Management and outcome of true visceral and renal artery aneurysm repair.

PURPOSE: Visceral and renal artery aneurysms (VAA, RAA) are very rare pathologies. Both surgical and endovascular therapies are discussed as therapeutic options for ruptured and non-ruptured aneurysm repair; we describe our experience in the open and endovascular management of these entities. METHODS: Retrospective database analysis of 60 treated VAA and RAA in 59 patients between 1994 and 2020. Outcome data was descriptively analyzed. RESULTS: Thirty-seven aneurysms were surgically treated and 23 interventionally. In the total study cohort, we observed a mortality of 1.7% and a morbidity of 18.6%. One major complication occurred. The morbidity was higher after surgical repair in ruptured and non-ruptured cases. The mean aneurysm diameter was 30.5 ± 15.6 mm. Patients with hepatic or pancreaticoduodenal artery aneurysms presented more often in the stage of rupture, without differences in aneurysm size. The length of hospital stay after endovascular repair was significantly shorter compared to open surgical treatment (7.2 ± 6.9 days versus 11.8 ± 6.7 days, p = 0.014), but only in elective cases. Primary technical success was significantly better in patients that underwent surgical repair in an intention to treat analysis (100% versus 79.3%). The mean follow-up of the cohort was 53.5 months (range 3-207 months). CONCLUSION: Elective endovascular therapy and open surgery of VAA and RAA are safe procedures with a good periprocedural and long-term outcome. Surgical revascularization showed a better primary technical success but was associated with longer length of hospital stays.

Predictive factors for better bypass patency and limb salvage after prosthetic above-knee bypass reconstruction.

BACKGROUND: Peripheral arterial disease (PAD) is one of the most underestimated diseases because of its high prevalence and unfavorable prognosis. Many PAD patients without suitable autologous veins or options for endovascular treatment receive prosthetic above-knee femoropopliteal bypass (PAKB). Until now predictors of prosthetic bypass failure and of increased amputation risk remain indistinct. This study aimed to identify predictive factors associated with better bypass patency and limb salvage to achieve a more favorable outcome after PAKB reconstruction. METHODS: Pre-, intra-, and postoperative data of 244 PAKB procedures performed at a German university medical center were collected and analyzed using univariate and multivariate methods. To our knowledge this 12-year experience is the largest retrospective study to identify predictors for patency and limb salvage after PAKB reconstruction. RESULTS: Of the PAD patients 94% (229/244) were followed for an average of 34.9 months. Patient cohorts characteristics were: mean age, 66.1 years, 181 men (74%), claudication (64%), rest pain (16%), ischemic lesions (20%), arterial hypertension (92%), smoking (79%), hyperlipidemia (65%) and type 2 diabetes (43%). Cumulative primary 1- and 3-year graft patency rates were 60.8% and 50.7%, respectively, and cumulative 1- and 3-year limb salvage rates were 89.3% and 86.1%, respectively. One hundred seven bypasses (43.9%) failed, 26 patients (10.7%) required a major and seven patients (2.9%) required a minor amputation. Overall survival rates of PAD patients after 1- and 3-years were 94.4% and 82.9%, respectively. Subjective symptom improvement was found to be the most important prognostic follow-up factor for graft patency and limb salvage. Patients with recurrent symptoms in the follow-up had an increased risk of emerging bypass failure compared with patients with subjective symptom improvement (patency at 1 year: 40.8% vs 100% and at 3 years: 26% vs 100%; P < .001). No patient with subjective improvement in symptoms during follow-up underwent an amputation (limb salvage at 1 year: 100% vs 79% and at 3 years: 100% vs 72.8%; P < .001). Therefore, subjective symptom improvement should be the decisive criterion to determine follow-up intervals of PAD patients. In univariate analysis further significant factors associated with better graft patency and limb salvage rates were: claudication compared with critical ischemia, larger graft diameter (>6 mm), pre- and postoperative antiplatelet therapy, statin therapy independent from lipid values after PAKB revascularization, and an experienced vascular surgeon. CONCLUSIONS: In our study, we determined the subjective improvement in symptoms as the most important prognostic factor for bypass function and limb salvage after PAKB. Furthermore, disease stage of critical ischemia, graft diameter, preoperative aspirin use, and postoperative statin medication were independent predictive factors. Therefore, PAD patients should be treated with aspirin pre- and postoperatively as well as with a statin postoperatively. In case of PAKB reconstruction only prostheses with a large diameter (>6 mm) should be used and the procedure should be performed by an experienced surgeon. Considering these results with regard to the predictive factors for better graft patency and limb salvage rates a significant more favorable outcome during the follow-up and an increased 5-year patency rate for PAKB reconstructions can be expected.

Alu elements in ANRIL non-coding RNA at chromosome 9p21 modulate atherogenic cell functions through trans-regulation of gene networks.

The chromosome 9p21 (Chr9p21) locus of coronary artery disease has been identified in the first surge of genome-wide association and is the strongest genetic factor of atherosclerosis known today. Chr9p21 encodes the long non-coding RNA (ncRNA) antisense non-coding RNA in the INK4 locus (ANRIL). ANRIL expression is associated with the Chr9p21 genotype and correlated with atherosclerosis severity. Here, we report on the molecular mechanisms through which ANRIL regulates target-genes in trans, leading to increased cell proliferation, increased cell adhesion and decreased apoptosis, which are all essential mechanisms of atherogenesis. Importantly, trans-regulation was dependent on Alu motifs, which marked the promoters of ANRIL target genes and were mirrored in ANRIL RNA transcripts. ANRIL bound Polycomb group proteins that were highly enriched in the proximity of Alu motifs across the genome and were recruited to promoters of target genes upon ANRIL over-expression. The functional relevance of Alu motifs in ANRIL was confirmed by deletion and mutagenesis, reversing trans-regulation and atherogenic cell functions. ANRIL-regulated networks were confirmed in 2280 individuals with and without coronary artery disease and functionally validated in primary cells from patients carrying the Chr9p21 risk allele. Our study provides a molecular mechanism for pro-atherogenic effects of ANRIL at Chr9p21 and suggests a novel role for Alu elements in epigenetic gene regulation by long ncRNAs.

Laparoscopic treatment of celiac artery compression syndrome in children and adolescents.

BACKGROUND: The celiac artery compression syndrome (CACS) is a rarely diagnosed disorder, which is characterized by chronic abdominal pain and vegetative symptoms. The role of surgical treatment in celiac artery decompression has been discussed controversially by numerous authors. After first casuistic descriptions of a laparoscopic treatment in adults we established this novel minimally invasive procedure for treatment in children and adolescents. PATIENTS AND METHODS: Between 2005 and 2014 we operated 58 patients (47 female, 11 male) from 7 to 25 years who had been diagnosed with celiac artery compression. The patients presented with severe chronic abdominal pain, vegetative symptoms and a reduced quality of life. Doppler sonography showed an increased blood flow velocity of the celiac artery with maximum of 190 - 450 cm/s (mean 259 cm/s).MR angiography demonstrated a characteristic hook-shaped appearance of the celiac artery with severe localized compression. RESULTS: All patients underwent laparoscopic decompression of the celiac artery. We observed complications in 3 patients (5,2 %). Postoperatively all patients (100 %) were immediately free of abdominal pain. Doppler sonography showed a marked reduction in celiac blood flow velocity to 70 - 190 cm/s postoperatively (mean 178 cm/s). A return of vessel diameters to normal dimensions was documented by postoperative MR angiography. During a median follow up of 62 months we observed a recurrence of the celiac artery compression in 4 patients (6,9 %). CONCLUSIONS: Laparoscopic treatment of celiac artery compression syndrome offers a novel, safe, reliable and, compared to open surgery, less invasive approach. The surgical treatment is indicated in patients with characteristic symptoms and typical findings at Doppler sonography and MRA after exclusion of other abdominal pathologies. The work-up of chronic abdominal pain in children and adolescents should include a color Doppler sonography to look for celiac artery compression.

Pulmonary artery pseudoaneurysm in a patient with aortic valve stenosis.

A 77-year-old, high-risk woman with symptomatic aortic valve stenosis (aortic valve area 0.77 cm(2)) underwent coronary artery catheterization and right heart catheterization. After catheterization, she suddenly developed hemoptysis, and became hypoxic and hypotonic. She was intubated and the bleeding was stopped using positive end-expiratory pressure. Chest X-ray and computed tomography showed a pulmonary artery (PA) pseudoaneurysm with a maximum diameter of 40 mm at the right middle lobe. Endovascular treatment approaches by coil embolization failed, so surgical resection was indicated. In preparation for the procedure and to reduce perioperative risk, transapical aortic valve implantation was performed. The operation took about 40 minutes and the intraoperative activated clotting time was controlled at 180-200 sec. After successful transapical aortic valve implantation, aneurysmectomy was performed. Intraoperatively, the PA pseudoaneurysm was found to occupy nearly the entire middle lobe. A right middle lobectomy was performed. The operative course was uneventful. Transapical aortic valve implantation may have eliminated the risk of rupture or re-bleeding in such bleeding-prone patient.

cAMP-dependent phosphorylation of PTB1 promotes the expression of insulin secretory granule proteins in beta cells.

Glucose stimulates the exocytosis of insulin secretory granules of pancreatic beta cells. Granule stores are quickly refilled by activation of posttranscriptional mechanisms that enhance the biosynthesis of granule components. Rapid replacement of granules is important to sustain insulin secretion, since new granules appear to be preferentially released. Posttranscriptional regulation of granule biogenesis includes the glucose-induced nucleocytoplasmic translocation of polypyrimidine tract binding protein 1 (PTB1), which binds mRNAs encoding granule proteins, and thus promotes their stabilization and translation. Glucagon-like peptide 1 (GLP-1) potentiates glucose-stimulated insulin gene expression and secretion by increasing cAMP levels in beta cells. Here, we show that elevation of cAMP levels causes the protein kinase A-dependent phosphorylation and nucleocytoplasmic translocation of PTB1, thereby preventing the rapid degradation of insulin mRNA and enhancing the expression of various granule proteins. Taken together, these findings identify PTB1 as a common downstream target of glucose and GLP-1 for the posttranscriptional upregulation of granule biogenesis.

Polypyrimidine tract-binding protein promotes insulin secretory granule biogenesis.

Pancreatic beta-cells store insulin in secretory granules that undergo exocytosis upon glucose stimulation. Sustained stimulation depletes beta-cells of their granule pool, which must be quickly restored. However, the factors promoting rapid granule biogenesis are unknown. Here we show that beta-cell stimulation induces the nucleocytoplasmic translocation of polypyrimidine tract-binding protein (PTB). Activated cytosolic PTB binds and stabilizes mRNAs encoding proteins of secretory granules, thus increasing their translation, whereas knockdown of PTB expression by RNA interference (RNAi) results in the depletion of secretory granules. These findings may provide insight for the understanding and treatment of diabetes, in which insulin secretion is typically impaired.

ANRIL expression is associated with atherosclerosis risk at chromosome 9p21.

OBJECTIVE: We tested the hypothesis that expression of transcripts adjacent to the chromosome 9p21 (Chr9p21) locus of coronary artery disease was affected by the genotype at this locus and associated with atherosclerosis risk. METHODS AND RESULTS: We replicated the locus for coronary artery disease (P=0.007; OR=1.28) and other manifestations of atherosclerosis such as carotid plaque (P=0.003; OR=1.31) in the Leipzig Heart Study, a cohort of 1134 patients with varying degree of angiographically assessed coronary artery disease. Expression analysis in peripheral blood mononuclear cells (n=1098) revealed that transcripts EU741058 and NR_003529 of antisense noncoding RNA in the INK4 locus (ANRIL) were significantly increased in carriers of the risk haplotype (P=2.1x10(-12) and P=1.6x10(-5), respectively). In contrast, transcript DQ485454 remained unaffected, suggesting differential expression of ANRIL transcripts at Chr9p21. Results were replicated in whole blood (n=769) and atherosclerotic plaque tissue (n=41). Moreover, expression of ANRIL transcripts was directly correlated with severity of atherosclerosis (EU741058 and NR_003529; P=0.02 and P=0.001, respectively). No consistent association of Chr9p21 or atherosclerosis was found with expression of other genes such as CDKN2A, CDKN2B, C9orf53, and MTAP. CONCLUSIONS: Our data provide robust evidence for an association of ANRIL but not CDKN2A, CDKN2B, C9orf53, and MTAP, with atherosclerosis and Chr9p21 genotype in a large cohort.

ICA512 signaling enhances pancreatic beta-cell proliferation by regulating cyclins D through STATs.

Changes in metabolic demands dynamically regulate the total mass of adult pancreatic beta-cells to adjust insulin secretion and preserve glucose homeostasis. Glucose itself is a major regulator of beta-cell proliferation by inducing insulin secretion and activating beta-cell insulin receptors. Here, we show that islet cell autoantigen 512 (ICA512)/IA-2, an intrinsic tyrosine phosphatase-like protein of the secretory granules, activates a complementary pathway for beta-cell proliferation. On granule exocytosis, the ICA512 cytoplasmic domain is cleaved and the resulting cytosolic fragment (ICA512-CCF) moves into the nucleus where it enhances the levels of phosphorylated STAT5 and STAT3, thereby inducing insulin gene transcription and granule biogenesis. We now show that knockdown of ICA512 decreases cyclin D1 levels and proliferation of insulinoma INS-1 cells, whereas beta-cell regeneration is reduced in partially pancreatectomized ICA512-/- mice. Conversely, overexpression of ICA512-CCF increases both cyclin D1 and D2 levels and INS-1 cell proliferation. Up-regulation of cyclin D1 and D2 by ICA512-CCF is affected by knockdown of STAT3 and STAT5, respectively, whereas it does not require insulin signaling. These results identify ICA512 as a regulator of cyclins D and beta-cell proliferation through STATs and may have implication for diabetes therapy.

Endovascular foreign body removal of a MynxGrip polyethylene glycol (PEG) sealant embolus using a cerebral stent retriever.

BACKGROUND: This is a rare case of removing an intra-arterial foreign body represented by MynxGrip polyethylene glycol (PEG) sealant as a rare complication of using the MynxGrip™ Vascular Closure Device (AccessClosure, Inc., Mountain View, CA) using a pRESET stent retriever (Phenox, Bochum, Germany) which is utilized mainly for treatment of endovascular stroke. CASE PRESENTATION: A 60-year-old female patient suffering from intermittent claudication in the right lower limb (stage IIb according to Fontaine) due to a peripheral arterial occlusive disease was presented for an elective revascularization using balloon angioplasty of a short chronic occlusion of the right superficial femoral artery. After a successful revascularization of the right superficial femoral artery using a retrograde femoral access from the left common femoral artery, the patient suffered from an acute limb ischemia in the left foot with distal popliteal embolization with involvement of BTK (below the knee) trifurcation. This is believed to be due to an intra-arterial foreign body embolism of MynxGrip polyethylene glycol sealant as a rare complication of using the MynxGrip™ Vascular Closure Device. CONCLUSIONS: Stent retrievers have been used previously in removing dislocated coils especially in the cerebral vessels. This case report however proves a high efficacy and safety of using stent retrievers in removing different and rather unusual intra-arterial foreign bodies such as MynxGrip polyethylene glycol sealant.

Quantitative perfusion analysis of transabdominal contrast-enhanced ultrasonography of pancreatic masses and carcinomas.

BACKGROUND & AIMS: Preoperative differential diagnosis of pancreatic ductal adenocarcinoma (PDAC) and focal masses in patients with chronic pancreatitis (CP) can be challenging. There are fine differences in the vascularization of these lesions; ultrasound contrast agents can aid in their differentiation. We evaluated the value of software-aided quantitative analysis of transabdominal contrast-enhanced ultrasonography for differential diagnosis of PDAC vs focal masses. METHODS: Sixty patients for whom it was not possible to differentiate between an inflammatory focal lesion of the pancreas and a pancreatic carcinoma underwent contrast-enhanced ultrasonography with a second-generation contrast agent. Time-intensity curves were obtained for all exams in 2 regions of interest within the lesion and within the normal pancreatic tissue. Images were processed using Axius ACQ software; the following parameters were obtained: maximum intensity, arrival time, time-to-peak, and area under the curve. Absolute values and differences between the lesion and the normal tissue were evaluated. RESULTS: Histology analysis revealed 45 PDACs and 15 inflammatory masses in patients with CP. Time-dependent parameters (arrival time and time to peak) were significantly longer in PDACs compared to focal masses. Although markedly lower than in healthy pancreata, the maximum intensity and area under the curve parameters were not significantly different between PDACs and focal lesions in patients with CP. CONCLUSIONS: In cases of CP, PDAC and focal masses exhibit different perfusion patterns at a capillary level that can be visualized using the small microbubbles of ultrasound contrast agents. Contrast quantification software supplements a subjective visual assessment with objective criteria to facilitate the differential diagnosis of focal lesions in pancreatic cancer and chronic pancreatitis.

Compression of the left renal artery and celiac trunk by diaphragmatic crura.

Symptomatic compression of the celiac trunk by crura of the diaphragm is a rare disorder. Even more infrequent external compression of renal arteries is found. Although the indication for surgical therapy is controversially discussed in the literature for celiac artery compression syndrome, it is unequivocally for renal artery entrapment. We present the case of a young woman who was assigned to our hospital with arterial hypertension and stenosis of the left renal artery. After percutaneous transluminal angioplasty was performed, immediate recoil occurred. Therefore, the suspicion of entrapment by diaphragmatic crura was expressed. Additionally performed diagnostic procedures including computed tomography (CT)-angiography verified our suspicion. Surgical decompression of both vessels was successfully performed.

Surgical therapy of intrapancreatic metastasis from renal cell carcinoma.

BACKGROUND: Pancreatic metastases from renal cell carcinoma (RCC) are clinically rare but highly resectable. The aim of this article is to identify patients who profit from pancreatic resection of RCC despite the invasiveness of the surgery. METHODS: Between January 1996 and December 2007, data from 744 patients were collected in a prospective pancreatic surgery database, and patients with metastasis into the pancreas from RCC were identified. RESULTS: Resective surgery was performed in 14 patients with metastasis to the pancreas from RCC. Most patients were clinically asymptomatic. The median interval between primary treatment of RCC and occurrence of pancreatic metastasis was 94 months (range 32-158). The morbidity rate was 42.8%. Patients with a metastasis size <2.5 cm had a much better survival after resection (100 months) than those with a metastasis size >2.5 cm (44 months). Moreover, the number of metastases predicts the survival after resection. CONCLUSIONS: In patients with pancreatic metastases from RCC who have only limited disease, complete resection of all lesions can be successfully performed with a low rate of complications. Thus, patients with a history of RCC should be monitored for more than 10 years after nephrectomy to detect recurrence.

Molecular Fingerprint for Terminal Abdominal Aortic Aneurysm Disease.

BACKGROUND: Clinical decision making in abdominal aortic aneurysms (AAA) relies completely on diameter. At this point, improved decision tools remain an unmet medical need. Our goal was to identify changes at the molecular level specifically leading up to AAA rupture. METHODS AND RESULTS: Aortic wall tissue specimens were collected during open elective (eAAA; n=31) or emergency repair of ruptured AAA (rAAA; n=17), and gene expression was investigated using microarrays. Identified candidate genes were validated with quantitative real-time polymerase chain reaction in an independent sample set (eAAA: n=46; rAAA: n=18). Two gene sets were identified, 1 set containing 5 genes linked to terminal progression, that is, positively associated with progression of larger AAA, and with rupture (HILPDA, ANGPTL4, LOX, SRPX2, FCGBP), and a second set containing 5 genes exclusively upregulated in rAAA (ADAMTS9, STC1, GFPT2, GAL3ST4, CCL4L1). Genes in both sets essentially associated with processes related to impaired tissue remodeling, such as angiogenesis and adipogenesis. In gene expression experiments we were able to show that upregulated gene expression for identified candidate genes is unique for AAA. Functionally, the selected upregulated factors converge at processes coordinated by the canonical HIF-1α signaling pathway and are highly expressed in fibroblasts but not inflammatory cells of the aneurysmatic wall. Histological quantification of angiogenesis and exploration of the HIF-1α network in rAAA versus eAAA shows enhanced microvessel density but also clear activation of the HIF-1α network in rAAA. CONCLUSIONS: Our study shows a specific molecular fingerprint for terminal AAA disease. These changes appear to converge at activation of HIF-1α signaling in mesenchymal cells. Aspects of this cascade might represent targets for rupture risk assessment.

Management and outcome of hemorrhage due to arterial pseudoaneurysms in pancreatitis.

BACKGROUND: Arterial pseudoaneurysm formation in pancreatitis is a rare complication. The optimal treatment modality is controversial. Operative treatment and interventional treatment, either alone or as a temporizing method with a later operation, are options. METHODS: In this single-center, patient-based cohort study, we managed 35 patients (8 with necrotizing pancreatitis and 27 with chronic pancreatitis) with bleeding pseudoaneurysms treated over a period of 10.5 years with a median follow-up of 4.6 years. Angiography was performed depending on the patient's hemodynamic condition. RESULTS: Angiography had a sensitivity of 96% for 26 patients. Angiographic embolization as primary treatment was performed in 16 patients (61% embolization rate); there were 2 rebleeding complications. No patients required intervention for embolization complications after discharge. Nineteen patients (54%) underwent an operation, 9 urgently without angiographic evaluation. The overall mortality rate for the 35 patients was 20% (19% for embolization, 21% after an operation). For necrotizing pancreatitis, an advantage of angiographic embolization was observed (mortality in 2/5 vs 2/3 after surgery). Ligation or repair of the bleeding vessel was complicated by higher rebleeding rates (6/13) than partial pancreatectomy (1/6). CONCLUSIONS: Concerns that angiographic embolization is unable to provide definitive hemostasis in both acute and chronic pancreatitis are unfounded. In the operative treatment of chronic pancreatitis, partial pancreatectomy is superior to vessel ligation, depending on the patient's general condition and degree of pancreatic inflammation. We propose an algorithm for the management of arterial pseudoaneurysms in the setting of pancreatitis.

Effect of oxygenated perfluorocarbons on isolated rat pancreatic islets in culture.

One impediment for a wider application of islet transplantation is the limited number of donor pancreata for islet isolation. A more efficient utilization of available organs could in part alleviate this problem. Perfluorocarbons (PFCs) have a high oxygen solubility coefficient and maintain high oxygen partial pressures for extended time. They serve also as oxygen "reservoirs" for harvested organs in pancreas organ transplantation. The aim of this study was to test whether the use of PFCs could also be beneficial for the secretory activity and overall viability of cultured purified islets before transplantation. Purified rat islets were cultured in static conditions with or without oxygen-saturated PFCs for 1 or 7 days. Cell death and apoptosis were assessed by trypan blue staining, DNA strand breaks, and caspase 3/7 activity. mRNA levels of insulin and ICA512/IA-2, a membrane marker of secretory granules (SGs), were quantitated by real-time PCR, whereas insulin content and secretion were measured by RIA. Polypyrimidine tract binding protein (PTB), which promotes SG biogenesis, was assessed by Western blotting. The number of SGs and the ultrastructural appearance of beta5-cells were analyzed by cryoimmunoelectronmicroscopy for insulin. Various parameters, including caspase activity, insulin and ICA512/IA-2 mRNA levels, PTB expression, number of secretory granules, and ultrastructural appearance did not significantly differ between control and PFC-cultured islets. On the other hand, PFC culture islets showed significantly increased DNA fragmentation and a reduced insulin stimulation index at both time points compared to control islets. While advantageous for the transport of human harvested organs, the use of PFH in the culture may be comparable to and/or not provide advantage over conventional protocols for culture of islets for transplantation.

Fulminant liver failure following infection by Clostridium perfringens.

BACKGROUND: Since the first description of gas gangrene of an internal organ by Fraenkel in 1889, few cases of acute organ failure following Clostridium perfringens infection have been described in the medical literature. Isolated Clostridium perfringens infection with subsequent sepsis syndrome is an extremely rare clinical syndrome. A consecutive pattern of multiple organ failure generally has a very high mortality rate. METHODS: Individual case report and literature review. RESULTS: A 58-year-old male patient developed fulminant necrotic liver failure following a Clostridium perfringens infection. Despite all intensive care measures, including computed tomography-guided drainage, the condition of the patient deteriorated rapidly and the patient died. In this case report, we characterize the symptoms of gas gangrene isolated to the liver and compare the treatment measures instituted with the medical literature. CONCLUSIONS: In our presented case, primary malignant disease of the papilla of Vater and resection by a Whipple procedure with a hepatico-jejunostomy were a decisive cause of the gas gangrene in the liver. The origin is probably ascension up the common hepatic duct of gut-derived bacteria.

Expression of Chr9p21 genes CDKN2B (p15(INK4b)), CDKN2A (p16(INK4a), p14(ARF)) and MTAP in human atherosclerotic plaque.

OBJECTIVE: The pathophysiology underlying the chromosome (Chr) 9p21 locus of atherosclerosis susceptibility is presently unknown. Here, we sought to determine whether protein coding genes in the Chr9p21 region, i.e. cyclin-dependent kinase inhibitors CDKN2B (p15(INK4b)), CDKN2A (p16(INK4a), p14(ARF)) and methylthioadenosine phosphorylase (MTAP) were expressed in human atherosclerotic lesions and whether expression was correlated with lesion composition. METHODS AND RESULTS: Protein expression of p15(INK4b), p16(INK4a), p14(ARF) and MTAP was demonstrated by immunostaining in normal and atherosclerotic coronary arteries and co-localized with CD68 and smooth muscle alpha-actin positive cells. Quantitative RT-PCR in human endarteryectomy specimens (n = 57) revealed increased p16(INK4a) and decreased MTAP expression in macrophage-rich lesions (P<0.001 and P = 0.007, respectively). Functional studies suggest that decreased MTAP expression in macrophage-rich lesions might be mediated through down-regulation by TNF-alpha. No clear association of p15(INK4b), p16(INK4a), p14(ARF), and MTAP expression in plaque tissue with Chr9p21 haplotypes was found. The latter finding was corroborated by the lack of correlation of RNA expression of 9p21-regulated transcripts EU741058 and NR_003529 of antisense non-coding RNA in the INK4 locus (ANRIL) with mRNA expression of these genes. In contrast, ANRIL DQ485454 which is not genetically determined by the 9p21 genotype was significantly correlated with MTAP expression (P = 0.01). CONCLUSION: CDKN2B (p15(INK4b)), CDKN2A (p16(INK4a), p14(ARF)), and MTAP are abundantly expressed in atherosclerotic lesions. While expression levels showed no clear association with Chr9p21 genotype, association of high p16(INK4a) and low MTAP expression with a less stable plaque phenotype suggests a more general role of these proteins in atherogenesis.