The roles of galectin-3 in monocyte and lymphocite lineages

Galektini-1 i -3 moduliraju mnoge stanične procese, a regulacijom migracije, fagocitoze i degranulacije upalnih stanica, te sinteze citokina i medijatora upale, ovi su lektini uključeni u sve faze upalnih reakcija uroĎenog i stečenog imunosnog odgovora. Djelovanje mu izrazito ovisi o lokalizaciji i tipu stanica, no galektin-1 općenito se smatra jakim protu-upalnim signalom, dok galektin-3 uglavnom potiče upalu. Ovim radom ispitana je uloga galektina-3 u fiziologiji limfocita, te uloga i ekspresija galektina-1 i -3 u monocita, te klasično i alternativno diferenciranih i aktiviranih makrofaga. Humani limfociti i monociti izolirani su iz krvi zdravih dobrovoljnih davatelja. Uzgojem u hranidbenom mediju uz dodatak granulocitno-makrofagnog, odnosno makrofagnog faktora stimulacije rasta kolonija, monociti su diferencirani u makrofage tipa M1 i M2. Diferencirani makrofagi M1 aktivirani su klasično, dodatkom lipopolisaharida i interferona-γ, ili alternativno u fenotip M2a/M2c, dodatkom interleukina (IL)-4/IL-10. UtvrĎena je ekspresija galektina-1 i -3 na genskoj i proteinskoj razini, te njihova prisutnost na membrani stanica. U hranidbenom mediju spomenutih stanica odreĎena je koncentracija galektina-3. UtvrĎen je učinak egzogeno dodanog galektina-3 na fiziologiju limfocita, monocita i aktiviranih makrofaga. Dobiveni rezultati upućuju na to da diferencijaciju i polarizaciju humanih monocita u klasično (M1) i alternativno (M2a/M2c) aktivirane makrofage prate izrazite promjene razine ekspresije i proteolitičkog kidanja galektina-3. Ekspresija i sekrecija galektina-3 usko su regulirane i znatno se razlikuju u klasično, u odnosu na alternativno aktivirane makrofage, dok u galektina-1 razlike u razini ekspresije nisu toliko naglašene. Zamijećene su izrazite razlike ekspresijskih profila i kidanja galektina-3 u istih podtipova makrofaga podrijetlom od različitih donora krvi. U klasično aktiviranih makrofaga, temeljem intenziteta ekspresije membranskog galektina-3, zamijećene su dvije odvojene populacije stanica. Humani monociti pokazuju izrazito velik kapacitet vezanja egzogeno dodanog galektina-3, dok su u aktiviranih makrofaga receptori tog proteina u potpunosti zasićeni. Egzogeno dodani galektin-3 ne utječe na izlučivanje citokina limfocita i aktiviranih makrofaga. Razlike u razini i obrascu ekspresije galektina-3 u različito diferenciranih/aktiviranih makrofaga u odnosu na galektin-1 su značajne. Stoga, specifičan uzorak ekspresije i sekrecije ovog proteina u diferenciranih i aktiviranih makrofaga pridonosi boljem razumijevanju uloge i regulacije galektina-3 u tim stanicama. Novi uvid u biološke karakteristike različito diferenciranih i aktiviranih makrofaga, te limfocita baca svjetlo na galektin-3 kao modulator ovih stanica.Galectins-1 and -3 modulate many cellular processes, and through regulation of cell migration, phagocytosis, immune cell degranulation and modulation of cytokine and inflammatory mediator production, these lectins are intimately involved in all phases of inflammatory reactions of innate and acquired immunity. Galectin-1 is generally considered a strong anti-inflammatory and galectin-3 a pro-inflammatory signal, but their effects tremendously vary with respect to their localization and the cell type. In this work we address the role of galectin-3 in the physiology of lymphocytes and the role and expression of galectins-1 and -3 in human monocytes and classically or alternatively differentiated and activated macrophages. Human lymphocytes and monocytes were isolated from the blood of healthy donors and differentiated into M1 and M2 subtype of macrophages by cultivation in culture media supplemented with granulocyte-macrophage or macrophage colony-stimulating factor, respectively. M1 macrophages were activated classically by lipopolysaccharide and interpheron-γ or alternatively into M2a/M2c phenotypes by interleukin (IL)-4/IL-10, respectively. The expression of galectins-1 and -3 was determined on gene and protein levels, and the amount of galectins bound to the cell membranes was estimated. Culture media were probed for secreted galectin-3. The effect of exogenously added galectin-3 on the physiology of lymphocytes, monocytes and activated macrophages was investigated. Obtained results imply that differentiation and activation of monocytes into classically (M1) and alternatively (M2a/M2c) activated macrophages is followed by marked changes of expression and proteolitic cleavage of galectin-3. Expression and secretion of galectin-3 was tightly regulated and significantly differed among classically and alternatively activated macrophages, while the differences of galectin-1 expression profiles were not pronounced. Significant differences in galectin-3 expression profiles were observed between the same macrophage subtypes obtained from different blood donors. Moreover, classically activated macrophages polarize into two distinct populations with respect to the expression of membrane galectin-3. Human monocytes exhibited high amount of free galectin-3 receptors, while on both types of activated macrophages the receptors were fully saturated. Exogenously added galectin-3 does not affect cytokine secretion of lymphocytes or activated macrophages. Galectin-3 is more distinctive descriptor of macrophage differentiation/activation than galectin-1. Its specific expression and secretion pattern in M1 vs. M2a/M2c macrophages contributes to better understanding of its role and regulation in these cells and provides a new insight on biological characteristics of these cells

The future of the cave Muda labudova research

Jama Muda labudova (duljina: 4676 m; dubina: 682 m) nalazi se na JI Velebitu i dio je podzemnog sustava Crnopca. Ovdje se u neposrednoj blizini nalaze dva speleološka objekata čije spajanje u sustav od preko 40 kilometara očekujemo u narednih godinu dana. Istraživanja u Mudima labudovim dobila su u posljednje dvije godine snažan novi zamah otkrićem spleta prostranih horizontalnih kanala u dotada izrazito vertikalnom objektu. Horizontalne etaže otvorile su put u nove prostrane vertikalne hodnike s brojnim neistraženim kanalima pa u jami ima desetak mjesta na kojima očekujemo značajne speleološke rezultate. Nova otkrića pokazala su jama Muda labudova ima mofološke karakteristike kapitalnih objekata Crnopca, odnosno da se sastoji od horizontalnih etaža na 300 i 600 metara dubine koje su povezane širokim vertikalnim dimnjacima. Ova činjenica ukazuje na to da smo tek zagrebli površinu s horizontalnim dijelom objekta i da ćemo u vremenu pred nama u njoj istražiti kilometre novih kanala.Cave Muda labudova (4676 m long, 682 m deep) is situated on the south-eastern end of Velebit as a part of Crnopac masif underground. There are two capital caves in close proximity, which are expected to all join in a >40 km system within next year. The survey of Muda labudova was revitalised in last two years, following the discovery of vast horizontal passages forming an mostly unexplored labyrinth. As the previously known passages were mostly vertical, this opened the oportunity of exploration new horizontal parts, levelled with horizontal system in the nearby Kita Gaćešina cave system. The new horizontal parts show similar patterns of interlinking horizontal (300 m and 600 m depth) and vertical parts, as seen in other capital caves nearby. It gives the impression of just starting to discover a kilometer-scale horizontal potential of yet unknown shafts

Onečišćeni speleološki objekti Republike Hrvatske

Polovicu teritorija Hrvatske karakterizira krš, izniman prirodni resurs koji se ujedno intenzivno gospodarstveno i turistički iskorištava. Daleko od ljudskih očiju, u krškim špiljama i jamama, krije se većina zaliha pitke vode, ali i jedna od najvećih prijetnji krškom podzemlju Hrvatske. Speleolozima je jedan od ciljeva zaštita krškog podzemlja koje desetljećima revno istražuju, a nedavno su ukazali na problem koji je bio vidljiv samo njima, a to su divlji deponiji otpada u speleološkim objektima. Trenutno ih Hrvatska broji više od 800, a rasprostiru se diljem našeg krškog područja. Kako bi se bolje razumjeli pojedinačni utjecaji onečišćenih lokacija na stanje okoliša, a time i usmjerili napori prilikom čišćenja speleoloških objekata, izrađena je primarna analiza podataka „Katastra onečišćenih speleoloških objekata“ te je razrađen okolišni kontekst onečišćenja

Distribution of phytoplasma diseases in the Lombardy poplar tree population of Zagreb urban area

Phytoplasmas are uncultivable prokaryotic wall-less pathogens belonging to the class Mollicutes that inhabit plant phloem and insects. Their identification and classification is difficult and mainly based on the polymorphism of their 16S rRNAgene sequences. Aster yellows (AY; \u27Candidatus Phytoplasma asteris\u27) phytoplasmas (ribosomal subgroup 16SrI-P) had been previously identified in several Populus nigra L. \u27Italica\u27 (Lombardy poplar) trees from the urban area of Zagreb. The aim of this research was to examine phytoplasmosis distribution in the poplar tree population of the wider Zagreb urban area. Total nucleic acids were extracted from leaf samples of 30 symptomatic and 4 asymptomatic trees. Phytoplasma 16S rDNAwas amplified in direct and nested PCRs by using universal and group-specific primers. The pathogens were classified on the basis of 16S rDNA amplicon RFLP analyses. Phytoplasmas belonging to the 16SrI ribosomal group (AY) were detected in 12 out of 34 trees examined. In addition, a phytoplasma putative gene for aa kinase was analyzed for positive samples. RFLP profiles from 10 samples were referable to the phytoplasma 16SrI-P ribosomal subgroup previously found only in poplars from Zagreb area. In two samples, unique restriction patterns were found, showing the presence of molecular variability within this conserved gene region. In the northern and north-western part of the area the infection was equally distributed, while in the southern part of the city phytoplasmas were not detected in sampled trees. Further research, including a search for potential insect vectors, is needed in order to indentify the ecological and epidemiological implications of these diseases and their impact on the sanitary status of ornamental trees in the city of Zagreb