The CpxRA two-component system is involved in the maintenance of the integrity of the cell envelope in the rumen bacterium Mannheimia succiniciproducens.

In this study, we characterized the CpxRA two-component signal transduction system of the rumen bacterium Mannheimia succiniciproducens. The truncated form of the CpxA sensor kinase protein without its transmembrane domain was able to autophosphorylate and transphosphorylate the CpxR response regulator protein in vitro. We identified 152 putative target genes for the Cpx system in M. succiniciproducens, which were differentially expressed by more than twofold upon overexpression of the CpxR protein. Genes of a putative 16-gene operon related to the cell wall and lipopolysaccharide biosynthesis were induced strongly upon CpxR overexpression. The promoter region of the first gene of this operon, wecC encoding UDP-N-acetyl-D-mannosaminuronate dehydrogenase, was analyzed and found to contain a sequence homologous to the CpxR box of Escherichia coli. An electrophoretic mobility shift assay showed that the phosphorylated CpxR proteins were able to bind specifically to PCR-amplified DNA fragments containing the promoter sequence of wecC. Furthermore, a cpxR-disrupted mutant strain exhibited increased envelope permeability compared with a wild-type strain. These results suggest that the Cpx system of M. succiniciproducens is involved in the maintenance of the integrity of the cell envelope.

The mixture of different parts of Nelumbo nucifera and two bioactive components inhibited tyrosinase activity and melanogenesis.

Melanin is the pigment responsible for the color of the eyes, hair, and skin in humans. Tyrosinase is well known to be the key enzyme in melanin biosynthesis. JKTM-12 is composed of the flowers, roots, seeds, and receptacles of Nelumbo nucifera (lotus). In this study, JKTM-12 was investigated for its inhibitory effects on tyrosinase activity and melanin biosynthesis in B16F10 melanoma cells. Moreover, two main bioactive compounds (hyperoside and astragalin) were found from the receptacles of N. nucifera, which are used as the main material of JKTM-12. JKTM-12 was shown to inhibit tyrosinase activity and melanin biosynthesis in alpha-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells. Hyperoside and astragalin, which are the main bioactive compounds of JKTM-12, not only inhibited tyrosinase activity and melanogenesis but also tyrosinase-related protein 1 and tyrosinase-related protein 2 mRNA expression without cytotoxicity at various experiment doses (0.1, 1, and 10 µg/ml). These results suggest that JKTM-12 has the potential for skin whitening with hyperoside and astragalin as the main bioactive compounds.

Scolopendra subspinipes mutilans protected the cerulein-induced acute pancreatitis by inhibiting high-mobility group box protein-1.

AIM: To evaluate the inhibitory effects of Scolopendra subspinipes mutilans (SSM) on cerulein-induced acute pancreatitis (AP) in a mouse model. METHODS: SSM water extract (0.1, 0.5, or 1 g/kg) was administrated intraperitoneally 1 h prior to the first injection of cerulein. Once AP developed, the stable cholecystokinin analogue, cerulein was injected hourly, over a 6 h period. Blood samples were taken 6 h later to determine serum amylase, lipase, and cytokine levels. The pancreas and lungs were rapidly removed for morphological examination, myeloperoxidase assay, and real-time reverse transcription polymerase chain reaction. To specify the role of SSM in pancreatitis, the pancreatic acinar cells were isolated using collagenase method. Then the cells were pre-treated with SSM, then stimulated with cerulein. The cell viability, cytokine productions and high-mobility group box protein-1 (HMGB-1) were measured. Furthermore, the regulating mechanisms of SSM action were evaluated. RESULTS: The administration of SSM significantly attenuated the severity of pancreatitis and pancreatitis associated lung injury, as was shown by the reduction in pancreatic edema, neutrophil infiltration, vacuolization and necrosis. SSM treatment also reduced pancreatic weight/body weight ratio, serum amylase, lipase and cytokine levels, and mRNA expression of multiple inflammatory mediators such as tumor necrosis factor-α and interleukin-1ß. In addition, treatment with SSM inhibited HMGB-1 expression in the pancreas during AP. In accordance with in vivo data, SSM inhibited the cerulein-induced acinar cell death, cytokine, and HMGB-1 release. SSM also inhibited the activation of c-Jun NH2-terminal kinase, p38 and nuclear factor (NF)-κB. CONCLUSION: These results suggest that SSM plays a protective role during the development of AP and pancreatitis associated lung injury via deactivating c-Jun NH2-terminal kinase, p38 and NF-κB.

Piperine inhibits lipopolysaccharide-induced maturation of bone-marrow-derived dendritic cells through inhibition of ERK and JNK activation.

Piperine, one of the main components of Piper longum Linn. and P. nigrum Linn., is a plant alkaloid with a long history of medicinal use. Piperine has been shown to modulate the immune response, but the mechanism underlying this modulation remains unknown. Here, we examined the effects of piperine on lipopolysaccharide (LPS)-induced inflammatory responses in bone-marrow-derived dendritic cells (BMDCs). Piperine significantly inhibited the expression of major histocompatibility complex class II, CD40 and CD86 in BMDCs in a dose-dependent manner. Furthermore, piperine treatment led to an increase in fluorescein-isothiocyanate-dextran uptake in LPS-treated dendritic cells and inhibited the production of tumour necrosis factor alpha and interleukin (IL)-12, but not IL-6. The inhibitory effects of piperine were mediated via suppression of extracellular signal-regulated kinases and c-Jun N-terminal kinases activation, but not p38 or nuclear factor-κB activation. These findings provide insight into the immunopharmacological role of piperine.

Myrrh inhibits LPS-induced inflammatory response and protects from cecal ligation and puncture-induced sepsis.

Myrrh has been used as an antibacterial and anti-inflammatory agent. However, effect of myrrh on peritoneal macrophages and clinically relevant models of septic shock, such as cecal ligation and puncture (CLP), is not well understood. Here, we investigated the inhibitory effect and mechanism(s) of myrrh on inflammatory responses. Myrrh inhibited LPS-induced productions of inflammatory mediators such as nitric oxide, prostaglandin E(2), and tumor necrosis factor-α but not of interleukin (IL)-1ß and IL-6 in peritoneal macrophages. In addition, Myrrh inhibited LPS-induced activation of c-jun NH(2)-terminal kinase (JNK) but not of extracellular signal-regulated kinase (ERK), p38, and nuclear factor-κB. Administration of Myrrh reduced the CLP-induced mortality and bacterial counts and inhibited inflammatory mediators. Furthermore, administration of Myrrh attenuated CLP-induced liver damages, which were mainly evidenced by decreased infiltration of leukocytes and aspartate aminotransferase/alanine aminotransferase level. Taken together, these results provide the evidence for the anti-inflammatory and antibacterial potential of Myrrh in sepsis.

Dimethylsulfoxide (DMSO) induces downregulation of heme oxygenase-1 (HO-1) in HL-60 cells: involvement of HO-1 in HL-60 cell differentiation.

Heme oxygenase-1 (HO-1), an inducible enzyme with broad tissue expression, is wel1-regulated in response to hematopoietic stress and preserves vascular homeostasis. We investigated the involvement of HO-1 in HL-60 cell differentiation. Dimethyl sulfoxide (DMSO) completely decreased HO-1 expression in a time-dependent manner, but clearly induced HL-60 cell differentiation, as evidenced by a marked increase in CD11b expression. Interestingly, zinc protoporphyrin (ZnPP), a strong inhibitor of HO-1, induced HL-60 cell differentiation. In contrast, treatment with cobalt protoporphyrin (CoPP), an activator of HO-1, decreased CD11b expression. Additionally, ZnPP downregulated HO-1 protein expression in HL-60 cells, whereas CoPP induced upregulation. These results suggest that HO-1 might have a negative function in DMSO-induced HL-60 cell differentiation. This study provides the first evidence that HO-1 plays an important role in DMSO-induced HL-60 cell differentiation.

A combined approach of classical mutagenesis and rational metabolic engineering improves rapamycin biosynthesis and provides insights into methylmalonyl-CoA precursor supply pathway in Streptomyces hygroscopicus ATCC 29253.

Rapamycin is a macrocyclic polyketide with immunosuppressive, antifungal, and anticancer activity produced by Streptomyces hygroscopicus ATCC 29253. Rapamycin production by a mutant strain (UV2-2) induced by ultraviolet mutagenesis was improved by approximately 3.2-fold (23.6 mg/l) compared to that of the wild-type strain. The comparative analyses of gene expression and intracellular acyl-CoA pools between wild-type and the UV2-2 strains revealed that the increased production of rapamycin in UV2-2 was due to the prolonged expression of rapamycin biosynthetic genes, but a depletion of intracellular methylmalonyl-CoA limited the rapamycin biosynthesis of the UV2-2 strain. Therefore, three different metabolic pathways involved in the biosynthesis of methylmalonyl-CoA were evaluated to identify the effective precursor supply pathway that can support the high production of rapamycin: propionyl-CoA carboxylase (PCC), methylmalonyl-CoA mutase, and methylmalonyl-CoA ligase. Among them, only the PCC pathway along with supplementation of propionate was found to be effective for an increase in intracellular pool of methylmalonyl-CoA and rapamycin titers in UV2-2 strain (42.8 mg/l), indicating that the PCC pathway is a major methylmalonyl-CoA supply pathway in the rapamycin producer. These results demonstrated that the combined approach involving traditional mutagenesis and metabolic engineering could be successfully applied to the diagnosis of yield-limiting factors and the enhanced production of industrially and clinically important polyketide compounds.

The roots of Nardostachys jatamansi inhibits lipopolysaccharide-induced endotoxin shock.

Nardostachys jatamansi (NJ) has been used in the treatment of inflammatory diseases. However, it is not clear how NJ produces anti-inflammatory effects. In the present study, using an experimental model of lipopolysaccharide (LPS)-induced endotoxin shock, the protective effects and mechanisms of action of NJ were investigated. The water extract of roots of NJ was administrated to mice orally (1, 5, and 10 mg/kg) 1 h after or before LPS challenge. The administration of NJ inhibited LPS-induced endotoxin shock and the production of inflammatory mediators, such as interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-α/ß. Murine peritoneal macrophages were used to determine the production of inflammatory mediators. In peritoneal macrophages, NJ also inhibited LPS-induced production of inflammatory mediators, such as IL-1ß, IL-6, TNF-α, and IFN-α/ß. In addition, NJ reduced the activation of mitogen-activated protein kinases (MAPKs) and the level of expression of interferon regulatory factor (IRF)-1 and IRF-7 mRNA. Furthermore, post-treatment with NJ reduced LPS-induced endotoxin shock and the production of inflammatory mediators. These results suggest that NJ inhibits endotoxin shock by inhibiting the production of IL-1ß, IL-6, TNF-α, and IFN-α/ß through the inhibition of MAPKs activation and IRF induction.

Inhibition of lipopolysaccharide-induced inflammatory responses by piperine.

Piperine, a main component of Piper longum Linn. and Piper nigrum Linn., is a plant alkaloid with a long history of medical use. Piperine exhibits anti-inflammatory activity; however, the underlying mechanism remains unknown. We examined the effects of piperine on lipopolysaccharide (LPS)-induced inflammatory responses. Administration of piperine inhibited LPS-induced endotoxin shock, leukocyte accumulation and the production of tumor necrosis factor-alpha (TNF-alpha), but not of interleukin (IL)-1beta and IL-6. In peritoneal macrophages, piperine inhibited LPS/poly (I:C)/CpG-ODN-induced TNF-alpha production. Piperine also inhibited LPS-induced endotoxin shock in TNF-alpha knockout (KO) mice. To clarify the inhibitory mechanism of LPS-induced endotoxin shock, type 1 interferon (IFN) mRNA expression was determined. Piperine inhibited LPS-induced expression of type 1 IFN mRNA. Piperine inhibited the levels of interferon regulatory factor (IRF)-1 and IRF-7 mRNA, and the phosphorylation and nuclear translocation of IRF-3. Piperine also reduced activation of signal transducer and activator of transcription (STAT)-1. In addition, activation of STAT-1 was inhibited in IFN-alpha/beta-treated cells by piperine. These results suggest that piperine inhibits LPS-induced endotoxin shock through inhibition of type 1 IFN production.

Selective GSK-3beta inhibitors attenuate the cisplatin-induced cytotoxicity of auditory cells.

Glycogen synthase kinase-3 (GSK-3) plays an important role in the regulation of apoptosis. However, the role of GSK-3 in the auditory system remains unknown. Here we examined whether the GSK-3-specific inhibitors, SB 216763 and LiCl, could protect against cisplatin-induced cytotoxicity of auditory cells. GSK-3 was activated by cisplatin treatment of HEI-OC1 cells. SB 216763 or LiCl treatments inhibited cisplatin-induced apoptosis in a dose-dependent manner and activated caspase-9, -8 and -3. In rat primary explants of the organ of Corti, SB 216763 or LiCl treatments completely abrogated the cisplatin-induced destruction of outer hair cell arrays. Administration of SB 216763 or LiCl inhibited cochlear destruction and the production of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and IL-6 in cisplatin-injected mice. Furthermore, administration of SB 216763 or LiCl reduced the thresholds of the auditory brainstem response (ABR) in cisplatin-injected mice. Collectively, these results suggest that cisplatin-induced ototoxicity might be associated with modulation of GSK-3 activation.

Gardenia jasminoides protects against cerulein-induced acute pancreatitis.

AIM: To investigate the effect of Gardenia jasminoides (GJ) on cerulein-induced acute pancreatitis (AP) in mice. METHODS: C57BL/6 mice weighing 18-20 g were divided into three groups. (1) Normal saline-treated group, (2) treatment with GJ at a dose of 0.1 g/kg, (3) treatment with GJ at a dose of 1 g/kg. GJ was administered orally (n = 6 per group) for 1 wk. Three hours later, the mice were given an intraperitoneal injection of cerulein (50 microg/kg), a stable cholecystokinin (CCK) analogue, every hour for a total of 6 h as described previously. The mice were sacrificed at 6 h after completion of cerulein injections. Blood samples were obtained to determine serum amylase, lipase and cytokine levels. The pancreas was rapidly removed for morphologic examination and scoring. A portion of pancreas was stored at -70 degree and prepared for the measurement of tissue myeloperoxidase (MPO) activity, an indicator of neutrophil sequestration, and for reverse-transcriptase PCR (RT-PCR) and real-time PCR measurements. RESULTS: Treatment with GJ decreased significantly the severity of pancreatitis and pancreatitis-associated lung injury. Treatment with GJ attenuated the severity of AP compared with saline-treated mice, as shown by reduction in pancreatic edema, neutrophil infiltration, serum amylase and lipase levels, serum cytokine levels, and mRNA expression of multiple inflammatory mediators. CONCLUSION: These results suggest that GJ attenuated the severity of AP as well as pancreatitis-associated lung injury.

Heterologous production of epothilones B and D in Streptomyces venezuelae.

Epothilones, produced from the myxobacterium Sorangium cellulosum, are potential anticancer agents that stabilize microtubules in a similar manner to paclitaxel. The entire epothilone biosynthetic gene cluster was heterologously expressed in an engineered strain of Streptomyces venezuelae bearing a deletion of pikromycin polyketide synthase gene cluster. The resulting strains produced approximately 0.1 microg/l of epothilone B as a sole product after 4 days cultivation. Deletion of an epoF encoding the cytochrome P450 epoxidase gave rise to a mutant that selectively produces 0.4 microg/l of epothilone D. To increase the production level of epothilones B and D, an additional copy of the positive regulatory gene pikD was introduced into the chromosome of both S. venezuleae mutant strains. The resulting strains showed enhanced production of corresponding compounds (approximately 2-fold). However, deletion of putative transport genes, orf3 and orf14 in the epothilone D producing S. venezuelae mutant strain, led to an approximately 3-fold reduction in epothilone D production. These results introduce S. venezuelae as an alternative heterologous host for the production of these valuable anticancer agents and demonstrate the possibility of engineering this strain as a generic heterologous host for the production of polyketides and hybrid polyketide-nonribosomal peptides.

Characterization of the Arc two-component signal transduction system of the capnophilic rumen bacterium Mannheimia succiniciproducens.

The ArcB/A two-component signal transduction system of Escherichia coli modulates the expression of numerous operons in response to redox conditions of growth. We demonstrate that the putative arcA and arcB genes of Mannheimia succiniciproducens MBEL55E, a capnophilic (CO2-loving) rumen bacterium, encode functional proteins that specify a two-component system. The Arc proteins of the two bacterial species sufficiently resemble each other that they can participate in heterologous transphosphorylation in vitro, and the arcA and arcB genes of M. succiniciproducens confer toluidine blue resistance to E. coli arcA and arcB mutants. However, neither the quinone analogs (ubiquinone 0 and menadione) nor the cytosolic effectors (d-lactate, acetate, and pyruvate) affect the net phosphorylation of M. succiniciproducens ArcB. Our results indicate that different types of signaling molecules and distinct modes of kinase regulation are used by the ArcB proteins of E. coli and M. succiniciproducens.

Effects of bee venom on cholecystokinin octapeptide-induced acute pancreatitis in rats.

OBJECTIVES: Bee venom (BV) has frequently been used as a remedy for inflammatory diseases. The aim of this study was to investigate the effect of BV on cholecystokinin octapeptide (CCK-8)-induced acute pancreatitis (AP) in rats. METHODS: The BV pretreatment group: 0.25 mg/kg BV was administered subcutaneously, followed by 75 mug/kg CCK-8 subcutaneously 3 times after 1, 3, and 5 hours. This whole procedure was repeated for 5 days. CONTROL GROUP: CCK-8 subcutaneously 3 times after 1, 3, and 5 hours for 5 days. The BV posttreatment group: CCK-8 subcutaneously 3 times at an interval of 2 hours for 3 days, and then 0.25 mg/kg of BV was administered subcutaneously. CONTROL GROUP: CCK-8 subcutaneously 3 times at an interval of 2 hours for 3 days. RESULTS: The BV pretreatment and posttreatment ameliorated many of the examined laboratory parameters (the pancreatic weight [PW]/body weight [BW] ratio, the serum amylase and lipase activity) and reduced histological damages in pancreas. Furthermore, BV pretreatment reduced the production of tumor necrosis factor-alpha, interleukin 1, and interleukin 6 and also decreased pancreatic nuclearfactor-kappaB binding activity compared with saline-treated group in the AP model. The BV also increased heat shock protein 60 (HSP60) and heat shock protein 72 (HSP72) compared with the saline-treated group in the AP model. CONCLUSIONS: These findings suggest that the anti-inflammatory effect of BV in CCK-8-induced AP seems to be mediated by inhibiting nuclear factor-kappaB binding activity, and that BV may have a protective effect against AP.

Selective cyclooxygenase-2 inhibitor ameliorates cholecystokinin-octapeptide-induced acute pancreatitis in rats.

AIM: To investigate the effect of selective Cycloo-xygenase-2 (COX-2) inhibitor 4-[5-(4-Chloro-phenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzenesulfonamide (SC-236), on the cholecystokinin (CCK)-octapeptide-induced acute pancreatitis (AP) in rats. METHODS: Wistar rat weighing 240 g to 260 g were divided into three groups. (1) Normal DMSO treated group, (2) SC-236 at 4 mg/kg treated group; SC-236 systemically administered via the intravenous (i.v.) catheter, followed by 75 microg/kg CCK octapeptide subcutaneously three times, after 1, 3 and 5 h. This whole procedure was repeated for 5 d. (3) Dimethyl sulfoxide (DMSO) treated group: an identical protocol was used in this group as in the SC-236 cohort (see 2. above). Repeated CCK octapeptide treatment resulted in a typical experimentally induced pancreatitis in the Wistar rats. RESULTS: SC-236 improved the severity of CCK-octapeptide-induced AP as measured by laboratory criteria [the pancreatic weight/body weight (p.w/b.w) ratio, the level of serum amylase and lipase]. The SC-236 treated group showed minimal histologic evidence of pancreatitis and a significant reduction in myeloperoxidase activity. SC-236 also increased heat shock protein (HSP)-60 and HSP72 compared with the DMSO-treated group in the CCK-octapeptide-induced AP and also reduced the pancreatic levels of COX-2. Furthermore, SC-236 reduced proinflammatory cytokine synthesis and inhibited NF-kappaB activation compared with the DMSO-treated group in the CCK-octapeptide-induced AP. CONCLUSION: Our results suggested that COX-2 plays pivotal role in the development of AP and COX-2 inhibitors may play a beneficial role in preventing AP.