Beata Machnicka

Spectrin-based skeleton as an actor in cell signaling.

This review focuses on the recent advances in functions of spectrins in non-erythroid cells. We discuss new data concerning the commonly known role of the spectrin-based skeleton in control of membrane organization, stability and shape, and tethering protein mosaics to the cellular motors and to all major filament systems. Particular effort has been undertaken to highlight recent advances linking spectrin to cell signaling phenomena and its participation in signal transduction pathways in many cell types.

Spectrins: A structural platform for stabilization and activation of membrane channels, receptors and transporters☆

This review focuses on structure and functions of spectrin as a major component of the membrane skeleton. Recent advances on spectrin function as an interface for signal transduction mediation and a number of data concerning interaction of spectrin with membrane channels, adhesion molecules, receptors and transporters draw a picture of multifaceted protein. Here, we attempted to show the current depiction of multitask role of spectrin in cell physiology. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.

microRNAs: fine tuning of erythropoiesis

Cell proliferation and differentiation is a complex process involving many cellular mechanisms. One of the best-studied phenomena in cell differentiation is erythrocyte development during hematopoiesis in vertebrates. In recent years, a new class of small, endogenous, non-coding RNAs called microRNAs (miRNAs) emerged as important regulators of gene expression at the post-transcriptional level. Thousands of miRNAs have been identified in various organisms, including protozoa, fungi, bacteria and viruses, proving that the regulatory miRNA pathway is conserved in evolution. There are many examples of miRNA-mediated regulation of gene expression in the processes of cell proliferation, differentiation and apoptosis, and in cancer genesis. Many of the collected data clearly show the dependence of the proteome of a cell on the qualitative and quantitative composition of endogenous miRNAs. Numerous specific miRNAs are present in the hematopoietic erythroid line. This review attempts to summarize the state of knowledge on the role of miRNAs in the regulation of different stages of erythropoiesis. Original experimental data and results obtained with bioinformatics tools were combined to elucidate the currently known regulatory network of miRNAs that guide the process of differentiation of red blood cells.

Spectrin and phospholipids - the current picture of their fascinating interplay.

The spectrin-based membrane skeleton is crucial for the mechanical stability and resilience of erythrocytes. It mainly contributes to membrane integrity, protein organization and trafficking. Two transmembrane protein macro-complexes that are linked together by spectrin tetramers play a crucial role in attaching the membrane skeleton to the cell membrane, but they are not exclusive. Considerable experimental data have shown that direct interactions between spectrin and membrane lipids are important for cell membrane cohesion. Spectrin is a multidomain, multifunctional protein with several distinctive structural regions, including lipid-binding sites within CH tandem domains, a PH domain, and triple helical segments, which are excellent examples of ligand specificity hidden in a regular repetitive structure, as recently shown for the ankyrin-sensitive lipid-binding domain of beta spectrin. In this review, we summarize the state of knowledge about interactions between spectrin and membrane lipids.

A novel L1340P mutation in the ANK1 gene is associated with hereditary spherocytosis

Carbonnel, F., Lavergne, A., Messing, B., Tsapis, A., Berger, R., Galian, A., Nemeth, J., Brouet, J.C. & Rambaud, J.C. (1994) Extensive small intestinal T-cell lymphoma of low-grade malignancy associated with a new chromosomal translocation. Cancer, 73, 1286–1291. Carbonnel, F., d’Almagne, H., Lavergne, A., Matuchansky, C., Brouet, J.C., Sigaux, F., Beaugerie, L., Nemeth, J., CoYn, B., Cosnes, J., Gendre, J.P. & Rambaud, J.C. (1999) The clinicopathological features of extensive small intestinal CD4 T cell infiltration. Gut, 45, 662– 667. Egawa, N., Fukayama, M., Kawaguchi, K., Hishima, T., Hayashi, Y., Funata, N., Ibuka, T., Koike, M., Miyashita, H. & Tajima, T. (1995) Relapsing oral and colonic ulcers with monoclonal T-cell infiltration. A low grade mucosal T-lymphoproliferative disease of the digestive tract. Cancer, 75, 1728–1733. Hirakawa, K., Fuchigami, T., Nakamura, S., Daimaru, Y., Ohshima, K., Sakai, Y. & Ichimaru, T. (1996) Primary Gastrointestinal T-cell lymphomas resembling multiple lymphomatous polyposis. Gastroenterology, 111, 778–782. Isaacson, P.G., Chott, A., Ott, G. & Stein, H. (2008). Enteropathy-associated T-cell lymphoma. In: WHO Classification of Tumours of the Haematopoietic and Lymphoid Tissues (ed. by S.H. Swerdlow, E. Campo, N.L. Harris, E.S. Jaffe, S.A. Pileri, H. Stein, J. Thiele & J.W. Vardiman), 4th ed. pp. 289–291. IARC, Lyon. Malamut, G., Meresse, B., Kaltenbach, S., Derrieux, C., Verkarre, V., Macintyre, E., Ruskone-Fourmestraux, A., Fabiani, B., Radford-Weiss, I., Brousse, N., Hermine, O., Cerf-Bensussan, N. & Cellier, C. (2014) Small intestinal CD4 T-cell lymphoma is a heterogeneous entity with common pathology features. Clinical Gastroenterology and Hepatology, 12, 599–608. Margolskee, E., Jobanputra, V., Lewis, S.K., Alobeid, B., Green, P.H. & Bhagat, G. (2013) Indolent Small Intestinal CD4 + T-cell lymphoma is a distinct entity with unique biologic and clinical features. PLoS ONE, 8, e68343. Perry, A.M., Warnke, R.A., Hu, Q., Gaulard, P., Copie-Bergman, C., Alkan, S., Wang, H.Y., Cheng, J.X., Bacon, C.M., Delabie, J., Ranheim, E., Kucuk, C., Hu, X., Weisenburger, D.D., Jaffe, E.S. & Chan, W.C. (2013) Indolent T-cell lymphoproliferative disease of the gastrointestinal tract. Blood, 122, 3599–3606. Svrcek, M., Garderet, L., Sebbagh, V., Rosenzwajg, M., Parc, Y., Lagrange, M., Bennis, M., Lavergne-Slove, A., Fl ejou, J.F. & Fabiani, B. (2007) Small intestinal CD4 + T-cell lymphoma: a rare distinctive clinicopathological entity associated with prolonged survival. Virchows Archiv, 451, 1091–1093. Epub 2007, Aug 3. Zivny, J., Banner, B.F., Agrawal, S., Pihan, G. & Barnard, G.F. (2004) CD4 + T-cell Lymphoproliferative disorder of the gut clinically mimicking celiac sprue. Digestive Diseases and Sciences, 49, 551–555.

αII-spectrin in T cells is involved in the regulation of cell-cell contact leading to immunological synapse formation?

T-lymphocyte activation after antigen presentation to the T-Cell Receptor (TCR) is a critical step in the development of proper immune responses to infection and inflammation. This dynamic process involves reorganization of the actin cytoskeleton and signaling molecules at the cell membrane, leading to the formation of the Immunological Synapse (IS). The mechanisms regulating the formation of the IS are not completely understood. Nonerythroid spectrin is a membrane skeletal protein involved in the regulation of many cellular processes, including cell adhesion, signaling and actin cytoskeleton remodeling. However, the role of spectrin in IS formation has not been explored. We used molecular, imaging and cellular approaches to show that nonerythroid αII-spectrin redistributes to the IS during T-cell activation. The redistribution of spectrin coincides with the relocation of CD45 and LFA-1, two components essential for IS formation and stability. We assessed the role of spectrin by shRNA-mediated depletion from Jurkat T cells and show that spectrin-depleted cells exhibit decreased adhesion and are defective in forming lamellipodia and filopodia. Importantly, IS formation is impaired in spectrin-depleted cells. Thus, spectrin may be engaged in regulation of distinct events necessary for the establishment and maturity of the IS: besides the involvement of spectrin in the control of CD45 and LFA-1 surface display, spectrin acts in the establishment of cell-cell contact and adhesion processes during the formation of the IS.

A new frameshift mutation of the β-spectrin gene associated with hereditary spherocytosis.

Dear Editor, Hereditary spherocytosis (HS) is the most frequent congenital haemolytic anaemia in Caucasians. β-spectrin defects are typically inherited in an autosomal dominant manner with the clinical presentation of HS [5, 9].We report on a newmutation in the SPTB gene (466insG) leading to a frameshift and a premature stop codon 29 codons downstream in the region encoding the C-terminal part of the dimerization domain. Most probably, instability of mutant mRNA results in spectrin deficiency and clinically moderate to serious HS. The N-terminal region of the β-spectrin subunit consists of actin-binding domain and located downstream the dimerization domain consisting of the first two spectrin repeats. During our studies on HS cases in the population of Western Poland, we found a new mutation in a family with autosomal dominant HS [2–4]. Patients with moderate symptoms of the disease were recruited: mother (C10, splenectomized) and children (C14, C9), age ranged from 27 to 67 years. Diagnostic criteria for HS were based on typical features: spherocytes on peripheral blood smears, increased osmotic fragility, splenomegaly, increased bilirubin, reticulocytosis, anaemia and symptoms of gallstone disease (Supplemental Table I). The Ethics Committee of the Medical University of Wroclaw approved the study protocol. Informed consent was obtained from all patients and healthy individuals serving as a control before entering the protocol. Molecular genetic analyses of the studied patients and the unaffected family members were performed. The nucleotide sequence of the ANK1, SPTB and SLC4A1 genes were amplified by PCR from genomic DNA. During DNA analysis of these genes, several common polymorphisms were encountered (Supplemental Table II). DNA sequencing revealed that all of the studied patients were heterozygous for novel mutation 466insG in the exon 11 of the SPTB gene (Fig. 1a, b). RBC membrane protein gel electrophoresis demonstrated deficiency of some membrane proteins: β-spectrin and ankyrin-1, thereby supporting the diagnosis of HS (data not shown). Immunoblotting of erythrocyte membrane ghosts from C14 and C10 patients with this mutation with antibody recognising an actin binding domain of βspectrin [10] could not detect a truncated protein (data not shown), suggesting that this mutant transcript might be unstable. Electronic supplementary material The online version of this article (doi:10.1007/s00277-016-2838-0) contains supplementary material, which is available to authorized users.

[Liposomes as non-viral carriers for genetic drugs].

Methods in cancer therapy particularly in recent years, are rapidly changing, due to the need of design of new, more effective therapeutic strategies. Very promising approach to treatment of the neoplastic diseases is antisense gene therapy. Due to the low toxicity of treatment and eliminating not only the symptoms but also the molecular causes of the disease it may represent a breakthrough in cancer therapies. Delivery of a therapeutic DNA or RNA oligonucleotides to the target cells in vivo requires suitable carrier system. Non-viral drug carriers are increasingly used in new systems of targeted gene therapy. This review presents new generation of non-viral carriers, and is focused on immunoliposomes finding potential application in targeted gene therapy.