron results in only minimal changes in electrical potential in the rest of the cell.