The Long Noncoding RNA RP11-728F11.4 Promotes Atherosclerosis.

OBJECTIVE: Noncoding RNAs are emerging as important players in gene regulation and cardiovascular diseases. Their roles in the pathogenesis of atherosclerosis are not fully understood. The purpose of this study was to determine the role played by a previously uncharacterized long noncoding RNA, RP11-728F11.4, in the development of atherosclerosis and the mechanisms by which it acts. Approach and Results: Expression microarray analysis revealed that atherosclerotic plaques had increased expression of RP11-728F11.4 as well as the cognate gene FXYD6 (FXYD domain containing ion transport regulator 6), which encodes a modulator of Na+/K+-ATPase. In vitro experiments showed that RP11-728F11.4 interacted with the RNA-binding protein EWSR1 (Ewings sarcoma RNA binding protein-1) and upregulated FXYD6 expression. Lentivirus-induced overexpression of RP11-728F11.4 in cultured monocytes-derived macrophages resulted in higher Na+/K+-ATPase activity, intracellular cholesterol accumulation, and increased proinflammatory cytokine production. The effects of RP11-728F11.4 were enhanced by siRNA-mediated knockdown of EWSR1 and reduced by downregulation of FXYD domain containing ion transport regulator 6. In vivo experiments in apoE knockout mice fed a Western diet demonstrated that RP11-728F11.4 increased proinflammatory cytokine production and augmented atherosclerotic lesions. CONCLUSIONS: RP11-728F11.4 promotes atherosclerosis, with an influence on cholesterol homeostasis and proinflammatory molecule production, thus representing a potential therapeutic target. Graphic Abstract: A graphic abstract is available for this article.

TTDA inhibited apoptosis by regulating the p53-Bax/Bcl2 axis in glioma.

The trichothiodystrophy group A protein (TTDA) functions in nucleotide excision repair and basal transcription. TTDA plays a role in cancers and serves as a prognostic and predictive factor in high-grade serous ovarian cancer; however, its role in human glioma remains unknown. Here, we found that TTDA was overexpressed in glioma tissues. In vitro experiments revealed that TTDA overexpression inhibited apoptosis of glioma cells and promoted cell growth, whereas knockdown of TTDA had the opposite effect. Increased TTDA expression significantly decreased the Bax/Bcl2 ratio and the level of cleaved-caspase3. TTDA interacted with the p53 gene at the -1959 bp and -1530 bp region and regulated its transcription, leading to inhibition of the p53-Bax/Bcl2 mitochondrial apoptosis pathway in glioma cells. These results indicate that TTDA is an upstream regulator of p53-mediated apoptosis and acts as an oncogene, suggesting its value as a potential molecular target for the diagnosis and treatment of glioma.

Microarray profiling analysis and validation of novel long noncoding RNAs and mRNAs as potential biomarkers and their functions in atherosclerosis.

Long noncoding (lnc)RNAs have been implicated in the development and progression of atherosclerosis. However, the expression and mechanism of action of lncRNAs in atherosclerosis are still unclear. We implemented microarray analysis in human advanced atherosclerotic plaques and normal arterial intimae to detect the lncRNA and mRNA expression profile. Gene Ontology functional enrichment and pathway analyses were applied to explore the potential functions and pathways involved in the pathogenesis of atherosclerosis. A total of 236 lncRNAs and 488 mRNAs were selected for further Ingenuity Pathway Analysis. Moreover, quantitative RT-PCR tests of most selected lncRNAs and mRNAs with high fold changes were consistent with the microarray data. We also performed ELISA to investigate the corresponding proteins levels of selected genes and showed that serum levels of SPP1, CD36, ATP6V0D2, CHI3L1, MYH11, and BDNF were differentially expressed in patients with coronary heart disease compared with healthy subjects. These proteins correlated with some biochemical parameters used in the diagnosis of cardiovascular diseases. Furthermore, receiver operating characteristic analysis showed a favorable diagnostic performance. The microarray profiling analysis and validation of differentially-expressed lncRNAs and mRNAs in atherosclerosis not only provide new insights into the pathogenesis of this disease but may also reveal new biomarkers for its diagnosis and treatment.

Forkhead Box C2 Attenuates Lipopolysaccharide-Induced Cell Adhesion via Suppression of Intercellular Adhesion Molecule-1 Expression in Human Umbilical Vein Endothelial Cells.

Atherosclerosis is a chronic vascular inflammatory disease that involves diverse cell types and circulating regulatory factors, including intercellular adhesion molecule (ICAM)-1, a proinflammatory cytokine. Lipopolysaccharides (LPS) increase ICAM-1 expression and promote cell adhesion, but the mechanism is not clear. We found that LPS induced time- and dose-regulated upregulation of ICAM-1 expression and downregulation of forkhead box protein C2 (Foxc2) expression in human umbilical vein endothelial cells (HUVECs). Overexpression of Foxc2 significantly inhibited both LPS-induced ICAM-1 expression in HUVECs and LPS-induced adhesion of THP-1 cells to HUVECs. Foxc2 siRNA dramatically increased both LPS-induced ICAM-1 expression and LPS-induced adhesion of THP-1 human monocytes cells to HUVECs. We conclude that Foxc2 inhibited LPS-induced adhesion of THP-1 cells to HUVECs by suppressing ICAM-1 expression in HUVECs.

The role of the LncRNA-FA2H-2-MLKL pathway in atherosclerosis by regulation of autophagy flux and inflammation through mTOR-dependent signaling.

Atherosclerosis is a progressive, chronic inflammation in arterial walls. Long noncoding RNAs (lncRNAs) participate in inflammation, but the exact mechanism in atherosclerosis is unclear. Our microarray analyses revealed that the levels of lncRNA-FA2H-2 were significantly decreased by oxidized low-density lipoprotein (OX-LDL). Bioinformatics analyses indicated that mixed lineage kinase domain-like protein (MLKL) might be regulated by lncRNA-FA2H-2. In vitro experiments showed that lncRNA-FA2H-2 interacted with the promoter of the MLKL gene, downregulated MLKL expression, and the binding sites between -750 and 471 were necessary for lncRNA-FA2H-2 responsiveness to MLKL. Silencing lncRNA-FA2H-2 and overexpression of MLKL could activate inflammation and inhibited autophagy flux. Both lncRNA-FA2H-2 knockdown and overexpression of MLKL could significantly aggravate inflammatory responses induced by OX-LDL. We found that the 3-methyladenine (3-MA) and Atg7-shRNA enhanced inflammatory responses induced by knockdown of lncRNA-FA2H-2 and overexpression of MLKL. We demonstrated that the effects of MLKL on autophagy might be associated with a mechanistic target of rapamycin (mTOR)-dependent signaling pathways. In vivo experiments with apoE knockout mice fed a western diet demonstrated that LncRNA-FA2H-2 knockdown decreased microtubule-associated expression of microtubule-associated protein 1 light chain 3 II and lysosome-associated membrane protein 1, but increased expression of sequestosome 1 (p62), MLKL, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, and interleukin-6 in atherosclerotic lesions. Our findings indicated that the lncRNA-FA2H-2-MLKL pathway is essential for regulation of autophagy and inflammation, and suggested that lncRNA-FA2H-2 and MLKL could act as potential therapeutic targets to ameliorate atherosclerosis-related diseases.

LncRNA-RP11-714G18.1 suppresses vascular cell migration via directly targeting LRP2BP.

Atherosclerotic cardiovascular disease is considered as the leading cause of mortality and morbidity worldwide. Accumulating evidence supports an important role for long noncoding RNA (lncRNA) in the pathogenesis of atherosclerosis. Nevertheless, the role of lncRNA in atherosclerosis-associated vascular dysfunction and the underlying mechanism remain elusive. Here, using microarray analysis, we identified a novel lncRNA RP11-714G18.1 with significant reduced expression in human advanced atherosclerotic plaque tissues. We demonstrated in both human vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) that RP11-714G18.1 impaired cell migration, reduced the adhesion of ECs to monocytes, suppressed the neoangiogenesis, decreased apoptosis of VSMCs and promoted nitric oxide production. Mechanistically, RP11-714G18.1 could directly bind to its nearby gene LRP2BP and increased the expression of LRP2BP. Moreover, we showed that RP11-714G18.1 impaired cell migration through LRP2BP-mediated downregulation of matrix metalloproteinase (MMP)1 in both ECs and VSMCs. In atherosclerotic patients, the serum levels of LRP2BP were positively correlated with high-density lipoprotein cholesterol, but negatively correlated with cardiac troponin I. Our study suggests that RP11-714G18.1 may play an athero-protective role by inhibiting vascular cell migration via RP11-714G18.1/LRP2BP/MMP1 signaling pathway, and targeting the pathway may provide new therapeutic approaches for atherosclerosis.

[Carotid artery stenosis treated with modified carotid endarterectomy: report of two cases].

OBJECTIVE: Based on standard carotid endarterectomy, we performed modified carotid endarterectomy in two cases of carotid artery stenosis by changing the direction of the carotid artery incision to avoid restenosis of the internal carotid artery without using a patch. The two patients recovered smoothly without any complications. Compared with eversion or patch endarterectomy, this modified carotid endarterectomy avoids restenosis of the carotid artery and shortens operation time.

Hairy/enhancer of Split Homologue-1 Suppresses Vascular Endothelial Growth Factor-induced Angiogenesis via Downregulation of Osteopontin Expression.

Angiogenesis plays a critical role in the progression and vulnerability of atherosclerotic plaques; however, the orchestration of angiogenesis in atherosclerotic plaque formation remains unclear. The results of microarray analysis, real-time PCR and immunohistochemical analyses showed that Hairy/enhancer of split homologue-1 (Hes-1) expression was significantly decreased, while that of osteopontin (OPN) was increased, in atherosclerotic plaques. Meanwhile, immunofluorescence results demonstrated that both Hes-1 and OPN were expressed in endothelial cells (ECs) of neovessels in atherosclerotic plaques. The results of an in vitro study showed that Hes-1 was downregulated, while OPN was upregulated, in a time- and dose-dependent manner in human umbilical vein endothelial cells (HUVECs) by VEGF treatment. In addition, Hes-1 knockdown was found to have transcriptional promotion effect on OPN expression in HUVECs and enhance OPN-induced angiogenesis in response to VEGF. On the contrary, Hes-1 overexpression inhibited OPN expression in HUVECs and reduced angiogenesis in vitro and in vivo. The results of this study suggest that decreased Hes-1 expression in atherosclerotic plaques exaggerate VEGF-induced angiogenesis by upregulating OPN. Therefore, restoring Hes-1 expression and inhibiting OPN expression may be a promising strategy to prevent vulnerable plaque formation in patients with atherosclerosis.

Long Noncoding RNA HOXC-AS1 Suppresses Ox-LDL-Induced Cholesterol Accumulation Through Promoting HOXC6 Expression in THP-1 Macrophages.

Atherosclerosis is a common pathological basis of cardiovascular disease, which remains the leading cause of mortality. Long noncoding RNAs (lncRNAs) are newly studied non-protein-coding RNAs involved in gene regulation, but how lncRNAs exert regulatory effect on atherosclerosis remains unclear. In this study, we found that lncRNA HOXC cluster antisense RNA 1 (HOXC-AS1) and homeobox C6 (HOXC6) were downregulated in carotid atherosclerosis by performing microarray analysis. The results were verified in atherosclerotic plaques and normal arterial intima tissues by quantitative reverse transcription PCR and western blot analysis. Lentivirus-mediated overexpression of HOXC-AS1 induced HOXC6 expression at mRNA and protein levels in THP-1 macrophages. Besides, oxidized low-density lipoprotein (Ox-LDL) decreased expression of HOXC-AS1 and HOXC6 in a time-dependent manner. Induction of cholesterol accumulation by Ox-LDL could be partly suppressed by overexpression of HOXC-AS1.

VNN1 promotes atherosclerosis progression in apoE-/- mice fed a high-fat/high-cholesterol diet.

Accumulated evidence shows that vanin-1 (VNN1) plays a key part in glucose metabolism. We explored the effect of VNN1 on cholesterol metabolism, inflammation, apoptosis in vitro, and progression of atherosclerotic plaques in apoE(-/-) mice. Oxidized LDL (Ox-LDL) significantly induced VNN1 expression through an ERK1/2/cyclooxygenase-2/PPARα signaling pathway. VNN1 significantly increased cellular cholesterol content and decreased apoAI and HDL-cholesterol (HDL-C)-mediated efflux by 25.16% and 23.13%, respectively, in THP-1 macrophage-derived foam cells (P < 0.05). In addition, VNN1 attenuated Ox-LDL-induced apoptosis through upregulation of expression of p53 by 59.15% and downregulation of expression of B-cell lymphoma-2 127.13% in THP-1 macrophage (P < 0.05). In vivo, apoE(-/-) mice were divided randomly into two groups and transduced with lentivirus (LV)-Mock or LV-VNN1 for 12 weeks. VNN1-treated mice showed increased liver lipid content and plasma levels of TG (124.48%), LDL-cholesterol (119.64%), TNF-α (148.74%), interleukin (IL)-1ß (131.81%), and IL-6 (156.51%), whereas plasma levels of HDL-C (25.75%) were decreased significantly (P < 0.05). Consistent with these data, development of atherosclerotic lesions was increased significantly upon infection of apoE(-/-) mice with LV-VNN1. These observations suggest that VNN1 may be a promising therapeutic candidate against atherosclerosis.

Dihydrocapsaicin suppresses proinflammatory cytokines expression by enhancing nuclear factor IA in a NF-κB-dependent manner.

BACKGROUND: Atherosclerosis is a chronic inflammatory disease and represents the leading cause of morbidity and mortality throughout the world. Accumulating evidences have showed that Dihydrocapsaicin (DHC) has been found to exert multiple pharmacological and physiological effects. Nevertheless, the effects and possible mechanism of DHC on proinflammatory response remain largely unexplained. METHODS AND RESULTS: We found that DHC markedly upregulated NFIA and suppressed NF-κB expression in THP-1 macrophages. Up-regulation of proinflammatory cytokines induced by LPS including TNF-α, IL-1ß and IL-6 were markedly suppressed by DHC treatment. We also observed that protein level of NFIA was significantly increased while NF-κB and proinflammatory cytokines were decreased by DHC treatment in apoE(-/-) mice. Lentivirus-mediated overexpression of NFIA suppressed NF-κB and proinflammatory cytokines expression both in THP-1 macrophages and plaque tissues of apoE-/- mice. Moreover, treatment with lentivirus-mediated overexpression of NFIA made the down-regulation of DHC on NF-κB and proinflammatory cytokines expression notably accentuated in THP-1 macrophages and apoE(-/-) mice. In addition, treatment with siRNA targeting NF-κB accentuated the suppression of proinflammatory cytokines by lentivirus-mediated overexpression of NFIA. CONCLUSION: These observations demonstrated that DHC can significantly decrease proinflammatory cytokines through enhancing NFIA and inhibiting NF-κB expression and thus DHC may be a promising candidate as an anti-inflammatory drug for atherosclerosis as well as other disorders.

MicroRNA-125b-5p attenuates lipopolysaccharide-induced monocyte chemoattractant protein-1 production by targeting inhibiting LACTB in THP-1 macrophages.

BACKGROUND: Increasing evidence has shown that gene beta-lactamases (LACTB) has effect on obesity. Recent studies demonstrate that miR-125b-5p is a potential small molecular target to prevent atherosclerosis obliterans which may be inflammation-associated. However, the mechanism underlying miR-125b-5p on arteriosclerosis development, the association between miR-125b-5p and LACTB is still unknown. METHODS AND RESULTS: In this study, we found that miR-125b-5p was down-regulated while LACTB was up-regulated in atherosclerotic plaques. Our results showed that LACTB was a potential target of miR-125b-5p based on bioinformatics analyses and dual-luciferase reporter assays. Moreover, miR-125b-5p directly inhibited LACTB protein and mRNA expression by targeting LACTB 3'UTR. Meanwhile, the expression of monocyte chemotactic protein-1 (MCP-1) was decreased by miR-125b-5p mimics treatment in THP-1 macrophages. We also demonstrated that the level of MCP-1 was markedly increased when transfected with LACTB. In addition, the upregulation of MCP-1 expression through miR-125b-5p inhibitors was attenuate by siRNA-LACTB treatment in LPS-stimulated THP-1 macrophages. CONCLUSIONS: MiR-125b-5p attenuates the secretion of MCP-1 by directly targeting inhibiting LACTB in LPS-stimulated THP-1 macrophages.

Lipoxin A4 promotes ABCA1 expression and cholesterol efflux through the LXRα signaling pathway in THP-1 macrophage-derived foam cells.

Adenosine triphosphate-binding cassette transporter A1 (ABCA1) is a crucial cholesterol transporter and plays a central role in the high density lipoproteins (HDL) cholesterol metabolism and lipid clearance from the foam cell. Lipoxin A4 (LXA4) is an endogenous lipid mediator that requires cell-cell interaction or cell-platelet interaction for its synthesis. The roles of LXA4 on inflammatory responses are well described, while its effects on mediating ABCA1 and underlying mechanisms remain unclear. In this study, we showed that LXA4 significantly increases expression of ABCA1 and LXRα in a dose-dependent manner in THP-1 macrophage-derived foam cells. Cellular cholesterol content was decreased while cholesterol efflux was increased by LXA4 treatment. However, after short interfering RNA of LXRα, the effects of LXA4 on ABCA1 expression and cholesterol metabolism were significantly abolished. These results provide evidence that LXA4 increases ABCA1 expression and promotes cholesterol efflux through LXRα pathway in THP-1 macrophage-derived foam cells.

Ox-LDL Upregulates IL-6 Expression by Enhancing NF-κB in an IGF2-Dependent Manner in THP-1 Macrophages.

Interleukin 6 (IL-6) is a pro-inflammatory cytokine that is well established as a vital factor in determining the risk of coronary heart disease and pathogenesis of atherosclerosis. Moreover, accumulating evidences have shown that oxidized low-density lipoprotein (ox-LDL) can promote IL-6 expression in macrophages. Nevertheless, the underlying mechanism of how ox-LDL upregulates IL-6 expression remains largely unexplained. We found that the expression of insulin-like growth factor 2 (IGF2), nuclear factor kappa B (NF-κB), and IL-6 was upregulated at both the messenger RNA (mRNA) and protein levels in a dose-dependent manner when treated with 0, 25, 50, or 100 µg/mL of ox-LDL for 48 h in THP-1 macrophages. Moreover, overexpression of IGF2 significantly upregulated NF-κB and IL-6 expressions in THP-1 macrophages. However, the upregulation of NF-κB and IL-6 expressions induced by ox-LDL were significantly abolished by IGF2 small interfering RNA (siRNA) in THP-1 macrophages. Further studies indicated the upregulation of IL-6 induced by ox-LDL could be abolished when treated with NF-κB siRNA in THP-1 macrophages. Ox-LDL might upregulate IL-6 in the cell and its secretion via enhancing NF-κB in an IGF2-dependent manner in THP-1 macrophages.

ApoM Suppresses TNF-α-Induced Expression of ICAM-1 and VCAM-1 Through Inhibiting the Activity of NF-κB.

To explore the anti-inflammatory effect of apolipoprotein M (apoM) on regulation of tumor necrosis factor-α (TNF-α)-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and further investigate the molecular mechanism of apoM in this process. We found that TNF-α could decrease expression of apoM and inhibitor of NF-κB-α (IκBα) in HepG2 cells. Overexpression of apoM caused a significant decrease of ICAM-1 and VCAM-1 expression, while it caused a significant increase of IκBα expression in HepG2 cells. Furthermore, the treatment with TNF-α could increase ICAM-1 and VCAM-1 expression, decrease IκBα protein expression, and increase nuclear factor-κB (NF-κB) activity, and these effects were markedly enhanced by small interfering RNA (siRNA)-mediated silencing of apoM in HepG2 cells. Our findings demonstrated that apoM suppressed TNF-α-induced expression of ICAM-1 and VCAM-1 through inhibiting the activity of NF-κB.

Ox-LDL upregulates CRP expression through the IGF2 pathway in THP-1 macrophages.

C-reactive protein (CRP) is an acute-phase reactant protein that not only plays a predictive role in determining atherogenesis risk but also represents an active participant in atherogenesis onset and progression. Moreover, an increasing number of studies have reported that oxidized low-density lipoprotein (Ox-LDL) plays a significant role in the initiation and progression of atherosclerosis. However, the effect and underlying mechanism of Ox-LDL on CRP expression remains unclear. THP-1 macrophages were treated with 0, 25, 50, or 100 µg/mL of Ox-LDL for 48 h, or 50 µg/mL of Ox-LDL for 0, 12, 24, and 48 h, respectively. Messenger RNA (mRNA) and protein levels were measured by real-time quantitative PCR and Western blot analysis, respectively. We found that Ox-LDL markedly increased insulin-like growth factor 2 (IGF2) and CRP mRNA and protein levels in a dose- and time-dependent manner in THP-1 macrophages. Treatment with Ox-LDL increased CRP protein expression, and this effect was completely abolished by siRNA-mediated silencing of IGF2 in THP-1 macrophages. Moreover, treatment with pcDNA3.1-IGF2 significantly enhanced CRP protein expression in Ox-LDL-stimulated THP-1 macrophages. CRP expression is upregulated by Ox-LDL through the IGF2 pathway in THP-1 macrophages.

An agomir of miR-144-3p accelerates plaque formation through impairing reverse cholesterol transport and promoting pro-inflammatory cytokine production.

AIMS: ATP-binding cassette transporter A1 (ABCA1) mediates the efflux of cholesterol and phospholipids to lipid-poor apolipoproteins, which then form nascent HDL, a key step in the mechanism of reverse cholesterol transport (RCT). While a series of microRNAs (miRNAs) have been identified as potent post-transcriptional regulators of lipid metabolism, their effects on ABCA1 function and associated mechanisms remain unclear. METHODS AND RESULTS: ABCA1 was identified as a potential target of miR-144-3p, based on the results of bioinformatic analysis and the luciferase reporter assay, and downregulated after transfection of cells with miR-144-3p mimics, as observed with real-time PCR and western blot. Moreover, miR-144-3p mimics (agomir) enhanced the expression of inflammatory factors, including IL-1ß, IL-6 and TNF-α, in vivo and in vitro, inhibited cholesterol efflux in THP-1 macrophage-derived foam cells, decreased HDL-C circulation and impaired RCT in vivo, resulting in accelerated pathological progression of atherosclerosis in apoE-/- mice. Clinical studies additionally revealed a positive correlation of circulating miR-144-3p with serum CK, CK-MB, LDH and AST in subjects with AMI. CONCLUSIONS: Our findings clearly indicate that miR-144-3p is essential for the regulation of cholesterol homeostasis and inflammatory reactions, supporting its utility as a potential therapeutic target of atherosclerosis and a promising diagnostic biomarker of AMI.

A lincRNA-DYNLRB2-2/GPR119/GLP-1R/ABCA1-dependent signal transduction pathway is essential for the regulation of cholesterol homeostasis.

Accumulated evidence shows that G protein-coupled receptor 119 (GPR119) plays a key role in glucose and lipid metabolism. Here, we explored the effect of GPR119 on cholesterol metabolism and inflammation in THP-1 macrophages and atherosclerotic plaque progression in apoE(-/-) mice. We found that oxidized LDL (Ox-LDL) significantly induced long intervening noncoding RNA (lincRNA)-DYNLRB2-2 expression, resulting in the upregulation of GPR119 and ABCA1 expression through the glucagon-like peptide 1 receptor signaling pathway. GPR119 significantly decreased cellular cholesterol content and increased apoA-I-mediated cholesterol efflux in THP-1 macrophage-derived foam cells. In vivo, apoE(-/-) mice were randomly divided into two groups and infected with lentivirus (LV)-Mock or LV-GPR119 for 8 weeks. GPR119-treated mice showed decreased liver lipid content and plasma TG, interleukin (IL)-1ß, IL-6, and TNF-α levels, whereas plasma levels of apoA-I were significantly increased. Consistent with this, atherosclerotic lesion development was significantly inhibited by infection of apoE(-/-) mice with LV-GPR119. Our findings clearly indicate that, Ox-LDL significantly induced lincRNA-DYNLRB2-2 expression, which promoted ABCA1-mediated cholesterol efflux and inhibited inflammation through GPR119 in THP-1 macrophage-derived foam cells. Moreover, GPR119 decreased lipid and serum inflammatory cytokine levels, decreasing atherosclerosis in apoE(-/-) mice. These suggest that GPR119 may be a promising candidate as a therapeutic agent.

[Change of renal graft dendritic cells in the early stage following transplantation: a dynamic observation in rats].

OBJECTIVE: To observe the dynamic changes of dendritic cells (DCs) in the renal graft of rats within 72 h after renal transplantation. METHODS: Using SD rats as the donors and Wistar rats as the recipients, renal transplantation was performed in 30 pairs of rats, with another 5 donor kidneys that were not transplanted serving as the sham operation group. The transplanted kidneys were harvested at 1, 6, 12, 24, 48 and 72 h after recovery of blood circulation, paraffin-embedded and sectioned ,followed by HE staining and immunohistochemical staining for S-100 protein for DC identification. The pathological changes and the DC density per glomerulus in the renal graft were observed with optical microscope. RESULTS: No signs of acute rejection were found in these sections. Few DCs were observed in the sham operation group and in the renal graft 1 h after transplantation. The number of DCs in the renal graft increased with time and reached the maximum 24 h after transplantation followed by gradual decrease. CONCLUSIONS: Within 72 h after renal transplantation, the number of DCs in the graft varies following a curve with a single peak. Increased DC density in the graft may result from recipient DC migration into the graft, and accordingly, decreased recipient DC migration results in decrease of DC density in the graft. The pattern of DC number variation in the graft can be helpful to further improve the therapy against graft rejection.