RESUMO
Objective SCAP are seen as seed cells of peri-apical tissue regeneration and used in periapical tissue regeneration project based on stem cells .In this study, we aim to explore the ef-fectdifferent mechanical stretch stress on the proliferation and differen-tiation potential of human stem cells from the apical papilla ( SCAP ) ,and to clarify the mechanism of how mechanical stretch stress regulate human SCAP ,which will provide theoretical guidance for ortho-dontic treatment . Methods Human SCAP was isolated , cultured and identified by combined explants method and enzymatic separa-tion method and limited dilution .MTT assay was used to detect the effect different static mechanical stretch stress stimulation have on the proliferation of SCAP .Western blot was used to detect the expression changes of SCAP osteogenesis /odontoblast differentiation-re-lated protein (ALP, OSX,DSP) under mechanical stretch stressand to detect the expression of SCAP endoplasmic reticulum stress mo -lecular chaperone GRP 78 under different static mechanical stretch stress . Results SCAP were successfully isolated and cultured , and we induced SCAP to differentiate into osteoblasts and adipocytes successfully by osteogenic medium and adipogenic medium .Flow cytometry was performed in accordance with SCAP immunophenotype .Compared with the control group , 150g mechanical stretch stress stimulation promoted SCAP proliferation first and then inhibited SCAP proliferation [(0.481±0.226),(1.375±0.104),(1.425± 0.136),(1.556±0.268),(0.589±0.29),P<0.05].It was same in the 200g group.250g mechanical stretch stress stimulation signifi-cantly inhibited SCAP proliferation [(0.373±0.146),(0.545±0.069),(0.745±0.273),(0.967±0.278),(1.060±0.362),P<0.05]. The expression levels of ALP , OSX and DSP protein in each group were higher than those in the control group (P<0.05).Compared with the control group, the expression of GRP78 protein was up-regulated (P<0.05). Conclusion Mechanical stretch stress could regulate the SCAP proliferation and osteogenesis/odontoblast differentiation .What′s more,endoplasmic reticulum stress played a role in osteogenesis/odontoblast differentiation under mechanical stretch stress and promoted SCAP osteogenesis /odontoblast differentiation .
RESUMO
Objective SCAP are seen as seed cells of peri-apical tissue regeneration and used in periapical tissue regeneration project based on stem cells .In this study, we aim to explore the ef-fectdifferent mechanical stretch stress on the proliferation and differen-tiation potential of human stem cells from the apical papilla ( SCAP ) ,and to clarify the mechanism of how mechanical stretch stress regulate human SCAP ,which will provide theoretical guidance for ortho-dontic treatment . Methods Human SCAP was isolated , cultured and identified by combined explants method and enzymatic separa-tion method and limited dilution .MTT assay was used to detect the effect different static mechanical stretch stress stimulation have on the proliferation of SCAP .Western blot was used to detect the expression changes of SCAP osteogenesis /odontoblast differentiation-re-lated protein (ALP, OSX,DSP) under mechanical stretch stressand to detect the expression of SCAP endoplasmic reticulum stress mo -lecular chaperone GRP 78 under different static mechanical stretch stress . Results SCAP were successfully isolated and cultured , and we induced SCAP to differentiate into osteoblasts and adipocytes successfully by osteogenic medium and adipogenic medium .Flow cytometry was performed in accordance with SCAP immunophenotype .Compared with the control group , 150g mechanical stretch stress stimulation promoted SCAP proliferation first and then inhibited SCAP proliferation [(0.481±0.226),(1.375±0.104),(1.425± 0.136),(1.556±0.268),(0.589±0.29),P<0.05].It was same in the 200g group.250g mechanical stretch stress stimulation signifi-cantly inhibited SCAP proliferation [(0.373±0.146),(0.545±0.069),(0.745±0.273),(0.967±0.278),(1.060±0.362),P<0.05]. The expression levels of ALP , OSX and DSP protein in each group were higher than those in the control group (P<0.05).Compared with the control group, the expression of GRP78 protein was up-regulated (P<0.05). Conclusion Mechanical stretch stress could regulate the SCAP proliferation and osteogenesis/odontoblast differentiation .What′s more,endoplasmic reticulum stress played a role in osteogenesis/odontoblast differentiation under mechanical stretch stress and promoted SCAP osteogenesis /odontoblast differentiation .
RESUMO
Objective To investigate the effects and mechanisms of omega-3 polyunsaturated fatty acids (ω-3 PUFA) supplementation on colonic macroscopic and histological score , inflammatory response , and endo-plasmic reticulum stress ( ERS ) response in experimental rat models of colitis .Methods Experimental rat models of colitis were induced by trinitro-benzene-sulfonic acid (TNBS).Totally 100 male SD rats were ran-domly divided into 5 groups according to the random data tables:sham operation group ( Sham group ) , inflam-matory bowel disease group (IBD group),ω-3 PUFA supplementation group (IBD+ω-3 group), 5-aminosali-cylic acid group ( IBD +5-ASA group ) , and ERS activation 2-deoxy-D-glucose group ( IBD +ω-3 +2-DG group).Colonic macroscopic and histological scores were evaluated on days 1, 3, 7 and 14 after modeling.The serum levels of tumor necrosis factor-α(TNF-α), interleukin (IL) -1, and IL-6 were measured using en-zyme-linked immunosorbent assay , whereas ERS cytokines including glucose-regulated protein 78 ( GRP78 ) , inositol-requiring enzyme 1 (IRE-1), and C/EBP homologous protein (CHOP) were tested by Western blot. Results Compared with the Sham group , colonic macroscopic and histological score , the serum levels of in-flammation relatived factors (TNF-α, IL-1, IL-6) and ERS relatived factors (GRP78、 IRE-1, CHOP) were significantly increased on the rest of the four groups ( all P<0.001 ) .Compared with the IBD group , ω-3 PUFA supplementation reduced colonic macroscopic [7 d: 3.55 ±0.29 vs.4.37 ±0.39, P=0.03, 14 d:2.46 ±0.17 vs.3.86 ±0.21, P=0.04] and histological score [7 d: (2.56 ±0.27) scores vs.(3.45 ± 0.40) scores, P=0.02, 14 d: (2.23 ±0.20) scores vs.(3.06 ±0.26) scores, P=0.04].Meanwhile,ω-3 PUFA supplementation suppressed the expressions of inflammation [TNF-α:(43.71 ±11.39) pg/ml vs. (84.97 ±13.81) pg/ml, P=0.02, IL-1:(38.51 ±10.60) pg/ml vs.(73.04 ±12.48) pg/ml, P=0.01, IL-6:(28.91 ±7.27) pg/ml vs.(53.45 ±9.40) pg/ml, P=0.02] and ERS relatived factors (GRP78:2.41 ±0.29 vs.1.47 ±0.21, P=0.01, IRE-1:2.83 ±0.31 vs.1.23 ±0.20, P<0.001, CHOP:1.89 ± 0.17 vs.1.32 ±0.11 , P=0.04 ) .However , the salutary effects of ω-3 PUFA would been reversed by ERS activation 2-deoxy-D-glucose [ TNF-α: (72.67 ±10.37 ) pg/ml vs.(43.71 ±11.39 ) pg/ml, P =0.02, IL-1:(57.66 ±13.88) pg/ml vs.(38.51 ±10.60) pg/ml, P=0.02, IL-6: (46.10 ±9.67) pg/ml vs. (28.91 ±7.27) pg/ml, P=0.01, GRP78:1.47 ±0.21 vs.1.82 ±0.24, P=0.03, IRE-1:1.23 ±0.20 vs.2.21 ±0.23, P=0.02, CHOP:1.32 ±0.11 vs.1.61 ±0.16, P=0.04].Conclusion The salutary effects of ω-3 PUFA supplementation on the colitis induced by TNBS appear to be mediated by inhibited inflam -matory responses , which may suppress the activation of ERS response .
RESUMO
Aim To explore the role of resveratrol (Res)on cardiomyocyte hypertrophy induced by iso-proterenol (ISO)and the relationship with endoplas-mic reticulum stress (ERS).Methods Hypertrophic model of cardiomyocytes was induced by ISO.Hyper-trophy status of cardiomyocytes was determined by measuring the cell surface area and the gene expression of ANP.The value of apoptosis was measured by flow cytometry,the content of LDH and MDA was measured in different groups,and the gene and protein expres-sions of GRP78 and CHOP were detected by real-time PCR and Western blot.Results Res could attentuate ISO-induced cardiomyocyte hypertrophy and apoptosis by reducing the cell surface area,the gene expression of ANP and the value of apoptosis.Res could inhibit ERS by downregulating the gene and protein expression of GRP78 and CHOP.Meanwhile,the content of LDH and MDA was decreased.Conclusions The results suggest that treatment of Res may protect cardiomyocyte hypertrophy,which is partially mediated by inhibiting the expression of ERS factors GRP78 and CHOP.