Comparison Between 5-Aminosalicylic Acid (5-ASA) and Para-Aminosalicylic Acid (4-PAS) as Potential Protectors Against Mn-Induced Neurotoxicity

Manganese (Mn) is an essential metal for biological systems; however, occupational or clinical exposure to high levels of Mn can produce a neurological disorder called manganism. Oxidative stress and neuroinflammation play major roles in the Mn-induced neurodegeneration leading to dysfunction of the basal ganglia. We investigated the toxic effects of MnCl₂ in an immortalized rat brain endothelial cell line (RBE4) and the protective effects of the radical scavenging aminosalicylic acids, 5-aminosalicylic acid (5-ASA) and 4-aminosalicylic acid (4-PAS). Mn cytotoxicity was determined with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) reduction and lactate dehydrogenase (LDH) activity. A significant decrease in MTT reduction concomitant with increased LDH release was noted in RBE4 cells exposed for 24 h to MnCl₂ (600 and 800 μM; p?<?0.0001). Our results establish that compared to 4-PAS, 5-ASA has greater efficacy in protecting RBE4 cells from Mn-induced neurotoxicity after preexposure to MnCl₂ 800 μM (p?<?0.0001).     

Effects of High Zinc Levels on the Lipid Synthesis in Rat Hepatocytes

Zinc deficiency impairs the hepatic lipid metabolism. Previous studies were focused on the negative effects of zinc deficiency on the hepatic lipid metabolism. A few studies investigated the effects of high zinc levels on the lipid metabolism in hepatocytes. In this study, rat hepatocytes were cultured and treated with different and high concentrations of zinc to investigate the effects of high zinc levels on the lipid synthesis in hepatocytes in vitro. The levels of hepatocytes functional markers, including alkaline phosphatase, lactate dehydrogenase, and albumin, were significantly higher in the zinc treatment groups than in the control group (p?<?0.05, p?<?0.01). The mRNA and protein levels of sterol regulatory element-binding protein 1c (SREBP-1c) were significantly higher in the zinc treatment groups than in the control group (p?<?0.05, p?<?0.01). Furthermore, the mRNA expression levels of acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase (FAS) were significantly higher in the medium- and high-dose zinc treatment groups than in the control group (p?<?0.01). The mRNA levels of stearoyl-CoA desaturase-1 (SCD-1) were significantly higher in the high-dose group (p?<?0.01). These results indicate that high levels of zinc increase hepatocytes activity and SREBP-1c expression, which upregulate the expression of ACC1, FAS, and SCD-1, thereby improving the lipid metabolism in the hepatocytes.     

Reproductive axis response to repeated lipopolysaccharide administration in peripubertal female rats

Immune system disorders are often accompanied by alterations in the reproductive axis. Several reports have shown that administration of bacterial lipopolysaccharide (LPS) has central inflammatory effects and activates cytokine release in the hypothalamus where the luteinizing hormone releasing hormone (Gn-RH) neurons are located. The present study was designed to investigate the effect of repeated LPS administration on the neuroendocrine mechanisms of control of the reproductive axis in peripubertal female rats (30-day-old rats). With this aim, LPS (50 μg/kg weight) was administered to the animals during 25, 27 and 29 days of age and sacrificed on 30 day of life. Gn-RH, γ?amino butyric acid (GABA) and glutamic acid (GLU), two amino acids involved in the regulation of Gn-RH secretion, hypothalamic content were measured. LH and estradiol serum levels were also determined and the day of vaginal opening examined. The results showed a significant increase in Gn-RH and GLU content (p?<?0.0001), shared by a reduction of GABA one (p?<?0.0001). LH and estradiol serum levels were decreased (p?<?0.01, p?<?0.001) and delay in the day of vaginal opening was also observed in treated animals. Present results show that repeated LPS administration impaired reproductive function, modifying the neuroendocrine mechanisms of control of the axis in peripubertal female rats.     

Levels of Metallic Elements and Their Potential Relationships to Cognitive Function among Elderly from Federal Land Development Authority (FELDA) Settlement in Selangor Malaysia

Exposure to toxic metals and excessive amount of trace elements is a risk factor of cognitive decline. Continuous monitoring of these elements by the use of metabolically inactive tissues such as fingernails may help in taking preventive measures to delay the cognitive decline process. In this study, the cognitive function of 54 elderlies (60–72 years old) from FELDA Sungai Tengi, Selangor, was evaluated using the Malay version of Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). The levels of arsenic (As), cadmium (Cd), copper (Cu), manganese (Mn), lead (Pb), and zinc (Zn) in fingernail were detected using Inductively Coupled Plasma-Mass Spectrometry. Results showed that (92.6 %) our population was cognitively impaired based on the MoCA with mean score of 18.07?±?5.11. The mean level of elements in fingernails for As, Cd, Cu, Mn, Pb, and Zn were 16.68?±?3.52, 4.26?±?0.91, 4.81?±?1.16, 1.00?±?0.23, 1.83?±?0.47, and 40.86?±?10.81 μg/g, respectively. Significant inverse correlations were observed between MoCA with age (r?=??0.543, p?<?0.01), Cu level (r?=??0.330, p?<?0.05), and Mn level (r?=??0.496, p?<?0.01). MMSE was correlated to age (r?=??0.346, p?<?0.05) only. In conclusion, besides aging, the progression of cognitive decline among the elderly FELDA population was associated with increased levels of copper and manganese.     

Thiamine deficiency induces oxidative stress in brain mitochondria of Mus musculus

The present investigation evaluates the changes in the levels of antioxidant enzymes, lipid peroxidation (LPO), and protein carbonyl content (PCC) in brain mitochondria following thiamine deficiency (TD). The study was carried out on Mus musculus allocated into three groups, namely control and thiamine-deficient group for 8 (TD 8) and 10 (TD 10) days. The LPO was measured in terms of reduced glutathione (GSH) and thiobarbituric acid reactive substance (TBARS). Antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were measured biochemically. A significant increase in the TBARS (p?<?0.0001) and PCC (p?<?0.001) levels in group II (TD 8) and group III (TD 10) animals was observed in comparison to controls. The GSH levels were found to be reduced in both the treated groups compared to the control. A significant reduction in the activities of SOD was also observed in group II (p?<?0.01) and group III (p?<?0.0001) animals in comparison to the control. Enzymatic activities of CAT (p?<?0.001) and GPx (p?<?0.05) were found to be significantly reduced in group III (TD 10) in comparison to the control. In conclusion, reduction in the activities of antioxidant enzymes as well as an increase in LPO and PCC following TD implies oxidative stress in brain mitochondria that may further leads to neurodegeneration.     

Changes in Brain Metallome/Metabolome Pattern due to a Single i.v. Injection of Manganese in Rats

Exposure to high concentrations of Manganese (Mn) is known to potentially induce an accumulation in the brain, leading to a Parkinson related disease, called manganism. Versatile mechanisms of Mn-induced brain injury are discussed, with inactivation of mitochondrial defense against oxidative stress being a major one. So far, studies indicate that the main Mn-species entering the brain are low molecular mass (LMM) compounds such as Mn-citrate. Applying a single low dose MnCl₂ injection in rats, we observed alterations in Mn-species pattern within the brain by analysis of aqueous brain extracts by size-exclusion chromatography—inductively coupled plasma mass spectrometry (SEC-ICP-MS). Additionally, electrospray ionization—ion cyclotron resonance-Fourier transform-mass spectrometry (ESI-ICR/FT-MS) measurement of methanolic brain extracts revealed a comprehensive analysis of changes in brain metabolisms after the single MnCl₂ injection. Major alterations were observed for amino acid, fatty acid, glutathione, glucose and purine/pyrimidine metabolism. The power of this metabolomic approach is the broad and detailed overview of affected brain metabolisms. We also correlated results from the metallomic investigations (Mn concentrations and Mn-species in brain) with the findings from metabolomics. This strategy might help to unravel the role of different Mn-species during Mn-induced alterations in brain metabolism.     

A Comparative Study of the Oxidative Profile in Graves’ Disease, Hashimoto’s Thyroiditis, and Papillary Thyroid Cancer

The aim of this study was to evaluate and compare the oxidative profiles of three thyroid disorders: Graves’ disease (GD), Hashimoto thyroiditis (HT), and papillary thyroid cancer (PTC). Malondialdehyde levels (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities were examined in the plasma of 52 patients (29 untreated HT, 16 untreated GD, and 7 PTC who underwent surgical therapy). Results were compared with those of 30 healthy controls and among the three groups of patients. The GD, HT, and PTC patients exhibited increased plasma MDA levels and SOD activities compared with the controls (p?<?0.05, p?<?0.05, and p?<?0.001, respectively). CAT activities significantly increased only for the PTC and HT patients (p?<?0.001 and p?<?0.05, respectively), whereas GPx activities significantly decreased only in the GD and PTC (p?<?0.05 and p?<?0.01, respectively). The comparison among the three groups of patients has shown increased MDA level and SOD activity for the PTC patients as compared to the GD patients (p?<?0.01 and p?<?0.001, respectively). Compared with HT, PTC patients exhibited significant higher MDA level, SOD, and CAT activities and a significant lower GPx activity (p?<?0.01, p?<?0.001, p?<?0.05, and p?<?0.05, respectively). No significant discrepancies were noted between the GD and HT patients. Our results have clearly shown an oxidative profile that is highly disturbed for the PTC patients as compared to those of autoimmune disorders. Future studies are needed to determine whether or not the oxidative stress has a prognostic value in this pathology.     

Textural and Rheological Properties of Soy Protein Isolate Tofu-Type Emulsion Gels: Influence of Soybean Variety and Coagulant Type

The contribution of soybean variety and coagulant type to the textural and rheological properties of soy protein isolate (SPI) tofu-type emulsion gels was studied. SPIs from eight soybean varieties were subjected to amino acid and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis, and results showed that the 11S fraction proteins (r?=?0.833, p?<?0.05) and the ratio of 11S to 7S (r =?0.920, p <?0.01) were positively correlated with the hardness of CaSO₄-induced emulsion gels and glucono-δ-lactone (GDL)-induced gels, with the correlation coefficients of 0.827 (p <?0.05) and 0.893 (p <?0.01), respectively. In the case of microbial transglutaminase (MTGase), strong relations between the content of glutamate (r =?0.886, p?<?0.01) and lysine (r =?0.810, p <?0.05) and gel hardness were found. Rheological data demonstrated that CaSO₄-induced emulsion gel was stiffer with high rigidity but gel induced by MTGase performed better elasticity. The findings of this study are of great importance to further understand the gelation mechanisms of different coagulants and provide useful information for the development of SPI-based filled tofu.     

Manganese elevates manganese superoxide dismutase protein level through protein kinase C and protein tyrosine kinase

Three experiments were conducted to investigate the effects of inorganic and organic Mn sources on MnSOD mRNA, protein and enzymatic activity and the possible signal pathways. The primary broiler myocardial cells were treated with MnCl₂ (I) or one of organic chelates of Mn and amino acids with weak, moderate (M) or strong (S) chelation strength for 12 and 48 h. Cells were preincubated with superoxide radical anions scavenger N-acetylcysteine (NAC) or specific inhibitors for MAPKs and protein tyrosine kinase (PTK) or protein kinase C (PKC) for 30 min before treatments of I and M. The MnSOD mRNA, protein and enzymatic activity, phosphorylated MAPKs or protein kinases activations were examined. The results showed that additions of Mn increased (P < 0.05) MnSOD mRNA levels and M was more effective than I. Additions of Mn elevated (P < 0.05) MnSOD protein levels and enzymatic activities, and no differences were found among I and M. Addition of NAC did not decrease (P > 0.05) Mn-induced MnSOD mRNA and protein levels. None of the three MAPKs was phosphorylated (P > 0.05) by Mn. Additions of Mn decreased (P < 0.05) the PTK activities and increased (P < 0.05) the membrane PKC contents. Inhibitors for PTK or PKC decreased (P < 0.05) Mn-induced MnSOD protein levels. The results suggested that Mn-induced MnSOD mRNA and protein expressions be not related with NAC, and MAPK pathways might not involve in Mn-induced MnSOD mRNA expression. PKC and PTK mediated the Mn-induced MnSOD protein expression.     

Weight loss and regain in obese individuals: a link with adipose tissue metabolism indices?

This study was performed to examine whether changes in subcutaneous adipose tissue (SCAT) metabolism indices after weight loss were related to the magnitude of weight regain. Nine men and ten premenopausal women whose body mass index ranged from 30 to 42 kg/m², 35–48 years old, were studied before and after a 15-week weight loss program, as well as at a 17–22-month follow-up period. Although body composition was evaluated at all study periods, abdominal and femoral SCAT-lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) activities, and α2- and β-adrenoceptors (ARs) were measured before and after weight loss, exclusively. Although the SCAT-LPL activity did not change after weight loss in men, it tended to decrease in the femoral depot of women (p?=?0.06). SCAT-HSL activity remained unchanged after weight reduction in men, while the post-weight loss lipase activity tended to be higher in both regions of women (p?=?0.06). Although the post-weight loss number of β-ARs was higher irrespective of the fat depot (0.001?<?p?<?0.05), the number of α2-ARs was increased in the femoral (p?<?0.05), but not in the abdominal SCAT (p?=?0.08) after weight reduction, in men. Neither the α2- nor the β-AR density changed after weight reduction, in women. Abdominal SCAT-LPL activity after weight reduction was negatively related to weight regain indices, in women (?0.65?<?Rhô?<??0.75; 0.01?<?p?<?0.05). Both the post-weight loss abdominal SCAT α2-AR density and the α2-/β-AR balance were positively associated with weight regain indices, in men (0.69?<?Rhô?<?0.88; 0.01?<?p?<?0.05). These results suggest that selected SCAT metabolism indices could predict failure to weight loss maintenance, in both genders.     

Skeletal muscle post-conditioning by diazoxide, anti-oxidative and anti-apoptotic mechanisms

Pretreatment with diazoxide, K_ATP channel opener, increases tissue tolerance against ischemia reperfusion (IR) injury. In clinical settings pretreatment is rarely an option therefore we evaluated the effect of post-ischemic treatment with diazoxide on skeletal muscle IR injury. Rats were treated with either saline, diazoxide (K_ATP opener; 40?mg/kg) or 5-hydroxydecanoate (5-HD; mitochondrial K_ATP inhibitor; 40?mg/kg) after skeletal muscle ischemia (3?h) and reperfusion (6, 24 or 48?h). Tissue contents of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) activities, Bax and Bcl-2 protein expression and muscle histology were determined. Apoptosis was examined (24 and 48?h) after ischemia. IR induced severe histological damage, increased MDA content and Bax expression (24 and 48?h; p?<?0.01) and decreased CAT and SOD activities (6 and 24?h, p?<?0.01 and 48?h, p?<?0.05), with no significant effect on Bcl-2 expression. Diazoxide reversed IR effects on MDA (6 and 24?h; p?<?0.05), SOD (6 and 24?h; p?<?0.01) and CAT (6 and 48?h, p?<?0.05 and 24?h p?<?0.01) and tissue damage. Diazoxide also decreased Bax (24 and 48?h; p?<?0.05) and increased Bcl-2 protein expression (24 and 48?h; p?<?0.01). Post-ischemic treatment with 5-HD had no significant effect on IR injury. Number of apoptotic nuclei in IR and 5-HD treated groups significantly increased (p?<?0.001) while diazoxide decreased apoptosis (p?<?0.01). The results suggested that post-ischemic treatment with diazoxide decrease oxidative stress in acute phase which modulates expression of apoptotic proteins in the late phase of reperfusion injury. Involvement of KATP channels in this effect require further evaluations.     

Plasma metabolic profile in COPD patients: effects of exercise and endurance training

The study examines plasma metabolic profiles of patients with chronic obstructive pulmonary disease (COPD) to prove whether the disease influences metabolism at rest and after endurance training. This is based on the hypothesis that metabolome levels should reflect impaired skeletal muscle bioenergetics in COPD. The study aims to test this hypothesis by evaluating plasma metabolic profiles in COPD patients before and after 8?weeks of endurance exercise training. We studied blood samples from 18 COPD patients and 12 healthy subjects. Pre- and post-training blood plasma samples at rest and after constant-work rate exercise (CWRE) at 70% of pre-training Watts peak were analyzed by ¹H-nuclear magnetic resonance spectroscopy to assess metabolite profiles. The two groups presented training-induced physiological changes in the VO₂ peak and in blood lactate levels (P?<?0.01 each). Before training, the two groups also showed differences in metabolic profiles at rest (P?<?0.05). Levels of valine (r?=?0.51, P?<?0.01), alanine (r?=?0.45, P?<?0.05) and isoleucine (r?=?0.51, P?<?0.01) were positively associated with body composition (Fat Free Mass Index). While training showed a significant impact on the metabolic profile in healthy subjects (P?<?0.001), with changes in levels of amino acids, creatine, succinate, pyruvate, glucose and lactate (P?<?0.05 each), no equivalent training-induced effects were seen in COPD patients in whom only lactate decreased (P?<?0.05). This study shows that plasma metabolic profiling contributes to the phenotypic characterization of COPD patients.     

The Effects of Zinc Treatment on the Blood–Brain Barrier Permeability and Brain Element Levels During Convulsions

We evaluated the effect of zinc treatment on the blood–brain barrier (BBB) permeability and the levels of zinc (Zn), natrium (Na), magnesium (Mg), and copper (Cu) in the brain tissue during epileptic seizures. The Wistar albino rats were divided into four groups, each as follows: (1) control group, (2) pentylenetetrazole (PTZ) group: rats treated with PTZ to induce seizures, (3) Zn group: rats treated with ZnCl₂ added to drinking water for 2 months, and (4) Zn?+?PTZ group. The brains were divided into left, right hemispheres, and cerebellum?+?brain stem regions. Evans blue was used as BBB tracer. Element concentrations were analyzed by inductively coupled plasma optical emission spectroscopy. The BBB permeability has been found to be increased in all experimental groups (p?<?0.05). Zn concentrations in all brain regions in Zn-supplemented groups (p?<?0.05) showed an increase. BBB permeability and Zn level in cerebellum?+?brain stem region were significantly high compared to cerebral hemispheres (p?<?0.05). In all experimental groups, Cu concentration decreased, whereas Na concentrations showed an increase (p?<?0.05). Mg content in all the brain regions decreased in the Zn group and Zn?+?PTZ groups compared to other groups (p?<?0.001). We also found that all elements’ levels showed hemispheric differences in all groups. During convulsions, Zn treatment did not show any protective effect on BBB permeability. Chronic Zn treatment decreased Mg and Cu concentration and increased Na levels in the brain tissue. Our results indicated that Zn treatment showed proconvulsant activity and increased BBB permeability, possibly changing prooxidant/antioxidant balance and neuronal excitability during seizures.     

Lead Accumulation as Possible Risk Factor for Primary Open-Angle Glaucoma

The objective of this study was to investigate the relationship between preeclampsia and iodine levels and magnesium concentration in the blood of subjects in the northeast Anatolia region where iodine deficiency is common. Blood specimens were obtained from 24 preeclamptic and 16 healthy pregnant women. Iodine levels in blood were determined by the Foss method based on the Sandell–Kolthoff reaction. Serum protein-bound iodine (PBI) levels and magnesium concentration in maternal blood were lower in patients with severe preeclampsia compared to normal pregnant women (8.46?±?1.22 vs. 11.46?±?1.71 μg/dL, p?<?0.001, 1.63?±?0.05 vs. 1.86?±?0.05 mg/dL, p?<?0.001, respectively). Serum PBI levels and magnesium concentration in umbilical cord blood were higher in patients with severe preeclampsia than in normal pregnant women (8.84?±?1.9 vs. 7.33?±?1.07 μg/dL, p?<?0.05, 2.48?±?0.03 vs. 2.02?±?0.01 mg/dL, p?<?0.001, respectively). There was a positive correlation between the serum PBI levels in maternal blood and magnesium concentration in maternal blood in patients with severe preeclampsia (r?=?0.41, p?<?0.05). Thus, iodine may be one factor contributing to the pathophysiology of preeclampsia. Iodine supplementation may be effective therapy in preeclamptic in pregnant women.     

Heat acclimation increases mitochondrial respiration capacity of C2C12 myotubes and protects against LPS-mediated energy deficit

This work investigated the effect of a 6-day heat acclimation (HA) protocol on myotube metabolic responses at baseline and in response to a subsequent lipopolysaccharide (LPS) challenge. C2C12 myotubes were incubated for 2 h/day at 40 °C for 6 days (HA) or maintained at 37 °C (C). Following 24-h recovery, myotubes were challenged with 500 ng/ml LPS for 2 h, then collected for analysis of protein markers of mitochondrial biogenesis and macronutrient storage. Functional significance of these changes was confirmed with mitochondrial respiration and glycolytic measurements on a Seahorse XF-96 analyzer. HA stimulated mitochondrial biogenesis and increased indicators of mitochondrial content [SIRT1 (+?62%); PGC-1α (+?57%); NRF-1 (+?40%); TFAM (+?141%); CS (+?25%); CytC (+?38%); all p?<?0.05]. Altered lipid biosynthesis enzymes [p-ACCa:ACC (+?59%; p?=?0.04) and FAS (??86%; p?<?0.01)] suggest fatty acid generation may have been downregulated, whereas increased GLUT4 (+?69%; p?<?0.01) and LDH-B (+?366%; p?<?0.01) suggest aerobic glycolytic capacity may have been improved. Mitochondrial biogenesis signaling in HA myotubes was suppressed by 500 ng/ml LPS (PGC-1α, NRF-1, TFAM; all p?> 0.05) but increased LDH-B (+?30%; p?=?0.02) and CPT-1 (+?55%; p?<?0.01) suggesting improved catabolic function. Basal respiration was increased in HA myotubes (+?8%; p?<?0.01) and HA myotubes maintained elevated basal respiration during LPS challenge (+?8%; p?<?0.01). LPS reduced peak respiration in C myotubes (??6%; p?<?0.01) but did not impair peak respiration in HA myotubes (p?>?0.05). Oxidative reliance was elevated in HA over that in control (+?25%; p?<?0.01) and in HA?+?LPS over C?+?LPS (+?30%; p?<?0.01). In summary, HA stimulated mitochondrial biogenesis in C2C12 myotubes. HA myotubes exhibited (1) elevated basal/peak mitochondrial respiration capacities; (2) greater oxidative reliance; and (3) protection against LPS-mediated respiration impairment. Collectively, these data suggest HA may improve aerobic metabolism in skeletal muscle and protect against LPS-mediated energy deficit.     

Selenium, Zinc, and Copper Plasma Levels in Patients with Schizophrenia: Relationship with Metabolic Risk Factors

The aim of this study was to determine the plasma selenium (Se), copper (Cu), and zinc (Zn) levels and to evaluate their possible association with metabolic syndrome (MetS) components in patients with schizophrenia. The study group consisted of 60 patients with schizophrenia and 60 sex- and age-matched healthy controls. Anthropometric measurements, blood pressure, and biochemical analysis of fasting blood were performed in all subjects. Patients with schizophrenia had significantly higher plasma Cu concentrations compared with controls (0.97?±?0.31 vs. 0.77?±?0.32 mg/L, p?=?0.001). The plasma Cu concentration showed a positive correlation with plasma glucose and diastolic blood pressure in the patient groups (r _s ?=?0.263, p?<?0.05 and r _s ?=?0.272, p?<?0.05, respectively). The plasma Se level correlated positive with MetS score (r _s ?=?0.385, p?<?0.01), waist circumference (r _s ?=?0.344, p?<?0.05), plasma glucose (r _s ?=?0.319, p?<?0.05), and triglyceride concentrations (r _s ?=?0.462, p?<?0.001) in patients with schizophrenia. Plasma Zn did not correlate with any of the MetS components. These results suggest that alterations in plasma Cu and Se levels in medicated patients with schizophrenia could be associated with metabolic risk factors.     

Quantitative Mass Spectrometry Analysis Reveals that Deletion of the TRPV1 Receptor in Mice Alters Substance P and Neurokinin A Expression in the Central Nervous System

Vanilloid receptors have a central role in the processing of nociceptive stimuli. TRPV1 null mice showed significant decrease in response to heat noxious stimuli. However, thermal sensitivity is still present suggesting that the TRPV1 is not an exclusive transducer of thermal stimuli. Additionally, tachykinin peptides play a central role in pain processing and expression levels may also contribute in modifying the pain threshold. The LC?CMS/MS analysis revealed that SP and NKA were significantly down-regulated in TRPV1^?/? in spinal cord and brain tissues. In spinal cord, SP concentrations were 23.4?% lower (p?<?0.0049) and NKA concentrations were 22.0?% lower (p?<?0.0022) in TRPV1 null mice. Additionally, brain SP concentrations were 26.9?% lower (p?<?0.0260) and brain NKA concentrations were 31.9?% lower (p?<?0.0063) in TRPV1 null mice. These results clearly demonstrate that TPRV1 null mice exhibit lower SP and NKA concentrations in the central nervous system. The deficit of thermal responses may also be related to the down-regulations of SP and NKA.     

Interleukin-6 and Lipopolysaccharide Modulate Hepcidin mRNA Expression by Hepg2 Cells

Iron homeostasis is controlled by hepcidin (Hpc) as well as other ways. Hpc expression is regulated by iron (Fe) storage and by inflammation, but the joint effect of both stimuli remains unclear. We studied the modulatory role of inflammatory agents (IL6 and LPS) over Hpc and DMT1 mRNA expression in HepG2 cells preloaded with Fe. HepG2 cells were preloaded with different Fe concentrations (holo-Tf or Fe-NTA) and then incubated with IL6 or LPS. We measured intracellular Fe levels by AAS with graphite furnace, transferrin receptor (TfR) by ELISA and mRNA relative abundance of Hpc and DMT1 by qRT-PCR. The maximum effect on Fe uptake was observed in cells incubated with 30?ng/ml IL6 (p?<?0.01) and 500?ng/ml LPS (p?<?0.05). In HepG2 cells preloaded with holo-Tf or Fe-NTA and challenged with IL6 and LPS, we observed a decreased: (a) Hpc mRNA relative abundance (two-way ANOVA: p?<?0.05 and p?<?0.001, respectively), (b) DMT1 mRNA relative abundance and TfR1 protein levels (two-way ANOVA: p?<?0.001), and (c) intracellular Fe concentration (two-way ANOVA: p?<?0.001 and p?<?0.01, respectively) compared to control cells incubated only with Fe (holo-Tf or Fe-NTA). Our results support the idea that Fe storage and inflammation act together to regulate Fe homeostasis and suggest a negative regulation in this hepatic cellular model to prevent excessive increases in Hpc.