Desmin: molecular interactions and putative functions of the muscle intermediate filament protein

Desmin is the intermediate filament (IF) protein occurring exclusively in muscle and endothelial cells. There are other IF proteins in muscle such as nestin, peripherin, and vimentin, besides the ubiquitous lamins, but they are not unique to muscle. Desmin was purified in 1977, the desmin gene was characterized in 1989, and knock-out animals were generated in 1996. Several isoforms have been described. Desmin IFs are present throughout smooth, cardiac and skeletal muscle cells, but can be more concentrated in some particular structures, such as dense bodies, around the nuclei, around the Z-line or in costameres. Desmin is up-regulated in muscle-derived cellular adaptations, including conductive fibers in the heart, electric organs, some myopathies, and experimental treatments with drugs that induce muscle degeneration, like phorbol esters. Many molecules have been reported to associate with desmin, such as other IF proteins (including members of the membrane dystroglycan complex), nebulin, the actin and tubulin binding protein plectin, the molecular motor dynein, the gene regulatory protein MyoD, DNA, the chaperone alphaB-crystallin, and proteases such as calpain and caspase. Desmin has an important medical role, since it is used as a marker of tumors' origin. More recently, several myopathies have been described, with accumulation of desmin deposits. Yet, after almost 30 years since its identification, the function of desmin is still unclear. Suggested functions include myofibrillogenesis, mechanical support for the muscle, mitochondrial localization, gene expression regulation, and intracellular signaling. This review focuses on the biochemical interactions of desmin, with a discussion of its putative functions.

Disintegrins: integrin selective ligands which activate integrin-coupled signaling and modulate leukocyte functions

Extracellular matrix proteins and cell adhesion receptors (integrins) play essential roles in the regulation of cell adhesion and migration. Interactions of integrins with the extracellular matrix proteins lead to phosphorylation of several intracellular proteins such as focal adhesion kinase, activating different signaling pathways responsible for the regulation of a variety of cell functions, including cytoskeleton mobilization. Once leukocytes are guided to sites of infection, inflammation, or antigen presentation, integrins can participate in the initiation, maintenance, or termination of the immune and inflammatory responses. The modulation of neutrophil activation through integrin-mediated pathways is important in the homeostatic control of the resolution of inflammatory states. In addition, during recirculation, T lymphocyte movement through distinct microenvironments is mediated by integrins, which are critical for cell cycle, differentiation and gene expression. Disintegrins are a family of low-molecular weight, cysteine-rich peptides first identified in snake venom, usually containing an RGD (Arg-Gly-Asp) motif, which confers the ability to selectively bind to integrins, inhibiting integrin-related functions in different cell systems. In this review we show that, depending on the cell type and the microenvironment, disintegrins are able to antagonize the effects of integrins or to act agonistically by activating integrin-mediated signaling. Disintegrins have proven useful as tools to improve the understanding of the molecular events regulated by integrin signaling in leukocytes and prototypes in order to design therapies able to interfere with integrin-mediated effects.

Determination of renal function in long-term heart transplant patients by measurement of urinary retinol-binding protein levels

Significant improvements have been noted in heart transplantation with the advent of cyclosporine. However, cyclosporine use is associated with significant side effects, such as chronic renal failure. We were interested in evaluating the incidence of long-term renal dysfunction in heart transplant recipients. Fifty-three heart transplant recipients were enrolled in the study. Forty-three patients completed the entire evaluation and follow-up. Glomerular (serum creatinine, creatinine clearance measured, and creatinine clearance calculated) and tubular functions (urinary retinol-binding protein, uRBP) were re-analyzed after 18 months. At the enrollment time, the prevalence of renal failure ranged from 37.7 to 54% according to criteria used to define it (serum creatinine > or = 1.5 mg/dL and creatinine clearance <60 mL/min). Mean serum creatinine was 1.61 ± 1.31 mg/dL (range 0.7 to 9.8 mg/dL) and calculated and measured creatinine clearances were 67.7 ± 25.9 and 61.18 ± 25.04 mL min-1 (1.73 m²)-1, respectively. Sixteen of the 43 patients who completed the follow-up (37.2%) had tubular dysfunction detected by increased levels of uRBP (median 1.06, 0.412-6.396 mg/dL). Eleven of the 16 patients (68.7%) with elevated uRBP had poorer renal function after 18 months of follow-up, compared with only eight of the 27 patients (29.6%) with normal uRBP (RR = 3.47, P = 0.0095). Interestingly, cyclosporine trough levels were not different between patients with or without tubular and glomerular dysfunction. Renal function impairment is common after heart transplantation. Tubular dysfunction, assessed by uRBP, correlates with a worsening of glomerular filtration and can be a useful tool for early detection of renal dysfunction.

A phonological and tonal analysis of Samue using Optimality Theory

The topic of the present doctoral dissertation is the analysis of the phonological and tonal structures of a previously largely undescribed language, namely Samue. It is a Gur language belonging to the Niger-Congo language phulym, which is spoken in Burkina Faso. The data were collected during the fieldwork period in a Sama village; the data include 1800 lexical items, thousands of elicited sentences and 30 oral texts. The data were first transcribed phonetically and then the phonological and tonal analyses were conducted. The results show that the phonological system of Samue with the phoneme inventory and phonological processes has the same characteristics as other related Gur languages, although some particularities were found, such as the voicing and lenition of stop consonants in medial positions. Tonal analysis revealed three level tones, which have both lexical and grammatical functions. A particularity of the tonal system is the regressive Mid tone spreading in the verb phrase. The theoretical framework used in the study is Optimality theory. Optimality theory is rarely used in the analysis of an entire language system, and thus an objective was to see whether the theory was applicable to this type of work. Within the tonal analysis especially, some language specific constraints had to be created, although the basic Optimality Theory principle is the universal nature of the constraints. These constraints define the well-formedness of the language structures and they are differently ranked in different languages. This study gives new insights about typological phenomena in Gur languages. It is also a fundamental starting point for the Samue language in relation to the establishment of an orthography. From the theoretical point of view, the study proves that Optimality theory is largely applicable in the analysis of an entire sound system.

Nitric oxide synthesis and biological functions of nitric oxide released from ruthenium compounds

During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO) as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC) modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP) production, which in turn leads to protein kinase G (PKG) activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS) activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described.

Silencing HIF-1α reduces the adhesion and secretion functions of acute leukemia hBMSCs

Hypoxia inducible factor-1α (HIF-1α) is an important transcription factor, which plays a critical role in the formation of solid tumor and its microenviroment. The objective of the present study was to evaluate the expression and function of HIF-1α in human leukemia bone marrow stromal cells (BMSCs) and to identify the downstream targets of HIF-1α. HIF-1α expression was detected at both the RNA and protein levels using real-time PCR and immunohistochemistry, respectively. Vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1α (SDF-1α) were detected in stromal cells by enzyme-linked immunosorbent assay. HIF-1α was blocked by constructing the lentiviral RNAi vector system and infecting the BMSCs. The Jurkat cell/BMSC co-cultured system was constructed by putting the two cells into the same suitable cultured media and conditions. Cell adhesion and secretion functions of stromal cells were evaluated after transfection with the lentiviral RNAi vector of HIF-1α. Increased HIF-1α mRNA and protein was detected in the nucleus of the acute myeloblastic and acute lymphoblastic leukemia compared with normal BMSCs. The lentiviral RANi vector for HIF-1α was successfully constructed and was applied to block the expression of HIF-1α. When HIF-1α of BMSCs was blocked, the expression of VEGF and SDF-1 secreted by stromal cells were decreased. When HIF-1α was blocked, the co-cultured Jurkat cell’s adhesion and migration functions were also decreased. Taken together, these results suggest that HIF-1α acts as an important transcription factor and can significantly affect the secretion and adhesion functions of leukemia BMSCs.

The role of oxytocin in cardiovascular regulation

Studies of body volume expansion have indicated that lesions of the anteroventral third ventricle and median eminence block the release of atrial natriuretic peptide (ANP) into the circulation. Detailed analysis of the lesions showed that activation of oxytocin (OT)-ergic neurons is responsible for ANP release, and it has become clear that activation of neuronal circuitry elicits OT secretion into the circulation, activating atrial OT receptors and ANP release from the heart. Subsequently, we have uncovered the entire functional OT system in the rat and the human heart. An abundance of OT has been observed in the early development of the fetal heart, and the capacity of OT to generate cardiomyocytes (CMs) has been demonstrated in various types of stem cells. OT treatment of mesenchymal stem cells stimulates paracrine factors beneficial for cardioprotection. Cardiovascular actions of OT include: i) lowering blood pressure, ii) negative inotropic and chronotropic effects, iii) parasympathetic neuromodulation, iv) vasodilatation, v) anti-inflammatory activity, vi) antioxidant activity, and vii) metabolic effects. OT actions are mediated by nitric oxide and ANP. The beneficial actions of OT may include the increase in glucose uptake by CMs and stem cells, reduction in CM hypertrophy, oxidative stress, and mitochondrial protection of several cell types. In experimentally induced myocardial infarction in rats, continuous in vivo OT delivery improves cardiac healing and cardiac work, reduces inflammation, and stimulates angiogenesis. Because OT plays anti-inflammatory and cardioprotective roles and improves vascular and metabolic functions, it demonstrates potential for therapeutic use in various pathologic conditions.

Acute effect of alcohol intake on sine-wave Cartesian and polar contrast sensitivity functions

The aim of this study was to assess contrast sensitivity for angular frequency stimuli as well as for sine-wave gratings in adults under the effect of acute ingestion of alcohol. We measured the contrast sensitivity function (CSF) for gratings of 0.25, 1.25, 2.5, 4, 10, and 20 cycles per degree of visual angle (cpd) as well as for angular frequency stimuli of 1, 2, 4, 24, 48, and 96 cycles/360°. Twenty adults free of ocular diseases, with normal or corrected-to-normal visual acuity, and no history of alcoholism were enrolled in two experimental groups: 1) no alcohol intake (control group) and 2) alcohol ingestion (experimental group). The average concentration of alcohol in the experimental group was set to about 0.08%. We used a paradigm involving a forced-choice method. Maximum sensitivity to contrast for sine-wave gratings in the two groups occurred at 4 cpd sine-wave gratings and at 24 and 48 cycles/360° for angular frequency stimuli. Significant changes in contrast sensitivity were observed after alcohol intake compared with the control condition at spatial frequency of 4 cpd and 1, 24, and 48 cycles/360° for angular frequency stimuli. Alcohol intake seems to affect the processing of sine-wave gratings at maximum sensitivity and at the low and high frequency ends for angular frequency stimuli, both under photopic luminance conditions.

Urana työllistyminen

Tutkimuksen tarkoituksena on ollut selvittää pitkään työttömänä olleiden ammatinvaihtajien ammatinvaihdon ja työllistymisen etenemistä. Tämän lisäksi tutkimuksessa on tarkasteltu kohderyhmän mielikuvaa ohjaavasta koulutuksesta. Pitkittäistutkimus on toteutettu seurannalla, jonka välietappina on ollut kohderyhmän osallistuminen ohjaavaan koulutukseen. Työvoimapoliittinen ohjaava koulutus edusti erityisesti vaikeasti työllistettäville kohdistettavaa interventiota, jolla pyrittiin puuttumaan työttömyyskierteeseen ja ehkäisemään syrjäytymiskehityksen jatkuminen. Tutkimuksen kohderyhmäksi valitut ihmiset (51) ovat suoranaisessa keskiössä tutkittaessa työelämästä syrjäytymistä. Heikentyneet työelämävalmiudet ja työmarkkinakelpoisuus ovat tehneet heistä vaikeasti työllistettäviä. Heidän valintansa kohderyhmäksi, työhallinnon tekemän kurssiosoituksen kriteereinä olevien pitkäaikaistyöttömyyden sekä epäonnistuneen ammatinvaihdon perusteella, osoittaa heidän olevan erityisen ohjauksen ja tuen tarpeessa. On kuitenkin huomattava, että heidät on valittu kohderyhmäksi paitsi kurssiosoituksen saaneina pitkäaikaistyöttöminä myös ammatinvaihtajina, jotka itse haluavat vaihtaa ammattiaan. Tutkimusaineistona ovat olleet työhallinnon asiakasrekisteritiedot ja seurantatutkimuksen perusteella muodostetuista ryhmistä valittujen neljän tapaushenkilön teemahaastatteluaineistot. Tutkimusaineistoa on käsitelty laadullisesti, koska tutkimus kuuluu laadullisen tutkimuksen piiriin sekä tutkimuksen kohteena olevan ilmiön, tutkimuskysymysten ja -aineistojen että tarkoituksensa perusteella. Tutkimuksessa on kuvattu pitkäaikaistyöttömien henkilöiden ammatinvaihtoa ja työllistymistä. Kuvatuissa tapauksissa ammatinvaihtotarve perustuu suurimmalla osalla terveydellisiin rajoitteisiin, joiden vuoksi aikaisemmassa työssä toimiminen on mahdotonta. Useimmiten vajaakuntoisuus on merkittävästi pitkittänyt heidän työttömyyttään. Tämän vuoksi seurantatutkimuksessa on keskitytty tarkastelemaan ammatinvaihtoprosessin etenemistä. Muun muassa työttömyyttä laajasti tutkineet Aho ja Vähätalo ovat todenneet vajaakuntoisuuden olevan merkittävä työttömyyden pitkittymiseen vaikuttava tekijä. Ahon mukaan vajaakuntoisiksi diagnosoituja on jopa viidennes kroonisesti pitkäaikaistyöttömistä työhallinnon asiakasrekisteriin kirjatuista henkilöistä. Monen tekijän summana pitkään työttömänä olleet henkilöt ovat vaarassa ajautua tilanteeseen, jossa he eivät enää kykene omin avuin löytämään ulospääsyä työttömyydestä Tämän seurantatutkimuksen perusteella vain hyvin harvalla kohderyhmään kuuluvista on ammatinvaihdossa ja työllistymisessä tapahtunut merkittävää edistymistä huolimatta useiden vuosien yrittämisestä. Ammatinvaihdon ja työllistymisen edistymistä on tarkasteltu sen perusteella, miten työelämään ja/tai koulutukseen sijoittumiset tai muut toiminnot ovat edesauttaneet tavoitteen toteutumista. Seurantatutkimuksessa on muodostettu neljä tyyppiryhmää ammatinvaihdon ja työllistymisen etenemisen perusteella. Ryhmät ovat: Ammatinvaihdossa onnistuneet (5), ammatinvaihdossa edistyneet (19), pitkäaikaistyöttömäksi jääneet (12) ja epätarkoituksenmukaisesti sijoittuneet (15). Ammatinvaihdossa onnistuneet ovat toteuttaneet ammatinvaihtonsa siirtymällä suoraan työelämään uudelle alalle, työllistymällä koulutusta vastaavaan työhön uudelleenkoulutuksen jälkeen tai kouluttautumalla uuteen ammattiin työllistymättä. Kuitenkin vain kolme heistä on sijoittunut seurannan päättyessä pysyväisluonteiseen terveydelleen soveltuvaan työhön muiden ollessa edelleen työttömänä. Ammatinvaihdossa edistyneet ovat suurimmaksi osaksi edistyneet ammatinvaihdossaan soveltuvien tukitöiden avulla. Työttömyys on kuitenkin jatkunut valtaosalla ja vain yksi heistä on sijoittuneena työelämään seurannan päättyessä. Tämä sijoittuminen ei ole kuitenkaan edistänyt ammatinvaihtoa. Pitkäaikaistyöttömäksi jääneet ovat olleet yhtäjaksoisesti työttömänä kokoseurantajakson ajan. Epätarkoituksenmukaisesti sijoittuneet ovat enimmäkseen sijoittuneet terveytensä kannalta haitallisiin ja/tai ammatinvaihtosuunnitelmilleen soveltumattomiin sijoitustöihin ja määräaikaisuuksiin. Seurannan päättyessä heovat joko työttömänä tai toimivat ammatinvaihtotavoitteensa kannalta haitallisissa työtehtävissä. Tämä on vahvistanut mielikuvaa, joka usealle heille on muodostunut ohjaavasta koulutuksesta työttömille suunnattuna sanktiona, joka ei edistä työllistymistä. Ohjaavassa koulutuksessa suurin osa heistä on kokenut hyötyneensä työharjoittelujaksosta, joka on antanut käyttökelpoista tietoa ammatinvalintaa varten. Lukuun ottamatta kolmea henkilöä, jotka ovat seurannan päättyessä pysyväisluonteisessa työssä terveydelleen soveltuvassa ammatissa, ovat kaikki muut kohderyhmään kuuluvat edelleen erityisen ohjauksen ja tuen tarpeessa johtuen ammatinvaihdon keskeneräisyydestä ja/tai työttömyyden jatkumisesta. Yhdistävänä tekijänä ammatinvaihdossa onnistuneilla vaikuttaa olleen tulevaisuususkon säilyminen pitkäaikaistyöttömyydessä. Sekä ammatinvaihdossa onnistuneet että edistyneet ovat kokeneet työttömyyteen katkoksia tuoneet työt merkityksellisinä riippumatta siitä, ovatko työtehtävät edistäneet ammatinvaihtoa.

Models to study intermediate filament dynamics and functions

Intermediate filaments are part of the cytoskeleton and nucleoskeleton; they provide cells with structure and have important roles in cell signalling. The IFs are a large protein family with more than 70 members; each tightly regulated and expressed in a cell type-specific manner. Although the IFs have been known and studied for decades, our knowledge about their specific functions is still limited, despite the fact that mutations in IF genes cause numerous severe human diseases. In this work, three IF proteins are examined more closely; the nuclear lamin A/C and the cytoplasmic nestin and vimentin. In particular the regulation of lamin A/C dynamics, the role of nestin in muscle and body homeostasis as well as the functions and evolutionary aspects of vimentin are investigated. Together this data highlights some less well understood functions of these IFs. We used mass-spectrometry to identify inter-phase specific phosphorylation sites on lamin A. With the use of genetically engineered lamin A protein in combination with high resolution microscopy and biochemical methods we discovered novel roles for this phosphorylation in regulation of lamin dynamics. More specifically, our data suggests that the phosphorylation of certain amino acids in lamin A determines the localization and dynamics of the protein. In addition, we present results demonstrating that lamin A regulates Cdk5-activity. In the second study we use mice lacking nestin to gain more knowledge of this seldom studied protein. Our results show that nestin is essential for muscle regeneration; mice lacking nestin recover more slowly from muscle injury and show signs of spontaneous muscle regeneration, indicating that their muscles are more sensitive to stresses and injury. The absence of nestin also leads to decreased over-all muscle mass and slower body growth. Furthermore, nestin has a role in controlling testicle homeostasis as nestin-/- male mice show a greater variation in testicle size. The common fruit fly Drosophila melanogaster lacks cytoplasmic IFs as most insects do. By creating a fly that expresses human vimentin we establish a new research platform for vimentin studies, as well as provide a new tool for the studies of IF evolution.

Nature of the state economic expanded functions in the Brazilian economy*

ABSTRACT The paper discusses the dynamics of capital accumulation in Latin America economies. The hypothesis is that in these economies the role of the State is comparatively broader than in the economies of the centers of the capitalism by structural reasons. The argument is mainly based on Marx and Kalecki, besides historical elements of Latin America economies, particularly the Brazilian economy. Then the paper explores the dynamics consequences of this nature at the national levels, concluding that this condition gives a higher degree of instability.