The goal of our research is to generate cryopreservation agents derived from antifreeze glycoproteins. One postulated mechanism of cell cryo-injury is ice recrystallization. It is known that simple saccharides and cryopreservation agents (DMSO) display ice recrystallization inhibition (IRI). This study assessed the cytotoxicity and cryopreservation ability of these sugars in relation to their IRI. It was determined that compounds with greater IRI have increased cytotoxicity yet confer cryoprotection. To further investigate how structure is affecting IRI activity, several galactopyranoside derivatives were synthesized. A series of deoxy and α-Callyl- deoxy galactopyranoses were prepared. Testing determined that removal of any hydroxyl group removes IRI. 3-deoxy-β-thiophenyl galactose was also synthesized and had surprisingly better IRI than β-thiophenylgalactose. Also, 6-azido galactose had similar IRI to 6-deoxy galactose. Lastly, a series of β- thioalkylgalactosides was synthesized and testing gave contradicting results which suggest that predicting IRI based on hydrophilicity is more complicated than initially hypothesized.

The goal of our research is to generate cryopreservation agents derived from antifreeze glycoproteins. One postulated mechanism of cell cryo-injury is ice recrystallization. It is known that simple saccharides and cryopreservation agents (DMSO) display ice recrystallization inhibition (IRI). This study assessed the cytotoxicity and cryopreservation ability of these sugars in relation to their IRI. It was determined that compounds with greater IRI have increased cytotoxicity yet confer cryoprotection. To further investigate how structure is affecting IRI activity, several galactopyranoside derivatives were synthesized. A series of deoxy and α-Callyl- deoxy galactopyranoses were prepared. Testing determined that removal of any hydroxyl group removes IRI. 3-deoxy-β-thiophenyl galactose was also synthesized and had surprisingly better IRI than β-thiophenylgalactose. Also, 6-azido galactose had similar IRI to 6-deoxy galactose. Lastly, a series of β- thioalkylgalactosides was synthesized and testing gave contradicting results which suggest that predicting IRI based on hydrophilicity is more complicated than initially hypothesized.

The goal of our research is to generate cryopreservation agents derived from antifreeze glycoproteins. One postulated mechanism of cell cryo-injury is ice recrystallization. It is known that simple saccharides and cryopreservation agents (DMSO) display ice recrystallization inhibition (IRI). This study assessed the cytotoxicity and cryopreservation ability of these sugars in relation to their IRI. It was determined that compounds with greater IRI have increased cytotoxicity yet confer cryoprotection. To further investigate how structure is affecting IRI activity, several galactopyranoside derivatives were synthesized. A series of deoxy and α-Callyl- deoxy galactopyranoses were prepared. Testing determined that removal of any hydroxyl group removes IRI. 3-deoxy-β-thiophenyl galactose was also synthesized and had surprisingly better IRI than β-thiophenylgalactose. Also, 6-azido galactose had similar IRI to 6-deoxy galactose. Lastly, a series of β- thioalkylgalactosides was synthesized and testing gave contradicting results which suggest that predicting IRI based on hydrophilicity is more complicated than initially hypothesized.

The goal of our research is to generate cryopreservation agents derived from antifreeze glycoproteins. One postulated mechanism of cell cryo-injury is ice recrystallization. It is known that simple saccharides and cryopreservation agents (DMSO) display ice recrystallization inhibition (IRI). This study assessed the cytotoxicity and cryopreservation ability of these sugars in relation to their IRI. It was determined that compounds with greater IRI have increased cytotoxicity yet confer cryoprotection. To further investigate how structure is affecting IRI activity, several galactopyranoside derivatives were synthesized. A series of deoxy and α-Callyl- deoxy galactopyranoses were prepared. Testing determined that removal of any hydroxyl group removes IRI. 3-deoxy-β-thiophenyl galactose was also synthesized and had surprisingly better IRI than β-thiophenylgalactose. Also, 6-azido galactose had similar IRI to 6-deoxy galactose. Lastly, a series of β- thioalkylgalactosides was synthesized and testing gave contradicting results which suggest that predicting IRI based on hydrophilicity is more complicated than initially hypothesized.

The synthesis of galactose clusters that are linked to a steroid moiety by a peptide-like spacer unit is described. The galactose cluster is obtained by Koenigs-Knorr glycosylation of TRIS-Gly-Fmoc (2b) under Helferich conditions. Peptide and ester bonds are formed after activation of carboxylic acids as diphenylthiophene dioxide (TDO) esters. 6a is synthesized in a convergent way by coupling of (Ac4Gal)3-TRIS-Gly (3e) with cholesteryl TDO succinate (5b). Coupling of (Ac4Gal)3-TRIS-Gly hydrogen succinate (3f) with Gly-O-Chol (5d) by means of EEDQ yields 6d. Reaction of (Ac4Gal)3-TRIS-Gly-SUCC-O-TDO (3g) with 25-hydroxycholesterol leads in a linear sequence to the oxysterol derivative 6f. Selective cleavage of the acetyl groups from galactose units yields the known compound 6b and the new derivatives 6e and 6g.

Galectina-1 (Gal-1) pertence à família de lectinas que reconhecem -galactosídeos e pode ser expressa em vários tipos celulares, incluindo as células endoteliais e músculo liso. Esta lectina endógena possui propriedades imunomodulatórias e antiinflamatórias, dependentes de processos celulares, essenciais incluindo ativação, diferenciação, sobrevivência, fagocitose e adesão celular. Os eventos iniciais da lesão vascular são pouco conhecidos e, na literatura, são escassos os dados sobre a participação da Gal-1 nesses eventos. Portanto, neste trabalho, pretendeu-se avaliar a participação dessa lectina nos eventos iniciais da lesão vascular por hiperhomocisteinemia moderada induzida em camundongos. A dose padrão de 0,4g/Kg/dia de homocisteína-tiolactona foi administrada oralmente a camundongos selvagens (Gal-1+/+) e destituídos do gene da Gal-1 (Gal-1-/-), por diferentes tempos, causando uma elevação da concentração plasmática de homocisteína total, Este fato provocou alterações na reatividade vascular de contração na artéria aorta e de rolamento e adesão de leucócitos em vênulas mesentéricas. Foi detectada a presença da Gal-1 nas aortas de animais Gal-1+/+ em todos tempos de tratamento e no controle, observando, porém, um aumento dela no grupo tratados por 15 dias e, mais expressa em 24 horas (expressão protéica por Western blot e imunofluorescência e, gênica por Real Time PCR). Neste tempo, houve maiores alterações metabólicas significativas como triglicérides, LDL, colesterol total, glicose e de homocisteína. A análise da expressão das óxido nítrico sintases revelou não haver alterações para NOS induzida (iNOS) entre os grupos de animais Gal-1+/+ controle e tratados, nem mesmo em relação aos animais controles Gal-1-/-. Entretanto, o tratamento modulou a expressão da NOS endotelial (eNOS) nos animais Gal-1+/+, havendo uma redução da proteína para os tempos de 48 horas e 7dias (expressão protéica por imunohistoquímica - peroxidade e, gênica por RT-PCR). O tratamento não alterou a concentração plasmática de óxido nítrico (NO) em camundongos Gal-1+/+, mas foi detectada redução dos valores basais para animais Gal-1-/- e, uma redução com o tratamento por 15 dias. Portanto, foi verificado que a expressão de Gal-1 foi aumentada com o tratamento de Hcy-Taq nos tempos de 24 horas e 15 dias, onde se observam significativas e maiores alterações biológicas dos parâmetros de lesão vascular induzida pela hiperhomocisteinemia moderada analisadas: reatividade vascular, rolamento e adesão de leucócitos em vênulas mesentéricas, concentração de homocisteína plasmática, perfil lipídico e expressão da óxido nítrico sintase endotelial. / Galectin-1 (Gal-1) belongs to the lectin family of -galactosides-binding proteins and can be expressed by several cell types, including endothelial cells and vascular smooth cells. This endogenous lectin has immunological and anti-inflammatory properties dependent of essential cellular processes, including activation, differentiation, survival, phagocytosis and cell adhesion. There are few and inconclusive studies about the engagement of Gal-1 in vascular injury initial processes. Thus, this work was conducted to evaluate the engagement of Gal-1 in hyperhomocysteinemia-induced vascular injury. Wild type (Gal-1+/+) and Gal-1-knockout (Gal-1-/-) mice were fed with 0,4g/Kg/day with thiolactone-homocysteine (D,L Hcy-T) for different times, provoking increased plasmatic total homocysteine levels. That has indicated alterations in aortic vasomotor responses and mesenteric venial leukocyte rolling and adhesion. Gal-1 was detected in aortic frozen section of Gal-1+/+ mice for all times of treatment with D,L Hcy-T, but more detected for aorta of 15 days treated animal group and, more expressed, for 24 hours ones (protein expression by Western blot and immunofluorescence and, genetic by Real Time PCR). Besides, at 24 hours of treatment, many metabolic alterations were observed: increased LDL, triglycerides, cholesterol, glucose and homocysteine levels. Expressions for nitric oxide sintases (NOS) showed no alteration for inducible NOS (iNOS) for Gal-1+/+ mice (treated or not), even for Gal-1-/- untreat mice. However, the treatment was able to modulate endothelial NOS (eNOS) decreasing the expression at 48 hours and 7 days treated animals group (protein expression by imunoperoxidase and, genetic by RT-PCR). Gal-1-/- mice have less circulating constitutive nitric oxide (NO) than Gal-1+/+ ones, and, the treatment has reduced these levels only for Gal-1-/- 15 days treated mice but not for Gal-1+/+ ones . This work, therefore, has shown that Gal-1 is always expressed by aortas. However, increased expression of Gal-1 at 24 hours and 15 days of treatment has been often correlated to biological alterations in the in hyperhomocysteinemia-induced vascular injury: aortic vasomotor responses, leukocyte rolling and adhesion in mesenteric venues, plasmatic homocysteine, lipid metabolites and NOS expression.

Galectina-1 (Gal-1) pertence à família de lectinas que reconhecem -galactosídeos e pode ser expressa em vários tipos celulares, incluindo as células endoteliais e músculo liso. Esta lectina endógena possui propriedades imunomodulatórias e antiinflamatórias, dependentes de processos celulares, essenciais incluindo ativação, diferenciação, sobrevivência, fagocitose e adesão celular. Os eventos iniciais da lesão vascular são pouco conhecidos e, na literatura, são escassos os dados sobre a participação da Gal-1 nesses eventos. Portanto, neste trabalho, pretendeu-se avaliar a participação dessa lectina nos eventos iniciais da lesão vascular por hiperhomocisteinemia moderada induzida em camundongos. A dose padrão de 0,4g/Kg/dia de homocisteína-tiolactona foi administrada oralmente a camundongos selvagens (Gal-1+/+) e destituídos do gene da Gal-1 (Gal-1-/-), por diferentes tempos, causando uma elevação da concentração plasmática de homocisteína total, Este fato provocou alterações na reatividade vascular de contração na artéria aorta e de rolamento e adesão de leucócitos em vênulas mesentéricas. Foi detectada a presença da Gal-1 nas aortas de animais Gal-1+/+ em todos tempos de tratamento e no controle, observando, porém, um aumento dela no grupo tratados por 15 dias e, mais expressa em 24 horas (expressão protéica por Western blot e imunofluorescência e, gênica por Real Time PCR). Neste tempo, houve maiores alterações metabólicas significativas como triglicérides, LDL, colesterol total, glicose e de homocisteína. A análise da expressão das óxido nítrico sintases revelou não haver alterações para NOS induzida (iNOS) entre os grupos de animais Gal-1+/+ controle e tratados, nem mesmo em relação aos animais controles Gal-1-/-. Entretanto, o tratamento modulou a expressão da NOS endotelial (eNOS) nos animais Gal-1+/+, havendo uma redução da proteína para os tempos de 48 horas e 7dias (expressão protéica por imunohistoquímica - peroxidade e, gênica por RT-PCR). O tratamento não alterou a concentração plasmática de óxido nítrico (NO) em camundongos Gal-1+/+, mas foi detectada redução dos valores basais para animais Gal-1-/- e, uma redução com o tratamento por 15 dias. Portanto, foi verificado que a expressão de Gal-1 foi aumentada com o tratamento de Hcy-Taq nos tempos de 24 horas e 15 dias, onde se observam significativas e maiores alterações biológicas dos parâmetros de lesão vascular induzida pela hiperhomocisteinemia moderada analisadas: reatividade vascular, rolamento e adesão de leucócitos em vênulas mesentéricas, concentração de homocisteína plasmática, perfil lipídico e expressão da óxido nítrico sintase endotelial. / Galectin-1 (Gal-1) belongs to the lectin family of -galactosides-binding proteins and can be expressed by several cell types, including endothelial cells and vascular smooth cells. This endogenous lectin has immunological and anti-inflammatory properties dependent of essential cellular processes, including activation, differentiation, survival, phagocytosis and cell adhesion. There are few and inconclusive studies about the engagement of Gal-1 in vascular injury initial processes. Thus, this work was conducted to evaluate the engagement of Gal-1 in hyperhomocysteinemia-induced vascular injury. Wild type (Gal-1+/+) and Gal-1-knockout (Gal-1-/-) mice were fed with 0,4g/Kg/day with thiolactone-homocysteine (D,L Hcy-T) for different times, provoking increased plasmatic total homocysteine levels. That has indicated alterations in aortic vasomotor responses and mesenteric venial leukocyte rolling and adhesion. Gal-1 was detected in aortic frozen section of Gal-1+/+ mice for all times of treatment with D,L Hcy-T, but more detected for aorta of 15 days treated animal group and, more expressed, for 24 hours ones (protein expression by Western blot and immunofluorescence and, genetic by Real Time PCR). Besides, at 24 hours of treatment, many metabolic alterations were observed: increased LDL, triglycerides, cholesterol, glucose and homocysteine levels. Expressions for nitric oxide sintases (NOS) showed no alteration for inducible NOS (iNOS) for Gal-1+/+ mice (treated or not), even for Gal-1-/- untreat mice. However, the treatment was able to modulate endothelial NOS (eNOS) decreasing the expression at 48 hours and 7 days treated animals group (protein expression by imunoperoxidase and, genetic by RT-PCR). Gal-1-/- mice have less circulating constitutive nitric oxide (NO) than Gal-1+/+ ones, and, the treatment has reduced these levels only for Gal-1-/- 15 days treated mice but not for Gal-1+/+ ones . This work, therefore, has shown that Gal-1 is always expressed by aortas. However, increased expression of Gal-1 at 24 hours and 15 days of treatment has been often correlated to biological alterations in the in hyperhomocysteinemia-induced vascular injury: aortic vasomotor responses, leukocyte rolling and adhesion in mesenteric venues, plasmatic homocysteine, lipid metabolites and NOS expression.