Obesity-associated family with sequence similarity 13, member A (FAM13A) is dispensable for adipose development and insulin sensitivity.

BACKGROUND: Obesity and its associated morbidities represent the major and most rapidly expanding world-wide health epidemic. Recent genome-wide association studies (GWAS) reveal that single nucleotide polymorphism (SNP) variant in the Family with Sequence Similarity 13, Member A (FAM13A) gene is strongly associated with waist-hip ratio (WHR) with adjustment for body mass index (BMI) (WHRadjBMI). However, the function of FAM13A in adipose development and obesity remains largely uncharacterized. METHODS: The expression of FAM13A in adipose tissue depots were investigated using lean, genetic obese and high fat diet-induced obese (DIO) animal models and during adipocyte differentiation. Stromal vascular cells (SVCs) or 3T3-L1 cells with gain and loss of function of FAM13A were used to determine the involvement of FAM13A in regulating adipocyte differentiation. Adipose development and metabolic homeostasis in Fam13a-/- mice were characterized under normal chow and high fat diet feeding. RESULTS: Murine FAM13A expression was nutritionally regulated and dramatically reduced in epididymal and subcutaneous fat in genetic and diet-induced obesity. Its expression was enriched in mature adipocytes and significantly upregulated during murine and human adipogenesis potentially through a peroxisome proliferator-activated receptor-gamma (PPARγ)-dependent mechanism. However, Fam13a-/- mice only exhibited a tendency of higher adiposity and were not protected from DIO and insulin resistance. While Fam13a-/- SVCs maintained normal adipogenesis, overexpression of FAM13A in 3T3-L1 preadipocytes downregulated ß-catenin signaling and rendered preadipocytes more susceptible to apoptosis. Moreover, FAM13A overexpression largely blocked adipogenesis induced by a standard hormone cocktail, but adipogenesis can be partially rescued by the addition of PPARγ agonist pioglitazone at an early stage of differentiation. CONCLUSIONS: Our results suggest that FAM13A is dispensable for adipose development and insulin sensitivity. Yet the expression of FAM13A needs to be tightly controlled in adipose precursor cells for their proper survival and downstream adipogenesis. These data provide novel insights into the link between FAM13A and obesity.

Sex and the basal mRNA synthesis machinery.

Evolution and change generated an incredible diversity of organisms on this earth. Yet, some processes are so central to life that change is strongly selected against. Synthesis of the eukaryotic messenger RNA is one example. The assemblies that carry out transcription and processing (capping, polyadenylation, and splicing) are so conserved that most genes have recognizable orthologs in yeast and humans. Naturally, most would conclude transcription and processing are identical in both sexes. However, this is an assumption. Men and women vastly differ in their physiologies. The incidence of pathologies, symptom presentation, disease outcome, and therapeutic response in each sex vary enormously. Despite the harm ignorance causes women, biological research has been historically carried out without regard to sex. The male mouse was the default mammal. A cultured cell's sex was considered irrelevant. Attempts to fill this knowledge gap have revealed molecular dissimilarities. For example, the earliest embryonic male and female transcriptomes differ long before fetal sex hormones appear. We used public data to challenge the assumption of sameness by reviewing reports of sex-biased gene expression and gene targeting. We focused on 120 genes encoding nonregulatory proteins involved in mRNA synthesis. Remarkably, genes with recognizable orthologs in yeast and thus LEAST likely to differ, did differ between the sexes. The rapidly growing public databases can be used to compare the expression of any gene in male and female tissues. Appreciating the principles that drive sex differences will enrich our understanding of RNA biology in all humans-men and women. This article is categorized under: RNA in Disease and Development > RNA in Development RNA Evolution and Genomics > Computational Analyses of RNA.

Hepatic neddylation deficiency triggers fatal liver injury via inducing NF-κB-inducing kinase in mice.

The conjugation of neural precursor cell expressed, developmentally downregulated 8 (NEDD8) to target proteins, termed neddylation, participates in many cellular processes and is aberrant in various pathological diseases. Its relevance to liver function and failure remains poorly understood. Herein, we show dysregulated expression of NAE1, a regulatory subunit of the only NEDD8 E1 enzyme, in human acute liver failure. Embryonic- and adult-onset deletion of NAE1 in hepatocytes causes hepatocyte death, inflammation, and fibrosis, culminating in fatal liver injury in mice. Hepatic neddylation deficiency triggers oxidative stress, mitochondrial dysfunction, and hepatocyte reprogramming, potentiating liver injury. Importantly, NF-κB-inducing kinase (NIK), a serine/Thr kinase, is a neddylation substrate. Neddylation of NIK promotes its ubiquitination and degradation. Inhibition of neddylation conversely causes aberrant NIK activation, accentuating hepatocyte damage and inflammation. Administration of N-acetylcysteine, a glutathione surrogate and antioxidant, mitigates liver failure caused by hepatic NAE1 deletion in adult male mice. Therefore, hepatic neddylation is important in maintaining postnatal and adult liver homeostasis, and the identified neddylation targets/pathways provide insights into therapeutically intervening acute liver failure.

A crude method of DNA extraction and identification from exfoliated human buccal mucosa cells.

BACKGROUND: DNA analysis has a key role in forensic dentistry. However, techniques of DNA extraction and analysis are far from the reach of majority of medical professionals owing to its expensive set up. AIM: The present study was aimed at formulating a crude method of extracting DNA from human buccal mucosa cells using materials commonly available in the laboratory so that the medical professionals could get more exposure to molecular biology techniques. The objectives were to identify the DNA and to assess its purity. METHODS: Buccal mucosa cells from 10 healthy volunteers were taken for DNA extraction following the protocol of cell lysis, purification, and precipitation. DNA was identified using standardized techniques like Diphenylamine test and its purity was assessed using a spectrophotometer. A gel electrophoresis apparatus was also constructed using readily available materials. RESULTS: DNA was extracted from human buccal mucosa cells using a crude method. The standardized tests confirmed the presence of DNA contaminated with proteins. The locally made Gel electrophoresis model exhibited a faint halo around the wells instead of DNA bands. CONCLUSION: DNA extraction from human buccal mucosa cells was made possible using locally available materials and a crude method, but it was not of high purity.

Cytomorphometric analysis and morphological assessment of oral exfoliated cells in type 2 diabetes mellitus and healthy individuals: A comparative study.

CONTEXT: Oral exfoliative cytology is a simple, nonaggressive technique that is well accepted by patients. Therefore, it is an attractive option, which aids in the diagnosis and observation of epithelial atypias associated with oral mucosal diseases. AIMS: The aim of this study was to evaluate and compare the quantitative and qualitative alterations in exfoliative smears from type 2 diabetics and healthy individuals. PATIENTS AND METHODS: The study includes 30 type 2 diabetics and 30 healthy persons of both sexes. PAP and hematoxylin and eosin (H and E) stained smears were prepared from buccal mucosa (BM), tongue (T), floor of the mouth (FOM), and palate (P). Under a light microscope, 50 clearly defined unfolded epithelial cells were quantitatively evaluated for cellular area (CA), nuclear area (NA), and cellular-to-nuclear area ratio (CA:NA) and assessed for morphological features. STATISTICAL ANALYSIS: Collected data was manually entered into the Statistical Package for the Social Sciences version 13.5 for analysis. Student's t-test was used at 95% confidence interval. RESULTS: Quantitative assessment of the overall mean CA was less, mean NA was more, and mean CA:NA was less in diabetics than that in healthy persons at all the four sites. Diabetic oral cells showed qualiative cytoplasmic and nuclear alterations: cytoplasmic vacuoles, karyorrhexis, karyolysis, pyknosis, peri-nuclear halo, binucleation, nuclear vacuoles, inflammation, and microbial colonies. CONCLUSION: Oral cytology from type 2 diabetics is associated with detectable cytomorphological changes with alteration in size of the cell and nucleus, which is site specific, indicating epithelial cell degeneration in cytoplasm and nucleus.

Osseous choristoma of submental region: A rare occurrence.

Osseous choristoma is a rare, benign lesion of the oral cavity. This report presents a case of osseous choristoma in the submental region of a 30-year-old female subject. Her chief complaint was a painless swelling in the submental region. Panoramic radiography showed a well-defined, round, radiopaque lesion near the inferior border of the left mental region. The lesion was diagnosed as an osseous choristoma based on the histopathological examination of the surgical specimen. This paper is an attempt to bring forward a unique occurrence of osseous choristoma, which would further help the medical fraternity in improvising their knowledge, diagnosis, and treatment of this entity.

Stromal fibers in oral squamous cell carcinoma: A possible new prognostic indicator?

BACKGROUND: Many studies have been carried out to study the role of extracellular matrix proteins, growth factors and matrix metalloproteinases on tumor invasion. However, literature related to the analysis of connective tissue fibers in varying grades of oral squamous cell carcinoma (OSCC) is very limited. AIM: To analyze the changes in collagen and elastic fibers in varying grades of (OSCC). SETTINGS AND DESIGN: This retrospective study was carried out using a light and polarizing microscope. MATERIALS AND METHODS: Three sections each were cut from fifty samples of varying grades of OSCC and ten samples of control followed by staining with H and E, Picrosirius-Red and Verhoeff-Van Gieson. Qualitative and quantitative analysis of collagen and elastic fibers were accomplished using set criteria. STATISTICAL ANALYSIS: Data were entered into the Statistical Package for Social Sciences (SPSS) version 13.5 for analysis. RESULTS: A change in colors of collagen fibers was seen on progressing from well to poorly differentiated OSCC. Thin collagen fibers predominantly exhibited greenish yellow, but the thick fibers exhibited a variety of colors. As the grade of OSCC progressed, collagen fibers were loosely packed haphazardly arranged. Statistically insignificant results were obtained for quantitative analysis of collagen and qualitative analysis of elastic fibers. CONCLUSION: The collagen fibers undergo a change in color, orientation and packing in the stroma of varying grades of OSCC. The uniqueness of this study lies in the exploration of elastic fibers in OSCC which has not been done so far.

Architectural Analysis of Picrosirius Red Stained Collagen in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma using Polarization Microscopy.

INTRODUCTION: Collagen degradation is important both for carcinogenesis and in its progression. Research regarding the co-relation of collagen with Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC) is less explored. AIM: To elucidate the nature of collagen in Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC) using Picrosirius Red Stain (PSR) under polarizing microscopy. MATERIALS AND METHODS: The study consisted of a total 40 samples which were divided into three groups. Group I included buccal mucosa as negative and irritation fibroma as positive control, group II consisted of OED and group III consisted of Oral Squamous Cell Carcinoma (OSCC). A histochemical analysis was conducted using PSR-polarization method by two independent observers. RESULTS: The control group shows predominantly reddish-orange birefringence. In OED with the advancement of grades, the colour changed from yellowish-orange colour to yellow-greenish with progressive increase in greenish hue. As OSCC regresses from well to poorly differentiated, the colour changed from reddish-orange to yellowish orange to greenish-yellow suggesting a transition from mature to immature collagen. CONCLUSION: An observable gradual change in collagen of both OED and OSCC was noted as they were proceeding from benign to critical step. Thus, PSR is a useful tool for studying stromal changes as supporting collagen shows the transition in the form besides the alterations in epithelial cells.

Cytological artifacts masquerading interpretation.

BACKGROUND: Cytological artifacts are important to learn because an error in routine laboratory practice can bring out an erroneous result. AIMS: The aim of this study was to analyze the effects of delayed fixation and morphological discrepancies created by deliberate addition of extraneous factors on the interpretation and/or diagnosis of an oral cytosmear. MATERIALS AND METHODS: A prospective study was carried out using papanicolaou and hematoxylin and eosin-stained oral smears, 6 each from 66 volunteer dental students with deliberate variation in fixation delay timings, with and without changes in temperature, undue pressure while smear making and intentional addition of contaminants. The fixation delay at room temperature was carried out at an interval of every 30 minutes, 1 day and 1 week and was continued till the end of 1 day, 1 week, and 1 month, respectively. The temperature variations included 60 to 70°C and 3 to 4°C. RESULTS: Light microscopically, the effect of delayed fixation at room temperature appeared first on cytoplasm followed by nucleus within the first 2 hours and on the 4(th) day, respectively, till complete cytoplasmic degeneration on the 23(rd) day. However, delayed fixation at variable temperature brought faster degenerative changes at higher temperature than lower temperature. Effect of extraneous factors revealed some interesting facts. CONCLUSIONS: In order to justify a cytosmear interpretation, a cytologist must be well acquainted with delayed fixation-induced cellular changes and microscopic appearances of common contaminants so as to implicate better prognosis and therapy.