Rehabilitation of a patient with orbital defect is highly a challenging task, requiring an individualized design of the technique for each patient. The disfigurement associated with the loss of facial structures causes significant emotional stress and physical burdens.Various treatment modalities are available, one of which is the use of implants. Although implant-supported orbital prosthesis has a superior outcome, it may not be advisable in all the patients due to economic factors. The treatment of choice includes the silicone orbital prosthesis due to its life-like appearance. This article describes three different techniques, it’s advantages and limitations of fabricating a silicone orbital prosthesis for the same patient to achieve ideal fit and aesthetics.
Maxillofacial prosthesis; Orbital prosthesis; Retention aids; Silicone; Total maxillectomy
Hutchinson – Gilford Progeria Syndrome is a rare genetic disorder characterized by premature aging involving the skin, bones, heart, and blood vessels. We report a three-year-old boy with clinical manifestations characteristic of this syndrome. He had a characteristic “plucked-bird” appearance, prominent eyes and scalp veins, senile look, loss of scalp hair, eyebrows, and eyelashes, stunted growth, and mottled pigmentation with sclerodermatous changes over the trunk and lower limbs. Radiological changes and decreased high-density lipoprotein (HDL) levels were also characteristic of the syndrome. This interesting case is reported for its rarity.
Hutchinson – Gilford syndrome; premature aging; progeria
The objective of the study was to compare the efficacy of external fixation and volar plating on the functional parameter of displaced intra-articular (Cooney’s type IV) distal end radius fractures using the Green and O’Brien scoring system.
Materials and methods
This prospective randomized study comprised 68 patients treated with external fixation and 42 patients treated with volar locking plates. The patients were followed up at 6 months and 1 year after surgery. The assessment of pain, range of motion, grip strength and activity were assessed at each follow-up visit and scored according to the Green and O’Brien scoring system.
At 1 year after surgery, we observed that external fixation showed significantly better results than volar locking plates using the Green and O’Brien scores for range of motion (22.0 ± 4.77 vs 19.89 ± 5.05), grip strength (19.91 ± 5.4 vs 16.89 ± 4.4) and final outcome (87.36 ± 11.62 vs 81.55 ± 11.32). No difference was found in pain and activity between these two groups of patients. Patients aged <50 years treated with external fixation showed excellent results (final score (91.57 ± 9.01) at 1 year follow-up.
External fixation showed superiority over volar locked plating after 1 year of surgery.
Level of evidence
Distal end radius fracture; External fixation; Volar locking plate; Green and O’Brien score
Eye is a vital organ not only for vision, but also an important component of facial expression, and over-all personality of a person. Loss of eye, apart from leading to impaired vision has a crippling effect on the psychology of the patient. Prosthodontic rehabilitation of such cases includes fabrication of prosthesis by acrylic resin, silicone and implants. However, not all patients are willing to use implants for maxillofacial rehabilitation. Therefore, a custom made orbital prosthesis serves as an affordable and satisfactory alternative.
Custom made orbital prosthesis; Esthetics; Orbital defect
Nanotechnology is a relatively newer field of science that is finding enormous scope in the dental & medical science. Use of endosseous dental implant surfaces having nano-scale topography is fast becoming part of modern implantology. The purpose of this review is to discuss and understand the role of nanoscale surface modification of titanium materials for the purpose of improving various phases of implantology including osseointegration. Nanotechnology equips bioengineers with newer ways of interacting with relevant biological processes. On the other hand, the field of nanotechnology provides means of understanding and achieving cell specific functions. An understanding of the role of nano-topography leads to the significant osseointegration modulations by nanoscale modification of the implants surface. Use of nanotechnology to modify the topography of titanium endosseous implant can drastically improve cellular and tissue responses that may benefit osseointegration and dental implant procedures.
Dental implants; Osteogenesis; Osseointegration; Topography; Surface treatment; Nanotechnology
In this paper, a combined approach for enhancement and segmentation of mammograms is proposed. In preprocessing stage, a contrast limited adaptive histogram equalization (CLAHE) method is applied to obtain the better contrast mammograms. After this, the proposed combined methods are applied. In the first step of the proposed approach, a two dimensional (2D) discrete wavelet transform (DWT) is applied to all the input images. In the second step, a proposed nonlinear complex diffusion based unsharp masking and crispening method is applied on the approximation coefficients of the wavelet transformed images to further highlight the abnormalities such as micro-calcifications, tumours, etc., to reduce the false positives (FPs). Thirdly, a modified fuzzy c-means (FCM) segmentation method is applied on the output of the second step. In the modified FCM method, the mutual information is proposed as a similarity measure in place of conventional Euclidian distance based dissimilarity measure for FCM segmentation. Finally, the inverse 2D-DWT is applied. The efficacy of the proposed unsharp masking and crispening method for image enhancement is evaluated in terms of signal-to-noise ratio (SNR) and that of the proposed segmentation method is evaluated in terms of random index (RI), global consistency error (GCE), and variation of information (VoI). The performance of the proposed segmentation approach is compared with the other commonly used segmentation approaches such as Otsu's thresholding, texture based, k-means, and FCM clustering as well as thresholding. From the obtained results, it is observed that the proposed segmentation approach performs better and takes lesser processing time in comparison to the standard FCM and other segmentation methods in consideration.
Mammogram segmentation; mammogram enhancement; modified fuzzy c-means segmentation; mutual information; performance evaluation; wavelet based segmentation
Tumor necrosis factor alpha receptor 3 interacting protein 1 (Traf3ip1), also known as MIPT3, was initially characterized through its interactions with tubulin, actin, TNFR-associated factor-3 (Traf3), IL-13R1, and DISC1. It functions as an inhibitor of IL-13-mediated phosphorylation of Stat6 and in sequestration of Traf3 and DISC1 to the cytoskeleton. Studies of the Traf3ip1 homologs in C. elegans (DYF-11), Zebrafish (elipsa), and Chlamydomonas (IFT54) revealed that the protein localizes to the cilium and is required for ciliogenesis. Similar localization data has now been reported for mammalian Traf3ip1. This raises the possibility that Traf3ip1 has an evolutionarily conserved role in mammalian ciliogenesis in addition to its previously indicated functions. To evaluate this possibility, a Traf3ip1 mutant mouse line was generated. Traf3ip1mutant cells are unable to form cilia. Homozygous Traf3ip1 mutant mice are not viable and have both neural developmental defects and polydactyly, phenotypes typical of mouse mutants with ciliary assembly defects. Furthermore, in Traf3ip1 mutants the hedgehog pathway is disrupted, as evidenced by abnormal dorsal-ventral neural tube patterning and diminished expression of a hedgehog reporter. Analysis of the canonical Wnt pathway indicates that it was largely unaffected; however, specific domains in the pharyngeal arches have elevated levels of reporter activity. Interestingly, Traf3ip1 mutant embryos and cells failed to show alterations in IL-13 signaling, one of the pathways associated with its initial discovery. Novel phenotypes observed in Traf3ip1 mutant cells include elevated cytosolic levels of acetylated microtubules and a marked increase in cell size in culture. The enlarged Traf3ip1 mutant cell size was associated with elevated basal mTor pathway activity. Taken together, these data demonstrate that Traf3ip1 function is highly conserved in ciliogenesis and is important for proper regulation of a number of essential developmental and cellular pathways. The Traf3ip1 mutant mouse and cell lines will provide valuable resources to assess cilia function in mammalian development and also serve as a tool to explore the potential connections between cilia and cytoskeletal dynamics, mTor regulation, and cell volume control.
primary cilia; IFT; Traf3ip1; MIPT3
Restoration of aesthetics, function and comfort in badly compromised dentition and its supporting tissues often poses a great challenge. The long term success of such cases depends largely on simultaneous achieving of satisfying aesthetics and a harmonious occlusion. Proper examination, evaluation and diagnosis of the prevailing oral conditions serve as a prelude to a rationalized treatment plan and its ultimate success. Invariably, it also becomes significant to understand and recognize the consequences of long term negligence by the patient. An unattended such condition, apart from causing compromised oral functions may also lead to neuromuscular problems in and around temporo-mandibular joint (TMJ) causing frequent pain in the region and unyielding headaches. Restoring physiologically advised health conditions from habitual positions and functions may require time, patience and effort by both – the patient and the dentist. A complete rehabilitation may also require involvement of more than one disciplines of dentistry. The case report highlights the contributions from prosthodontists, periodontists, endodontists and the radiologist as a team in complete rehabilitation of the patient.
Vertical Dimension; Scaling & Root Planing; Root Canal Treatment; TMJ
Type 2 diabetes (T2D) is a common metabolic disorder which is caused by multiple genetic perturbations affecting different biological pathways. Identifying genetic factors modulating the susceptibility of this complex heterogeneous metabolic phenotype in different ethnic and racial groups remains challenging. Despite recent success, the functional role of the T2D susceptibility variants implicated by genome-wide association studies (GWAS) remains largely unknown. Genetic dissection of transcript abundance or expression quantitative trait (eQTL) analysis unravels the genomic architecture of regulatory variants. Availability of eQTL information from tissues relevant for glucose homeostasis in humans opens a new avenue to prioritize GWAS-implicated variants that may be involved in triggering a causal chain of events leading to T2D. In this article, we review the progress made in the field of eQTL research and knowledge gained from those studies in understanding transcription regulatory mechanisms in human subjects. We highlight several novel approaches that can integrate eQTL analysis with multiple layers of biological information to identify ethnic-specific causal variants and gene-environment interactions relevant to T2D pathogenesis. Finally, we discuss how the eQTL analysis mediated search for “missing heritability” may lead us to novel biological and molecular mechanisms involved in susceptibility to T2D.
Type 2 diabetes; Single nucleotide polymorphisms; Expression quantitative trait locus; Expression regulatory SNPs; Gene-environment interaction; Genome-wide association study
Human NK cells express cell surface class I MHC receptors (KIR) in a probabilistic manner. Previous studies have shown that a distal promoter acts in conjunction with a proximal bidirectional promoter to control the selective activation of KIR genes. We report here the presence of an intron 2 promoter in several KIR genes that produces a spliced antisense transcript. This lncRNA transcript contains antisense sequence complementary to KIR-coding exons 1 and 2 as well as the proximal promoter region of the KIR genes. The antisense promoter contains MZF-1 binding sites, a transcription factor found in hematopoietic progenitors and myeloid precursors. The KIR antisense lncRNA was only detected in progenitor cells or pluripotent cell lines, suggesting a function that is specific for stem cells. Overexpression of MZF-1 in developing NK cells led to decreased KIR expression, consistent with a role for the KIR antisense lncRNA in silencing KIR gene expression early in development.
human; NK cells; KIR; antisense; transcription; lncRNA
Allelic heterogeneity in disease-causing genes presents a substantial challenge to the translation of genomic variation to clinical practice. Few of the almost 2,000 variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene have empirical evidence that they cause cystic fibrosis. To address this gap, we collected both genotype and phenotype data for 39,696 cystic fibrosis patients in registries and clinics in North America and Europe. Among these patients, 159 CFTR variants had an allele frequency of ≥0.01%. These variants were evaluated for both clinical severity and functional consequence with 127 (80%) meeting both clinical and functional criteria consistent with disease. Assessment of disease penetrance in 2,188 fathers of cystic fibrosis patients enabled assignment of 12 of the remaining 32 variants as neutral while the other 20 variants remained indeterminate. This study illustrates that sourcing data directly from well-phenotyped subjects can address the gap in our ability to interpret clinically-relevant genomic variation.
Disruption of the primary cilium is associated with a growing number of human diseases collectively termed ciliopathies. Ciliopathies present with a broad range of clinical features consistent with the near ubiquitous nature of the organelle and its role in diverse signaling pathways throughout development and adult homeostasis. The clinical features associated with cilia dysfunction can include such phenotypes as polycystic kidneys, skeletal abnormalities, blindness, anosmia, and obesity. Although the clinical relevance of the primary cilium is evident, the effects that cilia dysfunction has on the cell and how this contributes to disease remains poorly understood. Here, we show that loss of ciliogenesis genes such as Ift88 and Kif3a lead to increases in post-translational modifications on cytosolic microtubules. This effect was observed in cilia mutant kidney cells grown in vitro and in vivo in cystic kidneys. The hyper-acetylation of microtubules resulting from cilia loss is associated with both altered microtubule stability and increased α-tubulin acetyl-transferase activity. Intriguingly, the effect on microtubules was also evident in renal samples from patients with autosomal recessive polycystic kidneys. These findings indicate that altered microtubule post-translational modifications may influence some of the phenotypes observed in ciliopathies.
cilia; tubulin; acetylation; microtubules; Polycystic Kidney Disease
The aesthetic requirement of severely mutilated primary anterior teeth in case of Early Childhood Caries (ECC) has been a challenge to paediatric dentists. ECC involves the upper anterior teeth early in life and by the time the dentist sees the child, most of the coronal structure is lost. This article presents the clinical sequence of rehabilitation of maxillary anterior primary teeth, and the mandibular posterior teeth.
Early childhood caries; Aesthetics; Hybrid composite; Polyethylene fibre
We aimed to define effects of PPARγ and PPARα agonist mono and combination therapy on adipose tissue and skeletal muscle gene expression in relation to insulin sensitivity. We further investigated the role of genetic polymorphisms in PPAR ligand-modulated genes in transcriptional regulation and glucose homeostasis.
Genome-wide transcript profiles of subcutaneous adipose and skeletal muscle and metabolic phenotypes were determined before and after 10 weeks of pioglitazone and fenofibrate mono or combination therapy in 26 subjects with impaired glucose tolerance. To establish the functional role of SNPs in genes modulated by pioglitazone alone or in combination with fenofibrate, we interrogated genome-wide association data of continuous glycemic phenotypes from the MAGIC study and adipose eQTL data from the MuTHER study.
PPARγ, alone or in combination with PPARα agonists, mediated up-regulation of genes involved in the TCA cycle, branched chain amino acid metabolism, fatty acid metabolism, PPAR signaling, AMPK and cAMP signaling, and insulin signaling pathways, and downregulation of genes in antigen processing and presentation, immune and inflammatory response in adipose tissue. Remarkably few changes were found in muscle. Strong enrichment of genes involved in propanoate metabolism, fatty acid elongation in mitochondria, and acetyl-CoA metabolic process were observed only in adipose tissue of the combined pioglitazone and fenofibrate treatment group. After interrogating MAGIC data, SNPs in 22 genes modulated by PPAR ligands were associated with fasting plasma glucose and the expression of 28 transcripts modulated by PPAR ligands was under control of local genetic regulators (cis-eQTLs) in adipose tissue of MuTHER study twins.
We found differences in transcriptional mechanisms that may describe insulin sensitizing effects of PPARγ agonist monotherapy or in combination with PPARα agonist. The regulatory and glucose homeostasis trait-associated SNPs in PPAR agonist-modulated genes are important candidates for future studies that may explain the inter-individual variability in response to thiazolidinedione and fenofibrate treatment.
insulin resistance; gene expression profile; muscle; adipose; pioglitazone; fenofibrate; eQTL
Recent studies have identified links between phospholipid composition and altered cellular functions in animal models of obesity, but the involvement of phospholipid biosynthesis genes in human obesity are not well understood. We analyzed the transcript of four phospholipid biosynthesis genes in adipose and muscle from 170 subjects. We examined publicly available genome-wide association data from the GIANT and MAGIC cohorts to investigate the association of SNPs in these genes with obesity and glucose homeostasis traits, respectively. Trait-associated SNPs were genotyped to evaluate their roles in regulating expression in adipose. In adipose tissue, expression of PEMT, PCYT1A, and PTDSS2 were positively correlated and PCYT2 was negatively correlated with percent fat mass and body mass index (BMI). Among the polymorphisms in these genes, SNP rs4646404 in PEMT showed the strongest association (p = 3.07E-06) with waist-to-hip ratio (WHR) adjusted for BMI. The WHR-associated intronic SNP rs4646343 in the PEMT gene showed the strongest association with its expression in adipose. Allele “C” of this SNP was associated with higher WHR (p = 2.47E-05) and with higher expression (p = 4.10E-04). Our study shows that the expression of PEMT gene is high in obese insulin-resistant subjects. Intronic cis-regulatory polymorphisms may increase the genetic risk of obesity by modulating PEMT expression.
Acetyl coenzyme A carboxylase B gene (ACACB) single nucleotide polymorphism (SNP) rs2268388 is reproducibly associated with type 2 diabetes (T2DM)-associated nephropathy (DN). ACACB knock-out mice are also protected from obesity. This study assessed relationships between rs2268388, body mass index (BMI) and gene expression in multiple populations, with and without T2DM. Among subjects without T2DM, rs2268388 DN risk allele (T) associated with higher BMI in Pima Indian children (n = 2021; p-additive = 0.029) and African Americans (AAs) (n = 177; p-additive = 0.05), with a trend in European Americans (EAs) (n = 512; p-additive = 0.09), but not Germans (n = 858; p-additive = 0.765). Association with BMI was seen in a meta-analysis including all non-T2DM subjects (n = 3568; p-additive = 0.02). Among subjects with T2DM, rs2268388 was not associated with BMI in Japanese (n = 2912) or EAs (n = 1149); however, the T allele associated with higher BMI in the subset with BMI≥30 kg/m2 (n = 568 EAs; p-additive = 0.049, n = 196 Japanese; p-additive = 0.049). Association with BMI was strengthened in a T2DM meta-analysis that included an additional 756 AAs (p-additive = 0.080) and 48 Hong Kong Chinese (p-additive = 0.81) with BMI≥30 kg/m2 (n = 1575; p-additive = 0.0033). The effect of rs2268388 on gene expression revealed that the T risk allele associated with higher ACACB messenger levels in adipose tissue (41 EAs and 20 AAs with BMI>30 kg/m2; p-additive = 0.018) and ACACB protein levels in the liver tissue (mixed model p-additive = 0.03, in 25 EA bariatric surgery patients with BMI>30 kg/m2 for 75 exams). The T allele also associated with higher hepatic triglyceride levels. These data support a role for ACACB in obesity and potential roles for altered lipid metabolism in susceptibility to DN.
To estimate the prevalence of metabolic syndrome among adolescents attending school in the Jammu region, India.
Materials and Methods:
This is a cross-sectional study conducted between November 2009 and December 2010, among a total of 1160 school-going adolescents of both sexes aged 10-18 years. Relevant metabolic and anthropometric variables were analyzed and criteria suggested by National Cholesterol Education Program Adult Treatment Panel Third (NCEP-ATP III) modified forage was used to define metabolic syndrome.
The overall prevalence of metabolic syndrome was 2.6%. Prevalence of metabolic syndrome was higher in males (3.84%) than in females (1.6%) and slightly higher in urban area (2.80%) than in rural area (2.52%), whereas prevalence of metabolic syndrome among centrally obese subjects was as high as 33.33%. High density lipoprotein cholesterol was the most common and high blood pressure was the least common constituent of metabolic syndrome. Metabolic syndrome was most prevalent in 16-18 years age group (4.79%).
This study demonstrates that metabolic syndrome phenotype exists in substantial number (up to 3%) of adolescent population in the Jammu region, India, and particularly 33% of obese adolescents are at risk to develop metabolic syndrome. These findings pose a serious threat to the current and future health of these young people.
Adolescents; metabolic syndrome; obesity; prevalence
Killer immunoglobulin-like receptors (KIR) are expressed in a variegated, clonally restricted fashion on natural killer (NK) cells and are important determinants of NK cell function. Although silencing of individual KIR genes is strongly correlated with the presence of CpG dinucleotide methylation within the promoter, the mechanism responsible for silencing has not been identified. Our results show that antisense transcripts mediate KIR transcriptional silencing through a novel PIWI-like 28 base small RNA. Although PIWI RNA-mediated silencing of transposable elements within germ cells have been described, this is the first report that identifies a PIWI-like RNA in an immune somatic cell lineage and identifies a mechanism which may be broadly used in orchestrating immune development.
Primary malignant melanoma of the oral cavity is a rare neoplasm. The tumors tend to metastasize or locally invade tissue more readily than other malignant tumors in the oral region. The survival of patients with mucosal melanomas is less than for those with cutaneous melanomas. Tumor size and metastases are related to the prognosis of the disease. Early detection, therefore, is important.
Foreign bodies may be deposited in the oral cavity either by traumatic injury or iatrogenically. Among the commonly encountered iatrogenic foreign bodies are restorative materials like amalgam, obturation materials, broken instruments, needles, and so forth. The discovery of foreign bodies in the teeth is a special situation, which is often diagnosed accidentally. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, location of the foreign body, and the difficulty involved in its retrieval. It is more common to find this situation in children as it is a well-known fact that children often tend to have the habit of placing foreign objects in the mouth. Sometimes the foreign objects get stuck in the root canals of the teeth, which the children do not reveal to their parents due to fear. These foreign objects may act as a potential source of infection and may later lead to a painful condition. This paper discusses the presence of unusual foreign bodies—a tip of the metallic compass, stapler pin, copper strip, and a broken sewing needle impregnated in the gingiva and their management.
Prior type 2 diabetes (T2D) genome-wide association studies (GWASs) have generated a list of well-replicated susceptibility loci in populations of European and Asian ancestry. In order to validate the trans-ethnic contribution of these GWAS SNPs, we performed a family-based association analysis of 32 selected GWAS SNPs in a cohort of 1496 African American (AA) subjects from the GENNID study. Functional roles of these SNPs were evaluated by screening cis-eQTLs in transformed lymphoblast cell lines available for a sub-group of GENNID families from Arkansas. Only three of the 32 GWAS-derived SNPs showed nominally significant association with T2D in our AA cohort. Among the replicated SNPs rs864745 in JAZF1 and rs10490072 in BCL11A gene (p= 0.006 and 0.03, respectively, after adjustment for BMI) were within the 1-lod drop support interval of T2D linkage peaks reported in these families. Genotyping of 19 Tag-SNPs in these two loci revealed no further common SNPs or haplotypes that may be a stronger predictor of T2D susceptibility than the index SNPs. Six T2D GWAS SNPs (rs6698181, rs9472138, rs730497, rs10811661, rs11037909, and rs1153188) were associated with nearby transcript expression in transformed lymphoblast cell lines of GENNID AA subjects. Thus, our study indicates a nominal role for JAZF1 and BCL11A variants in T2D susceptibility in AAs and suggested little overlap in known susceptibility to T2D between European and African derived populations when considering GWAS SNPs alone.
Association; Diabetes; eQTL; gene expression; linkage disequilibrium; SNP
Adenomatoid odontogenic tumor (AOT) is a rare odontogenic tumor which is often misdiagnosed as odontogenic cyst and accounts for about 1% until 9% of all odontogenic tumors. It is predominantly found in young and female patients, located more often in the maxilla in most cases associated with an unerupted permanent tooth. It is a benign (hamartomatous), noninvasive lesion with slow but progressive growth. There are three variants of AOT: follicular, extrafollicular, and peripheral. We report a rare case of follicular-type AOT in the mandible of a 14-year-old male patient who presented with right -sided jaw swelling.
Adenomatoid odontogenic tumor; benign; hamartoma; odontogenic tumors
Recent studies in mice and human identified osteocalcin (OCN) as a bone-derived hormone that modulates insulin secretion and insulin sensitivity. OCN is synthesized by the bone gamma-carboxyglutamate protein (BGLAP) gene located in the well replicated region of type 2 diabetes (T2D) linkage on chromosome 1q22. We resequenced BGLAP gene in 192 individuals with T2D and performed case-control studies in 766 Caucasian (461 T2D and 305 controls) and 563 African American individuals (371 T2D and 192 controls). Metabolic effects of BGLAP variants were examined in 127 nondiabetic members of Caucasian T2D families and in 498 unrelated nondiabetic African American and Caucasian individuals. BGLAP expression was tested in transformed lymphocytes from 60 Caucasian individuals. We identified 17 single nucleotide polymorphisms (SNPs) in African Americans, but observed only the two known SNPs in Caucasians. No SNP was associated with T2D. Promoter SNP rs1800247 was not associated with metabolic traits including insulin sensitivity (SI) or fasting glucose in either population, but nonsynonymous SNP rs34702397 (R94Q) was nominally associated with SI (uncorrected p=0.05) and glucose-mediated glucose disposal (SG; uncorrected p=0.03) in African Americans. No SNP altered measures of insulin secretion or obesity, nor was BGLAP expression associated with rs1800247. Our study was sufficiently powered to exclude BGLAP variants as a major risk factor (OR>1.5) for T2D in Caucasians, but coding variants in exon 4 may alter glucose homeostasis and diabetes risk in African Americans.
Osteocalcin; Diabetes; Polymorphism; Transcript; Association; Insulin sensitivity
To determine altered gene expression profiles in subcutaneous adipose and skeletal muscle from nondiabetic, insulin-resistant individuals compared with insulin-sensitive individuals matched for BMI.
RESEARCH DESIGN AND METHODS
A total of 62 nondiabetic individuals were chosen for extremes of insulin sensitivity (31 insulin-resistant and 31 insulin-sensitive subjects; 40 were European American and 22 were African American) and matched for age and obesity measures. Global gene expression profiles were determined and compared between ethnic groups and between insulin-resistant and insulin-sensitive participants individually and using gene-set enrichment analysis.
African American and European American subjects differed in 58 muscle and 140 adipose genes, including many inflammatory and metabolically important genes. Peroxisome proliferator–activated receptor γ cofactor 1A (PPARGC1A) was 1.75-fold reduced with insulin resistance in muscle, and fatty acid and lipid metabolism and oxidoreductase activity also were downregulated. Unexpected categories included ubiquitination, citrullination, and protein degradation. In adipose, highly represented categories included lipid and fatty acid metabolism, insulin action, and cell-cycle regulation. Inflammatory genes were increased in European American subjects and were among the top Kyoto Encyclopedia of Genes and Genomes pathways on gene-set enrichment analysis. FADS1, VEGFA, PTPN3, KLF15, PER3, STEAP4, and AGTR1 were among genes expressed differentially in both adipose and muscle.
Adipose tissue gene expression showed more differences between insulin-resistant versus insulin-sensitive groups than the expression of genes in muscle. We confirm the role of PPARGC1A in muscle and show some support for inflammation in adipose from European American subjects but find prominent roles for lipid metabolism in insulin sensitivity independent of obesity in both tissues.