Title Izražaj koneksina i dendrina u kralježničnoj moždini čovjeka tijekom razvoja i štakora nakon izlaganja kroničnom stresu i kastraciji Title (english) Expression of connexin and dendrin in the human spinal cord during development and rats after exposure to chronic stress and castration Author Marija Jurić Mentor Natalija Filipović (mentor)Committee member Ivica Grković (predsjednik povjerenstva)Committee member Radenka Kuzmanić-Šamija (član povjerenstva)Committee member Maja Valić (član povjerenstva)Granter University of Split Defense date and country 2022, Croatia Scientific / art field, BIOMEDICINE AND HEALTHCARE Universal decimal classificationUDC ) 611 - Anatomy Abstract Ciljevi doktorske disertacije su bili opisati i usporediti specifične prostorno-vremenske uzorke izražaja koneksina (Cx) 37, 43 i 45 i dendrina u kralježničnoj moždini (KM) i ganglijima čovjeka tijekom razvoja, kao i prikazati promjene u izražaju koneksina Cx37, 40 i 43 i dendrina, u KM nakon izlaganja štakora kroničnom stresu i/ili kastraciji uz pomoć dvostruke imunofluorescencije i transmisijske elektronske mikroskopije (TEM).
Izravna međustanična komunikacija putem pukotinskih spojišta ima
... More važnu ulogu u razvoju živčanog sustava, od migracije stanica i diferencijacije neurona do stvaranja obrazaca neuronske aktivnosti, te bi mogla biti potencijalno objašnjenje spolnih razlika u stanjima kronične boli povezane sa stresom. Dendrin je sinaptički protein za kojeg se smatra da ima ulogu u jačanju sinapsi. Njegov specifični izražaj u područjima KM za obradu boli ukazuje na njegovu moguću ulogu u percepciji i modulaciji boli.
Pronašli smo izražaj Cx37, 43 i 45 tijekom ranog razvoja čovjeka u svim područjima od interesa, u KM, spinalnom gangliju, paravertebralnim ganglijima simpatičkog lanca, notokordu i u sve tri meningealne ovojnice, s dominantnim izražajem Cx37. Nismo pronašli značajne razlike uspoređujući izražaj različitih koneksina između razvojnih razdoblja. Nadalje, dendrin je tijekom ranog ljudskog razvoja bio prisutan u ventrikularnom sloju i bazalnoj ploči KM, kao i u spinalnom i simpatičkom gangliju. S druge strane, kastrirane ili lažno operirane štakore izložili smo protokolu kroničnog ili lažnog stresa koji se sastojao od tri odvojena razdoblja primjene, svako u trajanju od 10 dana. Kastracija je rezultirala povećanjem izražaja Cx37 u dorzalnom rogu štakora ženskog spola, dok je izloženost kroničnom stresu potisnula učinke kastracije. U štakora muškog spola samo je združeni učinak kastracije i kroničnog stresa povećao izražaj Cx37. Utjecaj kroničnog stresa na izražaj Cx40 imao je obrnuti učinak nakon kastracije, doveo je do porasta kod ovarijektomiranih ženki, te do smanjenja kod orhidektomiranih mužjaka. Nismo pronašli nikakav učinak kroničnog stresa i kastracije na izražaj Cx43 u dorzalnom rogu, ali postotak Cx43 koji se preklapao s astrocitnim biljegom, glijalnim fibrilarnim kiselim proteinom (GFAP), povećao se u skupini kastriranih mužjaka štakor izloženoj stresu. Specifičan izražaj dendrina u KM vidljiv je u površinskim laminama dorzalnog roga i lamini X (oko CC). Značajno povećanje izražaja dendrina u području dorzalnog roga nakon izlaganja kroničnom stresu ovisi o spolu i primijećeno je samo kod štakora ženskog spola. Štoviše, muški spolni hormoni imaju potencijalno supresivni učinak, s obzirom na to da je povećanje izražaja dendrina nakon izlaganja kroničnom stresu vidljivo samo kod štakora muškog spola nakon kastracije, tj. nakon smanjenja količine testosterona. Kolokalizacija dendrina s izolektinom B4 (IB4) u središnjim projekcijama neurona spinalnog ganglija bila je 7,43 ± 3,36%, dok je s kalcitonin gen-povezanim peptidom (CGRP) bila 8,47 ± 4,45%. Uz to, prisutnost dendrina vidljiva je u somi i jezgrama neurona dorzalnog roga KM.
Specifični prostorno-vremenski uzorak izražaja koneksina mogao bi ukazivati na njihovu važnu ulogu u razvoju svih istraživanih područja od interesa putem međustaničnog povezivanja i sinkronizacije tijekom kasnog embrionalnog i ranog fetalnog razdoblja ljudskog razvoja. Osim toga, međusobni učinci kroničnog stresa i smanjenja spolnih hormona koji dovode do poremećaja izražaja koneksina i dendrina u područjima KM odgovornima za obradu boli mogu biti mogući mehanizam koji uzrokuje poremećaj percepcije boli nakon izlaganja kroničnom stresu. Less Abstract (english) The objectives of the doctoral thesis were to characterize and compare the specific spatio-temporal expression patterns of connexins (Cxs) 37, 43 and 45 and dendrin during early human developmental stages of the spinal cord (SC) and ganglia, as well as to determine whether the exposure to chronic stress and/or performance of gonadectomy might lead to disturbance in the expression of connexin Cx37, 40 and 43 and dendrin in the SC using double immunofluorescence and transmission electron
... More microscopy (TEM).
Direct intercellular communication via gap junctions has an important role in the development of the nervous system, ranging from cell migration and neuronal differentiation to the formation of neuronal activity patterns and could be a potential explanation for sex differences in stress-related chronic pain conditions. Dendrin is synapse strengthening protein and its specific expression in the pain-processing areas of the SC indicates its possible role in pain perception and modulation.
We found the expression of all three investigated Cxs during early human development in all the areas of interest, in the SC, spinal and developing paravertebral ganglia of the sympathetic trunk, notochord and all three meningeal layers, with predominant expression of Cx37. Comparing the expression of different Cxs between distinct developmental periods, we did not find significant differences. Dendrin, on the other hand, during early human development was present in ventricular layer and basal plate of the SC, as well as in spinal and sympathetic ganglia. Furthermore, we applied three 10-day-sessions stress or sham stress protocol after the rats were sham-operated or gonadectomized. The gonadectomies resulted in an increase of Cx37 expression in the dorsal horn of the female rats, but exposure to chronic stress suppressed the effects of castration. In male rats, only the combined effects of castration and chronic stress increased Cx37 expression. The influence of chronic stress on the dorsal horn Cx40 expression was inversely evident after the castration: increased in the ovariectomized female rats, while decreased in the orchidectomized male rats. We did not find any effect of chronic stress and castration, alone or together, on Cx43 expression in the dorsal horn, but the percentage of Cx43 overlapping the astrocyte marker glial fibrillary acidic protein (GFAP) increased in the male stressed group after the castration. Dendrin expression in the SC was prominent in the superficial laminae of the dorsal horn and lamina X (around central canal). A significant increase in dendrin expression in the dorsal horn after exposure to chronic stress was dependent on sex and only observed in female rats. Moreover, male sex hormones have a potentially suppressive effect, given that the increase in dendrin expression after exposure to chronic stress is seen only in male rats after castration, i.e. after a decrease in testosterone. Co-localization with the α-d-galactosyl-specific isolectin B4 (IB4) in central projections of the DRG neurons was 7.43 ± 3.36%, while with the calcitonin gene-related peptide (CGRP) was 8.47 ± 4.45%. Furthermore, localization of dendrin was observed in soma and nuclei of neurons in the dorsal horn.
Specific spatio-temporal pattern of Cxs expression might reflect their relevance in the development of all areas of interest via cellular interconnectivity and synchronization during the late embryonic and early fetal period of human development. In addition, an association of the chronic stress with sex hormone depletion results in disturbances of Cxs and dendrin expression in pain-processing areas of the SC and might be a possible mechanism of disturbed pain perception after chronic stress exposure. Less Keywords
Kralježnična moždina
Koneksini
Dendrin
Fiziološki stres
Psihološki stres
Keywords (english)
Spinal Cord
Connexins
Dendrin
Stress Physiological
Stress Psychological
Language croatian URN:NBN urn:nbn:hr:171:599913 Study programme Title: Biology of Neoplasms Type of resource Text File origin Born digital Access conditions Open access Terms of use Created on 2022-02-25 13:23:57
