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Researchers have developed a method for scientists to track a single blood stem cell in a live organism and then describe the ultrastructure, or architecture, of that same cell using electron microscopy. For the first time, researchers can get a high-resolution view of single blood stem cells thanks to a little help from microscopy and zebrafish. Researchers at the University of Wisconsin-Madison and the University of California San Diego have developed a method for scientists to track a single blood stem cell in a live organism and then describe the ultrastructure, or architecture, of that same cell using electron microscopy. This new technique will aid researchers as they develop therapies for blood diseases and cancers. "Currently, we look at stem cells in tissues with a limited number of markers and at low resolution, but we are missing so much information," says Owen Tamplin, an assistant professor in UW-Madison's Department of Cell & Regenerative Biology, a member of the Stem Cell & Regenerative Medicine Center, and a co-author on the new study, which was published Aug. 9 in eLife. "Using our new techniques, we can now see not only the stem cell, but also all the surrounding niche cells that are in contact." The niche is a microenvironment found within tissues like the bone marrow that contain the blood stem cells that support the blood system. The niche is where specialized interactions between blood stem cells and their neighboring cells occur every second, but these interactions are hard to track and not clearly understood. As a part of the new study, Tamplin and his co-lead author, Mark Ellisman, a professor of neuroscience at UC San Diego, identified a way to integrate multiple types of microscopic imaging to investigate a cell's niche. With the newly developed technique that uses confocal microscopy, X-ray microscopy, and serial block-face scanning electron microscopy, researchers will now be able to track the once elusive cell-cell interactions occurring in this space. "This has allowed us to identify cell types in the microenvironment that we didn't even know interacted with stem cells, which is opening new research directions," Tamplin says. As a part of this study, Tamplin, and his colleagues, including co-first authors Sobhika Agarwala and Keunyoung Kim, identified dopamine beta-hydroxylase positive ganglia cells, which were previously an uncharacterized cell type in the blood stem cell niche. This is crucial, as understanding the role of neurotransmitters like dopamine in regulating blood stem cells could lead to improved therapeutics. "Transplanted blood stem cells are used as a curative therapy for many blood diseases and cancers, but blood stem cells are very rare and difficult to locate in a living organism," Tamplin says. "That makes it very challenging to characterize them and understand how they interact and connect with neighboring cells." While blood stem cells are difficult to locate in most living organisms, the zebrafish larva, which is transparent, offers researchers a unique opportunity to view the inner workings of the blood stem cell niche more easily. "That's the really nice thing about the zebrafish and being able to image the cells," Tamplin says of animal's transparent quality. "In mammals, blood stem cells develop in utero in the bone marrow, which makes it basically impossible to see those events happening in real time. But, with zebrafish you can actually watch the stem cell arrive through circulation, find the niche, attach to it, and then go in and lodge there." While the zebrafish larva makes it easier to see blood stem cell development, specialized imaging is needed to find such small cells and then detail their ultrastructure. Tamplin and his colleagues spent over six years perfecting these imaging techniques. This allowed them to see and track the real-time development of a blood stem cell in the microenvironment of a live organism, then zoom in even further on the same cell using electron microscopy. "First, we identified single fluorescently labeled stem cells by light sheet or confocal microscopy," Tamplin says. "Next, we processed the same sample for serial block-face scanning electron microscopy. We then aligned the 3D light and electron microscopy datasets. By intersecting these different imaging techniques, we could see the ultrastructure of single rare cells deep inside a tissue. This also allowed us to find all the surrounding niche cells that contact a blood stem cell. We believe our approach will be broadly applicable for correlative light and electron microscopy in many systems." Tamplin hopes that this approach can be used for many other types of stem cells, such as those in the gut, lung, and the tumor microenvironment, where rare cells need to be characterized at nanometer resolution. But, as a developmental biologist, Tamplin is especially excited to see how this work can improve researchers' understanding of how the blood stem cell microenvironment forms. "I think this is really exciting because we generate all of our blood stem cells during embryonic development, and depending on what organism you are, a few hundred or maybe a few thousand of these stem cells will end up producing hundreds of billions of new blood cells every day throughout your life," Tamplin says. "But we really don't know much about how stem cells first find their home in the niche where they're going to be for the rest of the life of the organism. This research will really help us to understand how stem cells behave and function. A better understanding of stem cell behavior, and regulation by surrounding niche cells, could lead to improved stem cell-based therapies." This research was supported by grants from the National Institutes of Health (R01HL142998, K01DK103908, 1U24NS120055-01, R24 GM137200) and the American Heart Association (19POST34380221).

Los Angeles, USA, Aug. 24, 2021 (GLOBE NEWSWIRE) -- Pulmonary Arterial Hypertension Pipeline Insight Research Report Around 55+ key companies are developing therapies for Pulmonary Arterial Hypertension, among which the drug of Liquidia Technologies is in the advanced stage (Pre Registration) DelveInsight’s “Pulmonary Arterial Hypertension (PAH) Pipeline Insight” report provides comprehensive insights about 55+ companies and 55+ pipeline drugs in the Pulmonary Arterial Hypertension pipeline landscapes. It comprises Pulmonary Arterial Hypertension pipeline drug profiles, including clinical and non-clinical stage products. It also includes the Pulmonary Arterial Hypertension therapeutics assessment by product type, stage, route of administration, and molecule type and further highlights the inactive Pulmonary Arterial Hypertension pipeline products. Some of the key takeaways from the Pulmonary Arterial Hypertension Pipeline Report Get an overview of pipeline landscape @ Pulmonary Arterial Hypertension Clinical Trials Analysis Pulmonary Arterial Hypertension (PAH) is a rare, progressive disorder characterized by high blood pressure in the arteries of the lungs for no apparent reason. Pulmonary Arterial Hypertension Emerging Drugs Sotatercept is a first-in-class therapeutic fusion protein composed of the extracellular domain of human activin receptor type IIA, fused to the Fc domain of human immunoglobulin G1 (IgG1). The United States Food and Drug Administration (FDA) has granted Orphan Drug designation and Breakthrough Therapy designation to sotatercept for the treatment of PAH; the European Medicines Agency (EMA) has granted Priority Medicines (PRIME) designation to sotatercept for the treatment of PAH. Sotatercept is in Phase III clinical trials for the treatment of PAH. LIQ861 is an investigational, inhaled dry powder formulation of treprostinil designed using the Company’s novel PRINT technology and engineered to enhance deep-lung delivery of treprostinil in PAH patients using a convenient, palm-sized dry powder inhaler. Liquidia resubmits New Drug Application for LIQ861 under the 505(b)(2) regulatory pathway for the treatment of pulmonary arterial hypertension (PAH). Gossamer Bio is developing Seralutinib (GB002) for the treatment of Pulmonary Arterial Hypertension. It is currently in the Phase II stage of development (NCT04456998). It acts as an inhibitor of Platelet-derived growth factor receptors,  CSF1R, c-KIT. Bial is developing Zamicastat for the treatment of Pulmonary Arterial Hypertension. It is currently in the Phase II stage of development (NCT04316143).  It acts as an inhibitor of Dopamine beta-hydroxylase. For further information, refer to the detailed report @ Pulmonary Arterial Hypertension Pipeline Therapeutics Scope of Pulmonary Arterial Hypertension Pipeline Drug Insight ·       Pulmonary Arterial Hypertension Therapies Late-stage (Phase III)  ·       Pulmonary Arterial Hypertension Therapies Mid-stage (Phase II)·       Pulmonary Arterial Hypertension Therapies Early-stage (Phase I) ·       Pulmonary Arterial Hypertension Preclinical stage and Discovery candidates     ·       Discontinued and Inactive candidates ·      Epoprostenol receptor agonists·      Activin inhibitors·      Platelet-derived growth factor receptor antagonists·      Dopamine beta-hydroxylase inhibitors·      Vasoactive intestinal peptide type II receptor agonists·      Angiogenesis inhibitors; Bcr-abl tyrosine kinase inhibitors ·      Cyclin-dependent kinase 4 inhibitors; Cyclin-dependent kinase 6 inhibitors·      Galectin 3 inhibitors ·     Peptides·     Monoclonal antibodies·    Small molecules ·    Proteins·    Gene therapy ·     Parenteral ·      Oral·      Intravenous·      Subcutaneous ·       Monotherapy·       Combination·       Mono/Combination Key Questions regarding Current Pulmonary Arterial Hypertension Treatment Landscape and Emerging Therapies Answered in the Pipeline Report Table of Contents Get a customized pipeline report @ Pulmonary Arterial Hypertension Drugs Pipeline Report Other Reports About DelveInsightDelveInsight is a leading Business Consultant, and Market Research firm focused exclusively on life sciences. It supports Pharma companies by providing comprehensive end-to-end solutions to improve their performance. It also provides Healthcare Consulting services comprising credible market analysis that will help accelerate the business growth and overcome challenges with a practical approach.