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Francesca Passaretta Domenico Bosco Lucia Centurione Maria Antonietta Centurione Fabio Marongiu Roberta Di Pietro 《Journal of cellular and molecular medicine》2020,24(7):4350-4355
Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications. 相似文献
3.
MgATP-dependent glucose 6-phosphate-stimulated Ca2+ accumulation in liver microsomal fractions. Effects of inositol 1,4,5-trisphosphate and GTP 总被引:3,自引:0,他引:3
A Benedetti R Fulceri A Romani M Comporti 《The Journal of biological chemistry》1988,263(7):3466-3473
Ca2+ release triggered by inositol 1,4,5-trisphosphate (IP3) and/or GTP has been studied with rough and smooth microsomes isolated from rat liver. Microsomes were loaded with Ca2+ in the presence of MgATP and in the presence or in the absence of glucose 6-phosphate (glucose-6-P) which markedly stimulated the MgATP-dependent Ca2+ accumulation in rough and smooth microsomes (5- and 10-fold, respectively). Upon addition of IP3 (5 microM), rough and smooth microsomes rapidly release a part (not exceeding 20%) of the Ca2+ previously accumulated both in the absence and in the presence of glucose-6-P. Under the same experimental conditions, inositol 1,3,4,5-tetrakisphosphate was ineffective in triggering any Ca2+ release. Upon addition of GTP (10 microM) both the microsomal fractions progressively release the Ca2+ previously accumulated in the presence of glucose-6-P, when 3% polyethylene glycol was also present. In the absence of polyethylene glycol, GTP released Ca2+ from rough microsomes only, and GTP plus IP3 caused a Ca2+ release which was the sum of the Ca2+ releases caused by GTP and IP3 independently. Both IP3 and GTP, added to microsomes at the beginning of the glucose-6-P-stimulated Ca2+ uptake, reduced the Ca2+ accumulation into rough and smooth microsomes without modifying the initial rate (3 min) of Ca2+ uptake. Also in these conditions, the effects of GTP and IP3 were merely additive. These results indicate that both rough and smooth liver microsomes are responsive to IP3 and GTP with respect to Ca2+ release and that IP3 and GTP likely act independently. 相似文献
4.
Studies on the mechanism of formation of 4-hydroxynonenal during microsomal lipid peroxidation 总被引:5,自引:0,他引:5
H Esterbauer A Benedetti J Lang R Fulceri G Fauler M Comporti 《Biochimica et biophysica acta》1986,876(1):154-166
The mechanism of the formation of 4-hydroxynonenal through the NADPH-linked microsomal lipid peroxidation was investigated. The results were as follows: 4-hydroxynonenal arises exclusively from arachidonic acid contained in the polar phospholipids, neither arachidonic acid of the neutral lipids nor linoleic acid of the polar or neutral lipids are substrates for 4-hydroxynonenal generation. This finding results from the estimation of the specific radioactivity of 4-hydroxynonenal produced by microsomes prelabelled in vivo with [U-14C]arachidonic acid. Phospholipid-bound 15-hydroperoxyarachidonic acid would have the structural requirements needed for 4-hydroxynonenal (CH3-(CH2)4-CH(OH)-CH=CH-CHO). Microsomes supplemented with 15-hydroperoxyarachidonic acid and NADPH, ADP/iron converted only minimal amounts (0.6 mol%) of 15-hydroperoxyarachidonic acid into 4-hydroxynonenal; similarly, 15-hydroperoxyarachidonic acid incubated at pH 7.4 in the presence of ascorbate/iron yielded only small amounts of 4-hydroxynonenal with a rate orders of magnitude below that observed with microsomes. Phospholipid-bound 15-hydroperoxyarachidonic acid is therefore not a likely intermediate in the reaction pathway leading to 4-hydroxynonenal. The rate of 4-hydroxynonenal formation is highest during the very initial phase of its formation and the onset does not show a lag phase, suggesting a transient intermediate predominantly formed during the early phase of microsomal lipid peroxidation. After 60 min of incubation, 204 nmol polyunsaturated fatty acids (20 nmol 18:2, 143 nmol 20:4, 41 nmol 22:6) were lost per mg microsomal protein and the incubation mixture contained 206 nmol lipid peroxides, 71.6 nmol malonic dialdehyde and 4.6 nmol 4-hydroxynonenal per mg protein. Under artificial conditions (pH 1.0, ascorbate/iron, 20 h of incubation) not comparable to the microsomal peroxidation system, 15-hydroperoxyarachidonic acid can be decomposed in good yields (15 mol%) into 4-hydroxynonenal. Autoxidation of arachidonic acid in the presence of ascorbate/iron gave after 25 h of incubation 2.8 mol% (pH 7.4) and 1.5 mol% (pH 1.0) 4-hydroxynonenal. The most remarkable difference between the non-enzymic system and the enzymic microsomal system is that the latter forms 4-hydroxynonenal at a much higher rate. 相似文献
5.
Translational regulation of the synthesis of a major heat shock protein in HeLa cells 总被引:7,自引:0,他引:7
The synthesis of a major heat shock protein (HSP 70) was measured in HeLa cells incubated at 42.5 degrees C and then transferred to 37 degrees C or 30 degrees C. After 90 min, synthesis of HSP 70 decreased by 54 and 85%, respectively, whereas HSP 70 mRNA was reduced at most by 20%. Therefore, the reduced synthesis of HSP 70 could not be accounted for by mRNA turnover. HSP 70 was associated with large polyribosomes (6-10 ribosomes) in cells kept at 42.5 degrees C, but with medium or small polyribosomes in cells transferred to 37 degrees C or 30 degrees C (5-6 or 2-3 ribosomes, respectively). Addition of puromycin to these cells resulted in the release of all ribosomes from HSP 70 mRNA, indicating that they were translationally active. The regulation of HSP 70 synthesis was investigated in cell-free systems prepared from heat-shocked or control cells and incubated at 30 degrees C and 42 degrees C. After 5 min at 42 degrees C, the cell-free system from heat-shocked cells synthesized protein at 3 times the rate of the control cell-free system. This difference was in large part due to synthesis of HSP 70. Addition of HSP mRNA to the control cell-free system stimulated protein synthesis at 42 degrees C, but not at 30 degrees C. These findings suggest that translation of HSP 70 mRNA is specifically promoted at high temperature and repressed during recovery from heat shock by regulatory mechanisms active at the level of initiation. 相似文献
6.
Inhibition of viral mRNA translation in interferon-treated L cells infected with reovirus. 总被引:2,自引:1,他引:1
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Murine L cells were treated with interferon (IFN) concentrations which reduced by 75 to 80% the synthesis of viral mRNA after infection with reovirus. Protein synthesis was not inhibited in these cells up to 6 h after infection, but a large fraction of the viral mRNA was not associated with polyribosomes and sedimented at about 50S. In contrast, most of the reovirus mRNA was associated with polyribosomes in control infected cells. This mRNA was of similar size to non-polyribosomal mRNA from IFN-treated cells when analyzed by Northern blot hybridization with a cloned cDNA for the s2 reovirus mRNA, indicating that the non-polyribosomal mRNA was not appreciably degraded. Viral mRNA was labeled with [3H]uridine and the non-polyribosomal mRNA was isolated from IFN-treated cells. This mRNA could quantitatively bind to 80S initiation complexes when incubated in a rabbit reticulocyte cell-free system. These findings indicated that the non-polyribosomal RNA was translatable, but that its binding to functional initiation complexes was inhibited in IFN-treated cells by a discriminatory mechanism, which did not affect translation of cellular mRNA. Previous experiments showed that mRNA is blocked in 48S complexes when the alpha subunit of initiation factor eIF-2 is phosphorylated by the double-stranded RNA-dependent protein kinase induced by IFN. A localized activation of this kinase could explain the block of viral mRNA in 48S complexes. By labeling the phosphoproteins of IFN-treated cells with 32P, eIF-2 (alpha P) was shown to cosediment with non-polyribosomal mRNA, presumably in 48S complexes. 相似文献
7.
C Toniolo G M Bonora A Bavoso E Benedetti B di Blasio V Pavone C Pedone 《Journal of biomolecular structure & dynamics》1985,3(3):585-598
The infrared absorption and 1H nuclear magnetic resonance analyses of chloroform solutions of the terminally-blocked segment corresponding to the 2-9 sequence of emerimicins III and IV, -(Aib)3-L-Val-Gly-L-Leu-(Aib)2-, are consistent with the presence of a 3(10)-helical structure of high thermal stability. The crystal structure of the octapeptide, obtained by X-ray diffraction indicates the formation of a right-handed 3(10)-helix, stabilized by six consecutive intramolecular N-H....O:C H-bonds, slightly distorted at the level of the L-Leu residue. 相似文献
8.
A M Bolognani Fantin A Franchini E Ottaviani L Benedetti 《Basic and applied histochemistry》1985,29(4):377-387
The effect of lead on ganglia of Viviparus ater were studied by histochemical and histomorphological procedures. The pollution experiment should be considered a "short-time static bioassay" because of its experimental characteristics. There was considerable accumulation of lead in the ganglia as determined by atomic absorbance (A.A.S.). The cytological damage principally affected the neuronal cell bodies which undergo degenerative processes. The most serious cytopathological changes occurred in the following sequence: nuclear damage leading to pyknosis; nucleolar damage until disappearance; changes in Nissl bodies, at times forming a uniform mass. These cytological disorders led to markedly altered protein synthesis. Nerve fibers and neuroglia did not appear affected by lead exposure, even at higher doses. Membrane enzymes, phosphorylase, NADHDH, NADPHDH and SDH activities were decreased, whereas D-LDH, G-6-PDH, G-6-Pase and MAO activities increased. GDH was unchanged. Changes in polar lipid composition were also observed with an increase of phospholipids and a decrease of sulpholipids and cerebrosides. 相似文献
9.
10.
Hung Cao Danh Margherita Strolin Benedetti Philippe Dostert 《Journal of neurochemistry》1983,41(3):618-622
Abstract: Aldehyde dehydrogenase (ALDH) activity was measured in brains, livers, and hearts of 23–26-month-old and 3-month-old rats. A significant increase of ALDH activity was found in whole brain of old rats with both acetaldehyde (39%) and propionylaldehyde (15%) used as substrates. In different brain areas of old rats, with acetaldehyde used as substrate, a significant increase of ALDH activity was found in striatum (30–50%) and cerebral cortex (37%). However, no significant difference in ALDH activity was found in livers and hearts of young and old rats. Preliminary experiments showed a significant increase of aldehyde reductase activity (52%) with p -nitrobenzaldehyde used as substrate in whole brain of old rats compared with young rats. The present work indicates that an increase of ALDH activity in brain of old rats may be an adaptive phenomenon. 相似文献