Celično-biološki mehanizmi delovanja amnijske membrane proti raku in možnosti za njeno uporabo pri zdravljenju raka

Izhodišče: Osnovna naloga amnijske membrane je zaščita ploda pred zunanjimi mehanskimi vplivi in izsušitvijo ter zagotavljanje primernega okolja za njegov razvoj. Razumevanje zgradbe in delovanja amnijske membrane je pomembno za njeno klinično uporabo, še posebej v regenerativni medicini. V prispevku opisujemo številne, za regenerativno medicino zelo zaželene mehanske in biološke lastnosti amnijske membrane ter predstavljamo njene protirakave lastnosti. Zaključek: Študije na modelih in vitro kot tudi študije na živalskih modelih dokazujejo, da amnijska membrana zavira proliferacijo rakavih celic in sproža njihovo apoptozo, deluje imunozaviralno, zavira energijsko presnovo rakavih celic in angiogenezo. Delo podaja pregled najnovejših spoznanj o protirakavem delovanju amnijske membrane in vrednoti njeno potencialno uporabo v zdravljenju raka in regenerativni medicini

Amnijska membrana kot biološki nosilec, njena priprava in uporaba v regenerativni medicini v Sloveniji

Izhodišča: Amnijska membrana (AM) je notranja stran posteljice, ki obdaja in ščiti zarodek. AM je večplastna struktura, ki je sestavljena iz amnijskih epitelijskih celic, amnijskih mezenhimskih stromalnih celic, bazalne lamine in vezivnega tkiva. Iz njene zgradbe izhajajo tudi lastnosti AM, zaradi katerih se že vrsto let uporablja v terapevtske namene, predvsem v oftalmologiji, saj pospešuje epitelizacijo, deluje kot substrat za celice, zmanjšuje fibrozo in neovaskularizacijo tkiva ter deluje protimikrobno. Zaradi mehanskih lastnosti AM, ki so posledica predvsem molekul zunajceličnega matriksa bazalne lamine in vezivnega tkiva, se AM v zadnjih letih vedno pogosteje uporablja tudi kot biološki nosilec v regenerativni medicini.   Zaključki: Regenerativna medicina je interdisciplinarno področje raziskav in kliničnih aplikacij, ki uporablja načela bioloških in inženirskih znanosti za razvoj živih tkivnih ali organskih nadomestkov. V regenerativni medicini ločimo tri pristope: 1) vsaditev funkcionalnih celic, med drugim tudi matičnih celic, v poškodovano ali okvarjeno tkivo, 2) uporaba različnih sintetičnih materialov ali materialov naravnega izvora, ki pomagajo pri ponovnem oblikovanju poškodovanega ali okvarjenega tkiva in 3) tkivno inženirstvo, tj. uporaba ustreznih nosilcev, ki spodbujajo rast tkivno specifičnih celic in oblikovanje novega tkiva. V prispevku predstavljamo tudi uporabo amnijske membrane kot biološkega nosilca v regenerativni medicini v Sloveniji

Uspješnost liječenja kroničnih rana alogenim trombocitnim gelom u usporedbi s hidrogelom: prospektivno istraživanje

The aim of the study was to evaluate the efficacy and safety of the new method of platelet-rich plasma activation in the form of platelet gel, used in the treatment of non-healing ­chronic lower leg ulcers. The study was prospectively randomized, double blind and placebo controlled. We treated 60 patients (42 males and 18 females, mean age 69.43 years, SD 14.74) with chronic lower leg ulcers of different etiologies. Thirty patients were treated with allogeneic platelet gel and 30 with ­hydrogel. Both groups were comparable for duration of ulcer and its size. Treatment was repeated once a week for three consecutive weeks and then the last examination was scheduled at 6 months of the first platelet gel application. The t-test was used to analyze independent samples. Healing of chronic wounds with platelet gel was statistically significantly more effective compared to the treatment with hydrogel (p<0.05). At 6 months of platelet gel application, the mean wound area in the experimental group decreased to 35.01% (SD 53.69) of the initial wound size. In the control group, the wound area decreased to 89.95% (SD 71.82) of the initial wound size (p=0.001). The circumference of the wounds diminished to 54.62% (SD 39.85) of the initial value in the experimental group, compared to 91.28% (SD 29.32) in the control group (p<0.001). Allogeneic platelet gel prepared by the new ­method used in this study was found to be a good treatment option for non-healing chronic wounds when other methods are ineffective.Cilj ove studije bio je procijeniti djelotvornost i sigurnost nove metode aktivacije plazme bogate trombocitima u obliku trombocitnog gela koji se rabi za liječenje kroničnih ulkusa potkoljenice koji ne cijele. Studija je bila prospektivno randomizirana, dvostruko slijepa i placebom kontrolirana. Liječili smo 60 bolesnika (42 muškarca, 18 žena, srednje dobi od 69,43 godine, SD 14,74) s kroničnim ulkusima potkoljenice različitih etiologija. Po 30 bolesnika liječeno je alogenim trombocitnim gelom odnosno hidrogelom. Obje skupine bile su usporedive po trajanju ulkusa i njegovoj veličini. Liječenje se ponavljalo jednom tjedno tijekom tri uzastopna tjedna i tada je posljednji pregled obavljen 6 mjeseci od prve primjene trombocitnog gela. Za analizu nezavisnih uzoraka primijenjen je t-test. Liječenje kroničnih rana trombocitnim gelom bilo je statistički značajno učinkovitije u odnosu na liječenje hidrogelom (p<0,05). Šest mjeseci nakon aplikacije gela srednja vrijednost površine rana u eksperimentalnoj skupini smanjila se na 35,01% (SD 53,69) početne veličine rane. U kontrolnoj skupini područje rana smanjilo se na 89,95% (SD 71,82), p=0,001. Opseg rana smanjio se na 54,62% (SD 39,85) početne vrijednosti u eksperimentalnoj skupini u usporedbi s 91,28% (SD 29,32) u kontrolnoj skupini (p<0,001). Alogeni trombocitni gel pripremljen novom metodom koja se rabila u ovom istraživanju dobar je izbor za liječenje kroničnih rana koje ne cijele kada druge metode nisu učinkovite

Regeneration of Chronic Wounds with Allogeneic Platelet Gel versus Hydrogel Treatment: a Prospective Study

The aim of the study was to evaluate the efficacy and safety of the new method of platelet-rich plasma activation in the form of platelet gel, used in the treatment of non-healing ­chronic lower leg ulcers. The study was prospectively randomized, double blind and placebo controlled. We treated 60 patients (42 males and 18 females, mean age 69.43 years, SD 14.74) with chronic lower leg ulcers of different etiologies. Thirty patients were treated with allogeneic platelet gel and 30 with ­hydrogel. Both groups were comparable for duration of ulcer and its size. Treatment was repeated once a week for three consecutive weeks and then the last examination was scheduled at 6 months of the first platelet gel application. The t-test was used to analyze independent samples. Healing of chronic wounds with platelet gel was statistically significantly more effective compared to the treatment with hydrogel (p<0.05). At 6 months of platelet gel application, the mean wound area in the experimental group decreased to 35.01% (SD 53.69) of the initial wound size. In the control group, the wound area decreased to 89.95% (SD 71.82) of the initial wound size (p=0.001). The circumference of the wounds diminished to 54.62% (SD 39.85) of the initial value in the experimental group, compared to 91.28% (SD 29.32) in the control group (p<0.001). Allogeneic platelet gel prepared by the new ­method used in this study was found to be a good treatment option for non-healing chronic wounds when other methods are ineffective

Lysosomal protease pathways to apoptosis - Cleavage of Bid, not pro-caspases, is the most likely route

We investigated the mechanism of lysosome-mediated cell death using purified recombinant pro-apoptotic proteins, and cell-free extracts from the human neuronal progenitor cell line NT2, Potential effectors were either isolated lysosomes or purified lysosomal proteases. Purified lysosomal cathepsins B, H, K, L, S, and X or an extract of mouse lysosomes did not directly activate either recombinant caspase zymogens or caspase zymogens present in an NT2 cytosolic extract to any significant extent. In contrast, a cathepsin L-related protease from the protozoan parasite Trypanosana cruzi, cruzipain, showed a measurable caspase activation rate. This demonstrated that members of the papain family can directly activate caspases but that mammalian lysosomal members of this family may have been negatively selected for caspase activation to prevent inappropriate induction of apoptosis, Given the lack of evidence for a direct role in caspase activation by lysosomal proteases, we hypothesized that an indirect mode of caspase activation may involve the Bcl-2 family member Bid. In support of this, Bid was cleaved in the presence of lysosomal extracts, at a site six residues downstream from that seen for pathways involving capase 8, Incubation of mitochondria with Bid that had been cleaved by lysosomal extracts resulted in cytochrome c release. Thus, cleavage of Bid may represent a mechanism by which proteases that have leaked from the lysosomes can precipitate cytochrome c release and subsequent caspase activation. This is supported by the finding that cytosolic extracts from mice ablated in the bid gene are impaired in the ability to release cytochrome c in response to lysosome extracts, Together these data suggest that Bid represents a sensor that allows cells to initiate apoptosis in response to widespread adventitious proteolysis