Acetylation targets HSD17B4 for degradation via the CMA pathway in response to estrone

Dysregulation of hormone metabolism is implicated in human breast cancer. 17β-hydroxysteroid dehydrogenase type 4 (HSD17B4) catalyzes the conversion of estradiol (E2) to estrone (E1), and is associated with the pathogenesis and development of various cancers. Here we show that E1 upregulates HSD17B4 acetylation at lysine 669 (K669) and thereby promotes HSD17B4 degradation via chaperone-mediated autophagy (CMA), while a single mutation at K669 reverses the degradation and confers migratory and invasive properties to MCF7 cells upon E1 treatment. CREBBP and SIRT3 dynamically control K669 acetylation level of HSD17B4 in response to E1. More importantly, K669 acetylation is inversely correlated with HSD17B4 in human breast cancer tissues. Our study reveals a crosstalk between acetylation and CMA degradation in HSD17B4 regulation, and a critical role of the regulation in the malignant progression of breast cancer.

Cullin 3 targets methionine adenosyltransferase IIα for ubiquitylation-mediated degradation and regulates colorectal cancer cell proliferation

Cullin 3 (CUL3) serves as a scaffold protein and assembles a large number of ubiquitin ligase complexes. It is involved in multiple cellular processes and plays a potential role in tumor development and progression. In this study, we demonstrate that CUL3 targets methionine adenosyltransferase IIα (MAT IIα) and promotes its proteasomal degradation through the ubiquitylation-mediated pathway. MAT IIα is a key enzyme in methionine metabolism and is associated with uncontrolled cell proliferation in cancer. We presently found that CUL3 down-regulation could rescue folate deprivation-induced MAT IIα exhaustion and growth arrest in colorectal cancer (CRC) cells. Further results from human CRC samples display an inverse correlation between CUL3 and MAT IIα protein levels. Our observations reveal a novel role of CUL3 in regulating cell proliferation by controlling the stability of MAT IIα.

Interleukin-4 regulates macrophage polarization via the MAPK signaling pathway to protect against atherosclerosis

Our study aimed to investigate the effects of interleukin-4 (IL-4) on macrophage polarization, as well as its role in the development of atherosclerosis. Human peripheral blood mononuclear cells (PBMCs) were isolated and randomly divided into 3 groups: control group, ox-LDL group, and ox-LDL + IL-4 groups. The expression of M1/M2 macrophage surface markers such as TNF-α, CD68, and CD206 were analyzed by western blot. Cell viability was determined using the MTT assay. Measurement of CD86/CD206 expression ratio (M1/M2 ratio) was performed via flow cytometry. In addition, ApoE(-/-) mice on a C57BL/6 background were subjected to high-fat diets, and were used as a model of atherosclerosis. Atherosclerotic lesion area was quantified after mice were treated with ox-LDL and IL-4. Finally, expression of phosphorylated MAPK signaling molecules such as p-ERK and p-JNK was quantified using western blot. The expression of TNF-α and CD86 markedly increased after cells were treated with ox-LDL, whereas the expression of CD206 markedly increased after PBMCs were treated with IL-4. It is possible that IL-4 could decrease ox-LDL-induced cell viability and the CD86/CD206 (M1/M2) ratio. Additionally, IL-4 intervention attenuated ox-LDL-induced atherosclerotic lesions in ApoE(-/-) mice, and decreased ox- LDL-induced expression of p-ERK and p-JNK. Our findings indicate that IL-4 may induce macrophages to take on an M2 phenotype in order to resolve inflammation via inhibition of MAPK signaling pathways, thereby protecting against atherosclerosis. IL-4 may serve as an intervention target for atherosclerosis.

Effect of an antidiabetic polysaccharide from Inula japonica on constipation in normal and two models of experimental constipated mice

OBJECTIVES

The aim of the present study was to investigate the effect of an antidiabetic polysaccharide (IJP) from Inula japonica on gastrointestinal transit in normal mice and on constipation in two models of constipated mice.

METHODS

Two models of constipation in mice were respectively induced by fasted water for 4 days or induced by diphenoxylate. The normal and constipated mice were administered IJP once at doses of 100 and 400 mg/kg (p.o.), the gastrointestinal vermicular motion, start time of defecation, number and weight of stool were investigated.

RESULTS

After administration of IJP, the gastrointestinal propulsive rate was increased by 9.79% and 10.42%, the start time of defecation was shortened by 37.27% and 44.06%, the number of feces increased by 115.4% and 130.8% in normal mice. In fasting-water constipated mice, the start time of defecation was shortened by 9.69% and 30.52% by IJP, defecation granules raised by 22.09% and 39.53%, wet feces weights were increased by 23.50% and 39.14% compared with the untreated constipated mice. In diphenoxylate-induced mice, the start time of defecation was shortened by 25.48% and 28.13%, defecation granules raised by 100.0% and 118.0%.

CONCLUSIONS

Consumption of IJP effectively improved bowel movement, stool output observed in this study. IJP may be practical in relieving constipation in the elderly diabetic population.

Mitochondrial modulation is involved in the hepatoprotection of Limonium sinense extract against liver damage in mice

AIM OF THE STUDY

Limonium sinense (Girard) Ktze is a Chinese folk medicine used to treat fever, hemorrhage, hepatitis, and other disorders. The present research focused on the protective effects of L. sinense extracts (LSE) against liver damage.

MATERIALS AND METHODS

In this study the extract from the root of Limonium sinense was used. Aminotransferase activity detection, electron microscopy, mitochondrial function evaluation, RT-PCR and western blot were used to evaluate the hepatoprotection of LSE in LPS/d-GalN-intoxicated mice.

RESULTS

Pretreatment with 100, 200 or 400mg/kg LSE significantly blocked the increase in both serum aspartate aminotransferase (sAST) and serum alanine aminotransferase (sALT) levels induced by treatment with LPS plus d-GalN (LPS/d-GalN). Ultrastructural observation by electron microscopy showed reduced hepatocyte nuclear condensation and less lipid deposition. The decrease in both the mitochondrial membrane potential (14.6%) and sensitivity to mitochondrial swelling induced by Ca(2+) (45.9%) observed in the liver of LPS/d-GalN-treated mice were prevented by pretreatment with LSE. In addition, different doses of LSE increased both the transcription and the translation of voltage-dependent anion channels (VDAC), which was down-regulated by LPS/d-GalN treatment.

CONCLUSIONS

In summary, LSE protects livers against LPS/d-GalN-induced damage, possibly by mitochondrial mechanisms related to increased expression of VDAC.

Preparation and Characterization of Straight and Zigzag AlN Nanowires

Hexagonal single-crystal AlN nanowires with straight or zigzag morphologies were successfully synthesized by the reaction of aluminum alloy in an ammonia/nitrogen atmosphere at 1100 degrees C. It is found that the crystal tropism of the nanowires is along [0001], whereas the growth directions of the zigzag nanowires shift between [2111] and [2111].

Phytochemical and antiinflammatory studies on Terminalia catappa

The antiinflammatory activity of Terminalia catappa leaves ethanolic extract was studied using 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema in acute and chronic models. A bioassay-oriented fractionation procedure showed that the activity concentrates in the chloroform fraction. Ursolic acid (1) and 2alpha,3beta,23-trihydroxyurs-12-en-28-oic acid (2), isolated from the chloroform fraction, exhibited strong antiinflammatory activities. The results suggest that the triterpenic acids 1 and 2 are responsible for the antiinflammatory activity of T. catappa leaves.

The role of NO and B-50 in neurotoxicity of excitatory amino acids

To investigate the direct evidence for the role which nitric oxide (NO) plays in the neurotoxicity of excitatory amino acids, we evaluated NO level by Greiss testing solution when glutamate (Glu) and kainate (KA) induced neuronal degeneration in primary cortical cultures. Glutamate-induced neurotoxicity was accompanied by a rise in NO. 5 mM hemoglobin (Hb) led to a decrease of NO content and prevented excitotoxicity induced by 1 mM glutamate. 1 mM L-arginine (L-Arg) reversed the effect of hemoglobin by raising the NO level. No change in NO content was found in KA-induced neurotoxicity, which was not affected by L-Arg, Hb or L-Arg + Hb. It is suggested that NO plays an important role in glutamate-, but not KA-induced neurotoxicity in primary cortical cultures. We also investigated the effects of glutamate on a growth-associated protein, B-50. The B-50 level declined significantly 24 h after exposure to 100 microM glutamate for 30 min and then recovered 2 days later. The effect of glutamate on B-50 was concentration-dependent. This indicates that B-50 might be involved in both glutamate neurotoxicity and the following neuronal repair process.

Quercetin decreased heart rate and cardiomyocyte Ca2+ oscillation frequency in rats and prevented cardiac hypertrophy in mice

AIM

To study the effects of quercetin (Que) on myocardial excitation-contraction coupling and cardiac remodeling.

METHODS

Left ventricles and femoral arteries of rats were cannulated for hemodynamic recording. Mouse cardiac hypertrophy was induced by abdominal aortic coarctation (AAC). Cultured myocardial cells in neonatal rats were loaded with Fura 2-AM. The intracellular calcium ([Ca2+]i) and spontaneous [Ca2+]i oscillations ([Ca2+]i-SO) were tested by AR-CM-MIC cation measurement system.

RESULTS

Que 3 or 25 mg.kg-1 i.v. in rats decreased heart rate from (420 +/- 19) to (390 +/- 15) and (314 +/- 18) beat.min-1, respectively, companied with very modest changes in both left ventricular pressures (LVP) and its differential dpLV/dtmax. Que 10, 50, 250 mumol.L-1 concentration-dependently slowed the frequency of [Ca2+]i-SO in cultured myocardial cells from (26 +/- 4) to (25 +/- 3), (18 +/- 4), and (12 +/- 3) time.min-1, respectively, but did not change their resting [Ca2+]i or amplitudes of [Ca2+]i-SO. Similarly, the increases in frequency of [Ca2+]i-SO caused by either isoproterenol (Iso) or ouabain (Oua) were prevented by Que 100 mumol.L-1, while the simultaneous increases in amplitude of [Ca2+]i-SO remained. Besides, [Ca2+]i rises excited by angiotensin II (Ang II) but not high [K+]o were prevented by Que 100 mumol.L-1. Daily administration of Que 120 mg.kg-1 i.g. for 5 d markedly prevented the cardiac hypertrophy in AAC mice, without effects on the ventricular mass to body weight ratio (VM/BW) in sham-operated mice.

CONCLUSION

Que decreased myocardial [Ca2+]i-oscillation frequency and prevented cardiac remodeling, but had no direct effect on cardiac excitation-contraction coupling.

Effects of dexamethasone on intracellular Ca2+ in its sensitive cells from neonatal mouse hippocampus and cultured cortical neurogliocytes

AIM

To investigate the effects of dexamethasone (Dex) on intracellular free calcium ([Ca2+]i) in the single neuron or neurogliocyte.

METHODS

Neonatal mouse hippocampal cells (NMHC) and cultured cortical neurogliocytes (CCN) were loaded with Fura 2-AM. The [Ca2+]i was measured with AR-CM-MIC-cation measurement system.

RESULTS

Most of freshly isolated NMHC exhibited a rapid and concentration-dependent [Ca2+]i increase after administration of Dex 40-200 mumol.L-1. Only 10% of NMHC showed their [Ca2+]i decreases in total 96 tested cells. Dex-triggered [Ca2+]i rise was prevented by incubating the cells with Mg(2+)-free solution and reduced by adding LaCl3. Suspended NMHC in Ca(2+)-free solution or pretreated cells with mifepristone or tetrodotoxin prevented the initial [Ca2+]i increases caused by Dex 40-90 mumol.L-1, but only diminished the later [Ca2+]i rises by Dex 200 mumol.L-1. About 50% of tested single CCN showed a rapid and concentration-related [Ca2+]i increase due to Dex 90-270 mumol.L-1 exposure. This effect was partially inhibited under extracellular Ca(2+)- or Mg(2+)-free and mifepristone pretreatment conditions.

CONCLUSION

Dex produces the rapid [Ca2+]i changes in both neurons and glia cells. Reactions among most cells include a Mg(2+)-dependent and glucocorticoid receptor-related extracellular Ca2+ influx and a high concentration of Dex-mediated intracellular Ca2+ release.

Neuron degeneration induced by verapamil and attenuated by EGb761

Calcium channel blockers are used as neuroprotective agents, as glutamate antagonists. However, it has been found that calcium channel blockers may compromise neuronal survival after long-term exposure. To explore the mechanisms of the toxicity of calcium channel blockers on neurons, we studied the morphological characteristics and biochemical changes of cultured cortical neurons treated with verapamil, a calcium channel blocker. We now report that cerebral cortical cultures exposed to verapamil for 48 h undergo neuronal degeneration in both concentration-dependent and time-dependent fashion, possibly partially through the activation of apoptosis. On the other hand, it was found that Ginkgo biloba extract (EGb761) attenuated verapamil-induced neuronal injury, suggesting the possibility of using verapamil combined with EGb761 clinically. Furthermore, both B-50 immunoactivity (BIA) and the concentration of intracellular calcium in single neurons ([Ca2+]i) decreased after a 48-h exposure to verapamil, suggesting that the mechanisms of verapamil-induced degeneration may be associated with the disruption of intracellular calcium homeostasis and the inhibition of normal axonal elongation.

Enhancing effects of beta-endorphin on glutamate neurotoxicity

AIM

To study the effect of beta-endorphin (beta-End) on monosodium glutamate (MSG)-induced neurotoxicity (GNT).

METHODS

Image analysis of neuronal areas and determination of mitochondrial membrane protein-bound Ca2+ and intracellular free Ca2+ ([Ca2+]i) were used.

RESULTS

beta-End aggravated MSG-induced neuronal injury in arcuate nucleus of hypothalamus in a dose-dependent manner in the range from 0.5 to 5.0 mg.kg-1. MSG-induced increase in mitochondrial membrane protein-bound Ca2+ was enhanced when treated with beta-End 2 g.L-1. MSG-induced elevation in [Ca2+]i in single neuron was also augmented from 320 +/- 84 to 589 +/- 78 nmol.L-1 by the treatment with beta-End 2 g.L-1.

CONCLUSION

beta-End enhanced GNT via aggravating the disruption of intracellular Ca2+ homeostasis induced by MSG.

Antagonistic effects of extract from leaves of ginkgo biloba on glutamate neurotoxicity

AIM

To determine whether the extract of leaves of Ginkgo biloba L (EGb) and several active constituents of EGb have protective effects against glutamate (Glu)-induced neuronal damage.

METHODS

Microscopy and image analysis of nucleus areas in the arcuate nuclei (AN) of mice were made. The neuronal viability in primary cultures from mouse cerebral cortex was assessed using MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] staining and the intracellular free calcium concentration ([Ca2+]i) of single neuron was measured using Fura-2.

RESULTS

EGb (2.5 mg.L-1) and its constituent ginkgolide B (Gin B, 2 mg.L-1) protected the neuronal viability against Glu-induced injury, and prevented the Glu-induced elevation in [Ca2+]i. EGb (3-10 mg.kg-1) attenuated the decrease of nucleus areas in arcuate nuclei induced by Glu (1 g.kg-1, s.c.).

CONCLUSION

EGb and Gin B prevent neurons from Glu neurotoxicity through reduction of the rise in [Ca2+]i.

[Effects of morphine on monosodium glutamate neurotoxicity and its mechanism]

The enhancing effects of morphine on monosodium glutamate (MSG) neurotoxicity and its blocking by naloxone were studied through morphological observation, together with detection of concentrations of intracellular free Ca2+ ([Ca2+]i) by Ca2+ indicator Fura-2/AM and lactate dehydrogenase (LDH) efflux in the bathing medium in primary cultures from 14-17 d old mouse fetal cortex. It was found that 10 min pre-incubation of young cortical neurons (7 day in vitro) with morphine 10(-7) or 10(-6) mol.L-1 substantially increased LDH release from 105.7% +/- 19.0% (treated with MSG alone) to 194.5% +/- 17.7% and 214.0% +/- 9.5% respectively after exposure to MSG 0.1 mmol.L-1, but pre-incubation with morphine (10(-7) or 10(-6) mol.L-1) plus naloxone (0.1 mmol.L-1) reversed the LDH release after treatment with the same concentration of MSG. Morphine (10(-7) or 10(-6) mol.L-1) produced little elevation of [Ca2+]i. However, when combined with MSG (0.1 mmol.L-1) morphine elevated the [Ca2+]i level much more than MSG alone. These results suggest that morphine markedly enhances excitotoxic neuron damage, which can be reversed by naloxone. Overloading of intracellular Ca2+ may be a simultaneous pathological mechanism underlying the neuronal damage and death that occur in excitatory toxicity.

[Enhancing effects of Herpesvirus hominis on sodium glutamate neurotoxicity]

The neurotoxic effects of sodium glutamate (MSG, 2.5 g.kg-1 sc) and the enhancing effects of neurotropic Herpesvirus hominis (HVH, 0.2 ml/mouse ip) on MSG toxicity were studied through histomorphological observations, together with detection of the concentration of both mitochondrial protein bound Ca2+ and intracellular free Ca2+ ([Ca2+]i) by the Tb3+ fluorescent probe and Ca2+ indicator Fura-2/AM, respectively. It was found that in 10-d-old mice the neurons in arcuate hypothalamic nucleus degenerated severely after treatment with HVH+MSG, showing swollen edematous cytoplasm, dark pyknotic nuclei as well as a decrease in the amount of the neurons. The hypothalamic and spinal cord mitochondrial Tb3+ relative fluorescent intensity increased from 20 +/- 3 and 20 +/- 1 to 28 +/- 5 and 34 +/- 6, ie, the mitochondrial protein bound Ca2+ reduced significantly. MSG elevated the [Ca2+]i levels from 0.11 +/- 0.03 to 0.69 +/- 0.19 mumol.L-1 by not only stimulating the Ca2+ influx but also releasing the Ca2+ from intracellular stores. These findings suggested that MSG neurotoxicity was probably related to the overloading of neuroplasmic Ca2+, the destruction of neuronal abilities to deplete or sequester the intracellular Ca2+, as well as the irreversible neuronal injury and death.

[Transplacental neurotoxic effects of monosodium glutamate on structures and functions of specific brain areas of filial mice]

Monosodium glutamate (MSG) was shown to penetrate placental barrier and distribute almost evenly among embryonic tissues using 3H-Glu as a tracer. When a lower (1.0 mg/g) and a higher (2.5 mg/g) doses of MSG were alternatively injected to Kunming maternal mice in every other days from mating to deliveries, obvious injury occurred in the ability of memory retention and Y-maze discrimination learning of adult filial mice pregnantly treated with higher doses (2.5 mg/g) of MSG. Meanwhile, the neuronal damages were observed in not only arcuate nucleus but also ventromedial nucleus of hypothalamus. Characteristic cytopathological changes induced by MSG showed swollen cytoplasm, dark pyknotic nuclei and loss of neurons. The radioligand-bindings in both hippocampus and hypothalamus altered significantly after the pregnant treatment of MSG. Possible mechanisms underlying MSG excitotoxic phenomena studied in single neuron by use of Ca2+ sensitive indicator Fura-2 with Spex AR-CM-MIC Cation Measurement System, might be due to increases of intracellular free Ca2+ concentration induced by MSG exposure, which was related to both the influx of Ca2+ and the depletion of Ca2+ from the intracellular Ca2+ stores. These experimental findings indicated that MSG performed its transplacental neurotoxicity in a dose-dependent manner. The excessive activation of Glu receptors and the overloading of intracellular Ca2+ induced by MSG ultimately leading to neuronal death may result in the reduction of the capability of learning and memory in adult filial mice pregnantly treated with MSG.

Abnormal hemoglobins in the Silk Road region of China

A review is presented of the occurrence of 24 abnormal hemoglobins (13 alpha-chain variants and 11 beta-chain variants) in populations in the Silk Road area of Northwestern China. Most frequently occurring were Hb D-Punjab [beta 121(GH4)Glu----Gln] in Uygurs, Kazaks, and Khalkhas, Hb G-Taipei [beta 22(B4)Glu----Gly] in persons of the Han nationality, and Hb G-Coushatta [beta 22 (B4)Glu----Ala] in the Uygurs, Kazaks, Hans, and related nationalities. The data suggest that these variants likely originated in Central Asia, in the Han nationality of China, and in the minorities of northern China, respectively. Other variants occurred at considerably lower frequencies and were imported from other countries or arose as independent mutations. Two variants [Hb Tashikuergan or alpha 19(AB1)Ala----Glu; Hb Tianshui or beta 39(C5) Gln----Arg] were observed for the first time. The data from this study of the many variants support the movements of various populations in this area, as reported in numerous historical documents.

[45Ca-uptake, mitochondrial protein bound Ca2+ and ultrastructural distribution of Ca2+ in some brain regions of mice during drug-induced analgesia]

After buprenorphine (Bup, 0.8 mg/kg ip) treatment 45Ca-uptake (cpm/mg fresh brain) in vivo by brain slices decreased from 589 +/- 12 and 486 +/- 12 to 522 +/- 14 and 408 +/- 10 and mitochondrial protein bound Tb3+ (Tb3+ relative fluorescent intensity) reduced from 41 +/- 5 and 32 +/- 2 to 30 +/- 3 and 22 +/- 2 in periaqueductal grey and hypothalamus, respectively. A large amount dense precipitate occurred in the myelin sheath and mitochondria in both regions. The 45Ca-uptake evoked by buprenorphine at 16 micrograms/40 microliter in vitro has the similar tendency with that in vivo. Treated by ruthenium red (20 micrograms/mouse ip or icv) before buprenorphine, the above-mentioned effects were all abolished. Similar results were obtained with morphine (Mor, 10 mg/kg ip) and verapamil (Ver, 8 micrograms/mouse icv) instead of buprenorphine and ruthenium red, respectively. These results suggest that Ca2+ transport across neuroplasmic membranes plays a mediator role in drug-induced analgesia.

Thalassemia in the Silk Road region of China

This paper summarizes data obtained during a screening program involving 11,563 persons from the Silk Road region in China. The mean incidence of thalassemia is 1.62% with an increase from east to west. The incidence in the Hui population (3.01%) is higher than in Kazaks (2.92%), and in Uygur (2.22%). The Han population also has a higher incidence (0.98%) than seen for other regions in Northern China. The thalassemias observed are classified into seven groups; beta-thalassemia accounts for 89.48% of the total, and alpha-thalassemia for 10.52%.