A scaffold fabricated with lysine/nerve growth factor (NGF)/poly (lactic acid coglycolic acid) copolymer (PLGA) and acellular pigskin was evaluated in vitro as a potential artificial nerve scaffold. Properties of the scaffold such as microstructure, mechanical property, degradation behavior in PBS and water, Schwann cell adhesion property, and release of NGF were investigated. Results showed PLGA had permeated into the porous structure of acellular pigskin; its breaking strength was 8.308 MPa, breaking extensibility was 38.98%, elastic modulus was 97.27 MPa. The porosities of the scaffold ranged from 68.3% to 81.2% with densities from 0.62 g/cm3 to 0.68 g/cm3. At 4 weeks of degradation in vitro, maximum mass loss ratio was 43.3%. The release of NGF could still be detected on the 30th day, and its accumulative release rate was 38%. Lysine added into the scaffold neutralized the acidoid preventing degradation of PLGA to maintain a solution pH value. Schwann cells had grown across the scaffold after co-cultivation for 15 days. These in vitro properties of the pigskin based composite might indicate its potentiality to be an artificial nerve scaffold.
Acellular Dermis ; Animals ; Biocompatible Materials ; Guided Tissue Regeneration ; Lactic Acid ; pharmacology ; Lysine ; pharmacology ; Nerve Growth Factors ; chemistry ; pharmacology ; Nerve Regeneration ; Polyglycolic Acid ; pharmacology ; Swine ; Tissue Engineering ; Tissue Scaffolds

OBJECTIVES: Primary tumor treatment through surgical resection and adjuvant therapy has been extensively studied, but there is a lack of effective strategies and drugs for the treatment of tumor metastases. Here, we describe a functional product based on a combination of compounds, which can be used as an adjuvant therapy and has well-known mechanisms for inhibiting cancer metastases, improving anti-cancer treatment, and enhancing immunity and antioxidant capacity. Our designed combination, named MVBL, consists of four inexpensive compounds: L-selenium-methylselenocysteine (MSC), D-‍α‍-tocopheryl succinic acid (VES), β‍-carotene (β‍-Ca), and L-lysine (Lys). METHODS: The effects of MVBL on cell viability, cell cycle, cell apoptosis, cell migration, cell invasion, reactive oxygen species (ROS), and paclitaxel (PTX)-combined treatment were studied in vitro. The inhibition of tumor metastasis, antioxidation, and immune enhancement capacity of MVBL were determined in vivo. RESULTS: MVBL exhibited higher toxicity to tumor cells than to normal cells. It did not significantly affect the cell cycle of cancer cells, but increased their apoptosis. Wound healing, adhesion, and transwell assays showed that MVBL significantly inhibited tumor cell migration, adhesion, and invasion. MVBL sensitized MDA-MB-231 breast cancer cells to PTX, indicating that it can be used as an adjuvant to enhance the therapeutic effect of chemotherapy drugs. In mice, experimental data showed that MVBL inhibited tumor metastasis, prolonged their survival time, and enhanced their antioxidant capacity and immune function. CONCLUSIONS This study revealed the roles of MVBL in improving immunity and antioxidation, preventing tumor growth, and inhibiting metastasis in vitro and in vivo. MVBL may be used as an adjuvant drug in cancer therapy for improving the survival and quality of life of cancer patients.
Mice ; Animals ; beta Carotene ; Lysine/pharmacology* ; Antioxidants/pharmacology* ; Quality of Life ; Paclitaxel/pharmacology* ; Apoptosis ; alpha-Tocopherol ; Succinates/pharmacology* ; Cell Line, Tumor ; Cell Proliferation ; Neoplasms

BACKGROUNDHyperglycemia in brain and spinal cord could aggravate neurologic impairment. Recent studies showed that L-lysine monohydrochloride (LMH) could increase the insulin secretion and regulate the blood glucose level. The aim of the present study was to investigate the effects of LMH on pancreatic islet B cells, the levels of endogenous insulin and blood glucose in spinal cord injured rats.

METHODSForty male Wistar rats were divided into four groups, namely, normal control group, model group, high-dose LMH group (621.5 mg/kg equal to LMH 1/8 LD50), and low-dose LMH group (310.8 mg/kg equal to LMH 1/16 LD50). The model of spinal cord injured rat was established by hemi-transection at the lower right thoracic spinal cord. LMH was administered via intraperitoneal injection once spinal cord injury was produced in rats. All rats were sacrificed 48 hours after spinal cord injured. The effects of LMH on pancreatic islet B cells, the content of endogenous insulin, and the level of blood glucose were observed with immunohistochemical method, radioimmunoassay method, and biochemical analyzer, respectively.

RESULTSThe insulin immunohistochemical intensities of islet B cells were significantly weaker in model group than those in normal control group (P < 0.01). The levels of endogenous insulin were significantly lower and the blood glucose levels were significantly higher in model group than those in normal control group (P < 0.01). The insulin immunohistochemical intensities of islet B cells were significantly stronger in high-dose LMH group than those in model group (P < 0.05). In addition, we found that the levels of endogenous insulin were significantly higher and the blood glucose levels were significantly lower in high-dose LMH group than those in model group (P < 0.05). There were no significant differences in the insulin immunohistochemical intensities of islet B cells, the levels of endogenous insulin and the blood glucose between low-dose LMH group and model group (P > 0.05).

CONCLUSIONLMH, but dose-dependent, might participate in the regulation of pancreatic islet B cells, and then reduce the blood glucose levels in the spinal cord injured rats.

Animals ; Blood Glucose ; analysis ; Hyperglycemia ; etiology ; Insulin ; blood ; Lysine ; pharmacology ; Male ; Neuroprotective Agents ; pharmacology ; Rats ; Rats, Wistar ; Spinal Cord Injuries ; blood ; complications

Eukaryotic initiation factor 5A (eIF-5A) contains an unusual amino acid, hypusine, which is formed post-translationally. Although eIF-5A and its hypusine modification are essential for eukaryotic cell viability, the precise physiological function of it has remained elusive. The aim of the study is to investigate how hypusine formation modulate the proliferation, cell cycle and apoptosis in leukaemia cells. The effects of 1,7-diaminoheptane (DAH), a potent inhibitor of deoxyhypusine synthase, on proliferation and cell viability of leukemia cell lines (Mo7e, TF-1 and THP-1) and MCF-7 cells, were investigated. eIF-5A expression level was detected after cell synchronization. The results showed that inhibition of cell proliferation by DAH was in a concentration-dependent manner while apoptosis was also induced at the same time. Upon treatment of the cell lines with DAH, cell growth was inhibited. Cell cycle analysis showed that DAH induced cell growth arrest at the G(1)-S boundary of the cell cycle. In synchronized MCF-7 cells, the expression level of eIF-5A peaked at G(1) phase but very low at S and G(2)/M phases. It is concluded that hypusine formation of eIF-5A exits in the regulation of cell cycle and the results suggest that eIF-5A is involved in the expression of proteins regulating transition of G(1)-S phase of cell cycle.
Cell Line, Tumor ; Diamines ; pharmacology ; G1 Phase ; physiology ; Humans ; Lysine ; analogs & derivatives ; metabolism ; Peptide Initiation Factors ; physiology ; RNA-Binding Proteins ; S Phase ; physiology

The xylose reductase of Pichia stipitis is one of the most important enzymes. It can be used to build up recombinant Saccharomyces cerevisiae strain for utilizing xylose and producing ethanol. Intercellular redox imbalance caused by NADPH preference over NADH for Pichia stipitis xylose reductase (PsXR) has been considered to be one of the main factors for poor ethanol productivity. Some key amino acids of PsXR, which affect the activity or coenzyme preference, were investigated in our previous study. In this study, Lys21 were rational designed for site-directed mutagenesis to alter coenzyme specificity of PsXR from NADPH and NADH into single NADH. The wild gene and mutagenesis genes were ligated into pET28b, and were transferred into E.coli BL21(DE3). After induced by IPTG, the xylose reductases were purified. Purified mutants K21A (Lys21-->Ala), K21R(Lys21-->Arg) were characterized by steady-state kinetic analysis. The results showed that the coenzyme dependence of K21A was completely reversed to NADH.
Aldehyde Reductase ; metabolism ; Amino Acid Substitution ; genetics ; Coenzymes ; pharmacology ; Escherichia coli ; genetics ; metabolism ; Ethanol ; pharmacology ; Lysine ; genetics ; Mutagenesis, Site-Directed ; NAD ; metabolism ; NADP ; metabolism ; Pichia ; chemistry ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Recombination, Genetic ; Xylose ; pharmacology

OBJECTIVE: To observe the effects of N-acetyl-L-cysteine (L-NAC) protect hair cells in the rat cochlea from injury of exposure to styrene. METHOD: Seventeen adult Long Evans rats were used in present study. The animals were randomly assigned into test group (n=9) and control group (n=8). The animals were exposed to styrene by gavage at 400 mg/kg (2 g styrene was mixed with 1 ml olive oil). Test group animals received styrene exposure plus L-NAC 325 mg/kg (L-NAC was dissolved in physiological saline solution) by intraperitoneal injection. Treatment was performed once a day, 5 days per week for 3 weeks. Control group animals received the same volume of saline injection on an identical time schedule used for the test group. The auditory brainstem response (ABR) thresholds of both ears elicited with clicks were measured before and at the end of the 3-week styrene or styrene plus L-NAC treatment. After hearing was re-assessed, animals were sacrificed and cochleae were quickly removed from the skull. Following fixation, whole specimens comprising the basilar membrane with Corti's organ were separated from the modiolus. The organs of Corti were stained with propidium iodide (PI) and the TUNEL assay to visualize the morphologic viability of hair cell nuclei, FITC-labeled phalloidin, a F-actin intercalating fluorescent probe used to visualize the morphologic viability of cuticular plate and the stereocilia in the hair cells. Each organ of Corti was thoroughly examined using fluorescence microscopy. The numbers of damaged OHCs (apoptotic, necrotic and missing OHCs) were documented. RESULT: There was a statistically significant decrease in ABR threshold shift (P<0.05) in the styrene-plus-L-NAC treated animals. The average percentage of damaged OHCs in the styrene-treated animals was 28.3%. In contrast, the average percentage of OHC damage in the styrene-plus-L-NAC treated group was only 10.6% (P<0.01). The percentage of reduction in the number of apoptotic cells in styrene-plus-L-NAC treated group was 78% (P<0.01). However, the mean reduction of necrotic cells was only 23% (P>0.05). CONCLUSION The results indicate that the treatment with L-NAC may effectively protect against the styrene-induced hair cells damage and preferably reduce the number of apoptotic OHCs.
Acetylcysteine ; analogs & derivatives ; pharmacology ; Animals ; Antioxidants ; pharmacology ; Cochlea ; cytology ; drug effects ; Evoked Potentials, Auditory, Brain Stem ; Hair Cells, Auditory ; drug effects ; pathology ; Lysine ; analogs & derivatives ; pharmacology ; Rats ; Rats, Long-Evans ; Styrene ; adverse effects

OBJECTIVETo investigate the anti-atherotic effects of heme-L-lysinate in a rabbit model of atherosclerosis and related machanisms.

METHODSAdult rabbits were treated with 1% cholesterol diet (chol group, n = 8) or 1% cholesterol diet plus heme-L-lysinate (9 mgxkg(-1)xd(-1), Heme group, n = 8) or 1% cholesterol diet plus isotonic Na chloride (Na chloride group, n = 8) for 10 weeks. Eight rabbits fed with normal diet served as normal control. Aortic carbon monoxide (CO) was quantified spectrophotometrically by the formation of carboxyhaemoglobin (HbCO). Aortic heme oxygenase-1 (HO-1) and HSP70 mRNA and protein expressions were detected by RT-PCR and immunohistochemical staining.

RESULTSAortic CO production and HO-1 activity were significantly increased in chol group and Na chloride group compared those in normal control group (P < 0.01). Aortic plaque area was significantly reduced in heme group (26.6% +/- 9.2%) than that in chol group (42.3% +/- 8.7%, P < 0.01). Aortic HO-1 expression, CO production and HSP70 were significantly increased in heme group than those in chol group and Na chloride group (all P < 0.01).

CONCLUSIONSHeme-L-lysinate could attenuate atherosclerotic progression through upregulating HO-1 and HSP70 expression and increasing CO production in this model.

Animals ; Atherosclerosis ; metabolism ; prevention & control ; Carbon Monoxide ; metabolism ; Cholesterol, Dietary ; Diet, Atherogenic ; Disease Models, Animal ; HSC70 Heat-Shock Proteins ; genetics ; metabolism ; Heme ; analogs & derivatives ; pharmacology ; Heme Oxygenase-1 ; metabolism ; Lysine ; analogs & derivatives ; pharmacology ; Male ; RNA, Messenger ; genetics ; Rabbits

The ventral pallidum (VP) is a crucial component of the limbic loop of the basal ganglia and participates in the regulation of reward, motivation, and emotion. Although the VP receives afferent inputs from the central histaminergic system, little is known about the effect of histamine on the VP and the underlying receptor mechanism. Here, we showed that histamine, a hypothalamic-derived neuromodulator, directly depolarized and excited the GABAergic VP neurons which comprise a major cell type in the VP and are responsible for encoding cues of incentive salience and reward hedonics. Both postsynaptic histamine H1 and H2 receptors were found to be expressed in the GABAergic VP neurons and co-mediate the excitatory effect of histamine. These results suggested that the central histaminergic system may actively participate in VP-mediated motivational and emotional behaviors via direct modulation of the GABAergic VP neurons. Our findings also have implications for the role of histamine and the central histaminergic system in psychiatric disorders.
Action Potentials ; drug effects ; Animals ; Basal Forebrain ; cytology ; Dimaprit ; pharmacology ; Dose-Response Relationship, Drug ; Electric Stimulation ; Female ; GABAergic Neurons ; drug effects ; Histamine ; pharmacology ; Histamine Agonists ; pharmacology ; Lysine ; analogs & derivatives ; metabolism ; Male ; Patch-Clamp Techniques ; Pyridines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Histamine H1 ; metabolism ; Receptors, Histamine H2 ; metabolism ; Sodium Channel Blockers ; pharmacology ; Tetrodotoxin ; pharmacology ; gamma-Aminobutyric Acid ; metabolism

OBJECTIVETo investigate the anti-damage effect of iminoethyl-lysine on noise-induced cochlea damage in guinea pig.

METHODS40 healthy red eye guinea pigs were randomly divided into 4 groups: Group A, normal control group; Group B, noise group; Group C, noise and drug group; Group D, iminoethyl-lysine group. Guinea pigs of both group B and group C were exposed to 115 dB white noise for 6 hours/day for 6 days. Group C and Group D were treated with iminoethyl-lysine(10 mg/kg) intraperitoneally, while Group B were treated with the same volume of physiological saline. ABR hearing threshold was measured in all animals before and after experiment. The expression of inducible nitric oxide synthase(NOS II) in the cochlea was examined by the method of immunohistochemistry. Also the cochlea of four groups were examined with scanning electronic microscope. ABR hearing threshold, expression of NOS II and structure of cochlea of four groups were compared with each other.

RESULTSThere was no significant difference in ABR hearing threshold among four groups before the experiment(P > 0.05). There was no significant ABR hearing threshold shift in Group A and Group D after the experiment(P > 0.05), and there was significant ABR hearing threshold shift in Group B and Group C(P < 0.05). After the experiment, the ABR hearing threshold of group B(60.23 +/- 11.23) dB, was higher than that of Group C(38.46 +/- 7.24) dB, P < 0.05. The expression of NOS II was negative in the cochlea of Group A and Group D, but was stronger in Group B than that in Group C. The damage of outer hair cells of cochlea of Group B was more severe than that of Group C.

CONCLUSIONSThe expression of NOS II in the guinea pig's cochlea damaged by noise is positive. Iminoethyl-lysine could inhibit the activity of NOS II and has the anti-damage effect on noise-induced cochlea damage. It is indicated that nitric oxide plays an important role in the pathogenesis of noise-induced hearing loss.

Animals ; Auditory Threshold ; Cochlea ; pathology ; Evoked Potentials, Auditory, Brain Stem ; Guinea Pigs ; Immunohistochemistry ; Lysine ; analogs & derivatives ; pharmacology ; Microscopy, Electron, Scanning ; Nitric Oxide ; physiology ; Nitric Oxide Synthase Type II ; analysis ; Noise ; adverse effects

OBJECTIVETo explore the mechanism of serotonin-promoted osteoblast differentiation.

METHODSExpression levels of collagen I and lysyl oxidase (LOX) in osteoblast were measured by RT-PCR after treated by (50, 100, 200 and 400 ng/L) serotonin. LOX siRNA effect was measured by Western blot, and protein levels of collagen I were determined by ELISA after treated by serotonin. Expression levels of Smad2 and Smad3 in osteoblasts were also measured by RT-PCR after treated by serotonin.Moreover, expression levels of LOX were measured by RT-PCR after Smad3 was knockout.

RESULTSSerotonin promoted collagen I and LOX expression. The expression level of collagen I was significantly decreased by LOX siRNA. Furthermore, serotonin up-regulated the expression of Smad2 and Smad3 in osteoblasts, and the expression level of LOX was inhibited by Smad3 siRNA.

CONCLUSIONSerotonin promoted collagen I expression by activating Smads signaling pathway and up-regulating the LOX expression.

Blotting, Western ; Cell Differentiation ; Cells, Cultured ; Collagen Type I ; metabolism ; Humans ; Osteoblasts ; drug effects ; metabolism ; Protein-Lysine 6-Oxidase ; metabolism ; RNA, Small Interfering ; Serotonin ; pharmacology ; Signal Transduction ; Smad2 Protein ; metabolism ; Smad3 Protein ; metabolism ; Up-Regulation