Diabetes induces compositional, structural and functional alterations on rat skeletal soleus muscle revealed by FTIR spectroscopy: a comparative study with EDL muscle

Studies on the effect of curcumin and quercetin in the liver of male albino rats exposed to gamma irradiation

Ionizing radiation produces deleterious effects on living organisms. The present investigation has been carried out to study the prophylactic as well as the therapeutic effects of treated rats with quercetin (Quer) and curcumin (Cur), which are two medicinal herbs known for their antioxidant activities against damages induced by whole-body fractionated gamma irradiation. Exposure of rats to whole-body gamma irradiation induced a significant decrease in erythrocyte (RBC), leukocyte (WBCs), platelet count (Plt), hemoglobin concentration (Hb), hematocrit (Hct %), mean erythrocyte hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and mean erythrocyte volume (MCV); a high increase in plasma thiobarbituric acid reactive substances (TBARS); a nonsignificant statistical decrease in the mean value of serum glutathione (GSH); a significant increase in plasma alanine transferase (ALT), aspartate transferase (AST), alkaline phosphates (ALP), serum total protein, serum total cholesterol levels, total triglycerides levels, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels; and with marked histological changes and structural changes measured by Fourier transform infrared (FTIR). Applying both quercetin and curcumin pre- and postexposure to gamma radiation revealed a remarkable improvement in all the studied parameters. The cellular damage by gamma radiation is greatly mitigated by the coadministration of curcumin and quercetin before radiation exposure.

Exploration of macromolecular phenotype of human skeletal muscle in diabetes using infrared spectroscopy

Introduction

The global burden of diabetes mellitus is escalating, and more efficient investigative strategies are needed for a deeper understanding of underlying pathophysiological mechanisms. The crucial role of skeletal muscle in carbohydrate and lipid metabolism makes it one of the most susceptible tissues to diabetes-related metabolic disorders. In tissue studies, conventional histochemical methods have several technical limitations and have been shown to inadequately characterise the biomolecular phenotype of skeletal muscle to provide a holistic view of the pathologically altered proportions of macromolecular constituents.

Materials and methods

In this pilot study, we examined the composition of five different human skeletal muscles from male donors diagnosed with type 2 diabetes and non-diabetic controls. We analysed the lipid, glycogen, and collagen content in the muscles in a traditional manner with histochemical assays using different staining techniques. This served as a reference for comparison with the unconventional analysis of tissue composition using Fourier-transform infrared spectroscopy as an alternative methodological approach.

Results

A thorough chemometric post-processing of the infrared spectra using a multi-stage spectral decomposition allowed the simultaneous identification of various compositional details from a vibrational spectrum measured in a single experiment. We obtained multifaceted information about the proportions of the different macromolecular constituents of skeletal muscle, which even allowed us to distinguish protein constituents with different structural properties. The most important methodological steps for a comprehensive insight into muscle composition have thus been set and parameters identified that can be used for the comparison between healthy and diabetic muscles.

Conclusion

We have established a methodological framework based on vibrational spectroscopy for the detailed macromolecular analysis of human skeletal muscle that can effectively complement or may even serve as an alternative to histochemical assays. As this is a pilot study with relatively small sample sets, we remain cautious at this stage in drawing definitive conclusions about diabetes-related changes in skeletal muscle composition. However, the main focus and contribution of our work has been to provide an alternative, simple and efficient approach for this purpose. We are confident that we have achieved this goal and have brought our methodology to a level from which it can be successfully transferred to a large-scale study that allows the effects of diabetes on skeletal muscle composition and the interrelationships between the macromolecular tissue alterations due to diabetes to be investigated.

Synchrotron-based FTIR evaluation of biochemical changes in cancer and noncancer cells induced by brominated marine coelenteramine

The mode of action toward gastric cancer cells of brominated Coelenteramine, an analog of a metabolic product of a marine bioluminescent reaction, was investigated by synchrotron radiation-based FTIR. This method revealed that the anticancer activity of brominated Coelenteramine is closely connected with cellular lipids, by affecting their organization and composition. More specifically, there is an increasing extent of oxidative stress, which result in changes in membrane polarity, lipid chain packing and lipid composition. However, this effect was not observed in a noncancer cell line, helping to explain its selectivity profile. Thus, synchrotron radiation-based FTIR helped to identity the potential of this Coelenteramine analog in targeting membrane lipids, while proving to be a powerful technique to probe the mechanism of anticancer drugs.

A combined X-ray fluorescence and infrared microspectroscopy study for new insights into elemental-biomolecular obesity-induced changes in rat brain structures

The objective of our research was to determine the brain changes at the molecular and elemental levels typical of early-stage obesity. Therefore a combined approach using Fourier transform infrared micro-spectroscopy (FTIR-MS) and synchrotron radiation induced X-ray fluorescence (SRXRF) was introduced to evaluate some brain macromolecular and elemental parameters in high-calorie diet (HCD)- induced obese rats (OB, n = 6) and in their lean counterparts (L, n = 6). A HCD was found to alter the lipid- and protein- related structure and elemental composition of the certain brain areas important for energy homeostasis. The increased lipid unsaturation in the frontal cortex and ventral tegmental area, the increased fatty acyl chain length in the lateral hypothalamus and substantia nigra as well as the decreased both protein α helix to protein β- sheet ratio and the percentage fraction of β-turns and β-sheets in the nucleus accumbens were revealed in the OB group reflecting obesity-related brain biomolecular aberrations. In addition, the certain brain elements including P, K and Ca were found to differentiate the lean and obese groups at the best extent. We can conclude that HCD-induced obesity triggers lipid- and protein- related structural changes as well as elemental redistribution within various brain structures important for energy homeostasis. In addition, an approach applying combined X-ray and infrared spectroscopy was shown to be a reliable tool for identifying elemental-biomolecular rat brain changes for better understanding the interplay between the chemical and structural processes involved in appetite control.

Radioprotective effects of quercetin and curcumin on hepatotoxicity and nephrotoxicity in male Albino rats.. [DOI: 10.21203/rs.3.rs-2727957/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The present study aimed to assess the radioprotective effects of curcumin in combination with quercetin against radiation-induced changes in some histopathological, immunohistochemical, and biophysical parameters. The current study rats had been grouped into control, curcumin, quercetin, gamma irradiated (8 Gy fractionated dose), curcumin pretreated irradiated, quercetin pretreated irradiated, and both curcumin and quercetin pretreated irradiated groups. Gamma radiation exposure resulted in hepatic and renal damage. Administration of curcumin along with quercetin before gamma radiation exposure reduced the liver and kidney damage caused by radiation, demonstrating the radioprotective effects of both curcumin and quercetin antioxidants through free radicals scavenging effects, P53, and TNF-α inhibition, and structural changes measured by Fourier Transform Infrared (FTIR). The cellular damage by gamma radiation is greatly mitigated by administration of curcumin and quercetin before radiation exposure.

The recovery effect of Vitamin C on structural alterations due to Streptozotocin-Induced diabetes in rat testicular tissues

Type I Diabetes is a multisystem disease that causes alterations in carbohydrate, protein, and fat metabolisms due to hyperglycemia. It has an extensive pathology, especially the mechanism involving oxidative stress is still complex. Type I diabetes is correlated with increased formation of free radicals and decreased levels of antioxidant potential. Vitamin C (Vit C) is a powerful antioxidant that participates in antioxidant defense, protecting lipid membranes and proteins from oxidative damage by donating electrons to free radicals. The effect of type I diabetes and the recovery role of Vit C on the structure and composition of the biomolecular content of testicular tissue is still unknown. Therefore, the current study aimed to investigate the alterations in the biomolecules of rat testes due to Streptozotocin (STZ)-induced type I diabetes using Attenuated Total Reflectance (ATR)-Fourier Transform Infrared (FTIR) spectroscopy and histological staining. The results revealed that the biomolecular structure and composition of testicular tissue are highly affected due to the development of diabetes. We obtained decreased saturation levels and increased unsaturation index in the lipids indicating the presence of lipid peroxidation in the diabetic state. The elevated lipid peroxidation levels have been implicated in the pathogenesis of naturally occurring and chemically induced diabetes. On the other hand, the protein content of diabetic rat testicular tissue was shown to decrease considerably, indicating an increase in proteolysis processes. Supporting the ratio of protein structural and conformational change, protein secondary structural components were also found to alter substantially in the diabetic state. Diabetes was also shown to lead to a decrease in the content of nucleic acids compared to proteins. These diabetes-induced alterations were found to be substantially recovered with the administration of Vit C. Although different doses and administration types of Vit C have been reported in the literature, there is no consensus yet. Therefore, we used three different doses of Vit C in our study as high (100 mg/kg/day), medium (50 mg/kg/day) and low (15 mg/kg/day) doses intraperitoneally in the present study, and the medium dose was found to be the most effective in the recovery from the diabetes-induced structural damages on rat testicular tissue. Vit C may have a therapeutic effect to be used as a complementary therapy in the treatment of diabetes.

Higher Protein Digestibility of Chicken Thigh than Breast Muscle in an In Vitro Elderly Digestion Model

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

Application of FTIR Spectroscopy to Detect Changes in Skeletal Muscle Composition Due to Obesity with Insulin Resistance and STZ-Induced Diabetes

Age, obesity, and diabetes mellitus are pathophysiologically interconnected factors that significantly contribute to the global burden of non-communicable diseases. These metabolic conditions are associated with impaired insulin function, which disrupts the metabolism of carbohydrates, lipids, and proteins and can lead to structural and functional changes in skeletal muscle. Therefore, the alterations in the macromolecular composition of skeletal muscle may provide an indication of the underlying mechanisms of insulin-related disorders. The aim of this study was to investigate the potential of Fourier transform infrared (FTIR) spectroscopy to reveal the changes in macromolecular composition in weight-bearing and non-weight-bearing muscles of old, obese, insulin-resistant, and young streptozotocin (STZ)-induced diabetic mice. The efficiency of FTIR spectroscopy was evaluated by comparison with the results of gold-standard histochemical techniques. The differences in biomolecular phenotypes and the alterations in muscle composition in relation to their functional properties observed from FTIR spectra suggest that FTIR spectroscopy can detect most of the changes observed in muscle tissue by histochemical analyses and more. Therefore, it could be used as an effective alternative because it allows for the complete characterization of macromolecular composition in a single, relatively simple experiment, avoiding some obvious drawbacks of histochemical methods.

High-sensitivity hyperspectral vibrational imaging of heart tissues by mid-infrared photothermal microscopy

Visualizing the spatial distribution of chemical compositions in biological tissues is of great importance to study fundamental biological processes and origin of diseases. Raman microscopy, one of the label-free vibrational imaging techniques, has been employed for chemical characterization of tissues. However, the low sensitivity of Raman spectroscopy often requires a long acquisition time of Raman measurement or a high laser power, or both, which prevents one from investigating large-area tissues in a nondestructive manner. In this work, we demonstrated chemical imaging of heart tissues using mid-infrared photothermal (MIP) microscopy that simultaneously achieves the high sensitivity benefited from IR absorption of molecules and the high spatial resolution down to a few micrometers. We successfully visualized the distributions of different biomolecules, including proteins, phosphate-including proteins, and lipids/carbohydrates/amino acids. Further, we experimentally compared MIP microscopy with Raman microscopy to evaluate the sensitivity and photodamage to tissues. We proved that MIP microscopy is a highly sensitive technique for obtaining vibrational information of molecules in a broad fingerprint region, thereby it could be employed for biological and diagnostic applications, such as live-tissue imaging.

Can fingernail quality predict bone damage in Type 2 diabetes mellitus? a pilot study

Type 2 diabetes mellitus (T2DM) adversely affects the normal functioning, intrinsic material properties, and structural integrity of many tissues, including bone. It is well known that the clinical utility of areal bone mineral density (aBMD) is limited to assess bone strength in individuals with T2DM. Therefore, there is a need to explore new diagnostic techniques that can better assist and improve the accuracy of assessment of bone tissue quality. The present study investigated the link between bone and fingernail material/compositional properties in type 2 diabetes mellitus (T2DM). For that, femoral head and fingernail samples were obtained from twenty-five adult female patients (with/without T2DM) with fragility femoral neck fractures undergoing hemi/total hip arthroplasty. Cylindrical cores of trabecular bone were subjected to micro-CT, and lower bone volume fraction was observed in the diabetic group than the non-diabetic group due to fewer and thinner trabeculae in individuals with T2DM. The material and compositional properties of bone/fingernail were estimated using nanoindentation and Fourier Transform Infrared Spectroscopy, respectively. Both bone/fingernails in T2DM had lower reduced modulus (E_r), hardness (H), lower Amide I and Amide II area ratio (protein content), higher sugar-to-matrix ratio, and relatively high carboxymethyl-lysine (CML) content compared with non-diabetic patients. Sugar-to-matrix ratio and relative CML content were strongly and positively correlated with HbA_1c for both bone/fingernail. There was a positive correlation between bone and fingernail glycation content. Our findings provide evidence that the degradation pattern of bone and fingernail properties go hand-in-hand in individuals with T2DM. Hence, the fingernail compositional/material properties might serve as a non-invasive surrogate marker of bone quality in T2DM; however, further large-scale studies need to be undertaken.

Fourier-transform infrared microspectroscopy of pulmonary edema fluid for postmortem diagnosis of diabetic ketoacidosis

Determination of the cause of death for diabetic ketoacidosis (DKA), a common and fatal acute complication of diabetes mellitus, is a challenging forensic task owing to the lack of characteristic morphological findings at autopsy. In this study, Fourier-transform infrared (FTIR) microspectroscopy coupled with chemometrics was employed to characterize biochemical differences in pulmonary edema fluid from different causes of death to supplement conventional methods and provide an efficient postmortem diagnosis of DKA. With this aim, FTIR spectra in three different situations (DKA-caused death, other causes of death with diabetes history, and other causes of death without diabetes history) were measured. The results of principal component analysis indicated different spectral profiles between these three groups, which mainly exhibited variations in proteins. Subsequently, two binary classification models were established using an algorithm of partial least squares discriminant analysis (PLS-DA) to determine whether decedents had diabetes and whether the diabetic patients died from DKA. Satisfactory prediction results of PLS-DA models demonstrated good differentiation among these three groups. Therefore, it is feasible to make a postmortem diagnosis of DKA and detect diabetes history via FTIR microspectroscopic analysis of the pulmonary edema fluid.

Biomolecular changes and subsequent time-dependent recovery in hippocampal tissue after experimental mild traumatic brain injury

Traumatic brain injury (TBI) is the main cause of disability and mortality in individuals under the age of 45 years. Elucidation of the molecular and structural alterations in brain tissue due to TBI is crucial to understand secondary and long-term effects after traumatic brain injury, and to develop and apply the correct therapies. In the current study, the molecular effects of TBI were investigated in rat brain at 24 h and 1 month after the injury to determine acute and chronic effects, respectively by Fourier transform infrared imaging. This study reports the time-dependent contextual and structural effects of TBI on hippocampal brain tissue. A mild form of TBI was induced in 11-week old male Sprague Dawley rats by weight drop. Band area and intensity ratios, band frequency and bandwidth values of specific spectral bands showed that TBI causes significant structural and contextual global changes including decrease in carbonyl content, unsaturated lipid content, lipid acyl chain length, membrane lipid order, total protein content, lipid/protein ratio, besides increase in membrane fluidity with an altered protein secondary structure and metabolic activity in hippocampus 24 h after injury. However, improvement and/or recovery effects in these parameters were observed at one month after TBI.

Vitamin E Derivative with Modified Side Chain Induced Apoptosis by Modulating the Cellular Lipids and Membrane Dynamics in MCF7 Cells

The vitamin E derivative with side chain modification (TC6OAc) has been shown to possess anticancer activity in our earlier in vivo studies. It was hypothesized that, as Vitamin E (VE) and VE derivative are fat soluble lipophilic molecules, they exert their function by modulating the lipid metabolism and related pathways. This study aimed to evaluate the cellular impact of this VE derivative (2,5,7,8-Tetramethyl-2-(4'-Methyl-3'-Pentenyl)-6-Acetoxy Chromane-TC6OH), using α-tocopherol as a reference compound throughout the experiments. Their effects on the cellular metabolism, the biophysical properties of cellular lipids and the functional characteristics of cells were monitored in human estrogen receptor (ER) positive breast cancer cells. It has been documented that TC6OH treatment induces tumor cell apoptosis by dissipating the mitochondrial membrane potential, modulating the lipid, transportation and degradation as well as downregulating certain anti-apoptotic and growth factor related proteins. Due to resistance of ER positive cells to the established therapies, the findings of this study are of translational value.

Shikimic acid protects skin cells from UV-induced senescence through activation of the NAD+-dependent deacetylase SIRT1

UV radiation is one of the main contributors to skin photoaging by promoting the accumulation of cellular senescence, which in turn induces a proinflammatory and tissue-degrading state that favors skin aging. The members of the sirtuin family of NAD⁺-dependent enzymes play an anti-senescence role and their activation suggests a promising approach for preventing UV-induced senescence in the treatment of skin aging. A two-step screening designed to identify compounds able to protect cells from UV-induced senescence through sirtuin activation identified shikimic acid (SA), a metabolic intermediate in many organisms, as a bona-fide candidate. The protective effects of SA against senescence were dependent on specific activation of SIRT1 as the effect was abrogated by the SIRT1 inhibitor EX-527. Upon UV irradiation SA induced S-phase accumulation and a decrease in p16^INK4A expression but did not protect against DNA damage or increased polyploidies. In contrast, SA reverted misfolded protein accumulation upon senescence, an effect that was abrogated by EX-527. Consistently, SA induced an increase in the levels of the chaperone BiP, resulting in a downregulation of unfolded protein response (UPR) signaling and UPR-dependent autophagy, avoiding their abnormal hyperactivation during senescence. SA did not directly activate SIRT1 in vitro, suggesting that SIRT1 is a downstream effector of SA signaling specifically in the response to cellular senescence. Our study not only uncovers a shikimic acid/SIRT1 signaling pathway that prevents cellular senescence, but also reinforces the role of sirtuins as key regulators of cell proteostasis.

Investigation of Mechanical, Material, and Compositional Determinants of Human Trabecular Bone Quality in Type 2 Diabetes

CONTEXT

Increased bone fragility and reduced energy absorption to fracture associated with type 2 diabetes (T2D) cannot be explained by bone mineral density alone. This study, for the first time, reports on alterations in bone tissue's material properties obtained from individuals with diabetes and known fragility fracture status.

OBJECTIVE

To investigate the role of T2D in altering biomechanical, microstructural, and compositional properties of bone in individuals with fragility fracture.

METHODS

Femoral head bone tissue specimens were collected from patients who underwent replacement surgery for fragility hip fracture. Trabecular bone quality parameters were compared in samples of 2 groups, nondiabetic (n = 40) and diabetic (n = 30), with a mean duration of disease 7.5 ± 2.8 years.

RESULTS

No significant difference was observed in aBMD between the groups. Bone volume fraction (BV/TV) was lower in the diabetic group due to fewer and thinner trabeculae. The apparent-level toughness and postyield energy were lower in those with diabetes. Tissue-level (nanoindentation) modulus and hardness were lower in this group. Compositional differences in the diabetic group included lower mineral:matrix, wider mineral crystals, and bone collagen modifications-higher total fluorescent advanced glycation end-products (fAGEs), higher nonenzymatic cross-link ratio (NE-xLR), and altered secondary structure (amide bands). There was a strong inverse correlation between NE-xLR and postyield strain, fAGEs and postyield energy, and fAGEs and toughness.

CONCLUSION

The current study is novel in examining bone tissue in T2D following first hip fragility fracture. Our findings provide evidence of hyperglycemia's detrimental effects on trabecular bone quality at multiple scales leading to lower energy absorption and toughness indicative of increased propensity to bone fragility.

Biomolecular alterations in acute traumatic brain injury (TBI) using Fourier transform infrared (FTIR) imaging spectroscopy

Acute injury is one of the substantial stage post-traumatic brain injury (TBI) occurring at the moment of impact. Decreased metabolism, unregulated cerebral blood flow and direct tissue damage are triggered by acute injury. Understating the biochemical alterations associated with acute TBI is critical for brain plasticity and recovery. The objective of this study was to investigate the biochemical and molecular changes in hippocampus, corpus callosum and thalamus brain regions post-acute TBI in rats. Fourier Transform Infrared (FTIR) imaging spectroscopy were used to collect chemical images from control and 3 hrs post-TBI (Marmarou model was used for the TBI induction) rat brains and adjacent sections were treated by hematoxylin and eosin (H&E) staining to correlate with the disruption in tissue morphology and injured brain biochemistry. Our results revealed that the total lipid and total protein content decreased significantly in the hippocampus, corpus callosum and thalamus after brain injury. Reduction in lipid acyl chains (-CH₂) associated with an increase in methyl (-CH₃) and unsaturated lipids olefin = CH concentrations is observed. Furthermore, there is a decrease in the lipid order (disorder), which leads to an increase in acyl chain fluidity in injured rats. The results suggest acute TBI damages brain tissues mechanically rather than chemical alterations. This will help in assessing successful therapeutic strategy in order to mitigate tissue damage in acute TBI period.

Biophysical and Lipidomic Biomarkers of Cardiac Remodeling Post-Myocardial Infarction in Humans

Few studies have analyzed the potential of biophysical parameters as markers of cardiac remodeling post-myocardial infarction (MI), particularly in human hearts. Fourier transform infrared spectroscopy (FTIR) illustrates the overall changes in proteins, nucleic acids and lipids in a single signature. The aim of this work was to define the FTIR and lipidomic pattern for human left ventricular remodeling post-MI. A total of nine explanted hearts from ischemic cardiomyopathy patients were collected. Samples from the right ventricle (RV), left ventricle (LV) and infarcted left ventricle (LV INF) were subjected to biophysical (FTIR and differential scanning calorimetry, DSC) and lipidomic (liquid chromatography-high-resolution mass spectrometry, LC-HRMS) studies. FTIR evidenced deep alterations in the myofibers, extracellular matrix proteins, and the hydric response of the LV INF compared to the RV or LV from the same subject. The lipid and esterified lipid FTIR bands were enhanced in LV INF, and both lipid indicators were tightly and positively correlated with remodeling markers such as collagen, lactate, polysaccharides, and glycogen in these samples. Lipidomic analysis revealed an increase in several species of sphingomyelin (SM), hexosylceramide (HexCer), and cholesteryl esters combined with a decrease in glycerophospholipids in the infarcted tissue. Our results validate FTIR indicators and several species of lipids as useful markers of left ventricular remodeling post-MI in humans.

Pterostilbene administration improves the recovery potential of extremely low-frequency magnetic field in acute renal ischemia-reperfusion injury: an FTIR spectroscopic study

Renal ischemia-reperfusion (I/R) injury, one of the drastic outcomes of renal failure and organ transplantation, tends to deteriorate over time; therefore, noninvasive therapeutic strategies will avail the progression-free survival of the patients. Magnetic field has been proposed as a noninvasive treatment strategy; however, with recent scientific advances, many controversies have arisen regarding its efficacy. Pterostilbene, a natural analog of resveratrol, was documented to be effective in treatment of I/R injuries. This study aims to assess the acute therapeutic effects of combined extremely low-frequency magnetic field (ELF-MF) and pterostilbene treatment on renal I/R injury. After induction of renal I/R in Wistar rats, treatments of 50 Hz, 1 mT ELF-MF applied alone or in combination with pterostilbene were applied for 5 consecutive days. Kidney homogenates were analyzed by Fourier transform infrared spectroscopy. I/R injury resulted in an altered protein and lipid structure with the dominance of longer acyl chains; a slight decrease in lipid, protein, unsaturated lipid, and unsaturated/saturated lipid content; and an increase in membrane fluidity and lipid peroxidation in rat kidneys. Although ELF-MF treatment alone was not sufficient to restore all ischemia-induced alterations, the combined treatment strategy of pterostilbene administration in the presence of ELF-MF was successful and warrants further investigation.

Mechanisms of soft tissue and protein preservation in Tyrannosaurus rex

The idea that original soft tissue structures and the native structural proteins comprising them can persist across geological time is controversial, in part because rigorous and testable mechanisms that can occur under natural conditions, resulting in such preservation, have not been well defined. Here, we evaluate two non-enzymatic structural protein crosslinking mechanisms, Fenton chemistry and glycation, for their possible contribution to the preservation of blood vessel structures recovered from the cortical bone of a Tyrannosaurus rex (USNM 555000 [formerly, MOR 555]). We demonstrate the endogeneity of the fossil vessel tissues, as well as the presence of type I collagen in the outermost vessel layers, using imaging, diffraction, spectroscopy, and immunohistochemistry. Then, we use data derived from synchrotron FTIR studies of the T. rex vessels to analyse their crosslink character, with comparison against two non-enzymatic Fenton chemistry- and glycation-treated extant chicken samples. We also provide supporting X-ray microprobe analyses of the chemical state of these fossil tissues to support our conclusion that non-enzymatic crosslinking pathways likely contributed to stabilizing, and thus preserving, these T. rex vessels. Finally, we propose that these stabilizing crosslinks could play a crucial role in the preservation of other microvascular tissues in skeletal elements from the Mesozoic.

Molecular characterization of acutely and gradually heavy metal acclimated aquatic bacteria by FTIR spectraoscopy

In the environment, bacteria can be exposed to the concentration gradient of toxic heavy metals (gradual) or sudden high concentration of them (acute). In both situations, bacteria get acclimated to toxic heavy metal concentrations. Acclimation causes metabolic and molecular changes in bacteria. In this study, we aimed to understand whether there are differences between molecular profiles of the bacteria (Brevundimonas, Gordonia and Microbacterium) which are under acute or gradual exposure to cadmium or lead by using ATR-FTIR spectroscopy. Our results revealed the differences between the acclimation groups in membrane dynamics including changes in the structure and composition of the membrane lipids and proteins. Furthermore, protein concentrations decreased in acclimated bacterial groups. Also, a remarkable increase in exopolymer production occurred in acclimated groups. Interestingly, bacteria under acute cadmium exposure produced the significantly higher amount of exopolymer than they did under gradual exposure. On the contrary, under lead exposure gradually acclimate strains produced significantly higher amounts of exopolymer than those of acutely acclimated ones. This information can be used in bioremediation studies to obtain bacterial strains producing a higher amount of exopolymer.

Nephroprotective Effect of Embryonic Stem Cells Reducing Lipid Peroxidation in Kidney Injury Induced by Cisplatin

Introduction

The acute kidney injury (AKI) is characterized by a sudden glomerular filtration reduction. Renal or intrinsic causes of AKI include nephrotoxicity induced by exogenous agents like cisplatin, which causes oxidative stress altering the biochemical process and leading to apoptosis. Therefore, this research is aimed at analyzing the embryonic stem cells (ESC) nephroprotective effect in AKI induced by cisplatin, employing genetic, phenotypic, and microspectroscopic techniques.

Methods

Thirty mice were randomly divided into three groups (n = 10): the healthy, isotonic salt solution (ISS), and mouse embryonic stem cells (mESC) groups. The ISS and mESC groups were subjected to AKI using cisplatin; 24 h post-AKI received an intraperitoneal injection of ISS or 1 × 10⁶ mESC, respectively. At days 4 and 8 post-AKI, five mice of each group were sacrificed to analyze the histopathological, genetic (PDK4 and HO-1), protein (p53), and vibrational microspectroscopic changes.

Results

Histopathologically, interstitial nephritis and acute tubular necrosis were observed; however, the mESC group showed a more preserved microarchitecture with high cellularity. Additionally, the PDK4 and HO-1 gene expression only increased in the ISS group on day 4 post-AKI. Likewise, p53 was more immunoexpressed at day 8 post-AKI in the ISS group. About biomolecular analysis by microspectroscopy, bands associated with lipids, proteins, and nucleic acids were evidenced. Besides, ratios related to membrane function (protein/lipid), unsaturated lipid content (olefinic/total lipid, olefinic/total CH₂, and CH₂/CH₃), and lipid peroxidation demonstrated oxidative stress induction and lipid peroxidation increase mainly in the ISS group. Finally, the principal component analysis discriminated against each group; nonetheless, some data of the healthy and mESC groups at day 8 were correlated.

Conclusions

The mESC implant diminishes cisplatin nephrotoxicity, once the protective effect in the reduction of lipid peroxidation was demonstrated, reflecting a functional and histological restoration.

Investigation of diabetic patient's fingernail quality to monitor type 2 diabetes induced tissue damage

Long-term Type 2 Diabetes (T2D) affects the normal functioning of heart, kidneys, nerves, arteries, bones, and joints. The T2D gradually alters the intrinsic material properties, and structural integrity of the tissues and prolonged hyperglycemia causes chronic damages to these tissues quality. Clinically no such technique is available which can assess the altered tissues quality associated with T2D. In the present study, the microstructural characterization (surface morphology, surface roughness and density and calcium content), material characterization (modulus, hardness), and macromolecular characterization (disulfide bond content, protein content and its secondary structure) are investigated among healthy, diabetic controlled (DC) and uncontrolled diabetic (UC) group of fingernail plate. It is found that T2D has an adverse effect on the human fingernail plate quality. The parameters of nail plate quality are changing in a pattern among all the three groups. The properties mentioned above are degrading in DC group, but the degradation is even worst in the case of severity of T2D (UC group) as compared to the healthy group (Healthy Collapse

Key Words Collapse

MESH Headings

• Adult
• Aged
• Bone and Bones/metabolism
• Chronic Disease
• Diabetes Mellitus, Type 2/metabolism
• Female
• Humans
• Male
• Middle Aged
• Nails/metabolism
• Nails/pathology

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Grants

• IIT Ropar

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Affiliation(s)

Praveer Sihota Department of Mechanical Engineering, Indian Institute of Technology (IIT) Ropar, Rupnagar, Punjab, 140001, India
Ram Naresh Yadav Department of Mechanical Engineering, Indian Institute of Technology (IIT) Ropar, Rupnagar, Punjab, 140001, India
Vandana Dhiman Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
Sanjay Kumar Bhadada Department of Endocrinology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
Vishwajeet Mehandia Department of Mechanical Engineering, Indian Institute of Technology (IIT) Ropar, Rupnagar, Punjab, 140001, India
Navin Kumar Department of Mechanical Engineering, Indian Institute of Technology (IIT) Ropar, Rupnagar, Punjab, 140001, India.

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New insight into the toxic effects of chloramphenicol and roxithromycin to algae using FTIR spectroscopy

Antibiotics have been frequently detected in the aquatic environment, and they may affect aquatic organisms such as algae. Here we investigated toxicity of chloramphenicol (CAP) and roxithromycin (ROX) on four species of green algae (Pseudokirchneriella subcapitata, Scenedesmus quadricauda, Scenedesmus obliquus, and Scenedesmus acuminatus) at biochemical level by Fourier transform infrared spectroscopy (FTIR). The results revealed that both CAP and ROX had negative effects on algal growth and caused alterations of biochemical components. The toxic effects varied among the four algal species and S. acuminatus was found to be less sensitive than the other three species to the antibiotics. Even with similar mechanism of action, ROX displayed more adverse effects to algae than CAP. Both antibiotics could affect algae by inhibiting fatty acid synthesis and promoting protein and DNA aggregation, thus leading to accumulation of lipid peroxidation products, increment of the loose β-sheet structure protein and transformation of B-DNA to Z-DNA. The findings from this study revealed the toxic mechanism of antibiotics to algae at the biochemical level.

Retinal oxidative stress at the onset of diabetes determined by synchrotron FTIR widefield imaging: towards diabetes pathogenesis

Diabetic retinopathy is a microvascular complication of diabetes that can lead to blindness. In the present study, we aimed to determine the nature of diabetes-induced, highly localized biochemical changes in the neuroretina at the onset of diabetes. High-resolution synchrotron Fourier transform infrared (s-FTIR) wide field microscopy coupled with multivariate analysis (PCA-LDA) was employed to identify biomarkers of diabetic retinopathy with spatial resolution at the cellular level. We compared the retinal tissue prepared from 6-week-old Ins2^Akita/+ heterozygous (Akita/+, N = 6; a model of diabetes) male mice with the wild-type (control, N = 6) mice. Male Akita/+ mice become diabetic at 4-weeks of age. Significant differences (P < 0.001) in the presence of biomarkers associated with diabetes and segregation of spectra were achieved. Differentiating IR bands attributed to nucleic acids (964, 1051, 1087, 1226 and 1710 cm^-1), proteins (1662 and 1608 cm^-1) and fatty acids (2854, 2923, 2956 and 3012 cm^-1) were observed between the Akita/+ and the WT samples. A comparison between distinctive layers of the retina, namely the photoreceptor retinal layer (PRL), outer plexiform layer (OPL), inner nucleus layer (INL) and inner plexiform layer (IPL) suggested that the photoreceptor layer is the most susceptible layer to oxidative stress in short-term diabetes. Spatially-resolved chemical images indicated heterogeneities and oxidative-stress induced alterations in the diabetic retina tissue morphology compared with the WT retina. In this study, the spectral biomarkers and the spatial biochemical alterations in the diabetic retina and in specific layers were identified for the first time. We believe that the conclusions drawn from these studies will help to bridge the gap in our understanding of the molecular and cellular mechanisms that contribute to the pathobiology of diabetic retinopathy.

Low dose dimethyl sulfoxide driven gross molecular changes have the potential to interfere with various cellular processes

Dimethyl sulfoxide (DMSO) is a small molecule with polar, aprotic and amphiphilic properties. It serves as a solvent for many polar and nonpolar molecules and continues to be one of the most used solvents (vehicle) in medical applications and scientific research. To better understand the cellular effects of DMSO within the concentration range commonly used as a vehicle (0.1-1.5%, v/v) for cellular treatments, we applied Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FT-IR) spectroscopy to DMSO treated and untreated epithelial colon cancer cells. Both unsupervised (Principal Component Analysis-PCA) and supervised (Linear Discriminant Analysis-LDA) pattern recognition/modelling algorithms applied to the IR data revealed total segregation and prominent differences between DMSO treated and untreated cells at whole, lipid and nucleic acid regions. Several of these data were supported by other independent techniques. Further IR data analyses of macromolecular profile indicated comprehensive alterations especially in proteins and nucleic acids. Protein secondary structure analysis showed predominance of β-sheet over α-helix in DMSO treated cells. We also observed for the first time, a reduction in nucleic acid level upon DMSO treatment accompanied by the formation of Z-DNA. Molecular docking and binding free energy studies indicated a stabilization of Z-DNA in the presence of DMSO. This alternate DNA form may be related with the specific actions of DMSO on gene expression, differentiation, and epigenetic alterations. Using analytical tools combined with molecular and cellular biology techniques, our data indicate that even at very low concentrations, DMSO induces a number of changes in all macromolecules, which may affect experimental outcomes where DMSO is used as a solvent.

Multifaceted Interweaving Between Extracellular Matrix, Insulin Resistance, and Skeletal Muscle

The skeletal muscle provides movement and support to the skeleton, controls body temperature, and regulates the glucose level within the body. This is the core tissue of insulin-mediated glucose uptake via glucose transporter type 4 (GLUT4). The extracellular matrix (ECM) provides integrity and biochemical signals and plays an important role in myogenesis. In addition, it undergoes remodeling upon injury and/or repair, which is also related to insulin resistance (IR), a major cause of type 2 diabetes (T2DM). Altered signaling of integrin and ECM remodeling in diet-induced obesity is associated with IR. This review highlights the interweaving relationship between the ECM, IR, and skeletal muscle. In addition, the importance of the ECM in muscle integrity as well as cellular functions is explored. IR and skeletal muscle ECM remodeling has been discussed in clinical and nonclinical aspects. Furthermore, this review considers the role of ECM glycation and its effects on skeletal muscle homeostasis, concentrating on advanced glycation end products (AGEs) as an important risk factor for the development of IR. Understanding this complex interplay between the ECM, muscle, and IR may improve knowledge and help develop new ideas for novel therapeutics for several IR-associated myopathies and diabetes.

Toxicity impact of fenvalerate on the gill tissue of Oreochromis mossambicus with respect to biochemical changes utilizing FTIR and principal component analysis

The use of pesticides in agriculture can make their way into the earth and wash into the amphibian system causing ecological stress. This study aims to understand the changes occurring in gill tissues as a result of fenvalerate exposure using Fourier-transform infrared spectroscopy. The intensity ratio of the selected bands I1545/I1657, I2924/I2853, and I1045/I1545 measures changes in proteins, lipids, and carbohydrates. Curve-fitting analysis was performed in the selected band region to analyze the quantitative changes of proteins, lipids, and carbohydrates. The band area ratio of CH3/asCH2+ sCH2 shows the absence of a long chain of fatty acids due to fenvalerate treatment. The band area ratio of asCH2/sCH2 increases for higher sublethal concentrations, which shows the lower disorder of lipid acyl chain flexibility. A decrease in lipids was found in lower sublethal concentrations. The secondary structure of proteins affirms β sheet development. Carbohydrate metabolism of gill tissues demonstrates a decrease in glycogen contents. A further decrease in glycogen content and an increase in lactic acid were observed when presented to a fenvalerate concentration. PCA plots indicate distinct variations among the biochemical parameters of the gill tissues. This study provides a quantitative examination of assessing pesticide toxicity in aquatic environments.

Triglyceride dependent differentiation of obesity in adipose tissues by FTIR spectroscopy coupled with chemometrics

The excess deposition of triglycerides in adipose tissue is the main reason of obesity and causes excess release of fatty acids to the circulatory system resulting in obesity and insulin resistance. Body mass index and waist circumference are not precise measure of obesity and obesity related metabolic diseases. Therefore, in the current study, it was aimed to propose triglyceride bands located at 1770-1720 cm^-1 spectral region as a more sensitive obesity related biomarker using the diagnostic potential of Fourier Transform Infrared (FTIR) spectroscopy in subcutaneous (SCAT) and visceral (VAT) adipose tissues. The adipose tissue samples were obtained from 10 weeks old male control (DBA/2J) (n = 6) and four different obese BFMI mice lines (n = 6 per group). FTIR spectroscopy coupled with hierarchical cluster analysis (HCA) and principal component analysis (PCA) was applied to the spectra of triglyceride bands as a diagnostic tool in the discrimination of the samples. Successful discrimination of the obese, obesity related insulin resistant and control groups were achieved with high sensitivity and specificity. The results revealed the power of FTIR spectroscopy coupled with chemometric approaches in internal diagnosis of abdominal obesity based on the spectral differences in the triglyceride region that can be used as a spectral marker.

Reduced complexity of force and muscle activity during low level isometric contractions of the ankle in diabetic individuals

BACKGROUND

This study evaluated the structure and amount of variability of surface electromyography (sEMG) patterns and ankle force data during low-level isometric contractions in diabetic subjects with different degrees of neuropathy.

METHODS

We assessed 10 control subjects and 38 diabetic patients, classified as absent, mild, moderate, or severe neuropathy, by a fuzzy system based on clinical variables. Multichannel sEMG (64-electrode matrix) of tibialis anterior and gastrocnemius medialis muscles were acquired during isometric contractions at 10%, 20%, and 30% of the maximum voluntary contraction, and force levels during dorsi- and plantarflexion were recorded. Standard deviation and sample entropy of force signals were calculated and root mean square and sample entropy were calculated from sEMG signals. Differences among groups of force and sEMG variables were verified using a multivariate analysis of variance.

FINDINGS

Overall, during dorsiflexion contractions, moderate and severe subjects had higher force standard deviation and moderate subjects had lower force sample entropy. During plantarflexion, moderate subjects had higher force standard deviation and all diabetic subjects had lower entropy. Tibialis anterior presented higher root mean square in absent group and lower entropy in mild subjects. For gastrocnemius medialis, entropy was higher in severe and lower in moderate subjects.

INTERPRETATION

Diabetic neuropathy affects the complexity of the neuromuscular system during low-level isometric contractions, reducing the system's capacity to adapt to challenging mechanical demands. The observed patterns of neuromuscular complexity were not associated with disease severity, with the majority of alterations recorded in moderate subject.

Valdecoxib Recovers the Lipid Composition, Order and Dynamics in Colon Cancer Cell Lines Independent of COX-2 Expression: An ATR-FTIR Spectroscopy Study

Prostanoids play an important role in a variety of physiological and pathophysiological processes including inflammation and cancer. The rate-limiting step in the prostanoid biosynthesis pathway is catalyzed by cyclooxygenases (COXs). Aberrant expression of the inducible isoform COX-2 plays a significant role in colon cancer initiation and progression. In this study, we have hypothesized that COX-2 specific inhibitors such as Valdecoxib (VLX), being highly hydrophobic, may alter biophysical properties of cellular lipids. In this study, COX-2 expressing (HT29) and COX-2 non-expressing (SW620) colon cancer cell lines were treated with VLX and examined using attenuated total reflection infrared spectroscopy. The results revealed that VLX treatment decreased lipid fluidity in the cells irrespective of COX-2 expression status and affected order parameters of the lipids in both cell lines. Cluster analysis also indicated that the spectral differences between the two cell lines are profound and could be successfully differentiated. Valdecoxib treatment could enhance the composition, order and dynamics of the lipids of colon cancer cells independently of its COX-2 inhibitory mechanism. Valdecoxib has therapeutic effects upon colon cancer, therefore it can be used as an adjuvant and/or chemopreventive agent for colon cancer.

Early Alterations in Bone Characteristics of Type I Diabetic Rat Femur: A Fourier Transform Infrared (FT-IR) Imaging Study

Alterations in microstructure and mineral features can affect the mechanical and chemical properties of bones and their capacity to resist mechanical forces. Controversial results on diabetic bone mineral content have been reported and little is known about the structural alterations in collagen, maturation of apatite crystals, and carbonate content in diabetic bone. This current study is the first to report the mineral and organic properties of cortical, trabecular, and growth plate regions of diabetic rat femurs using Fourier transform infrared (FT-IR) microspectroscopy and the Vickers microhardness test. Femurs of type I diabetic rats were embedded into polymethylmethacrylate blocks, which were used for FT-IR imaging and microhardness studies. A lower mineral content and microhardness, a higher carbonate content especially labile type carbonate content, and an increase in size and maturation of hydroxyapatite crystals were observed in diabetic femurs, which indicate that diabetes has detrimental effects on bone just like osteoporosis. There was a decrease in the level of collagen maturity in diabetic femurs, implying a decrease in bone collagen quality that may contribute to the decrease in tensile strength and bone fragility. Taken together, the findings revealed alterations in structure and composition of mineral and matrix components, and an altered quality and mechanical strength of rat femurs in an early stage of type I diabetes. The results contribute to the knowledge of structure-function relationship of mineral and matrix components in diabetic bone disorder and can further be used for diagnostic or therapeutic purposes.

Bladder cancer diagnosis from bladder wash by Fourier transform infrared spectroscopy as a novel test for tumor recurrence

This study proposes Fourier Transform Infrared (FTIR) spectroscopy as a more sensitive, rapid, non-destructive and operator-independent analytical diagnostic method for bladder cancer recurrence from bladder wash than other routinely used urine cytology and cystoscopy methods. A total of 136 patients were recruited. FTIR spectroscopic experiments were carried out as a blind study, the classification results of which were then compared with those of cytology and cystoscopy. Firstly, 71 samples (n = 37; bladder cancer and n = 34; control) were studied with transmittance FTIR spectroscopy. After achieving successful differentiation of the groups, to develop a more rapid diagnostic tool and check the reproducibility of the results, the work was continued with different samples (n = 65 as n = 44; bladder cancer and n = 21; control), using the reflection mode (ATR) of FTIR spectroscopy by a different operator. The results revealed significant alterations in moleculer content in the cancer group. Based on the spectral differences, using transmittance FTIR spectroscopy coupled with chemometrics, the diseased group was successfully differentiated from the control. When only carcinoma group was taken into consideration a sensitivity value of 100% was achieved. Similar results were also obtained by ATR-FTIR spectroscopy. This study shows the power of infrared spectroscopy in the diagnosis of bladder cancer.

Muscle fiber conduction velocity in different gait phases of early and late-stage diabetic neuropathy

We investigated the muscle fiber conduction velocity (MFCV) during gait phases of the lower limb muscles in individuals with various degrees of diabetic peripheral neuropathy (DPN). Forty-five patients were classified into severity degrees of DPN by a fuzzy model. The stages were absent (n=11), mild (n=14), moderate (n=11) and severe (n=9), with 10 matched healthy controls. While walking, all subjects had their sEMG (4 linear electrode arrays) recorded for tibialis anterior (TA), gastrocnemius medialis (GM), vastus lateralis (VL) and biceps femoris (BF). MFCV was calculated using a maximum likelihood algorithm with 30ms standard deviation Gaussian windows. In general, individuals in the earlier stages of DPN showed lower MFCV of TA, GM and BF, whilst individuals with severe DPN presented higher MFCV of the same muscles. We observed that mild patients already showed lower MFCV of TA at early stance and swing, and lower MFCV of BF at swing. All diabetic groups showed a markedly reduction in MFCV of VL, irrespective of DPN. Severe patients presented higher MFCV mainly in distal muscles, TA at early and swing phases and GM at propulsion and midstance. The absent group already showed MFCV of VL and GM reductions at the propulsion phase and of VL at early stance. Although MFCV changes were not as progressive as the DPN was, we clearly distinguished diabetic patients from controls, and severe patients from all others.

Single muscle fiber contractile properties in diabetic RAT muscle

INTRODUCTION

Diabetes is associated with accelerated loss of muscle mass and function. We compared the contractile properties of single muscle fibers in young rat soleus muscle of uncontrolled streptozotocin-induced diabetic animals (n = 10) and nondiabetic controls (n = 10).

METHODS

Single fiber maximal force, shortening velocity, and power were assessed during maximal activation with calcium using the slack test 4 weeks after induction. Myosin heavy chain expression was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Oxidized myosin levels were detected by analyzing protein carbonyls in muscle homogenates. All fibers expressed the type I myosin heavy chain isoform.

RESULTS

Diabetic rats had higher blood glucose (537 vs. 175 mg/dl; P < 0.001) and lower body weight (171 vs. 356 g; P < 0.001) than controls. Muscle fibers from diabetic rats showed smaller cross-sectional area (1128 vs. 1812 μm(2) ), lower maximal force (258 vs. 492 μN), and reduced absolute power (182 vs. 388 μN FL/s) (all P < 0.0001). No differences were seen in shortening velocity, specific force or specific power. Myosin carbonylation was higher (P < 0.01) in diabetic rats.

CONCLUSIONS

After 4 weeks of untreated diabetes, there are significant alterations in muscle at the level of isolated single fibers and myosin protein, although some contractile properties seem to be protected. Muscle Nerve, 2015 Muscle Nerve 53: 958-964, 2016.

Raman and infra-red microspectroscopy: towards quantitative evaluation for clinical research by ratiometric analysis

We demonstrate how ratioing spectral bands can circumvent experimental artefacts, and present a library of ratios from the biomedical literature.

Chemical Analysis in the Corpus Callosum Following Traumatic Axonal Injury using Fourier Transform Infrared Microspectroscopy: A Pilot Study

Evaluating traumatic axonal injury remains challenging in clinical and forensic sciences as its identification is difficult using routine diagnostic methods. This study used Fourier transform infrared microspectroscopy to detect TAI within the corpus callosum in an animal model. Protein conformational analysis revealed significantly increased β-sheet and β-turn contents paralleled by a decrease in α-helix content at 24 h postinjury, while the antiparallel β-sheet content was decreased at 12 h postinjury. Compared with the control group, the lipid/protein ratio was significantly reduced in all of the injured groups. At 24 h postinjury, there were increases in the olefinic=CH and CH3 group of lipids accompanied by the decreased CH2 group, but the results at 12 and 72 h were contrary to that at 24 h. Our study showed that FTIRM could differentiate injured from normal white matter at different time points following TBI via examination of these infrared spectral parameters.

Lipid profiles of adipose and muscle tissues in mouse models of juvenile onset of obesity without high fat diet induction: a Fourier transform infrared (FT-IR) spectroscopic study

The current study aims to determine lipid profiles in terms of the content and structure of skeletal muscle and adipose tissues to better understand the characteristics of juvenile-onset spontaneous obesity without high fat diet induction. For the purposes of this study, muscle (longissimus, quadriceps) and adipose (inguinal, gonadal) tissues of 10-week-old male DBA/2J and Berlin fat mouse inbred (BFMI) lines (BFMI856, BFMI860, BFMI861) fed with a standard breeding diet were used. Biomolecular structure and composition was determined using attenuated total reflection Fourier transform (ATR FT-IR) spectroscopy, and muscle triglyceride content was further quantified using high-performance liquid chromatography (HPLC) coupled with an evaporative light scattering detector (ELSD). The results revealed a loss of unsaturation in BFMI860 and BFMI861 lines in both muscles and inguinal adipose tissue, together with a decrease in the hydrocarbon chain length of lipids, especially in the BFMI860 line in muscles, suggesting an increased lipid peroxidation. There was an increase in saturated lipid and triglyceride content in all tissues of BFMI lines, more profoundly in longissimus muscle, where the increased triglyceride content was quantitatively confirmed by HPLC-ELSD. Moreover, an increase in the metabolic turnover of carbohydrates in muscles of the BFMI860 line was observed. The results demonstrated that subcutaneous (inguinal) fat also displayed considerable obesity-induced alterations. Taken together, the results revealed differences in lipid structure and content of BFMI lines, which may originate from different insulin sensitivity levels of the lines, making them promising animal models for spontaneous obesity. The results will contribute to the understanding of the generation of insulin resistance in obesity without high fat diet induction.

FTIR imaging of structural changes in visceral and subcutaneous adiposity and brown to white adipocyte transdifferentiation

FTIR microspectroscopy coupled with UCP1 immunohistological staining enables the detection of obesity-related molecular alterations and transdifferentiations in visceral and subcutaneous adipose tissues in spontaneously obese mice lines.

Vitamin A deficiency induces structural and functional alterations in the molecular constituents of the rat hippocampus

To date, no structural study has been carried out on the effects of vitamin A deficiency (VAD) on hippocampal macromolecules. Therefore, in the present study, the effect of dietary VAD on the structure, content and function of rat hippocampal molecules was investigated using Fourier transform IF spectroscopy. Male Wistar rats were randomly divided into three groups: an experimental group maintained on a vitamin A-deficient liquid diet (VAD,n7); a control group maintained on a vitamin A-supplemented liquid diet (CON,n9); a pure control group maintained on standard solid laboratory chow (PC,n7). The PC group was included in the study to ensure that the usage of liquid diet did not influence the outcomes of VAD. Both the CON and PC groups were successfully discriminated from the VAD group by principal component analysis and hierarchical cluster analysis. The spectral analysis indicated a significant decrease in the contents of saturated and unsaturated lipids, cholesteryl esters, TAG and nucleic acids in the VAD group when compared with the CON group (P≤ 0·05). In addition, a significant decrease in membrane fluidity and a significant increase in lipid order (e.g. acyl chain flexibility) were observed in the VAD group (P≤ 0·001). The results of the artificial neural network analysis revealed a significant decrease in the α-helix structure content and a significant increase in the turn and random coil structure contents, indicating protein denaturation, in the VAD group when compared with the CON and PC groups (P≤ 0·05). Dietary exclusion of vitamin A for 3 months apparently had an adverse impact on compositional, structural and dynamical parameters. These changes can be due to increased oxidative stress, confirming the antioxidant protection provided by vitamin A when used as a dietary supplement at low-to-moderate doses.

Protective effects of desferrioxamine and deferiprone on the spleen tissue of aluminum intoxicated mice: A Fourier transform infrared spectroscopy study

The present study was designed to examine the protective effects of the chelating agents desferrioxamine (DFO) and deferiprone (DFP) in aluminum intoxicated spleen tissue of mice by Fourier transform infrared (FTIR) spectroscopy. The finding revealed the alterations on the major biochemical constituents, such as lipids, proteins, phosphodiester and nucleic acids of the spleen tissue of mice at molecular level. The significant decreased in the peak areas of asymmetric and symmetric mode of the phosphodiester groups from control to aluminum intoxicated, but improved it by DFP and DFO+DFP treatments respectively for nearer control value. The bands ratio at I1081/I1232 significantly decreased from control to aluminum, but enhanced it by DFP and DFO+DFP respectively. This result suggests that DFO and DFP are the phosphodiesterase inhibitor, recovered from chronic growth of diseases in the spleen. Amide I and amide II peak area values decreased from control to aluminum intoxicated spleen tissue, but treated with DFP and DFO+DFP significantly improved. This result suggests an alteration in the protein profile. The absence of Olefinic=CH stretching in aluminum intoxicated spleen suggests an altered lipid levels. Concentrations of trace elements were found by ICP-OES. Histopathological findings confirmed the biochemical observations of this study. The results of the FTIR study were found to be in agreement with biochemical studies and demonstrated that FTIR can be used successfully applied to toxicological studies at molecular level.

Expression of interleukin-15 and inflammatory cytokines in skeletal muscles of STZ-induced diabetic rats: effect of resistance exercise training

Skeletal muscle atrophy is associated with type-1 diabetes. Skeletal muscle is the source of pro- and anti-inflammatory cytokines that can mediate muscle hypertrophy and atrophy, while resistance exercise can modulate both muscle mass and muscle cytokine expression. This study determined the effects of a 5-week resistance exercise training regimen on the expression of muscle cytokines in healthy and streptozotocin-induced diabetic rats, with special emphasis on interleukin-15 (IL-15), a muscle-derived cytokine proposed to be involved in muscle hypertrophy or responses to stress. Induction of diabetes reduced muscle weight in both the fast flexor hallucis longus (FHL) and slow soleus muscles, while resistance training preserved FHL muscle weight in diabetic rats. IL-15 protein content was increased by training in both FHL and soleus muscles, as well as serum, in normal and diabetic rats. With regard to proinflammatory cytokines, muscle IL-6 levels were increased in diabetic rats, while training decreased muscle IL-6 levels in diabetic rats; training had no effect on FHL muscle IL-6 levels in healthy rats. Also, tumor necrosis factor-alpha (TNF-α) and IL-1β levels were increased by diabetes, but not changed by training. In conclusion, we found that in diabetic rats, resistance training increased muscle and serum IL-15 levels, decreased muscle IL-6 levels, and preserved FHL muscle mass.

FTIR study of protective action of deferoxamine and deferiprone on the kidney tissues of aluminum loaded mice

The present study was designed to evaluate the FTIR spectra of the aluminum exposed kidney tissues and recovered by chelating agents DFO and DFP then showed significant alteration on the major biochemical constituents such as lipids, proteins and glycogen at molecular level. The significant increased in the peak area of glycogen from 0.006±0.001 to 0.187±0.032 may be the interruption of aluminum in the calcium metabolism and the reduced level of calcium. The peak area value of amide A significantly decreased from control (4.931±1.446) to aluminum (1.234±0.052), but improved by DFP and DFO+DFP from 2.658±0.153 to 3.252±0.070 respectively. Amide I and amide II peak area values also decreased from 1.690±0.133 to 0.811±0.192 and 1.158±0.050 to 0.489±0.047 but treated with DFP and DFO+DFP significantly improved. This result suggests an alteration in the protein profile. The absence of Olefinic=CH stretching band, C=O stretching of triglycerides and ring breathing mode in the DNA bases in aluminum exposure kidney suggests an altered lipid levels. Treated with DFP and DFO+DFP mice were considerably increased in lipid peroxidative markers. Further, assessed the activities of enzymatic antioxidants and measured the levels of nonenzymatic antioxidants. Concentrations of trace elements were found by ICP-OES. Histopathology of chelating agents treated kidney showed reduced renal damage in aluminum induced mice. Thus, histopathological findings confirmed the biochemical observations of this study. This results demonstrated that FTIR spectroscopy can be successfully applied to toxicological and biotoxicology studies.

Screening of chemopreventive effect of naringenin-loaded nanoparticles in DMBA-induced hamster buccal pouch carcinogenesis by FT-IR spectroscopy

The aim of the present study is to investigate the chemopreventive effects of the prepared naringenin-loaded nanoparticles (NARNPs) relative to efficacy of free naringenin (NAR) in modifying the functional, structural, and compositional changes at the molecular level during 7, 12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis by Fourier transform infrared (FT-IR) spectroscopy. The results revealed that a significant increase in the amount of proteins and nucleic acid contents and a decrease in the amount of lipids and glycogen contents are observed in DMBA-induced tumor tissues. In addition, in tumor tissues a decrease in lipid order and a significant increase in membrane dynamics were noticed. Further, the composition and secondary structure of proteins were found to be altered, which indicates some important structural alterations in the existing proteins and/or the expression of new types of proteins occurring under the tumor transformation. Furthermore, oral administration of free NAR and NARNPs significantly increased lipids and their order as well as increased the glycogen contents and decreased the levels of proteins and nucleic acid contents. On a comparative basis, NARNPs were found to have a more potent antitumor effect than free NAR in completely preventing the formation of squamous cell carcinoma and in improving the biochemical constituents to a normal range in DMBA-induced HBP carcinogenesis. The present study further shows a great potential of FT-IR spectroscopy as a complimentary tool for the screening of various anticancer drugs and follow-up, which may allow faster response to critical problems arising during treatment.