Mesenchymal Stromal Cell Derived Extracellular Vesicles Reduce Hypoxia-lschaemia Induced Perinatal Brain Injury

Background: Neonatal hypoxic-ischemic (HI) insult is a leading cause of disability and death in newborns, with therapeutic hypothermia being the only currently available clinical intervention. Thus there is a great need for adjunct and novel treatments for enhanced or alternative post-HI neuroprotection. Extracellular vesicles (EVs) derived from mesenchymal stromal/stem cells (MSCs) have recently been shown to exhibit regenerative effects in various injury models. Here we present findings showing neuroprotective effects of MSC-derived EVs in the Rice–Vannucci model of severe HI-induced neonatal brain insult. Methods: Mesenchymal stromal/stem cell-derived EVs were applied intranasally immediately post HI-insult and behavioral outcomes were observed 48 h following MSC-EV treatment, as assessed by negative geotaxis. Brains were thereafter excised and assessed for changes in glial responses, cell death, and neuronal loss as markers of damage at 48 h post HI-insult. Results: Brains of the MSC-EV treated group showed a significant decrease in microglial activation, cell death, and percentage tissue volume loss in multiple brain regions, compared to the control-treated groups. Furthermore, negative geotaxis test showed improved behavioral outcomes at 48 h following MSC-EV treatment. Conclusion: Our findings highlight the clinical potential of using MSC-derived EVs following neonatal hypoxia-ischaemia

Inhibition of microvesiculation sensitizes prostate cancer cells to chemotherapy and reduces docetaxel dose required to limit tumor growth in vivo

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/Microvesicles shed from cells carry constituents of the cell cytoplasm, including, of importance in multidrug resistance to cancer chemotherapy, drugs that the tumor cell attempts to efflux. To see whether such drugs could be used at lower concentrations with the same efficacy, it was first shown that microvesiculation of prostate cancer (PCa) cells, PC3, could be inhibited pharmacologically with calpeptin (calpain inhibitor) and by siRNA (CAPNS1). In cells treated with docetaxel (DTX), this inhibition resulted in a third-fold increase in intracellular concentrations of DTX. As a result, 20-fold lower concentrations of DTX (5 nM) could be used, in the presence of calpeptin (20μM) inducing the same degree of apoptosis after 48 h in PC3 cells, as 100 nM of DTX alone. Inhibition of microvesiculation similarly improved combination chemotherapy (DTX and methotrexate). In a mouse xenograft model of PCa, DTX (0.1 mg/kg) together with calpeptin (10 mg/kg), administered i.p., significantly reduced tumor volumes compared to DTX alone (0.1 mg/kg) and brought about the same reductions in tumor growth as 10 mg/kg of DTX alone. As well as further reducing vascularization, it also increased apoptosis and reduced proliferation of PC3 cells in tumor xenografts.Peer reviewe

A Note on the Re-collection and Conservation of Thelypteris kingii (Thelypteridaceae) – an Endemic Fern of India

A rare and little known, endemic fern Thelypteris kingii C.F.Reed was first described from a 19th Century collection from an unspecified locality in what was then "British Sikkim", now Darjeeling District, India. Recently a small population of the plant was rediscovered by the author from present-day Sikkim State. Herbarium records and field study reveal that this species is very rare and under great threat of extinction due to natural and man-made impact. This species is therefore little known to pteridologists and is readily confused with the similar, but common species, T. mollissima (Kunze) N.Thapa as well as with another S. E. Asian species T. leptogrammoides (Ross.) C.F. Reed due to nomenclatural similarities or being later homonymous. Although only known so far from India, and thus an endemic Indian species, its presence in Tibet and China etc. is probably to be expected. A brief history of its discovery, taxonomy, morphology, habitat and ecology is presented here to assist taxonomists and conservation biologists with its identification and conservation. It has been identified as Endangered and Globally Threatened and efforts have also been made by the present author to include it in the forthcoming volume of the Red Data Book of Indian plants

Treatment of Prostate Cancer Using Deimination Antagonists and Microvesicle Technology

Cellular microvesicle (MV) release, which occurs in most eukaryotic cells, is also involved in cancer progression and has recently been associated with peptidylarginine deiminase (PAD)-driven protein deimination. Evidence points to the involvement of deiminated cytoskeletal proteins and changes in histone deimination in the mechanism of MV biogenesis. Elevated PAD expression observed in cancers may contribute to increased MV shedding from cancer cells and contribute to cancer progression. The use of pan-PAD inhibitor Cl-Amidine (Cl-Am) showed that, following the pharmacological inhibition of PAD-mediated deimination, cellular MV release was significantly reduced, rendering prostate cancer cells significantly more susceptible to chemotherapeutic drugs. Combined Cl-Am and methotrexate (MTX) treatment of prostate cancer cells increased the cytotoxic effect of MTX. Refined PAD inhibitors that selectively manipulate MV biogenesis may form part of novel combination therapies in cancer treatment

Label-free real-time acoustic sensing of microvesicle release from prostate cancer (PC3) cells using a Quartz Crystal Microbalance

Using a Quartz Crystal Microbalance with dissipation monitoring, QCM-D (label-free system) measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, we showed the attachment, over a 60 min period, of a monolayer of PC3 cells to the gold electrodes of the quartz crystal sensor, which had been rendered hydrophilic. That MVs were released upon BzATP stimulation of cells was confirmed by NTA analysis (average 250 nm diameter), flow cytometry, showing high phosphatidylserine exposition and by fluorescent (Annexin V Alexa Fluor® 488-positive) and electron microscopy. Over a period of 1000s (16.7 min) during which early apoptosis increased from 4% plateauing at 10% and late apoptosis rose to 2%, the Δf increased 20 Hz, thereupon remaining constant for the last 1000s of the experiment. Using the Sauerbrey equation, the loss in mass, which corresponded to the release of 2.36 × 106 MVs, was calculated to be 23 ng. We therefore estimated the mass of an MV to be 0.24 pg. With the deposition on the QCM-D of 3.5 × 107 MVs over 200s, the decrease in Δf (Hz) gave an estimate of 0.235 pg per MV.Peer reviewe

Microvesicles in Health and Disease

Microvesicles (or MVs) are plasma membrane-derived vesicles released from most eukaryotic cells constitutively during early apoptosis or at higher levels after chemical or physical stress conditions. This review looks at some of the functions of MVs in terms of intercellular communication and ensuant signal transduction, including the transport of proteins (unconventional protein export) as well as of mRNA and microRNA. MVs also have roles in membrane repair, the removal of misfolded proteins, and in the control of apoptosis. We also discuss the role MVs have been shown to have in invasive growth and metastasis as well as in hypoxia in tumours and cerebral ischaemia. The association of MVs in infectious and autoimmune disease is also summarised together with their possible use as therapeutic agents