Congenital ptosis with aponeurotic maldevelopment: clinical and surgical perspectives : Aponeurotic maldevelopment in congenital ptosis.

PURPOSE: Levator muscle dystrophy has been commonly accused being the main pathology of congenital ptosis, nevertheless, few reports drew attention to the existence of congenital aponeurotic defects. This study aims at highlighting the detailed clinical and surgical features of aponeurotic maldevelopment together with the efficacy of simple aponeurosis repair. METHODS: This is a retrospective nonrandomised study including patients with congenital ptosis who underwent levator muscle surgery throughout 4 years. Patients' records were reviewed for the preoperative clinical assessment and photographs, intraoperative recorded data, and videos as well as postoperative data and photographs. RESULTS: Twenty-seven eyes of 22 patients (9.4%) out of 287 eyes were recorded to have absent levator muscle at its typical anatomical insertion site intraoperatively. The mean preoperative MRD1 was (0.44 ± 1.17 mm). The mean levator function was 8.56 ± 3.89 mm, with higher-than-normal crease position (mean value 10.07 ± 1.62 mm). 25 eyes of included cases (92.6%) showed total absence of the levator aponeurosis edge which only was revealed after cutting through the orbital septal covering of the preaponeurotic fat. CONCLUSION: Congenital aponeurotic defect is an established yet under reported entity of congenital ptosis with reproducible characteristic intraoperative findings. Simple aponeurosis repair could achieve ptosis correction in such cases.

CT volumetry study of microfat graft survival from different donor sites in augmenting the enophthalmic socket.

PURPOSE: To evaluate autologous fat grafts harvested from the abdomen versus the thigh for treating the enophthalmic socket using CT volumetry. METHODS: A randomized prospective interventional study including 20 patients suffering from unilateral enophthalmic socket. Pre-operative clinical assessment included photographs, exophthalmometry reading as well as CT volumetry for volume deficit calculations and the harvesting site was randomly allocated (abdomen or thigh). All patients completed 6 months of follow-up. Exophthalmometry change and percentage of retained fat with the globe included and without it at follow-up were measured. RESULTS: Microfat graft survival showed no statistically significant correlation with sex, age, or donor site. Mean percentage of retained fat with globe and without it were 14.75% and 25.31%, respectively. Difficulty of extraction and degree of volume deficit correlated significantly with percentage of fat retained. Exophthalmometer change correlated significantly with percentage of fat retained. CONCLUSION: Autologous fat grafting is a safe and effective technique for volume augmentation of enophthalmic sockets regardless of its harvesting site. CT volumetry has an important role in accurately measuring the volume deficit as well as the postoperative results.

An Innovative Use of Propolis in the Production of Dipping Sauce Powder as a Functional Food to Mitigate Testicular Toxicity Induced by Cadmium Chloride: Technological and Biological Evidence.

Propolis is a common natural ingredient used in food production, food packaging, and pharmaceutical products. Therefore, the aim of our study was to prepare dipping sauce powders as an innovative functional product with a regular and spicy taste from economical raw materials with high nutritional value. The developed products were fortified with propolis powder at 250, 500, and 750 mg/kg. All studied dipping sauces were subjected to a palatability test, a nutritional evaluation, and a microbiological assay performed during 6 months of storage. In addition, an in vivo study was designed to evaluate the efficacy of these products in preventing the testicular toxicity disorders induced by cadmium chloride (CdCl2) in albino rats. Based on the palatability test, the dipping sauces supplemented with propolis at 250 mg/kg and 500 mg/kg were preferred. Moreover, all samples were safe to consume within 6 months. Biological results showed that all investigated propolis-enriched dipping sauce samples caused an improvement in all CdCl2-induced testicular histopathological and biochemical changes, especially the spicy dipping sauce powder fortified with 500 mg/kg of propolis.

Contralateral Eye Study of Topography Guided versus Q Value Adjusted Photorefractive Keratectomy in Myopia and Myopic Astigmatism.

PURPOSE OF THE STUDY: To compare visual outcome, higher order aberrations (HOAs) of topography guided and Q value adjusted ablation in the fellow eye of patients undergoing photorefractive keratectomy (PRK) for the correction of myopia and myopic astigmatism. METHODS: Prospective randomized controlled interventional clinical study. The eyes of 52 patients undergoing PRK for myopia and astigmatism were included, that is, 104 eyes in total. In each patient, eyes were randomly allocated to group I: one eye received topography guided PRK using Contoura ablation software, or group II: the other eye received Q value adjusted PRK using Custom Q ablation software. FOLLOW-UP: Six months. RESULTS: At the end of 6 months, LogMAR UDVA was -0.04 ± 0.12 and -0.05 ± 0.11 (p = 0.688), while LogMAR CDVA was -0.06 ± 0.09 and -0.06 ± 0.1 in group I and group II, respectively (p = 0.972). Both groups showed a progressive oblate shift with time. This oblate shift was insignificantly less in group I by Topolyzer at 6mm, 15° and 30° at 6 months (p = 0.102, p = 0.138, p = 0.245, respectively). Topolyzer identified a significant difference between the change in coma and trefoil in both groups at 6 months (p<0.001 and p = 0.001, respectively). This was caused by the significant worsening of coma in group II (p<0.001) and the significant improvement of trefoil in group I (p = 0.007). No significant difference was found between groups in the change of ISV or ABR (p = 0.955 and 0.982, respectively). Ablation depth is a significant predictor of ΔQ at 6mm, 15° and 30° (p = 0.009, 0.039 and 0, respectively). No significant difference was found in the Strehl ratio or contrast sensitivity, although they were insignificantly better in group I (p = 0.785 and p = 0.745, respectively). CONCLUSION: TG PRK and CQ PRK yielded similar results regarding UDVA, CDVA, MRSE, safety, predictability and contrast sensitivity. Both groups showed a progressive oblate shift, which was less in the TG group but the difference was statistically insignificant. TG PRK showed significantly improved trefoil HOA as compared to CQ PRK.

Evaluation of peripapillary atrophy in early open-angle glaucoma using autofluorescence combined with optical coherence tomography.

PURPOSE: To quantitatively analyze α-zone and ß-zone peripapillary atrophy (PPA) in patients having early primary open-angle glaucoma (POAG) using fundus autofluorescence (FAF) in conjunction with spectral domain optical coherence tomography, colored photography and perimetry. DESIGN: This is an observational cross-sectional case-control study. METHODS: This study included 100 eyes (54 patients) of early to moderate POAG and 100 normal eyes (50 subjects). Ophthalmological examination, OCT for the optic nerve and FAF were performed. The extent of α-PPA and ß-PPA was measured. RESULTS: The extent of α-PPA and ß-PPA as measured by FAF had higher values in POAG group as compared to control group (p values 0.003 and ≤ 0.001 for the total nasal and temporal extents, respectively). However, the nasal alpha and temporal beta zones showed more values in POAG patients as compared to normal controls (p values 0.002 and 0.024). The difference between the total extents of either zones alone was not significant. B-scan OCT was able to positively detect both zones. Detecting the alpha zone was significantly higher in the control group, while beta zone detection was significantly higher in the POAG group (p values ≤ 0.001). CONCLUSION: The sensitivity of alpha zone detection was equal using colored photographs, FAF and B-scan OCT. FAF showed superior results in estimating the beta zone extent although OCT was more accurate in the anatomical delineation of Bruch's membrane and RPE termination. The nasal alpha and temporal beta zone extents could be taken as early indices for evaluating early glaucomatous optic neuropathy.

Orbital melanocytoma: When a tumor becomes a relieving surprise.

PURPOSE: Melanocytomas are rare pigmented tumors that arise form melanocytes and have been reported in the central nervous system. Orbital melanocytomas "also known as blue nevus" are rarely reported. The occurrence of choroidal melanoma and orbital melanocytomas has never been described. OBSERVATIONS: This is a case of orbital melanocytoma in a 34 year old female who presented with left proptosis and ecchymosis. She has the right eye enucleated to treat a large choroidal melanoma, 6 years earlier. Orbital metastasis was suspected. After orbital imaging and systemic evaluation, incisional biopsy was planned yet the mass could be totally excised and it turned out to be melanocytoma. The condition was not associated with nevus of Ota and the patient is not known to have any predisposing condition for melanocytic lesions. CONCLUSION AND IMPORTANCE: Melanocytoma and malignant melanoma share the same cell of origin. The benign course, the well differentiated cells, absence of anaplasia and the positive reaction to Human Melanoma Black-45 (HMB-45) and S-100 proteins established the diagnosis of the former. Such diagnosis was a relief for this one eyed patient.(HMB-45:human melanoma black-45).

Evaluation of planned bicanalicular nasolacrimal tube retention in treating punctal stenosis or occlusion secondary to trachoma.

This article evaluates retaining bicanalicular silicone nasolacrimal tube in patients susceptible to restenosis after punctoplasty. Sixty-nine eyes (38 patients) suffering from epiphora due to stenosis or occlusion of both punctae were included in this prospective study. All had 3 snip punctoplasty and bicanalicular silicone nasolacrimal duct insertion. Cases associated with proximal canalicular stenosis or obstructions were excluded. Tolerance to tube presence until the time of loss or removal was evaluated using a score (0 to 2). Average age was 49.71 ± 11.09 years. Tachomatous lesions were detected in all cases of punctal stenosis (48 eyes/69.57%) and membranous occlusion (21 eyes/30.43%). Common canalicular obstruction was additionally found in 12 eyes (17.39%). Absolute improvement was detected in 85% of cases and mean time for tube retention was (29.6 ± 10.2 months) with no difference in presence of common canalicular obstruction (P value: 0.138). Isolated punctal affection favoured tube retention that was well tolerated throughout the follow-up period (P value <0.001). Silicone bicanalicular nasolacrimal tube is an available option for treating acquired punctal stenosis. It is tolerated especially in cases suffering from isolated punctal stenosis. Tube retention could be of value in patients who are at risk of re-occlusion following tube removal.

The Evolving Role of Short-Term Professional Continuous Glucose Monitoring on Glycemic Control and Hypoglycemia Among Saudi Patients with Type 1 Diabetes: A Prospective Study.

INTRODUCTION: The aim of this study was to find out the evolving role of professional continuous glucose monitoring (PCGM) on hemoglobin A1c (HbA1c) and the frequency of hypoglycemia. METHODS: This was a 3-month, prospective study conducted among patients (aged 15-24 years) with type 1 diabetes mellitus who attended a diabetes clinic [Diabetes Treatment Center, Prince Sultan Military Medical City (PSMMC), Riyadh, Saudi Arabia] due to recurrent unexplained hypoglycemia unawareness episodes between July 2014 and December 2014. The respondents were purposively and conveniently selected and they were asked to wear the PCGM device (iPro(®)2; Medtronic MiniMed, Inc., Northridge, CA, USA) for 5 days. The PCGM results were collected by the diabetic educator and reviewed by the treating physician on the same day as removal of the device. Clinical and demographic data were also collected. RESULTS: Overall, 56 patients were included in the study. The mean (±SD) age of the study cohort was 18.1 ± 1.82 years and 27 (48.2%) patients were male. Compared with baseline, non-significant but positive differences were observed in HbA1c levels in both male and female patients and in those who were older (aged 20-24 years). Similar results were observed in the frequency of hypoglycemia and a significant change was observed for female patients (P < 0.05). Compared with baseline, a significant positive difference was observed in patients' overall frequency of hypoglycemia by the end of the study (P < 0.001). CONCLUSIONS: Professional continuous glucose monitoring is a valuable tool for detecting episodes of hypoglycemia and may help to decrease HbA1c levels and reduce the frequency of hypoglycemia.

Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography.

Purpose. To study features of the lower punctum in normal subjects using spectral domain anterior segment optical coherence tomography (SD AS-OCT). Methods. Observational cross-sectional study that included 147 punctae (76 subjects). Punctae were evaluated clinically for appearance, position, and size. AS-OCT was used to evaluate the punctal shape, contents, and junction with the vertical canaliculus. Inner and outer diameters as well as depth were measured. Results. 24 males and 52 females (mean age 44 ± 14.35 y) were included. Lower punctum was perceived by OCT to be an area with an outer diameter (mean 412.16 ± 163 µm), inner diameter (mean 233.67 ± 138.73 µm), and depth (mean 251.7 ± 126.58 µm). The OCT measured outer punctum diameter was significantly less than that measured clinically (P: 0.000). Seven major shapes were identified. The junction with the vertical canaliculus was detectable in 44%. Fluid was detected in 34%, one of which had an air bubble; however, 63% of punctae showed no contents and 4% had debris. Conclusions. AS-OCT can be a useful tool in understanding the anatomy of the punctum and distal lacrimal system as well as tear drainage physiology. Measuring the punctum size may play a role in plugs fitting.

Short term outcome of anterior lamellar reposition in treating trachomatous trichiasis.

Purpose. To evaluate the outcome of anterior lamellar reposition (ALR) in treating trachomatous trichiasis. Methods. Patients with trachomatous trichiasis or entropion with short tarsus were treated by ALR between February 2009 and November 2013. This included splitting of the lid margin behind the aberrant lash line to separate the lid lamellae. The anterior lamella was recessed and fixated using 4/0 silk sutures. The extra lashes and their routes were excised. Sutures were removed by the 3rd week and patients completed 6 months of follow-up. Recurrence of ≤5 lashes was treated by electrolysis. Results. The study included 752 eyelids (445 patients; 58.4% females, 41.6% males), mean age 53.2 ± 6.9 y. 179 (25.1%) lids had entropion while 287 (64.5%) patients had corneal affection. By the third week, 2.66% lid had trichiasis while 30.8% had no rubbing lashes. By the 6th month, 14.9% of lids showed recurrence while 66.1% were completely cured (CI = 0.63-0.69) and 19% had partial success (CI = 0.16-0.21). Abnormal lid appearance persisted in 2.66% and 12.9% required another surgery. Conclusion. ALR is a good option for treating trachomatous trichiasis especially without cicatricial entropion. Excision of dysplastic lashes is thought to augment the surgical outcome.

Orbital epidermoid cysts: a diagnosis to consider.

Background. Orbital epidermoids form a rare pathological entity that is separate from dermoid cysts. They have variable clinical and radiological presentations and they should be considered in the differential diagnosis of orbital cystic lesions. This work describes the various clinical and radiological presentations of 17 cases of epidermoid cysts and the surgical outcome. Method. A prospective interventional study was conducted on 17 patients diagnosed with epidermoid cysts. Patients' symptoms and signs were recorded; CT scan was done for all patients. All lesions were removed through anterior orbitotomy and histopathological diagnosis confirmed. Results. Mean age of patients was 16.3 years ± 10.54. Main complaints were lid swelling, masses, ocular dissimilarity, chronic pain, and ocular protrusion. Clinical signs varied from lid swelling and masses in all cases to proptosis, globe displacement, limitation of ocular motility, and scars. Radiological findings ranged from homogenous hypodense masses (58.8%) to homogenous radiolucent (17.6%) and heterogenous masses (23.5%). No recurrences following surgeries were reported throughout the follow-up (mean 18.8 months ± 0.72). Conclusion. Deep orbital epidemoid cysts are a separate entity that can behave like deep orbital epidermoid; however, they usually present at a relatively older age. They can be associated with increased orbital volume but not necessarily related to bony sutures.

Scleral shield: primary results of a new surgical technique in augmenting porous orbital implant protection.

PURPOSE: To evaluate the value of using an additional scleral shield in providing further protection of inserted Medpor® implants in eviscerated globes. METHODS: This was a prospective interventional case series that included 30 patients with blind and/or disfiguring globe that warranted evisceration. Cases with intraocular masses, retained intraocular foreign bodies, as well as secondary ball implantation were excluded. All patients underwent regular evisceration with porous polyethylene ball (Medpor®) implantation. The sutured wound was further covered by scleral patch graft followed by closure of Tenon capsule and conjunctiva in separate layers. Patients were evaluated for implant exposure and all of them completed at least 4 years of follow-up. RESULTS: The study involved 26 male and 4 female participants with age ranging from 16 to 65 years (mean 40.74 ± 15.86 years). The Medpor sizes varied from 16 to 22 mm in diameter. It is a simple extra step with no reported exposure, infection, or granulomas during the 4 years of follow-up. CONCLUSIONS: Scleral shield is a simple surgical technique that provides an extra layer of autogenous tissue to cover inserted orbital implant following evisceration with promising results in preventing their exposure.

Changes in retinal nerve fiber layer thickness following mechanical microkeratome-assisted versus femtosecond laser-assisted LASIK.

PURPOSE: To study the influence of the transient elevation of intraocular pressure during suction in laser-assisted in situ keratomileusis (LASIK) on the retinal nerve fiber layer (RNFL) thickness both in microkeratome assisted and femotsecond (FS) LASIK. PATIENTS AND METHODS: An interventional case series that included 40 eyes suffering from myopia who were candidates for LASIK. All underwent Wave Front Guided LASIK by the same surgeon using the VisX CustomVue platform. A corneal flap was created in 20 eyes using a mechanical microkeratome Moria M2 (MMK), while the IFS IntraLase™ was used in the remaining 20 eyes. Mean suction time was recorded from "Suction ON" to "Suction OFF" time. Optic cube and RNFL thickness analysis using Spectral Domain Optical Coherence Tomography (SD-OCT) Cirrus-HD was completed before, and 1 month after LASIK. RESULTS: The study included 40 eyes of 20 patients. All were females with mean age 33.5 ± 6.4 years. Mean preoperative spherical equivalent was -3.62 ± 2.31D. Average preoperative RNFL thickness was 94.6 ± 12.1µm in MMK group while the postoperative average thickness was 95.1 ± 11.9 um with no statistically significant difference (P-value: 0.37). Average preoperative RNFL thickness was 108.28 ± 8.4 µm in FS group compared to 108.38 ± 11.2 µm in the postoperative average with no statistically significant difference (P-value: 0.94). Mean "Suction ON" to "Suction OFF" time was 22 seconds in the MMK group compared to 41 seconds in the FS group. CONCLUSION: The rise of intraocular pressure during application of suction ring in LASIK surgery does not affect the RNFL thickness as measured by SD-OCT, whether the flap is created by MMK or FS.

Orbital foreign bodies: expect the unexpected.

Data of three pediatric patients with orbitofacial trauma were reviewed. Two patients presented with recurrent orbital inflammation with partial remission with antibiotics. One patient presented with diplopia. All patients underwent full opthalmic examination and computed tomography (CT) of the brain and orbit, followed by surgical intervention. The indication for surgery was either abscess evacuation, repair of blowout fracture, or mass excision. All of the patients had intraorbital wood foreign bodies that were not evident on CT and were not suspected from the history given by the parents. All were surgically removed. One patient had multiple wood foreign bodies (more than 10). Chronic or recurrent orbital inflammation, unexplained proptosis, or orbital masses following orbitofacial trauma in children should raise the suspicion of intraorbital foreign bodies even if not detected by CT studies. Presence of other sequelae of trauma such as blowout fracture does not exclude the possibility of associated foreign bodies.

The role of calcium/calmodulin-dependent protein kinase cascade on MIP-1alpha gene expression of ATL cells.

OBJECTIVE: Adult T-cell leukemia (ATL) is a mature CD4(+) T-cell malignancy caused by infection with human T-lymphotrophic virus type-1 and is associated with a marked hypercalcemia in many patients. Recently, it has been proposed that macrophage inflammatory protein-1alpha (MIP-1alpha) is the clinical hallmark of hypercalcemia in ATL. In this study, we investigated the effect of extracellular calcium on MIP-1alpha secretion in ATL cells and the role of Ca(2+)/calmodulin (CaM)-dependent protein kinase (CaM-K) cascade in transcriptional activation of MIP-1alpha. MATERIALS AND METHODS: MIP-1alpha protein levels in the culture supernatant collected from ATL cells were measured by enzyme-linked immunosorbent assay. Reporter plasmid containing the MIP-1alpha promoter was transfected to ATL cells, and the promoter activity was measured by luciferase assay. RESULTS: The addition of calcium to the culture medium enhanced the secretion of MIP-1alpha from ATL cells, which was inhibited by the CaM-KK inhibitor. The transfection of CaM-KIV stimulated MIP-1alpha promoter activity, and the upstream kinase CaM-KK enhanced the stimulatory effect of CaM-KIV on the promoter activity. Mutation in the cyclic adenosine 5' monophosphate response element (CRE) within the MIP-1alpha promoter significantly reduced the effect of CaM-KIV, and CRE mutant promoter activity was not significantly enhanced by the addition of calcium to the culture medium as compared to wild-type promoter activity. CONCLUSION: Hypercalcemia enhances MIP-1alpha secretion in ATL cells, and this mechanism requires the involvement of CaM-KK/CaM-KIV cascade through the CRE. These findings raise a possibility that the inhibitory effect of CaM-KK/CaM-KIV cascade may be a potential therapeutic target for ATL.

D-Psicose inhibits the expression of MCP-1 induced by high-glucose stimulation in HUVECs.

Monocyte chemoattractant protein-1 (MCP-1) is a 76-amino-acid chemokine thought to be the major chemotactic factor for monocytes. MCP-1 is found in macrophage-rich areas of atherosclerotic lesions. Recent report indicates that MCP-1 is induced by glucose-stimulation, raising the important link between diabetes mellitus and atherosclerosis. One of the rare sugars, d-psicose (d-ribo-2-hexulose) is present in small quantities in commercial carbohydrate complexes, however the physiological functions of d-psicose have not been evaluated. In this study, we examined the effects of d-psicose on MCP-1 expression in human umbilical vein endothelial cells (HUVECs). Results showed that MCP-1 mRNA and protein were stimulated following exposure to 22.4 mM glucose. Transcriptional activity of MCP-1 promoter paralleled endogenous expression of the gene and this activity was dependent on the dose of d-glucose. d-Psicose inhibited these effects. Next we used inhibitors of selected signal transduction pathways to show that high-glucose (HG) stimulated MCP-1 promoter activity was sensitive to p38-Mitogen-Activated Protein Kinase (p38-MAPK) pathway inhibitor. As expected, a dominant-negative p38-MAPK abolished the stimulatory effect of HG on the promoter activity. To incubate the cells with HG and d-psicose reduced the activation of p38-MAPK. Together, these results indicate that the d-psicose suppression of HG induced MCP-1 expression is mediated in part by inhibition of the p38-MAPK pathway and raise the possibility that d-psicose may be of therapeutic value in the treatment of diseases such as atherosclerosis.

Regulation of scavenger receptor class BI gene expression by angiotensin II in vascular endothelial cells.

High-density lipoprotein mediates a normal physiological process called reverse cholesterol transport. In this process, a scavenger receptor of the B class (SR-BI)/human homologue of SR-BI, CD36, and LIMPII analogous-1 (hSR-BI/CLA-1) facilitates the cellular uptake of cholesterol from high-density lipoprotein. In endothelial cells, high-density lipoprotein activates endothelial NO synthase via hSR-BI/CLA-1. Angiotensin II (Ang II) is a powerful accelerator of atherosclerosis and modulates the expression of endothelial NO synthase. In the present study, we have examined the role of Ang II on hSR-BI/CLA-1 expression in human umbilical vein endothelial cells. Our results showed that endogenous expression of hSR-BI/CLA-1 was suppressed by exposure to Ang II in human umbilical vein endothelial cells. Administration of the Ang II type-1 receptor blocker olmesartan inhibited Ang II-induced hSR-BI/CLA-1 protein repression. In Ang II-treated cells, high-density lipoprotein had no effect on endothelial NO synthase activation. Ang II decreased transcriptional activity of the hSR-BI/CLA-1 promoter. The inhibitory effect of Ang II on hSR-BI/CLA-1 promoter activity was abrogated by wortmannin and LY294002, specific inhibitors of phosphatidylinositol 3-kinase. Exposure of human umbilical vein endothelial cells to Ang II elicited a rapid phosphorylation of Akt and FoxO1, a known target of Akt signaling. Constitutively active Akt inhibits the activity of the hSR-BI/CLA-1 promoter, and a dominant-negative mutant of Akt or mutagenesis of a FoxO1 response element in the hSR-BI/CLA-1 abolished the ability of Ang II to suppress promoter activity. Together, these results indicate that the phosphatidylinositol 3-kinase/Akt/FoxO1 pathway participates in Ang II suppression of hSR-BI/CLA-1 expression and suggests that the endothelial receptor for hSR-BI/CLA-1 is downregulated by the renin-angiotensin system.

Pancreatic glucokinase is activated by insulin-like growth factor-I.

Glucokinase (GK) plays a key role in the regulation of glucose use and glucose-stimulated insulin secretion in pancreatic islet cells. Gene targeting of the IGF-I receptor down-regulated pancreatic islet GK activity. That finding prompted us to examine the potential mechanism that may control GK gene activity using an islet cell line, INS-1, known to express IGF-I receptor. Exposure of these cells to IGF-I induced GK protein expression and activity of the enzyme in a dose-dependent manner. In addition, IGF-I induced activity of a reporter construct containing the GK promoter in parallel with the effect on endogenous GK mRNA levels. The stimulatory effect of IGF-I on GK promoter activity was abrogated by wortmannin and LY294002, specific inhibitors of phosphatidylinositol 3-kinase. Exposure of cells to IGF-I elicited a rapid phosphorylation of Akt and FoxO1, a known target of Akt signaling. Constitutively active Akt stimulates the activity of the GK promoter, and a dominant-negative mutant of Akt or mutagenesis of a FoxO1 response element in the GK promoter abolished the ability of IGF-I to stimulate the promoter activity. Furthermore, cell knockdown of FoxO1 with small interfering RNA disrupted the effect of IGF-I on GK expression. These results demonstrate that the phosphatidylinositol 3-kinase/Akt/FoxO1 pathway contributes to the regulation of GK gene expression in response to IGF-I stimulation.

Platelet derived growth factor regulates ABCA1 expression in vascular smooth muscle cells.

The ATP-binding cassette transporter A1 (ABCA1) regulates lipid efflux from peripheral cells to High-density lipoprotein. The platelet-derived growth factor (PDGF) is a potent mitogen that enables vascular smooth muscle cells to participate in atherosclerosis. In this report, we showed that PDGF suppressed endogenous expression of ABCA1 in cultured vascular smooth muscle cells. Exposure of CRL-208 cells to PDGF elicited a rapid phosphorylation of a kinase downstream from PI3-K, Akt. The constitutively active form of both p110, a subunit of PI3-K, and Akt inhibited activity of the ABCA1 promoter. In conclusion, PI3-K-Akt pathways participate in PDGF-suppression of ABCA1 expression.

High-density lipoprotein is a potential growth factor for adrenocortical cells.

The entry of cholesterol contained within high-density lipoprotein (HDL) into adrenocortical cells is mediated by a human homologue of SR-BI, CD36, and LIMPII Analogous-1 (CLA-1) and thus augmenting their growth. To address the role of CLA-1, we created a mutant mCLA that lacked the C-terminal tail. HDL CE selective uptake by cells carrying the mCLA-1 receptor was fully active and equivalent to those transfected with full-length CLA-1 (fCLA-1). Expression of mCLA inhibited the proliferation of an adrenocortical cell line and the incorporation of [(3)H]thymidine into the cells. This effect was sensitive to wortmannin, an inhibitor of phosphoinositide 3-kinase (PI3K). Our transcriptional studies revealed that the inhibitory action of mCLA required the transcriptional factor AP-1 and the effect of HDL on AP-1 activation was also abrogated by wortmannin. These findings raise the possibility that the inhibitors of the effects of HDL may be of therapeutic value for adrenocortical tumor.