Characterization and Differentiation of Adipose Tissue by Spectroscopic and Spectral Imaging Techniques

Adipose tissue is a metabolically active endocrine organ having a distribution in a variety of locations in whole body; therefore, it is crucial to understand the adipocyte metabolism in health and disease. Spectroscopic techniques such as Fourier transform infrared (FTIR), Raman, nuclear magnetic resonance (NMR) are widely used to characterize biological systems by monitoring cellular molecules such as lipids, carbohydrates, and proteins. Obesity or insulin resistance-induced molecular alterations in adipose tissue can be detected using these techniques. Spectral imaging of adipose tissue provides high-quality information involving molecular compositional, structural, and functional alterations for characterization and differentiation of adipocytes (brown, white) in different adipose tissue regions (visceral, subcutaneous, etc.). In this chapter, applications of spectroscopic and spectral imaging techniques for characterization and differentiation of various adipose tissues will be discussed, which will shed light to better understand adipose tissue metabolism and provide new insight into diagnosis and treatment of some metabolic diseases such as obesity

Infrared spectroscopic studies on the dipalmitoyl phosphatidylcholine bilayer interactions with calcium phosphate: Effect of vitamin D 2

Abstract. In the present work, the interaction of calcium-phosphate with DPPC (dipalmitoyl phosphatidylcholine) model membranes has been studied in the presence and absence of vitamin D2 by using Fourier Transform Infrared (FTIR) spectroscopy. Calcium and phosphorus are the most abundant elements in the body. They combine in the form of calcium phosphate salt, called hydroxyapatite. Hydroxyapatite is the major structural component of the bone. Calcium phosphate assists with the digestion and absorption of food and is vitally important for the building of sturdy bone and body structures and a robust constitution. Phosphorus is extracted from foods and its use is controlled by vitamin D and calcium. FTIR spectral analysis results suggested that, calcium-phosphate complex, which is the major component of the bones, decreases the phase transition temperature to lower values, causes a loss in cooperativity of the acyl chains, decreases the order of the membrane in both phases and decreases the dynamics of the membrane in the liquid crystalline phase, increases the flexibility of the chains in the center of the bilayer in both phases, and increases the mobility of the head group of DPPC in the gel phase. The effect of calcium-phosphate on DPPC liposomes diminishes with the addition of vitamin D2 into the liposomes. Our results suggest how calcium-phosphate and/or vitamin D2, which have indispensable role for the functioning of the bone tissue, affect the thermal behaviour of DPPC liposomes at molecular level

Applications of Infrared Spectroscopy and Microscopy in Diagnosis of Obesity

Infrared (IR) spectroscopy is a vibrational spectroscopic technique based on the absorption of infrared radiation by matters that excite vibrations of molecular bonds. It is a powerful method for investigating structural, functional, and compositional changes in biomolecules, cells, and tissues. In recent years, scientific researchers have continued to increase the performance of this technique on clinical cases such as cancers and metabolic disorders. Obesity is one of the main factors that increases the risk of many diseases and contributes to functional disabilities in tissues such as adipose, liver, and muscle. Applications of IR spectroscopic techniques allow identifying molecular changes due to obesity, to understand the molecular mechanism of the disease, to identify specific spectral biomarkers that can be used in diagnosis. In addition, these spectral biomarkers can be used to identify the appropriate drugs and their doses for treatment. In this chapter, applications of IR spectroscopic and microscopic techniques to the characterization and understanding the obesity metabolism will be presented. The discriminatory power of these techniques in diagnosis of obesity will be discussed. In future, these novel approaches will shed light on the internal diagnosis of obesity in clinical application

Kas özellikleri ve obezite arasındaki ilişkinin genetik ve biyofiziksel yöntemlerle araştırılması

TÜBİTAK SBAG Proje01.04.2012Obesity, which arises from changes in lifestyle and feeding habits in developed and developing countries, is becoming a threat for human health due to its increasing prevelance. Especially, the increase in the consumption of high fat diets is one of the main factors that take role in the generation of obesity. Clinical disorders, such as type 2 diabetes, dislipidemia, cardiovascular diseases and hypertension, are all basic metabolic diseases in close relation with obesity. These metabolic disorders generally trigger each others’ prevalence. The common property shared by obesity and these metabolic disorders is the inability of insulin to exert its action on tissues, even though insulin is produced by the body. Impaired insulin sensitivity in skeletal muscle tissue is one of the most common symptom in pathophysiology of diabetes and obesity. While insulin resistance have not been yet fully established for clarity, in recent studies, more and more evidence reveals that the distribution and types of lipids are the deterministic factors in generation of insulin resistance. Therefore, determination of the distribution and types of lipids accumulated in the skeletal muscle are necessary in order to explain the generation of insulin resistance mechanism in obesity. The aim of this study was to establish the structural and functional changes in longissimus dorsi (LD) and quadriceps (Q) skeletal muscle tissue macromolecules, especially lipid, and determination of the types and distribution of the lipids within these tissues in control (C57BL/6J and DBA/2J), Berlin muscle mouse inbred (BMMI) lines and Berlin fat mouse inbred (BFMI) lines and thus, to do the characterization of these skeletal muscle tissues of inbred mouse models. For this this purpose, attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy was used to determine the properties of macromolecules, FTIR microspectroscopy was used to monitor the distribution of these macromolecules especially lipids within the skeletal muscles, confocal microscopy technique was used to monitor the lipid content of muscle fibers and to determine fibers types that these lipids accumulated more intensely and high performance liquid chromatography (HPLC) technique was used to determine the types and amounts of lipids stored in these muscles. In this study, skeletal muscle tissues of the control (C57BL/6J and DBA/2J), BMMI mice which were fed with standard breeding diet (SBD) and BFMI mice which were fed with either SBD or high-fat diet (HFD) were investigated. 14 In this study, serum levels of glucose, triglyceride and non-esterified fatty acid were found to be increased in BMMI806 among the BMMI lines and BFMI860, BFMI861 within the BFMI lines and these lines showed a slower response to insulin injection than the other lines. These results were the indicators of the development of insulin resistance in these lines. BMMI806, BFMI860 and BFMI861 lines represented different properties in comparison to the other lines. ATR-FTIR spectroscopic results revealed that BMMI806, BFMI860 ve BFMI861 mice possess higher amount of triglyceride, cholesterol ester and saturated lipid content, lower amount of unsaturated lipid content, more methly groups in lipid structure and lipids with shorther hydrocarbon chain lenght in comparison to other groups. The lipid content in skeletal muscles of all BFMI mice fed with a HFD increased, except for BFMI852 line which did not respond to feeding with HFD in terms of lipid content. The highest lipid content was found to be in BFMI860 line among the groups fed with a HFD. It had been demonstrated that the skeletal muscles of BMMI806 line amoung BMMI lines, BFMI860 and BFMI861 lines within BFMI mice had the lowest olefinic band area and unsaturation index; therefore these lines are more prone to lipid peroxidation. Lipids extracted from LD an Q skeletal muscles of control, BFMI and BMMI lines of SBD and also BFMI lines of HFD were separated, characterized and quantified by HPLC-ELSD technique. In BFMI lines, lipids were detected in higher concentrations regarding to BMMI lines. Among BFMI lines, the highest lipid concentrations were seen in BFMI860 and BFMI861 lines, respectively. In BFMI lines, other than BFMI860 and BFMI861, the concentration of detected lipids were low. The effects of HFD on the concentration of lipids were obvious. In BFMI lines which fed with HFD, had more lipid content compared to BFMI mice which fed with SBD. These findings support the ATRFTIR spectroscopic results, which was performed on the same tissues of same lines. In LD and Q muscles BMMI826 and BMMI866 lines, which were characterized as myostatin mutants, were found to have less lipid content. In myostatin wild-type BMMI806 line, the lipid concentration was detected to be higher than the other BMMI lines. These findings are also in agreement with the ATR-FTIR spectroscopic results. Lipid amounts in LD and Q skeletal muscles were also determined and compared with each other. According to the results, lipid concentration was found to be higher in LD skeletal muscle when compared to the lipid concentration in Q muscle. Via imaging techniques, higher amount of neutral lipid accumulation was observed in the cross-sections of skeletal muscle type IIa and intermediate muscle fiber, which do 15 have more oxidative metabolism. In these muscle fibers where high lipid accumulation is present, high lipit/protein distribution, high amount of methylene (CH2) groups, low amount of methyl groups (CH3) in the lipid structure, high amount of triglyceride content (carboynl, C=O) and lipids with longer chain lenght were observed. Furthermore, it was also found that, these fibers display a higher unsaturation index and lower glycogen content. This lipid accumulation was found to be the highest in the skeletal muscles of BFMI860 mice when compared to other obese mouse lines. The effect of HFD on BFMI860 mouse line regarding to the lipid accumulation, was observed to be more dramatic. When all results obtained were evaluated, with their genetically complex background, BFMI860 and BMMI806 were determined to be the most suitable lines for the investigation of spontaneous obesity in humans among all BFMI and BMMI lines. Furthermore, according to the results of this study, in LD muscles which is responsible for the posture and include more type IIa fibers than Q muscle, represented more significant results

Controlling complexity: the clinical relevance of mouse complex genetics.

Experimental animal models are essential to obtain basic knowledge of the underlying biological mechanisms in human diseases. Here, we review major contributions to biomedical research and discoveries that were obtained in the mouse model by using forward genetics approaches and that provided key insights into the biology of human diseases and paved the way for the development of novel therapeutic approaches

Agomelatin'in model membranlar ile etkileşmesinin yapısal ve işlevsel açıdan biyofiziksel yöntemlerle araştırılması

TÜBİTAK TBAG Proje15.04.201

Uzun Süreli Karbamazepit Terapisinin Sağlıklı Sıçan Kemik Dokularındaki Yan Etkilerinin Moleküler Düzeyde İncelenmesi.

Projede, İlacın sağlıklı sıçan kemik metabolizması ve mineral yoğunluğu üzerindeki etkilerini ortaya çıkarmak için gerçekleştirilen FTIR mikrospektroskopisi, kemik protein ikincil yapısı üzerindeki olası değişimleri göstermek için Yapay sinir ağları (NN) analizi, ilacın kemik dokusu kırılganlığı üzerindeki etkilerini ortaya çıkarmak için uygulanan biyomekanik Vickers mikrosertlik testi çalışmaları ve ilacın vitamin D ve kalsiyum metabolizması üzerindeki etkilerini ortaya çıkarmak için uygulanan elisa kan testleri tamamlanmıştır. Karbamazepin tedavisi kemik dokularının mineral içeriğini düşürerek, kemiğin yapısındaki karbonat iyonlarının içeriğini ve kolajen çapraz bağlarının yapısını değiştirerek, kemiği güçsüzleştirmektedir. Ayrıca kemik sertliğini azaltmaktadır.cekteki çalışmaların geliştirilmesini sağlamaktır

Diyabetin Sıçan Böbrek Hücre Membranı Üzerindeki Etkilerinin Ve Selenyumun Tedavi Edici Rolünün Araştırılması

Diyabet tüm dünyada olduğu gibi Türkiye'de de yaygın olarak görülen bir hastalıktır. Günümüzde diyabet hastalığı, patolojisi ve oluşum nedenleri hakkında çalışmalar sürdürülmektedir. Her ne kadar klinikte ve deneysel olarak belirtilen diyabete bağlı fonksiyon bozuklukları belirlenmiş olsa da, bu patolojilere neden olan mekanizmalar henüz tam olarak anlaşılamamıştır. Bu projede diyabetin böbrek hücre membranındaki etkisi ve selenyumun hücre membranındaki koruyucu ve tedavi edici etkisi, sözü edilen bu parametreler açısından incelenecek ve eksiklikler giderilmeye çalışılacaktır. Bu çalışmadan elde edilen sonuçlar ileride diyabetli hasta takibinde,diyabetin komplikasyonlarında ve hastalığın erken teşhisinde kullanılabilecektir. Bu projede ilk olarak streptozotosinle (STZ) uygulaması ile diyabet oluşturulacak ve diyabetin böbrek korteks hücre membranında meydana getirdiği değişimler başta FTIR spektroskopisi olmak üzere biyofiziksel teknikler ile incelencektir. Ayrıca selenyumun diyabetik hücre membranlarındaki tedavi edici etkileri araştırılacaktır. Böbrek korteks hücre membranı fraksiyonları FTIR spektroskopisinde sulu ortamda incelenecektir. Farklı gruplara ait spektrumlardaki protein, lipid ve karbohidratlardan kaynaklı soğurma bantlarının sinyal şiddet/alanları, frekans değerleri ve bant genişlikleri arasındaki değişimler tespit edilecektir. Bu analizler sonucunda diyabetin ve selenyumun protein ikincil yapılarında meydana getirdiği değişimler ayrıntılı olarak incelenebilecektir

Psikiyatrik Rahatsızlıklarda Kullanılanvaldoxan'ın Etken Maddesi Olan Agomelati'nin Model Beyin Membranı İle Etkileşmesi.

Psikiyatrik tedavi sırasında kullanılan ilaçların yan etkilerinin az ve etkinliğinin fazla olması tercih edilmekte ve bu amaç doğrultusunda yeni etken maddelere sahip ilaçlar piyasaya sürülmektedir. Bu kapsamda, yeni geliştirilen ve piyasaya Valdoxan adıyla sürülen ilacın etken maddesi olan Agomelatin, özellikle uyku bozukluğu ile birlikte seyreden depresyon tedavisinde büyük umut vaat etmektedir. İlaçların hücre ile etkileşimleri hücre membranından başlar ve bu etkileşim sonucunda membranlarda yapısal ve dinamik açıdan değişimler meydana gelir.Membranların yapılarında ve fonksiyonlarında oluşan bu makromoleküler değişimleri spektroskopik yöntemler kullanarak ayrıntılı bir biçimde incelemek mümkündür. Agomelatin oldukça yeni bir ajan olduğu için bu konu üzerine yapılan çalışmalar literatürde oldukça sınırlıdır. Agomelatin’in hücresel boyutta meydana getirdiği etkileri tam anlamıyla anlayabilmek için, bu ilacın model ve biyolojik membranlar ile etkileşiminin moleküler düzeyde bilinmesi ve membran içindeki konum ve konformasyonlarının belirlenmesi gerekmektedir. Bu projede, aktif ajan Agomelatin’in biyolojik membranlarda yüksek miktarda bulunan lipitleri içeren model membranlarla etkileşimi FTIR spektroskopisi ile DSC gibi biyofiziksel yöntemlerle araştırılacaktır.Söz konusu çalışmada Agomelatin’in i. Spingomiyelin, fosfatidiletanolamin, ve fosfatidilserin den elde edilen model membranlarla olan etkileşimlerinin incelenmesi ii. Ve bu lipit bileşenlerinden oluşan membranla etkileşmesi amaçlanmıştır. Bu amaç doğrultusunda Fourier Kızılötesi Dönüşüm (FTIR) Spektroskopisi ve Diferansiyel Tarama Kalorimetresi (DSC) ve kümeleme analizi gibi biyoinformatik ve kemometrik metotlar kullanılarak ilaç-membran etkileşimine bakılacaktır. Proje kapsamında yapılacak çalışmalarla Valdoxan’inaa etken maddesi olan Agomelatin’in, model membranlarda meydana getirdiği yapısal değişimler, membran akışkanlığındaki değişimler saptanabilecek ve ilacın membran içindeki konumu hakkında bilgi sahibi olunabilecektir