Apigenin Alleviates Autistic-like Stereotyped Repetitive Behaviors and Mitigates Brain Oxidative Stress in Mice

Studying the involvement of nicotinic acetylcholine receptors (nAChRs), specifically α7-nAChRs, in neuropsychiatric brain disorders such as autism spectrum disorder (ASD) has gained a growing interest. The flavonoid apigenin (APG) has been confirmed in its pharmacological action as a positive allosteric modulator of α7-nAChRs. However, there is no research describing the pharmacological potential of APG in ASD. The aim of this study was to evaluate the effects of the subchronic systemic treatment of APG (10-30 mg/kg) on ASD-like repetitive and compulsive-like behaviors and oxidative stress status in the hippocampus and cerebellum in BTBR mice, utilizing the reference drug aripiprazole (ARP, 1 mg/kg, i.p.). BTBR mice pretreated with APG (20 mg/kg) or ARP (1 mg/g, i.p.) displayed significant improvements in the marble-burying test (MBT), cotton-shredding test (CST), and self-grooming test (SGT) (all p < 0.05). However, a lower dose of APG (10 mg/kg, i.p.) failed to modulate behaviors in the MBT or SGT, but significantly attenuated the increased shredding behaviors in the CST of tested mice. Moreover, APG (10-30 mg/kg, i.p.) and ARP (1 mg/kg) moderated the disturbed levels of oxidative stress by mitigating the levels of catalase (CAT) and superoxide dismutase (SOD) in the hippocampus and cerebellum of treated BTBR mice. In patch clamp studies in hippocampal slices, the potency of choline (a selective agonist of α7-nAChRs) in activating fast inward currents was significantly potentiated following incubation with APG. Moreover, APG markedly potentiated the choline-induced enhancement of spontaneous inhibitory postsynaptic currents. The observed results propose the potential therapeutic use of APG in the management of ASD. However, further preclinical investigations in additional models and different rodent species are still needed to confirm the potential relevance of the therapeutic use of APG in ASD.

Spectroscopic, Biological, and Topological Insights on Lemonol as a Potential Anticancer Agent

A monoterpene alcohol known as lemonol was investigated experimentally as well as theoretically in order to gain insights into its geometrical structure, vibrational frequencies, solvent effects on electronic properties, molecular electrostatic potential, Mulliken atomic charge distribution, natural bond orbital, and Nonlinear Optical properties. The frontier molecular orbital energy gap values of 5.9084 eV (gas), 5.9261 eV (ethanol), 5.9185 eV (chloroform), 5.9253 eV (acetone), and 5.9176 eV (diethyl ether) were predicted, and it shows the kinetic stability and chemical reactivity of lemonol. Topological studies were conducted using Multiwfn software to understand the binding sites and weak interactions in lemonol. The antiproliferative effect of lemonol against the breast cancer cell line Michigan Cancer Foundation (MCF-7) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while nuclear damage, condensation, and reactive oxygen species generation were identified using acridine orange/ethidium bromide, propidium iodide, and dichlorodihydrofluorescein diacetate staining. The theoretical and experimental findings are highly correlated, confirming the structure, and the results of in vitro studies suggest that lemonol acts as a potent inhibitor against the human breast cancer cell line MCF-7, highlighting its strong antiproliferative activity.

The Potent and Selective Histamine H3 Receptor Antagonist E169 Counteracts Cognitive Deficits and Mitigates Disturbances in the PI3K/AKT/GSK-3β Signaling Pathway in MK801-Induced Amnesia in Mice

The role of histamine H3 receptors (H3Rs) in memory and the prospective of H3R antagonists in pharmacological control of neurodegenerative disorders, e.g., Alzheimer's disease (AD), is well-accepted. Therefore, the procognitive effects of acute systemic administration of H3R antagonist E169 (2.5-10 mg/kg, i.p.) on MK801-induced amnesia in C57BL/6J mice using the novel object recognition test (NORT) were evaluated. E169 (5 mg) provided a significant memory-improving effect on MK801-induced short- and long-term memory impairments in NORT. The E169 (5 mg)-provided effects were comparable to those observed with the reference phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and were abrogated with the H3R agonist (R)-α-methylhistamine (RAMH). Additionally, our results demonstrate that E169 ameliorated MK801-induced memory deficits by antagonism of H3Rs and by modulation of the level of disturbance in the expression of PI3K, Akt, and GSK-3β proteins, signifying that E169 mitigated the Akt-mTOR signaling pathway in the hippocampus of tested mice. Moreover, the results observed revealed that E169 (2.5-10 mg/kg, i.p.) did not alter anxiety levels and locomotor activity of animals in open field tests, demonstrating that performances improved following acute systemic administration with E169 in NORT are unrelated to changes in emotional response or in spontaneous locomotor activity. In summary, these obtained results suggest the potential of H3R antagonists such as E169, with good in silico physicochemical properties and stable retained key interactions in docking studies at H3R, in simultaneously modulating disturbed brain neurotransmitters and the imbalanced Akt-mTOR signaling pathway related to neurodegenerative disorders, e.g., AD.

Identification of Novel QTLs/Defense Genes in Spring Wheat Germplasm Panel for Seedling and Adult Plant Resistance to Stem Rust and Their Validation Through KASP Marker Assays

Stem rust is one of the major diseases threatening wheat production globally. To identify novel resistance quantitative trait loci (QTLs), we performed 35K Axiom Array SNP genotyping assays on an association mapping panel of 400 germplasm accessions, including Indian landraces, in conjunction with phenotyping for stem rust at seedling and adult plant stages. Association analyses using three genome wide association study (GWAS) models (CMLM, MLMM, and FarmCPU) revealed 20 reliable QTLs for seedling and adult plant resistance. Among these 20 QTLs, five QTLs were found consistent with three models, i.e., four QTLs on chromosome 2AL, 2BL, 2DL, and 3BL for seedling resistance and one QTL on chromosome 7DS for adult plant resistance. Further, we identified a total of 21 potential candidate genes underlying QTLs using gene ontology analysis, including a leucine rich repeat receptor (LRR) and P-loop nucleoside triphosphate hydrolase, which have a role in pathogen recognition and disease resistance. Furthermore, four QTLs (Qsr.nbpgr-3B_11, QSr.nbpgr-6AS_11, QSr.nbpgr-2AL_117-6, and QSr.nbpgr-7BS_APR) were validated through KASP located on chromosomes 3B, 6A, 2A, and 7B. Out of these QTLs, QSr.nbpgr-7BS_APR was identified as a novel QTL for stem rust resistance which has been found effective in both seedling as well as the adult plant stages. Identified novel genomic regions and validated QTLs have the potential to be deployed in wheat improvement programs to develop disease resistant varieties for stem rust and can diversify the genetic basis of resistance.

Canagliflozin Ameliorates Oxidative Stress and Autistic-like Features in Valproic-Acid-Induced Autism in Rats: Comparison with Aripiprazole Action

Based on their proven anti-inflammatory and antioxidant effects, recent studies have examined the therapeutic potential of the sodium-glucose cotransporter 2 (SGLT2) inhibitors in neurodevelopmental disorders such as autism spectrum disorder (ASD). Therefore, the aim of this study is to assess the effects of subchronic systemic treatment with intraperitoneal (i.p.) canagliflozin (20, 50, and 100 mg/kg) compared to aripiprazole (ARP) (3 mg/g, i.p.) in a valproic acid (VPA)-induced rat model of autism. The behavioral characteristics of ASD, oxidative stress, and acetylcholinesterase (AChE) activity in rats with ASD-like behaviors, which were induced by prenatal exposure to VPA, were evaluated. The behavioral assessment methods used for this study were the open field test (OFT), the marble-burying test (MBT), and the nestlet-shredding test (NST) to examine their exploratory, anxiety, and compulsiveness-like actions, while the biochemical assessment used for this study was an ELISA colorimetric assay to measure ASD biomarker activity in the hippocampus, prefrontal cortex, and cerebellum. Rats that were pretreated with 100 mg/kg of canagliflozin displayed a significantly lower percentage of shredding (1.12 ± 0.6%, p < 0.01) compared to the ARP group (3.52 ± 1.6%). Pretreatment with (20 mg/kg, 50 mg/kg, and 100 mg/kg) canagliflozin reversed anxiety levels and hyperactivity and reduced hyper-locomotor activity significantly (161 ± 34.9 s, p < 0.05; 154 ± 44.7 s, p < 0.05; 147 ± 33.6 s, p < 0.05) when compared with the VPA group (303 ± 140 s). Moreover, canagliflozin and ARP mitigated oxidative stress status by restoring levels of glutathione (GSH) and catalase (CAT) and increasing the levels of malondialdehyde (MDA) in all tested brain regions. The observed results propose repurposing of canagliflozin in the therapeutic management of ASD. However, further investigations are still required to verify the clinical relevance of canagliflozin in ASD.

Simultaneous Antagonism at H3R/D2R/D3R Reduces Autism-like Self-Grooming and Aggressive Behaviors by Mitigating MAPK Activation in Mice

Dysregulation in brain neurotransmitters underlies several neuropsychiatric disorders, e.g., autism spectrum disorder (ASD). Also, abnormalities in the extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway pave the way for neuroinflammation, neurodegeneration, and altered learning phenotype in ASD. Therefore, the effects of chronic systemic administration of the multiple-targeting antagonist ST-713 at the histamine H3 receptor (H3R) and dopamine D2/D3 receptors (D2/D3R) on repetitive self-grooming, aggressive behaviors, and abnormalities in the MAPK pathway in BTBR T + Itpr3tf/J (BTBR) mice were assessed. The results showed that ST-713 (2.5, 5, and 10 mg/kg, i.p.) mitigated repetitive self-grooming and aggression in BTBR mice (all p < 0.05), and the ameliorative effects of the most promising dose of ST-713 (5 mg/kg, i.p.) on behaviors were completely abrogated by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. Moreover, the elevated levels of several MAPK pathway proteins and induced proinflammatory markers such as tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and IL-6 were significantly suppressed following chronic administration of ST-713 (5 mg/kg, i.p.) (all p < 0.01). Furthermore, ST-713 significantly increased the levels of histamine and dopamine in hippocampal tissue of treated BTBR mice (all p < 0.01). The current observations signify the potential role of such multiple-targeting compounds, e.g., ST-713, in multifactorial neurodevelopmental disorders such as ASD.

Multi-locus genome-wide association studies (ML-GWAS) reveal novel genomic regions associated with seedling and adult plant stage leaf rust resistance in bread wheat (Triticum aestivum L.)

Leaf rust is one of the important diseases limiting global wheat production and productivity. To identify quantitative trait nucleotides (QTNs) or genomic regions associated with seedling and adult plant leaf rust resistance, multilocus genome-wide association studies (ML-GWAS) were performed on a panel of 400 diverse wheat genotypes using 35 K single-nucleotide polymorphism (SNP) genotyping assays and trait data of leaf rust resistance. Association analyses using six multi-locus GWAS models revealed a set of 201 significantly associated QTNs for seedling and 65 QTNs for adult plant resistance (APR), explaining 1.98-31.72% of the phenotypic variation for leaf rust. Among these QTNs, 51 reliable QTNs for seedling and 15 QTNs for APR were consistently detected in at least two GWAS models and were considered reliable QTNs. Three genomic regions were pleiotropic, each controlling two to three pathotype-specific seedling resistances to leaf rust. We also identified candidate genes, such as leucine-rich repeat receptor-like (LRR) protein kinases, P-loop containing nucleoside triphosphate hydrolase and serine-threonine/tyrosine-protein kinases (STPK), which have a role in pathogen recognition and disease resistance linked to the significantly associated genomic regions. The QTNs identified in this study can prove useful in wheat molecular breeding programs aimed at enhancing resistance to leaf rust and developing next-generation leaf rust-resistant varieties.

The histamine H3R and dopamine D2R/D3R antagonist ST-713 ameliorates autism-like behavioral features in BTBR T+tf/J mice by multiple actions

Several brain neurotransmitters, including histamine (HA), acetylcholine (ACh), and dopamine (DA) are suggested to be involved in several brain disorders including cognitive deficits, depression, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with Autism spectrum disorder (ASD). Therefore, the ameliorative effects of the novel multiple-active compound ST-713 with high binding affinities at histamine H3 receptor (H3R), dopamine D2sR and D3R on ASD-like behaviors in male BTBR T+tf/J mice model were assessed. ST-713 (3-(2-chloro-10H-phenothiazin-10-yl)-N-methyl-N-(4-(3-(piperidin-1-yl)propoxy)benzyl)propan-1-amine; 2.5, 5, and 10 mg/kg, i.p.) ameliorated dose-dependently social deficits, and significantly alleviated the repetitive/compulsive behaviors of BTBR mice (all P < 0.05). Moreover, ST-713 modulated disturbed anxiety levels, but failed to obliterate increased hyperactivity of tested mice. Furthermore, ST-713 (5 mg/kg) attenuated the increased levels of hippocampal and cerebellar protein expressions of NF-κB p65, COX-2, and iNOS in BTBR mice (all P < 0.05). The ameliorative effects of ST-713 on social parameters were entirely reversed by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. The obtained results demonstrate the potential of multiple-active compounds for the therapeutic management of neuropsychiatric disorders, e.g. ASD.

Mining of Indian wheat germplasm collection for adult plant resistance to leaf rust

Leaf rust (Puccinia triticina Eriks.) is a fungal disease of wheat (Triticum spp.), which causes considerable yield loss. Adult plant resistance (APR) is one of the most sustainable approaches to control leaf rust. In this study, field-testing was carried out across ten different locations, followed by molecular screening, to detect the presence of APR genes, Lr34+, Lr46+, Lr67+ and Lr68 in Indian wheat germplasm. In field screening, 190 wheat accessions were selected from 6,319 accessions based on leaf tip necrosis (LTN), disease severity and the average coefficient of infection. Molecular screening revealed that 73% of the accessions possessed known APR genes either as single or as a combination of two or three genes. The occurrence of increased LTN intensity, decreased leaf rust severity and greater expression of APR genes were more in relatively cooler locations. In 52 lines, although the presence of the APR genes was not detected, it still displayed high levels of resistance. Furthermore, 49 accessions possessing either two or three APR genes were evaluated for stability across locations for grain yield. It emerged that eight accessions had wider adaptability. Resistance based on APR genes, in the background of high yielding cultivars, is expected to provide a high level of race non-specific resistance, which is durable.

Curcumin potentiates the function of human α7-nicotinic acetylcholine receptors expressed in SH-EP1 cells

Effects of curcumin, a biologically active ingredient of turmeric, were tested on the Ca²⁺ transients induced by the activation of α₇ subunit of the human nicotinic acetylcholine (α₇ nACh) receptor expressed in SH-EP1 cells. Curcumin caused a significant potentiation of choline (1 mM)-induced Ca²⁺ transients with an EC₅₀ value of 133 nM. The potentiating effect of curcumin was not observed in Ca²⁺ transients induced by high K⁺ (60 mM) containing solutions or activation of α₄β₂ nACh receptors and the extent of curcumin potentiation was not altered in the presence of Ca²⁺ channel antagonists nifedipine (1 μM), verapamil (1 μM), ω-conotoxin (1 μM), and bepridil (10 μM). Noticeably the effect of curcumin was not observed when curcumin and choline were co-applied without curcumin pre-incubation. The effect of curcumin on choline-induced Ca²⁺ transients was not reversed by pre-incubation with inhibitors of protein C, A, and CaM kinases. Metabolites of curcumin such as tetrahydrocurcumin, demethylcurcumin, and didemethylcurcumin also caused potentiation of choline-induced Ca²⁺ transients. Notably, specific binding of [¹²⁵I]-bungarotoxin was not altered in the presence of curcumin. Collectively, our results indicate that curcumin allosterically potentiate the function of the α7-nACh receptor expressed in SH-EP1 cells.

The Pattern of mRNA Expression Is Changed in Sinoatrial Node from Goto-Kakizaki Type 2 Diabetic Rat Heart

BACKGROUND

In vivo experiments in Goto-Kakizaki (GK) type 2 diabetic rats have demonstrated reductions in heart rate from a young age. The expression of genes encoding more than 70 proteins that are associated with the generation and conduction of electrical activity in the GK sinoatrial node (SAN) have been evaluated to further clarify the molecular basis of the low heart rate.

MATERIALS AND METHODS

Heart rate and expression of genes were evaluated with an extracellular electrode and real-time RT-PCR, respectively. Rats aged 12-13 months were employed in these experiments.

RESULTS

Isolated spontaneous heart rate was reduced in GK heart (161 ± 12 bpm) compared to controls (229 ± 11 bpm). There were many differences in expression of mRNA, and some of these differences were of particular interest. Compared to control SAN, expression of some genes were downregulated in GK-SAN: gap junction, Gja1 (Cx43), Gja5 (Cx40), Gjc1 (Cx45), and Gjd3 (Cx31.9); cell membrane transport, Trpc1 (TRPC1) and Trpc6 (TRPC6); hyperpolarization-activated cyclic nucleotide-gated channels, Hcn1 (HCN1) and Hcn4 (HCN4); calcium channels, Cacna1d (Ca_v1.3), Cacna1g (Ca_v3.1), Cacna1h (Ca_v3.2), Cacna2d1 (Ca_vα2δ1), Cacna2d3 (Ca_vα2δ3), and Cacng4 (Cav _γ 4); and potassium channels, Kcna2 (K_v1.2), Kcna4 (K_v1.4), Kcna5 (K_v1.5), Kcnb1 (K_v2.1), Kcnd3 (K_v4.3), Kcnj2 (K_ir2.1), Kcnk1 (TWIK1), Kcnk5 (K_2P5.1), Kcnk6 (TWIK2), and Kcnn2 (SK2) whilst others were upregulated in GK-SAN: Ryr2 (RYR2) and Nppb (BNP).

CONCLUSIONS

This study provides new insight into the changing expression of genes in the sinoatrial node of diabetic heart.

Altered profile of mRNA expression in atrioventricular node of streptozotocin‑induced diabetic rats

Prolonged action potential duration, reduced action potential firing rate, upstroke velocity and rate of diastolic depolarization have been demonstrated in atrioventricular node (AVN) cells from streptozotocin (STZ)-induced diabetic rats. To further clarify the molecular basis of these electrical disturbances, the mRNA profiles encoding a variety of proteins associated with the generation and conduction of electrical activity in the AVN, were evaluated in the STZ-induced diabetic rat heart. Expression of mRNA was measured in AVN biopsies using reverse transcription-quantitative polymerase chain reaction techniques. Notable differences in mRNA expression included upregulation of genes encoding membrane and intracellular Ca²⁺ transport, including solute carrier family 8 member A1, transient receptor potential channel 1, ryanodine receptor 2/3, hyperpolarization-activated cyclic-nucleotide 2 and 3, calcium channel voltage-dependent, β2 subunit and sodium channels 3a, 4a, 7a and 3b. In addition to this, potassium channels potassium voltage-gated channel subfamily A member 4, potassium channel calcium activated intermediate/small conductance subfamily N α member 2, potassium voltage-gated channel subfamily J members 3, 5, and 11, potassium channel subfamily K members 1, 2, 3 and natriuretic peptide B (BNP) were upregulated in AVN of STZ heart, compared with controls. Alterations in gene expression were associated with upregulation of various proteins including the inwardly rectifying, potassium channel K_ir3.4, NCX1 and BNP. The present study demonstrated notable differences in the profile of mRNA encoding proteins associated with the generation, conduction and regulation of electrical signals in the AVN of the STZ-induced diabetic rat heart. These data will provide a basis for a substantial range of future studies to investigate whether variations in mRNA translate into alterations in electrophysiological function.

Phenylalanine derivatives with modulating effects on human α1-glycine receptors and anticonvulsant activity in strychnine-induced seizure model in male adult rats

The critical role of α1-glycine receptor (α1-GLYRs) in pathological conditions such as epilepsy is well known. In the present study, structure-activity relations for a series of phenylalanine derivatives carrying selected hydrogen bond acceptors were investigated on the functional properties of human α1-GLYR expressed in Xenopus oocytes. The results indicate that one particular substitution position appeared to be of special importance for control of ligand activity. Among tested ligands (1-8), the biphenyl derivative (2) provided the most promising antagonistic effect on α1-GLYRs, while its phenylbenzyl analogue (5) exhibited the highest potentiation effect. Moreover, ligand 5 with most promising potentiating effect showed in-vivo moderate protection when tested in strychnine (STR)-induced seizure model in male adult rats, whereas ligand 2 with highest antagonistic effect failed to provide appreciable anti(pro)convulsant effect. Furthermore, ligands 2 and 5 with the most promising effects on human α1-GLYRs were examined for their toxicity and potential neuroprotective effect against neurotoxin 6-hydroxydopamine (6-OHDA). The results show that ligands 2 and 5 possessed neither significant antiproliferative effects, nor necrotic and mitochondrial toxicity (up to concentration of 50μM). Moreover, ligand 2 showed weak neuroprotective effect at the 50μM against 100μM toxic dose of 6-OHDA. Our results indicate that modulatory effects of ligands 2 and 5 on human α1-GLYRs as well as on STR-induced convulsion can provide further insights for the design of therapeutic agents in treatment of epilepsy and other pathological conditions requiring enhanced activity of inhibitory glycine receptors.

Evolutionarily conserved dual lysine motif determines the non-chaperone function of secreted Hsp90alpha in tumour progression

Both intracellular and extracellular heat shock protein-90 (Hsp90) family proteins (α and β) have been shown to support tumour progression. The tumour-supporting activity of the intracellular Hsp90 is attributed to their N-terminal ATPase-driven chaperone function. What molecular entity determines the extracellular function of secreted Hsp90 and the distinction between Hsp90α and Hsp90β was unclear. Here we demonstrate that CRISPR/Case9 knocking out Hsp90α nullifies tumour cells' ability to migrate, invade and metastasize without affecting the cell survival and growth. Knocking out Hsp90β leads to tumour cell death. Extracellular supplementation with recombinant Hsp90α, but not Hsp90β, protein recovers tumourigenicity of the Hsp90α-knockout cells. Sequential mutagenesis identifies two evolutionarily conserved lysine residues, lys-270 and lys-277, in the Hsp90α subfamily that determine the extracellular Hsp90α function. Hsp90β subfamily lacks the dual lysine motif and the extracellular function. Substitutions of gly-262 and thr-269 in Hsp90β with lysines convert Hsp90β to a Hsp90α-like protein. Newly constructed monoclonal antibody, 1G6-D7, against the dual lysine region of secreted Hsp90α inhibits both de novo tumour formation and expansion of already formed tumours in mice. This study suggests an alternative therapeutic approach to target Hsp90 in cancer, that is, the tumour-secreted Hsp90α, instead of the intracellular Hsp90α and Hsp90β.

Different Profile of mRNA Expression in Sinoatrial Node from Streptozotocin-Induced Diabetic Rat

Background

Experiments in isolated perfused heart have shown that heart rate is lower and sinoatrial node (SAN) action potential duration is longer in streptozotocin (STZ)–induced diabetic rat compared to controls. In sino-atrial preparations the pacemaker cycle length and sino-atrial conduction time are prolonged in STZ heart. To further clarify the molecular basis of electrical disturbances in the diabetic heart the profile of mRNA encoding a wide variety of proteins associated with the generation and transmission of electrical activity has been evaluated in the SAN of STZ-induced diabetic rat heart.

Methodology/Principal Findings

Heart rate was measured in isolated perfused heart with an extracellular suction electrode. Expression of mRNA encoding a variety of intercellular proteins, intracellular Ca²⁺-transport and regulatory proteins, cell membrane transport proteins and calcium, sodium and potassium channel proteins were measured in SAN and right atrial (RA) biopsies using real-time reverse transcription polymerase chain reaction techniques. Heart rate was lower in STZ (203±7 bpm) compared to control (239±11 bpm) rat. Among many differences in the profile of mRNA there are some worthy of particular emphasis. Expression of genes encoding some proteins were significantly downregulated in STZ-SAN: calcium channel, Cacng4 (7-fold); potassium channel, Kcnd2 whilst genes encoding some other proteins were significantly upregulated in STZ-SAN: gap junction, Gjc1; cell membrane transport, Slc8a1, Trpc1, Trpc6 (4-fold); intracellular Ca²⁺-transport, Ryr3; calcium channel Cacna1g, Cacna1h, Cacnb3; potassium channels, Kcnj5, Kcnk3 and natriuretic peptides, Nppa (5-fold) and Nppb (7-fold).

Conclusions/Significance

Collectively, this study has demonstrated differences in the profile of mRNA encoding a variety of proteins that are associated with the generation, conduction and regulation of electrical signals in the SAN of STZ-induced diabetic rat heart. Data from this study will provide a basis for a substantial range of future studies to investigate whether these changes in mRNA translate into changes in electrophysiological function.

L-Methionine–succinic acid (2/1)

The asymmetric unit of the title compound, 2C5H11NO2S·C4H6O4, comprises two crystallographically independent methionine residues, which exist in the zwitterionic form, and a neutral succinic acid molecule. Both methionine residues have agauche-I conformation. In the crystal, the various components are linkedviaO—H...O, N—H...O and C—H...O hydrogen bonds forming slabs parallel to theabplane

Enhanced Glucose Tolerance and Pancreatic Beta Cell Function by Low Dose Aspirin in Hyperglycemic Insulin-Resistant Type 2 Diabetic Goto-Kakizaki (GK) Rats

BACKGROUND/AIM

Type 2 diabetes is the most common metabolic disorder, characterized by insulin resistance and pancreatic islet beta-cell failure. The most common complications associated with type 2 diabetes are hyperinsulinemia, hyperglycemia, hyperlipidemia, increased inflammatory and reduced insulin response. Aspirin (ASA) and other non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with the prevention of diabetes, obesity and related cardiovascular disorders. Aspirin has been used in many clinical and experimental trials for the prevention of diabetes and associated complications.

METHODS

In this study, five month old Goto-Kakizaki (GK) rats, which showed signs of mild hyperglycemia (fasting blood glucose 80-95 mg/dl vs 55-60 mg/dl Wistar control rats) were used. Two subgroups of GK and Wistar control rats were injected intraperitoneally with 100 mg aspirin/kg body weight/ day for 5 weeks. Animals were sacrificed and blood and tissues were collected after performing glucose tolerance (2 h post 2g IP glucose ingestion) tests in experimental and control groups.

RESULTS

Aspirin caused a moderate decrease in hyperglycemia. However, we observed a significant improvement in glucose tolerance after ASA treatment in GK rats compared to the nondiabetic Wistar rats. Also, the ASA treated GK rats exhibited a significant decrease in insulinemia. ASA treatment also caused a marked reduction in the pro-inflammatory prostaglandin, PGE2, which was significantly higher in GK rats. On the other hand, no significant organ toxicity was observed after ASA treatment at this dose and time period. However, the total cholesterol and lipoprotein levels were significantly increased in GK rats, which decreased after ASA treatment. Immunofluorescence staining for insulin/glucagon secreting pancreatic cells showed improved beta-cell structural and functional integrity in ASA-treated rats which was also confirmed by SDS-PAGE and Western blot analysis.

CONCLUSION

The improved glucose tolerance in ASA-treated GK rats may be associated with increased insulin responses due to the anti-inflammatory properties of ASA and enhanced nitric oxide (NO) level which facilitated insulin signaling and energy utilization in target tissues. These results may have implications in determining the therapeutic use of ASA in insulin-resistant type 2 diabetes.

Effects of a sucrose-enriched diet on the pattern of gene expression, contraction and Ca(2+) transport in Goto-Kakizaki type 2 diabetic rat heart

There has been a spectacular rise in the global prevalence of type 2 diabetes mellitus (T2DM), and cardiovascular disease is the major cause of morbidity and mortality in diabetic patients. A variety of diastolic and systolic dysfunctions have been demonstrated in type 2 diabetic heart. The consumption of sugar-sweetened beverages has been linked to rising rates of obesity, which in turn is a risk factor for development of T2DM. In this study, the effects of a sucrose-enriched diet on the pattern of gene expression, contraction and Ca(2+) transport in the Goto-Kakizaki T2DM rat heart were investigated. Genes encoding cardiac muscle proteins (Myh7, Mybpc3, Myl1, Myl3 and Mylpf), intercellular proteins (Gja4), cell membrane transport (Atp1b1), calcium channels (Cacna1c, Cacna1g and Cacnb1) and potassium channels (Kcnj11) were upregulated and genes encoding potassium channels (Kcnb1) were downregulated in GK compared with control rats. Genes encoding cardiac muscle proteins (Myh6, Mybpc3 and Tnn2), intercellular proteins (Gja1 and Gja4), intracellular Ca(2+) transport (Atp2a1 and Ryr2), cell membrane transport (Atp1a2 and Atp1b1) and potassium channel proteins (Kcnj2 and Kcnj8) were upregulated and genes encoding cardiac muscle proteins (Myh7) were downregulated in control rats fed sucrose compared with control rats. Genes encoding cardiac muscle proteins (Myh7) and potassium channel proteins (Kcnj11) were downregulated in control and GK rats fed sucrose compared with control and GK rats, respectively. The amplitude of shortening was reduced in myocytes from the control-sucrose group compared with control rats and in the GK-sucrose group compared with GK rats. The amplitude of the Ca(2+) transient was increased in myocytes from control-sucrose compared with control rats and decreased in GK-sucrose compared with GK rats. Subtle alterations in the pattern of expression of genes encoding a variety of cardiac muscle proteins are associated with changes in shortening and intracellular Ca(2+) transport in ventricular myocytes from GK T2DM and control rats fed a sucrose-enriched diet.

Molecular Evidence for the Occurrence of Abutilon mosaic virus, A New World Begomovirus in India

During an investigation in the year 2010, on the weed reservoir of begomovirus, Abutilon pictum showing bright yellow mosaic symptoms was observed in Udhagamandalam, Tamil Nadu, India. The complete bipartite genome of a begomovirus was cloned and sequenced which revealed association of Abutilon mosaic virus (AbMV). Nicotiana benthamiana plants inoculated biolistically with the concatemers generated through rolling circle amplification of the cloned DNAs were asymptomatic; however three out of nine plants showed presence of viral DNA A. A recombination event in the ORF BC1 with ToLCNDV DNA B (HM989846) was detected. This is the first molecular evidence of AbMV in India.

Effects of exercise training on excitation-contraction coupling and related mRNA expression in hearts of Goto-Kakizaki type 2 diabetic rats

Although, several novel forms of intervention aiming at newly identified therapeutic targets are currently being developed for diabetes mellitus (DM), it is well established that physical exercise continues to be one of the most valuable forms of non-pharmacological therapy. The aim of the study was to investigate the effects of exercise training on excitation-contraction coupling and related gene expression in the Goto-Kakizaki (GK) type 2 diabetic rat heart and whether exercise is able to reverse diabetes-induced changes in excitation-contraction coupling and gene expression. Experiments were performed in GK and control rats aged 10-11 months following 2-3 months of treadmill exercise training. Shortening, [Ca(2+)]i and L-type Ca(2+) current were measured in ventricular myocytes with video edge detection, fluorescence photometry and whole cell patch clamp techniques, respectively. Expression of mRNA was assessed in ventricular muscle with real-time RT-PCR. Amplitude of shortening, Ca(2+) transients and L-type Ca(2+) current were not significantly altered in ventricular myocytes from GK sedentary compared to control sedentary rats or by exercise training. Expression of mRNA encoding Tpm2, Gja4, Atp1b1, Cacna1g, Cacnb2, Hcn2, Kcna3 and Kcne1 were up-regulated and Gja1, Kcnj2 and Kcnk3 were down-regulated in hearts of sedentary GK rats compared to sedentary controls. Gja1, Cav3 and Kcnk3 were up-regulated and Hcn2 was down-regulated in hearts of exercise trained GK compared to sedentary GK controls. Ventricular myocyte shortening and Ca(2+) transport were generally well preserved despite alterations in the profile of expression of mRNA encoding a variety of cardiac muscle proteins in the adult exercise trained GK diabetic rat heart.

Vitamin E ameliorates the decremental effect of paraquat on cardiomyocyte contractility in rats

Background

Exposure to pesticides and industrial toxins are implicated in cardiovascular disease. Paraquat (PAR) is a toxic chemical widely used as an herbicide in developing countries and described as a major suicide agent. The hypothesis tested here is that PAR induced myocardial dysfunction may be attributed to altered mechanisms of Ca²⁺ transport which are in turn possibly linked to oxidative stress. The mechanisms of PAR induced myocardial dysfunction and the impact of antioxidant protection was investigated in rat ventricular myocytes.

Methodology

Forty adult male Wistar rats were divided into 4 groups receiving the following daily intraperitoneal injections for 3 weeks: Group 1 PAR (10 mg/kg), Control Group 2 saline, Group 3 vitamin E (100 mg/kg) and Group 4 PAR (10 mg/kg) and vitamin E (100 mg/kg). Ventricular action potentials were measured in isolated perfused heart, shortening and intracellular Ca²⁺ in electrically stimulated ventricular myocytes by video edge detection and fluorescence photometry techniques, and superoxide dismutase (SOD) and catalase (CAT) levels in heart tissue.

Principal Findings

Spontaneous heart rate, resting cell length, time to peak (TPK) and time to half (THALF) relaxation of myocyte shortening were unaltered. Amplitude of shortening was significantly reduced in PAR treated rats (4.99±0.26%) and was normalized by vitamin E (7.46±0.44%) compared to controls (7.87±0.52%). PAR significantly increased myocytes resting intracellular Ca²⁺ whilst TPK and THALF decay and amplitude of the Ca²⁺ transient were unaltered. The fura-2–cell length trajectory during the relaxation of the twitch contraction was significantly altered in myocytes from PAR treated rats compared to controls suggesting altered myofilament sensitivity to Ca²⁺ as it was normalized by vitamin E treatment. A significant increase in SOD and CAT activities was observed in both PAR and vitamin E plus PAR groups.

Conclusions

PAR exposure compromised rats heart function and ameliorated by vitamin E treatment.

Epidermal growth factor and its receptor in cervical cancer

Epidermal growth factor (EGF) is an important growth factor regulating both normal and malignant cells. The present study analyzes the expression pattern of EGF and its receptor (EGF-R) in 424 cases of various stages of tumor progression in the uterine cervix. In all the samples studied, EGF and EGF-R expression was predominant in the basal or basaloid cells. Increased expression of the two proteins correlated with increasing histological abnormality (dysplasia). In invasive cancer, alteration of EGF expression was more evident than EGF-R. The expression pattern showed significant correlation in the basal and spinal cell layers. This increased expression of EGF observed in dysplastic and malignant cells may be due to overexpression of EGF-R and suggests its role in cellular proliferation.

Proliferating cell nuclear antigen expression and the progression of cervical intraepithelial neoplasia

Cell proliferation is an important biological aspect of a tumor cell population which can affect clinical outcome. In addition to other well established clinical and histopathological prognostic criteria? cell kinetic data have significant predictive value. This study evaluates the proliferative activity of benign, premalignant and malignant cervical tissue by analyzing the expression of the proliferating cell nuclear antigen (PCNA). PCNA is a 36 kD nuclear protein associated with the cell cycle and is directly involved in DNA synthesis during cell proliferation. A total of 122 subjects were included in the study. This included 30 benign tissue samples, 30 low grade lesions (CIN 1), 30 high grade lesions (CIN 2/3) and 32 invasive squamous carcinomas. There was significant difference in PCNA index between benign and high grade lesions as well as benign and invasive cancer. The percentage of PCNA positive cells were significantly higher in invasive carcinoma when compared with non malignant lesions. Moreover, there was also good correlation between increasing histological abnormality and PCNA expression. These results suggest that cell proliferation index as detected by PCNA expression may be useful in the evaluation of alterations in cell kinetics of various grades of cervical lesions. Such data could also possibly help explain the biological behaviour of these lesions and be useful in planning of radiotherapy for invasive cervical cancer.

A pilot study on the effect of telmisartan & ramipril on 24 h blood pressure profile & dipping pattern in type 1 diabetes patients with nephropathy

Background & objectives:

Angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) have been used to normalize the blood pressure and the dipping pattern in patients with type 1 diabetes mellitus (T1DM) and nephropathy. However, there are no data on the effect of the dual blockade on the dipping pattern in these subjects. We therefore, carried out this study to evaluate the effect of administrating an ACEI followed by ARB in the optimum doses in T1DM patients with nephropathy on 24 h blood pressure (BP) profile and nocturnal dipping pattern.

Methods:

An open label interventional pilot study was done during a one year period involving 30 consecutive patients who were treated with telmisartan 80 mg (0800-1000 h) for eight weeks followed by addition of ramipril 10 mg (1200-1400 h) for the next eight weeks. Ambulatory BP, dipping pattern and albumin excretion rate were studied after each phase. Twenty patients were hypertensive and 10 patients had macro- and 20 patients had microalbuminuria.

Results:

Telmisartan produced a fall in the clinic BP by 4/1.3 mm Hg (P<0.05 and P<0.362, respectively), 2/1.9 mm Hg in the mean 24 h BP, 1.4/1.1 mm Hg in the day BP and 3.7/3 mm Hg in the trough BP. Addition of ramipril to telmisartan produced a further reduction of 6.3/5.9 mm Hg in the clinic BP (P<0.001 for both), 4.3/4.2 mm Hg in the mean 24 h BP (P<0.01 and P<0.0001, respectively), 5.8/3.9 mm Hg in the day BP (P<0.01 for both), 4.2/2.5 mm Hg in the trough BP, with a reduction of clinic SBP and DBP of 10.3/7.2 mm Hg from the baseline. Telmisartan restored normal systolic dipping pattern in 33.3 per cent of the nondippers (P<0.01) but addition of ramipril was not complimentary. Hyperkalamia (>5.5 mmol/l) was observed only in 2 patients towards the end of the study.

Interpretation & conclusions:

The dual blockade with telmisartan and ramipril had complimentary effect on lowering of the BP, however, similar beneficial effect on the nocturnal dipping was not observed. Further studies with large number of subjects with longer duration of follow-up are required to validate these observations.

Validation of bedside methods in evaluation of diabetic peripheral neuropathy

BACKGROUND & OBJECTIVES

Vibration perception threshold (VPT) is considered as a gold standard for diagnosis of diabetic peripheral neuropathy. However, the data are sparse comparing the VPT with commonly used bedside modalities. This study was carried out to evaluate the usefulness of simple bed side screening modalities for peripheral neuropathy in patients with diabetes mellitus.

METHODS

A total of 1044 patients with diabetes mellitus attending the Diabetes clinic from January 2007 to May 2008, were included in this study. All subjects had a detailed clinical assessment including Diabetic Neuropathy Symptom (DNS) score, Diabetic Neuropathy Examination (DNE) score, ankle reflex, vibration sensation with a 128 Hz tuning fork, 10 g Semmes-Weinstein monofilament and vibration perception threshold (VPT).

RESULTS

The prevalence of peripheral neuropathy was 34.9 per cent with VPT. Foot care practices were followed by only 214 (20.5%) of the study population. When compared with VPT, ankle reflex was the most sensitive (90.7%) but least specific (37.3%). The tuning fork and monofilament tests respectively had lower sensitivity (62.5 and 62.8%) but better specificity (95.3 and 92.9%) and accuracy (78.9 and 77.9%). Significant correlations were observed between the VPT score and the DNE (r = 0.532, P<0.001) and DNS (r = 0.546, P<0.001) scores and absent tuning fork sensation (r = 0.590; P<0.001), monofilament sensation (r = 0.573; P<0.001) and ankle reflex (r = 0.377, P = 0.01).

INTERPRETATION & CONCLUSIONS

The present findings show that simple bed side tests are useful for assessing peripheral diabetic neuropathy, even in those subjects in whom foot care practices are not followed.

Anti-albuminuric efficacy of a combination of angiotensin converting enzyme inhibitor & angiotensin receptor blocker in type 1 DM with nephropathy

BACKGROUND & OBJECTIVES

The efficacy of the combination of angiotensin receptor blockers (ARBs) and angiotensin converting enzyme (ACE) inhibitors in patients of type 1 diabetes mellitus (DM) with nephropathy is debatable. The antialbuminuric efficacy of dual blockade in patients of type 1 DM with micro- or macroabuminuria were evaluated.

METHODS

In this open label observational study 30 patients (20 male 10 female) with type 1 DM were included who were initially treated with telmisartan 80 mg for eight weeks followed by addition of ramipril 10 mg for a further eight weeks. Albuminuria reduction was studied at the end of each phase.

RESULTS

Therapy with telmisartan for 8 wk resulted in a 39 per cent (P<0.01) reduction in albumin excretion rate (AER). Combination therapy with telmisartan and ramipril produced a further reduction in AER of 33.4 per cent (P<0.01), amounting to a total AER reduction of 59 per cent (P<0.001). Dual blockade was more effective in the group of macroalbuminuric as compared to microalbuminuric subjects (P<0.05). Telmisartan produced a significant reduction in SBP (P<0.05). The addition of ramipril produced a further reduction in BP, the total reduction being 10.3 in SBP and 7.2 mmHg in DBP (P<0.001 for both). There was an increase in mean serum potassium of 0.39 mmol/l (P<0.01) from baseline at the end of the study period and two patients had hyperkalemia>5.5 mmol/l with dual blockade.

INTERPRETATION & CONCLUSION

Dual blockade with ramipril enhanced the antialbuminuric efficacy of telmisartan and further reduced blood pressure. The effect of dual blockade was more pronounced in the macroalbuminuric subjects and it was well tolerated. However, careful monitoring of serum potassium is required.

A rare cause of hypoglycaemia

We describe the case of a 77-year-old man who was admitted with recurrent episodes of altered behaviour. These episodes were related to insulin-like growth factor II (IGF-II) mediated hypoglycaemia. Imaging revealed a large retroperitoneal mass and he underwent debulking surgery uneventfully. Histopathology revealed a solitary fibroma with intense immunostaining positive for CD34 and vimentin, suggesting a mesenchymal origin of the tumour. Later he received chemo/radiotherapy and is on prednisolone with abatement of hypoglycaemic episodes.

Magnitude of foot problems in diabetes in the developing world: a study of 1044 patients

AIM

To gain insight into the prevalence of peripheral neuropathy, foot care practices, foot at risk and foot ulcers in patients with diabetes mellitus at a tertiary care centre.

METHODS

A prospective case study involving 1044 patients with diabetes mellitus attending the diabetes clinic of a tertiary care centre in north India from January 2007 to May 2008. All subjects underwent a detailed clinical assessment including vibration perception threshold (VPT) and ankle brachial pressure index (ABI), along with metabolic parameters, and were categorized into ulcer, foot at risk and patients with no risk factors. Foot care practices were assessed with a questionnaire. Peripheral neuropathy was defined as VPT score > or = 25 V. Peripheral vascular disease (PVD) was defined as ABI < 0.9. One hundred and forty-nine patients with foot at risk were followed up for 9.0 +/- 2.3 months (range 5-13 months).

RESULTS

The prevalence of peripheral neuropathy was 34.9% and of PVD 12.6%. Two thirds of the patients were at risk for foot ulceration; 9% had an ulcer and 20.2% of them required amputation. Correct foot care practices were followed by 214 (20.5%) subjects of the whole study population and by only 135 (19.3%) of the patients with foot at risk. Improvement in glycaemic control in the patients on follow-up was associated with improvement or stabilization of VPT score. Five (3.4%) patients developed new ulcers on follow-up.

CONCLUSION

The high prevalence of neuropathy and PVD, coexisting with poor adherence to foot care practices predisposes to foot problems in people with diabetes in our study population.

Hashimoto's encephalopathy: an under diagnosed entity

We describe a 60-year-old woman with Hashimoto's thyroiditis who presented with neuropsychiatric manifestations even on optimal and stable doses of levothyroxine replacement therapy. She had high anti-thyroid peroxidase antibody and responded to glucocorticoid treatment.

Precocious puberty and a sellar mass

Precocious puberty in a child less than 3 years of age is usually gonadotropin dependent and is often associated with extrasellar central nervous system disorders. The present report describes the case of a 2½-year-old girl who presented with gonadotropin-independent precocious puberty and had a sellar mass. She was referred for neurosurgical intervention to our institute. On investigation, she was found to have primary hypothyroidism of autoimmune aetiology, which is rarely associated with precocious puberty and sellar mass due to thyrotroph hyperplasia. She was successfully treated with levothyroxine, and with this secondary sexual characteristics progressively regressed and the sellar mass disappeared.

Electrospray ionization tandem mass spectrometric study on the effect of N-terminal beta- and gamma-carbo amino acids on fragmentation of GABA-hybrid peptides

The fragmentations of protonated and deprotonated ions of a new class of N-blocked hybrid Boc-carbopeptides containing repeats of gamma-Caa/gammaAbu- and beta-Caa/gammaAbu- (Caa==C-linked carbo gamma(4)-/beta(3)- amino acids derived from D-xylose, gammaAbu = gamma-aminobutyric acid) have been studied using electrospray ionization (ESI) ion-trap tandem mass spectrometry (MS/MS). MS/MS of a pair of these protonated diastereomers produces distinct fragmentation of the Boc group. The formation of [M + H-56](+) corresponding to loss of isobutylene is more pronounced for Boc-NH-(R)-gamma-Caa-gammaAbu-OH (2) whereas it is of low abundance for Boc-NH-(S)-gamma-Caa-gammaAbu--OH (1). Similarly, MS(2) of [M--H](-) of 2 produces an abundant [M--H--C(CH(3))(3)OH--CO(2)](-) ion, which is absent for its diastereomeric isomer 1. From this, it can be suggested that MS/MS of N-blocked Boc-protected carbopeptides may be helpful in distinguishing the stereochemistry of the N-terminus Caa. MS(3) of [M + H-Boc + H](+) ions of peptides with a gamma-amino acid (gamma-Caa/gammaAbu) at the N-terminus produces only abundant y(n) (+) ions. On the other hand, characteristic fragmentations involving the peptide backbone (b(n) (+) and y(n) (+)) and the side chain are seen when beta-Caa is at the N-terminus of the peptides. MS(3) of the [M--H--C(CH(3))(3)OH](-) ion of peptides containing gamma-Caa/gammaAbu at the N-terminus gave y(n) (-) and [M--H--C(CH(3))(3)OH--CO(2)](-) ions, whereas the presence of beta-Caa at the N-terminus yielded predominantly [M--H--C(CH(3))(3)OH--HNCO](-). Thus, on the basis of our previous study and that presented here we propose that the fragmentation of these hybrid carbopeptides is highly influenced by the type of carbo amino acid present at the N-terminus.

Differentiation of three pairs of Boc-beta,gamma- and gamma,beta-hybrid peptides by electrospray ionization tandem mass spectrometry

A new series of Boc-N-beta(3), gamma(4)-/gamma(4), beta(3)-isomeric hybrid peptides (containing repeats of beta(3)-Caa and gamma(4)-Caa's, Caa = C-linked carbo beta(3)-/gamma(4)-amino acids derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion-trap and high resolution quadrupole time-of-flight/tandem mass spectrometry (Q-TOF MS/MS). MS(n) of protonated isomeric peptides and [M+H-Boc+H](+) produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The positional isomers are differentiated from one another by the presence of y(n)(+), b(n)(+), and other fragment ions of different m/z values. It is observed that the peptides with beta-Caa at the N-terminus produce extensive fragmentation, whereas gamma-Caa gave rise to much less fragmentation. Peptides with gamma-Caa at the N-terminus lose NH(3), whereas this process is absent for the carbopeptides with beta-Caa at the N-terminus. Two pairs of dipeptide diastereomers are clearly differentiated by the collision-induced dissociation (CID) of their protonated molecules. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-(R)-beta-Caa-(R)-gamma-Caa-OCH(3) (6) and Boc-NH-(R)-gamma-Caa-(R)-beta-Caa-OCH(3) (12), whereas it is insignificant or totally absent for its protonated diastereomeric pair Boc-NH-(S)-beta-Caa-(S)-gamma-Caa-OCH(3) (1) and Boc-NH-(S)-gamma-Caa-(S)-beta-Caa-OCH(3) (7). Further, ESI negative ion tandem mass spectrometry has also been found to be useful for differentiating these isomeric peptide acids.