Treatment of bilateral developmental dysplasia of the hip joint with an improved technique: A case report.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a common osteoarticular deformity in pediatric orthopedics. A patient with bilateral DDH was diagnosed and treated using our improved technique "(powerful overturning acetabuloplasty)" combined with femoral rotational shortening osteotomy. CASE SUMMARY: A 4-year-old girl who was diagnosed with bilateral DDH could not stand normally, and sought surgical treatment to solve the problem of double hip extension and standing. As this child had high dislocation of the hip joint and the acetabular index was high, we changed the traditional acetabuloplasty to "powerful turnover acetabuloplasty" combined with femoral rotation shortening osteotomy. During the short-term postoperative follow-up (1, 3, 6, 9, 12, and 15 months), the child had no discomfort in her lower limbs. After the braces and internal fixation plates were removed, formal rehabilitation training was actively carried out. CONCLUSION: Our "powerful overturning acetabuloplasty" combined with femoral rotational shortening osteotomy is feasible in the treatment of DDH in children. This technology may be widely used in the clinic.

Revealing the impact of TOX3 on osteoarthritis: insights from bioinformatics.

Osteoarthritis, a prevalent long-term condition of the joints, primarily impacts older individuals, resulting in discomfort, restrictions in mobility, and a decrease in overall well-being. Although Osteoarthritis is widely spread, there is a lack of successful interventions to stop the advancement of the condition. Numerous signaling pathways have been emphasized in recent research on Osteoarthritis, yet the diagnostic significance of numerous genes has not been investigated. To identify genes that were expressed differently in osteoarthritis, we utilized the Gene Expression Omnibus database. To identify marker genes, we built machine learning models including Least Absolute Shrinkage and Selection Operator and Random Forest. We categorized Osteoarthritis samples and performed immune cell infiltration analysis based on the expression patterns of these characteristic genes. Both the Least Absolute Shrinkage and Selection Operator and Random Forest models selected six marker genes (TOX3, ARG1, CST7, RERGL, COL11A1, NCRNA00185) out of a total of 17 differentially expressed genes. The osteoarthritis samples were categorized into two groups, namely a high expression group and a low expression group, based on the median levels of TOX3 expression. Comparative analysis of these groups identified 85 differentially expressed genes, showing notable enrichment in pathways related to lipid metabolism in the group with high expression. Analysis of immune cell infiltration revealed noticeable differences in immune profiles among the two groups. The group with high expression of TOX3 showed a notable increase in Mast cells and Type II IFN Response, whereas B cells, Cytolytic activity, Inflammation-promoting cells, NK cells, pDCs, T cell co-inhibition, Th1 cells, and Th2 cells were significantly decreased. We constructed a ceRNA network for TOX3, revealing 57 lncRNAs and 18 miRNAs involved in 57 lncRNA-miRNA interactions, and 18 miRNA-mRNA interactions with TOX3. Validation of TOX3 expression was confirmed using an external dataset (GSE29746), revealing a notable increase in Osteoarthritis samples. In conclusion, our study presents a comprehensive analysis identifying TOX3 as a potential feature gene in Osteoarthritis. The distinct immune profiles and involvement in fat metabolism pathways associated with TOX3 expression suggest its significance in Osteoarthritis pathogenesis. The study establishes a basis for comprehending the intricate correlation between characteristic genes and Osteoarthritis, as well as for the formulation of individualized therapeutic approaches.

Application of state-target application of painful arthritis liver and kidney deficiency: A review.

In recent years, with the progress and development of the times, our eating habits and lifestyle changes have led to an increase in gouty arthritis annually, with the main use of nonsteroidal anti-inflammatory drugs and other drugs. These drugs are highly dependent, resulting in an unresponsive state, which is easy to recur. Therefore, more and more patients choose traditional Chinese medicine (TCM) to treat them. After years of continuous exploration and rich clinical experience accumulation, Academician TongXiaolin put forward the dialectical strategy of "combination of state and target" in TCM. He believed that the deficiency of liver and kidney is transformed into a state, with uric acid as the target. Through the target prescription Simiao decoction to clever heat and moisture, replenishing liver and kidney, the target medicine Bixie (Dioscorea Tokoro Makino) to rheumatism, Shujin;Tufuling (Rhizoma Smilacis Glabrae) for detoxification, dehydration gas, Weilingxian (Radix et Rhizoma Clematidis) to rheumatism, pass meridians, and the combination of the condition and target achieves a good clinical effect.

Deer antler extract promotes tibia fracture healing in mice by activating BMP-2/SMAD4 signaling pathway.

BACKGROUND: Deer antler is a traditional Chinese medicine with the function of tonifying kidney and strengthening bone, which is often used to treat orthopedic diseases. METHODS: Eight-week-old C57BL/6 mice were used as the fixation model of open tibial fracture with intramedullary nail. The mice were treated with deer antler extract (DAE) or PBS by oral gavage once daily. The tibial fracture samples were collected and performed to the tissue analysis, including X-ray, micro-CT, histology, qRT-PCR, immunohistochemistry. MC3T3-E1 cells were used to detect the effect of deer antler extract on ability of cell proliferation and migration by CCK-8 assay and cell scratch test. RESULTS: Imaging and micro-CT showed that DAE could promote the healing of tibial fracture in mice, and histological analysis showed that DAE could promote the transformation of cartilage callus to bone callus in fracture area. The results of qRT-PCR and immunohistochemistry showed that DAE could promote intrachondral ossification in fracture zone and the mechanism of promoting fracture healing may be related to the activation of BMP-2/SMAD4 signaling pathway. In the cytological experiment of DAE, it can be found that DAE promoted the proliferation of MC3T3-E1 cells and the migration of MC3T3-E1 cells at a certain concentration, which is also related to the promotion of fracture healing by DAE. CONCLUSION: DAE can promote fracture healing by activating BMP-2/SMAD4 signaling pathway. DAE has the potential to be used in clinic as an important means of promoting fracture healing.

Transcriptional sequencing analysis reveals the potential use of deer antler for "tonifying the kidney and strengthening bone".

BACKGROUND: It is recorded in the Chinese Pharmacopoeia that deer antlers can be used to tonify the kidney and strengthen bone. Although numerous studies have demonstrated that deer antler has protective effects on the kidney and bone, its molecular mechanisms remain to be elucidated. The aim of this study was to explore the molecular mechanism underlying its effects on the bone and kidney. METHODS: Water extract of pilose antler was prepared and then filtered through a 0.45 µm Hollow Fiber Cartridge (GE Healthcare, USA). The filtrate was freeze-dried by a Heto PowerDry LL3000 Freeze Dryer (Thermo, USA) and stored at - 80 °C. Rats were treated with deer antler extract (DAE) prepared in advance, and gene regulatory network in the kidney and bone was detected by RNA-Seq technique. Micro-CT was used to detect bone trabecular formation, bone mineral density (BMD) and bone volume fraction (BV/TV). RESULTS: The results demonstrate that DAE could jointly heighten renal function by maintaining renal homeostasis, combating renal fibrosis, and reducing renal inflammation by regulating ion transport. Furthermore, DAE can strengthen the bone system by stimulating osteoblast differentiation and regulating bone regeneration and the bone marrow microenvironment. Micro-CT results confirmed that DAE can promote bone trabecular formation and increase BMD and BV/TV. We also identified many genes that can regulate both the kidney and bone simultaneously, which explained the theory of "kidney governing bone" at the molecular level and provided possible strategies for further application of this theory to treat diseases. CONCLUSIONS: DAE enhances renal function, maintains renal homeostasis, positively regulates skeletal system development, and increases bone mineral density. The underlying mechanism involves improving the expression levels of functional genes involved in renal function and regulation and repair, as well as genes that positively regulate skeletal system development.

Giant intermuscular lipoma of hip: A case report.

INTRODUCTION: Lipomas are one of the most common benign tumors, but deep tissue and huge lipomas are rare. PRESENTATION OF CASE: A 59-year-old middle-aged woman was admitted to hospital for right hip mass resection because of numbness and pain in her right lower limb for 6 months. Ultrasound and nuclear magnetic resonance imaging (MRI) showed irregular mass. On the assumption of malignancy, the patient underwent a right hip mass resection and returned to normal with no short-term or long-term response. HE (hematoxylin-eosin) staining of the tumor showed the characteristics of a benign tumor. DISCUSSION: The pathogenesis of myolipoma is not clear, and it may be related to brown adipose tissue. When lipoma is huge, it needs interventional treatment. Complete encapsulated myolipoma can usually be completely removed, with low recurrence possibility and good prognosis. CONCLUSION: Giant intramuscular lipoma of hip and its clinical manifestations are relatively rare. And the results of ultrasound imaging are similar to those of the surrounding normal adipose tissue. No significant difference was observed by naked eye. In particular, postoperative pathological examination is needed to make a definite diagnosis and differential diagnosis. Clinically, surgical treatment is often used, and the prognosis is good, but recurrence is possible. The following report discusses the experience of one of our patients, with literature review.

Analysis of the prevalence, risk factors, and clinical characteristics of osteoporosis in patients with essential hypertension.

BACKGROUND: The present study investigated the prevalence of osteoporosis (OP) among patients with essential hypertension (EH) in the Changchun community and analysed the correlation between EH and OP. METHODS: The study included 425 subjects with EH and 425 age- and sex-matched healthy controls. Bone mineral density (BMD) and serum creatinine (CR) levels were measured, and the subjects' current EH and OP statuses were surveyed to analyse the correlation between EH and OP. RESULTS: The EH group exhibited lower BMD and a higher rate of having OP than the control group, and this difference was statistically significant (p < 0.05). A significant sex difference in the BMD T-score was observed among the subjects (male: - 1.19 ± 1.55, female: - 1.70 ± 1.34). In both the EH group and the control group, the rate of having OP in females was greater than that in males. However, the OP prevalence among subjects with EH varied significantly by age, body weight, fracture history, nocturnal urination frequency, depression and anxiety status, duration of hypertension, and antihypertensive medication use (p < 0.05). Two-way analysis of variance suggested an effect of the interaction between different EH statuses and bone mass conditions on the serum CR values (F = 3.584, p = 0.028, bias η2 = 0.008). CONCLUSIONS: The prevalence of OP and low BMD were significantly higher among subjects with EH than among healthy controls. Additionally, the findings indicate that age, weight, fracture history, nocturnal urination frequency, depression and anxiety, duration of hypertension and antihypertensive drug use may be correlated to having OP in EH subjects, requiring further studies. Moreover, serum CR levels in subjects with different bone mass profiles were strongly influenced by the presence or absence of EH, and the serum CR levels differed significantly with the interaction of these two factors.

Thunder-fire moxibustion for lumbar disc herniation: A systematic review and meta-analysis.

BACKGROUND: Lumbar disc herniation (LDH) is a common degenerative disease that severely impacts the quality of life of patients. Thunder-fire moxibustion is an ancient Chinese medicine-based external therapeutic procedure that has been employed for pain relief until this day. The focus of our study was to demonstrate the effectiveness and safety of thunder-fire moxibustion in the treatment of LDH. METHODS: The literature databases searched included the Cochrane Library, Web of Science, Springer, PubMed, Wanfang digital periodicals database, China national knowledge infrastructure, VIP, and Chinese biomedical literature database, and the search period was from database creation to March 2022. These include randomized controlled trials of Thunder-Fire moxibustion alone or in combination with other therapies for LDH. Two evaluators independently extracted data. We accessed the quality of inclusive studies through a Cochrane risk of bias tool. Meta-analyses were performed using Review Manager (Version 5.5). Data was analyzed using fixed-effects or random-effects models, depending on the heterogeneity test results. RESULTS: The meta-analysis included 17 studies involving 1344 patients with LDH. The analysis results were as follows: compared with other therapies, the efficacy of thunder-fire moxibustion was statistically significant; the total effective rate (RR = 1.20; 95%CI [1.15, 1.26]; P < .00001), the Japanese orthopaedic association score (MD = 4.42; 95%CI [4.10, 4.73]; P < .00001), the pain score (SMD = -2.66; 95% CI [-3.39, -1.94]; P < .00001). Only 2 reported no adverse events in the included literature, and the remaining had no relevant records. The quality of the evidence in the 17 papers we examined was low or very low. CONCLUSION: Thunder-Fire moxibustion is effective in relieving discomfort in patients with LDH. It has significant clinical efficacy, but there is still a need for prospective, multicentre, large-sample randomized controlled trials to enhance the clinical evidence due to the quality of included studies and methodological limitations.

hnRNPLL controls pluripotency exit of embryonic stem cells by modulating alternative splicing of Tbx3 and Bptf.

The regulatory circuitry underlying embryonic stem (ES) cell self-renewal is well defined, but how this circuitry is disintegrated to enable lineage specification is unclear. RNA-binding proteins (RBPs) have essential roles in RNA-mediated gene regulation, and preliminary data suggest that they might regulate ES cell fate. By combining bioinformatic analyses with functional screening, we identified seven RBPs played important roles for the exit from pluripotency of ES cells. We characterized hnRNPLL, which mainly functions as a global regulator of alternative splicing in ES cells. Specifically, hnRNPLL promotes multiple ES cell-preferred exon skipping events during the onset of ES cell differentiation. hnRNPLL depletion thus leads to sustained expression of ES cell-preferred isoforms, resulting in a differentiation deficiency that causes developmental defects and growth impairment in hnRNPLL-KO mice. In particular, hnRNPLL-mediated alternative splicing of two transcription factors, Bptf and Tbx3, is important for pluripotency exit. These data uncover the critical role of RBPs in pluripotency exit and suggest the application of targeting RBPs in controlling ES cell fate.

CDK5RAP3 Deficiency Restrains Liver Regeneration after Partial Hepatectomy Triggering Endoplasmic Reticulum Stress.

CDK5 regulatory subunit-associated protein 3 (CDK5RAP3) plays a crucial role in mammalian liver development and hepatic function by controlling hepatocyte proliferation and differentiation, glucose and lipid metabolism, UFMylation, and endoplasmic reticulum homeostasis. However, the role of CDK5RAP3 in liver regeneration remains unknown. A liver-specific Cdk5rap3 knockout (CKO) mouse model was used to study the function of CDK5RAP3 during liver regeneration induced by standard two-thirds partial hepatectomy (PHx). Twenty-four hours after PHx, the liver-to-body weight ratio was markedly higher in CKO mice than in wild-type mice. However, this ratio did not increase significantly and gradually over time after PHx in CKO mice. Hepatocyte proliferation was significantly delayed in CKO mice compared with wild-type mice. Meanwhile, CDK5RAP3 deficiency increased lipid accumulation, impaired glycogen synthesis, and lowered blood glucose levels after PHx. Critically, the absence of CDK5RAP3 seemed to promote an inflammatory response and induce apoptosis at a late stage of liver regeneration. In addition, CDK5RAP3 deficiency disrupted UFMylation homeostasis and aggravated endoplasmic reticulum stress in hepatocytes after PHx. Taken together, these data suggest that CDK5RAP3 enhances liver regeneration, at least partially via controlling cell cycle and glucose and lipid metabolism.

CDK5RAP3, a UFL1 substrate adaptor, is crucial for liver development.

Protein modification by ubiquitin and ubiquitin-like proteins (UBLs) regulates numerous biological functions. The UFM1 system, a novel UBL conjugation system, is implicated in mouse development and hematopoiesis. However, its broad biological functions and working mechanisms remain largely elusive. CDK5RAP3, a possible ufmylation substrate, is essential for epiboly and gastrulation in zebrafish. Herein, we report a crucial role of CDK5RAP3 in liver development and hepatic functions. Cdk5rap3 knockout mice displayed prenatal lethality with severe liver hypoplasia, as characterized by delayed proliferation and compromised differentiation. Hepatocyte-specific Cdk5rap3 knockout mice suffered post-weaning lethality, owing to serious hypoglycemia and impaired lipid metabolism. Depletion of CDK5RAP3 triggered endoplasmic reticulum stress and activated unfolded protein responses in hepatocytes. We detected the in vivo interaction of CDK5RAP3 with UFL1, the defined E3 ligase in ufmylation. Notably, loss of CDK5RAP3 altered the ufmylation profile in liver cells, suggesting that CDK5RAP3 serves as a novel substrate adaptor for this UBL modification. Collectively, our study identifies CDK5RAP3 as an important regulator of ufmylation and suggests the involvement of ufmylation in mammalian development.

Arrayed mutant haploid embryonic stem cell libraries facilitate phenotype-driven genetic screens.

Forward genetic screens using mammalian embryonic stem (ES) cells have identified genes required for numerous cellular processes. However, loss-of-function screens are more difficult to conduct in diploid cells because, in most cases, both alleles of a gene must be mutated to exhibit a phenotype. Recently, mammalian haploid ES cell lines were successfully established and applied to several recessive genetic screens. However, all these screens were performed in mixed pools of mutant cells and were mainly based on positive selection. In general, negative screening is not easy to apply to these mixed pools, although quantitative deep sequencing of mutagen insertions can help to identify some 'missing' mutants. Moreover, the interplay between different mutant cells in the mixed pools would interfere with the readout of the screens. Here, we developed a method for rapidly generating arrayed haploid mutant libraries in which the proportion of homozygous mutant clones can reach 85%. After screening thousands of individual mutant clones, we identified a number of novel factors required for the onset of differentiation in ES cells. A negative screen was also conducted to discover mutations conferring cells with increased sensitivity to DNA double-strand breaks induced by the drug doxorubicin. Both of these screens illustrate the value of this system.

Sorting of chromosomes on FACSAria(TM) SORP for the preparation of painting probes.

High purity chromosome sorting can be performed on instruments such as MoFlo MLS and BD influx, which are stream-in-air sorters equipped with water-cooled high power lasers. The FACSAria is a true fixed alignment, low laser powered instrument with a quartz flow cell gel-coupled to the collection optics. However, whether high purity mouse and human chromosomes can be obtained by sorting on the BD FACSAria(TM) Special Order Research Product (FACSAria SORP) remains to be determined. Here, we report that the high resolution flow karyotype of mouse lymphocytes and normal male human peripheral blood mononuclear cells (hPBMCs) can be obtained on the FACSAria SORP using laser power settings of 50 mW for 355 nm and 20 mW for 444 nm excitation. Furthermore, the use of Fluorescence in situ hybridization (FISH) confirmed that chromosome paints prepared from the sorted chromosomes demonstrated high purity and signal specificity. Notably, human chromosome 12 was separated from the chromosome 9-12 cluster in the flow karyotype, and its identity was confirmed using FISH in trisomy 12 human ES cell lines B2-C7 and B2-B8. In addition, multicolor FISH (mFISH) with human chromosome painting probes to 13,18, 21, and sex chromosomes X and Y showed high signal specificity in hPBMCs. Taken together, our findings demonstrated that high resolution flow karyotype can be obtained using FACSAria SORP. Moreover, a FISH analysis confirmed high purity of the sorted chromosomes. Additionally, in contrast to centromeric satellite probes, chromosome painting probes with high specificity are more suitable for detection of chromosome aberrations, such as deletions and translocations, in prenatal diagnosis. © 2016 International Society for Advancement of Cytometry.

Aneuploid embryonic stem cells exhibit impaired differentiation and increased neoplastic potential.

Aneuploidy leads to severe developmental defects in mammals and is also a hallmark of cancer. However, whether aneuploidy is a driving cause or a consequence of tumor formation remains controversial. Paradoxically, existing studies based on aneuploid yeast and mouse fibroblasts have shown that aneuploidy is usually detrimental to cellular fitness. Here, we examined the effects of aneuploidy on mouse embryonic stem (ES) cells by generating a series of cell lines that each carries an extra copy of single chromosomes, including trisomy 6, 8, 11, 12, or 15. Most of these aneuploid cell lines had rapid proliferation rates and enhanced colony formation efficiencies. They were less dependent on growth factors for self-renewal and showed a reduced capacity to differentiate in vitro Moreover, trisomic stem cells formed teratomas more efficiently, from which undifferentiated cells can be recovered. Further investigations demonstrated that co-culture of wild-type and aneuploid ES cells or supplementation with extracellular BMP4 rescues the differentiation defects of aneuploid ES cells.

Regulation of Cell Cycle Regulators by SIRT1 Contributes to Resveratrol-Mediated Prevention of Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a major cause of morbidity and mortality in rheumatic diseases. Vascular remodeling due to the proliferation of pulmonary arterial smooth muscle cells (PASMCs) is central to the development of PAH. To date, it is still unclear if Silence Information Regulator 1 (SIRT1) regulates cell cycle regulators in the proliferation of PASMCs and contributes to prevention of PAH by resveratrol. In this study, we found that a significant decrease of SIRT1 expression levels in platelet-derived growth factor BB (PDGF-BB) treated human PASMCs (HPASMCs) and in monocrotaline (MCT) induced PAH rat. Overexpression of SIRT1 induced G1 phase arrest and increased p21 expression but decreased cyclin D1 expression in PDGF-BB treated HPASMCs. Moreover, resveratrol attenuated pulmonary arterial remodeling, decreased pulmonary arterial pressure, and upregulated SIRT1 and p21 expression but downregulated cyclin D1 expression in MCT induced PAH rat. Notably, knockdown of SIRT1 eliminated the regulation of resveratrol on p21 and cyclin D1 expression in PDGF-BB treated HPASMCs. These results demonstrated that SIRT1 mediated the regulation of resveratrol on the expression of cell cycle regulatory molecules. It suggests that SIRT1 exerts a protective role in PAH associated with rheumatic diseases and can be a potential treatment target.

Rapidly generating knockout mice from H19-Igf2 engineered androgenetic haploid embryonic stem cells.

Haploid mammalian embryonic stem cells (ESCs) hold great promise for functional genetic studies and assisted reproduction. Recently, rodent androgenetic haploid ESCs (AG-haESCs) were generated from androgenetic blastocysts and functioned like sperm to produce viable offspring via the intracytoplasmic AG-haESCs injection into oocytes. However, the efficiency of this reproduction was very low. Most pups were growth-retarded and died shortly after birth, which is not practical for producing knockout animals. Further investigation suggested a possible link between the low birthrate and aberrant expression of imprinted genes. Here, we report the high-frequency generation of healthy, fertile mice from H19-Igf2 imprinting-locus modified AG-haESCs, which maintained normal paternal imprinting and pluripotency. Moreover, it is feasible to perform further genetic manipulations in these AG-haESCs. Our study provides a reliable and efficient tool to rapidly produce gene-modified mouse models and will benefit reproductive medicine in the future.

The involvement of NFAT transcriptional activity suppression in SIRT1-mediated inhibition of COX-2 expression induced by PMA/Ionomycin.

SIRT1, a class III histone deacetylase, acts as a negative regulator for many transcription factors, and plays protective roles in inflammation and atherosclerosis. Transcription factor nuclear factor of activated T cells (NFAT) has been previously shown to play pro-inflammatory roles in endothelial cells. Inhibition of NFAT signaling may be an attractive target to regulate inflammation in atherosclerosis. However, whether NFAT transcriptional activity is suppressed by SIRT1 remains unknown. In this study, we found that SIRT1 suppressed NFAT-mediated transcriptional activity. SIRT1 interacted with NFAT, and the NHR and RHR domains of NFAT mediated the interaction with SIRT1. Moreover, we found that SIRT1 primarily deacetylated NFATc3. Adenoviral over-expression of SIRT1 suppressed PMA and calcium ionophore Ionomycin (PMA/Io)-induced COX-2 expression in human umbilical vein endothelial cells (HUVECs), while SIRT1 RNAi reversed the effects in HUVECs. Moreover, inhibition of COX-2 expression by SIRT1 in PMA/Io-treated HUVECs was largely abrogated by inhibiting NFAT activation. Furthermore, SIRT1 inhibited NFAT-induced COX-2 promoter activity, and reduced NFAT binding to the COX-2 promoter in PMA/Io-treated HUVECs. These results suggest that suppression of NFAT transcriptional activity is involved in SIRT1-mediated inhibition of COX-2 expression induced by PMA/Io, and that the negative regulatory mechanisms of NFAT by SIRT1 may contribute to its anti-inflammatory effects in atherosclerosis.

Up-regulation of Fas ligand expression by sirtuin 1 in both flow-restricted vessels and serum-stimulated vascular smooth muscle cells.

OBJECTIVE: To study the role of sirtuin 1 (SIRT1) in Fas ligand (FasL) expression regulation during vascular lesion formation and to elucidate the potential mechanisms. METHODS: SIRT1 and FasL protein levels were detected by Western blotting in either mouse arteries extract or the whole rat aortic vascular smooth muscle cell (VSMC) lysate. Smooth muscle cell (SMC)-specific human SIRT1 transgenic (Tg) C57BL/6 mice and their littermate wild-type (WT) controls underwent complete carotid artery ligation (ligation groups) or the ligation-excluded operation (sham groups). The carotid arteries were collected 1 day after operation. Reverse transcription-polymerase chain reaction was performed to detect the mRNA levels of SIRT1 and FasL. Luciferase reporter assays were performed to detect the effect of WT-SIRT1, a dominant-negative form of SIRT1 (SIRT1H363Y), and GATA-6 on the promoter activity of FasL. Flow cytometry assay was applied to measure the hypodiploid DNA content of VSMC so as to monitor cellular apoptosis. RESULTS: SIRT1 was expressed in both rat aortic VSMCs and mouse arteries. Forced SIRT1 expression increased FasL expression both in injured mouse carotid arteries 1 day after ligation (P<0.001) and VSMCs treated with serum (P<0.05 at the transcriptional level, P<0.001 at the protein level). No notable apoptosis was observed. Furthermore, transcription factor GATA-6 increased the promoter activity of FasL (P<0.001). The induction of FasL promoter activity by GATA-6 was enhanced by WT-SIRT1 (P<0.001), while SIRT1H363Y significantly relieved the enhancing effect of WT-SIRT1 on GATA-6 (P<0.001). CONCLUSIONS: Overexpression of SIRT1 up-regulates FasL expression in both flow-restricted mouse carotid arteries and serum-stimulated VSMCs. The transcription factor GATA-6 participates in the transcriptional regulation of FasL expression by SIRT1.

SIRT1 suppresses PMA and ionomycin-induced ICAM-1 expression in endothelial cells.

Intercellular adhesion molecule-1 (ICAM-1) plays an important role in the recruitment of leukocytes to the endothelium, which causes inflammation and initiation of atherosclerosis. We have previously shown that endothelium-specific over-expression of class III deacetylase SIRT1 decreases atherosclerosis. We therefore addressed the hypothesis that SIRT1 suppresses ICAM-1 expression in the endothelial cells. Here, we found that expression of SIRT1 and ICAM-1 was significantly induced by PMA and ionomycin (PMA/Io) in human umbilical vein endothelial cells (HUVECs). Adenovirus-mediated over-expression of SIRT1 significantly inhibited PMA/Io-induced ICAM-1 expression in HUVECs. Knockdown of SIRT1 by RNA interference (RNAi) resulted in increased expression of ICAM-1 in HUVECs. Luciferase report assay showed that over-expression of SIRT1 suppressed ICAM-1 promoter activity both in basic and in PMA/Io-induced conditions. We further found that SIRT1 was involved in transcription complex binding on the ICAM-1 promoter by chromatin immunoprecipitation (ChIP) assays. Furthermore, SIRT1 RNAi increased NF-κB p65 binding ability to the ICAM-1 promoter by ChIP assays. Overall, these data suggests that SIRT1 inhibits ICAM-1 expression in endothelial cells, which may contribute to its anti-atherosclerosis effect.