A Method for Cytogenetic and Cytological Examination of Small Shelled Larvae of Bivalves and Other Zooplankton

Studies on chromosomes and nuclei of very small bivalve larvae have been impeded by the veliger shell. It has been determined that the alcohokacetic acid fixative commonly used in cytogenetic techniques can be made to act as a decalcifying agent upon repeated heating. In addition, transfer of formalin fixed shelled specimens, routinely used as marine bioassay organisms, into ethyl alcohohacetic acid (3:1) fixative also yields clear cells for cytological examination of decalcified but otherwise intact oyster larvae and other zoo-plankton. Identification of cell type, such as germ-line primordia, in, for example, reproductive and ploidy level studies, and observations on the presence of bacteria can be made from the preparations. Material can be examined up to at least a year after preservation. The method is evaluated and its modifications are discussed.     

Initiation and characterization of five embryonic cell lines from the cotton boll weevil anthonomus grandis in a commercial serum- free medium

Summary Five continuous cell lines were initiated from embryonic tissue of the cotton boll weevilAnthonomus grandis Boheman in a commercially available, serum-free medium (Excell 401) and have undergone in excess of 60 passages. Isoenzyme analysis confirmed that the lines originated from boll weevil tissue. Four of the lines grew as single attached cells of either epithelioid or fibroblastoid morphology. The fifth line, BRL-AG-2, grew primarily as cell aggregates and was found to release ecdysteroids (primarily ecdysone) into the culture medium. Evidence was also obtained suggesting that line BRL-AG-2 synthesizes chitin. Three lines, BRL-AG-1, BRL-AG-3A, and BRL-AG-3C, could be induced to produce an antibacterial factor(s) which was released into the culture medium.     

The circulatory small non-coding RNA landscape in community-acquired pneumonia on intensive care unit admission

Community-acquired pneumonia (CAP) is a major cause of sepsis. Despite several clinical trials targeting components of the inflammatory response, no specific treatment other than antimicrobial therapy has been approved. This argued for a deeper understanding of sepsis immunopathology, in particular factors that can modulate the host response. Small non-coding RNA, for example, micro (mi)RNA, have been established as important modifiers of cellular phenotypes. Notably, miRNAs are not exclusive to the intracellular milieu but have also been detected extracellular in the circulation with functional consequences. Here, we sought to determine shifts in circulatory small RNA levels of critically ill patients with CAP-associated sepsis and to determine the influence of clinical severity and causal pathogens on small RNA levels. Blood plasma was collected from 13 critically ill patients with sepsis caused by CAP on intensive care unit admission and from 5 non-infectious control participants. Plasma small RNA-sequencing identified significantly altered levels of primarily mature miRNAs in CAP relative to controls. Pathways analysis of high or low abundance miRNA identified various over-represented cellular biological pathways. Analysis of small RNA levels against common clinical severity and inflammatory parameters indices showed direct and indirect correlations. Additionally, variance of plasma small RNA levels in CAP patients may be explained, at least in part, by differences in causal pathogens. Small nuclear RNA levels were specifically altered in CAP due to Influenza infection in contrast to Streptococcus pneumoniae infection. Pathway analysis of plasma miRNA signatures unique to Influenza or Streptococcus pneumoniae infections showed enrichment for specific proteoglycan, cell cycle, and immunometabolic pathways.     

The Drosophila Platelet-derived Growth Factor and Vascular Endothelial Growth Factor-Receptor Related (Pvr) Protein Ligands Pvf2 and Pvf3 Control Hemocyte Viability and Invasive Migration

Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) family members are essential and evolutionary conserved determinants of blood cell development and dispersal. In addition, VEGFs are integral to vascular growth and permeability with detrimental contributions to ischemic diseases and metastatic cancers. The PDGF/VEGF-receptor related (Pvr) protein is implicated in the migration and trophic maintenance of macrophage-like hemocytes in Drosophila melanogaster embryos. pvr mutants have a depleted hemocyte population and a breakdown in hemocyte distribution. Previous studies suggested redundant functions for the Pvr ligands, Pvf2 and Pvf3 in the regulation of hemocyte migration, proliferation, and size. However, the precise roles that Pvf2 and Pvf3 play in hematopoiesis remain unclear due to the lack of available mutants. To determine Pvf2 and Pvf3 functions in vivo, we generated a genomic deletion that simultaneously disrupts Pvf2 and Pvf3. From our studies, we identified contributions of Pvf2 and Pvf3 to the Pvr trophic maintenance of hemocytes. Furthermore, we uncovered a novel role for Pvfs in invasive migrations. We showed that Pvf2 and Pvf3 are not required for the directed migration of hemocytes, but act locally in epithelial cells to coordinate trans-epithelial migration of hemocytes. Our findings redefine Pvf roles in hemocyte migration and highlight novel Pvf roles in hemocyte invasive migration. These new parallels between the Pvr and PDGF/VEGF pathways extend the utility of the Drosophila embryonic system to dissect physiological and pathological roles of PDGF/VEGF-like growth factors.     

Extracellular Heat Shock Protein 90 Signals through Subdomain II and the NPVY Motif of LRP-1 Receptor to Akt1 and Akt2: a Circuit Essential for Promoting Skin Cell Migration In Vitro and Wound Healing In Vivo

Normal cells secrete heat shock protein 90 alpha (Hsp90α) in response to tissue injury. Tumor cells have managed to constitutively secrete Hsp90α during invasion and metastasis. The sole function of extracellular Hsp90α (eHsp90α) is to promote cell motility, a critical event for both wound healing and tumor progression. The mechanism of promotility action by eHsp90α, however, has remained elusive. A key issue is whether eHsp90α still acts as a chaperone outside the cells or is a new and bona fide signaling molecule. Here, we have provided evidence that eHsp90α utilizes a unique transmembrane signaling mechanism to promote cell motility and wound healing. First, subdomain II in the extracellular part of low-density lipoprotein receptor-related protein 1 (LRP-1) receives the eHsp90α signal. Then, the NPVY but not the NPTY motif in the cytoplasmic tail of LRP-1 connects eHsp90α signaling to serine 473 but not threonine 308 phosphorylation in Akt kinases. Individual knockdown of Akt1, Akt2, or Akt3 revealed the importance of Akt1 and Akt2 in eHsp90α-induced cell motility. Akt gene rescue experiments suggest that Akt1 and Akt2 work in concert, rather than independently, to mediate eHsp90α promotility signaling. Finally, Akt1 and Akt2 knockout mice showed impaired wound healing that cannot be corrected by topical application with the eHsp90α protein.