GPNMB Modulates Autophagy to Enhance Functional Recovery After Spinal Cord Injury in Rats

Spinal cord injury (SCI) severely affects the quality of life and autonomy of patients, and effective treatments are currently lacking. Autophagy, an essential cellular metabolic process, plays a crucial role in neuroprotection and repair after SCI. Glycoprotein non-metastatic melanoma protein B (GPNMB) has been shown to promote neural regeneration and synapse reconstruction, potentially through the facilitation of autophagy. However, the specific role of GPNMB in autophagy after SCI is still unclear. In this study, we utilized the spinal cord transection method to establish SCI rats model and overexpressed GPNMB using adenoviral vectors. We assessed tissue damage using hematoxylin and eosin (H&E) and Nissl staining, and observed cell apoptosis using TUNEL staining. We evaluated the inflammatory response by measuring inflammatory factors using enzyme-linked immunosorbent assay (ELISA). In addition, we measured reactive oxygen species (ROS) levels using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), and assessed oxidative stress levels by measuring malondialdehyde (MDA) and glutathione (GSH) using ELISA. To evaluate autophagy levels, we performed immunofluorescence staining for the autophagy marker Beclin-1 and conducted Western blot analysis for autophagy-related proteins. We also assessed limb recovery through functional evaluation. Meanwhile, we induced cell injury using lipopolysaccharide (LPS) and added an autophagy inhibitor to verify the impact of GPNMB on SCI through autophagy modulation. The results demonstrated that GPNMB alleviated the inflammatory response, reduced oxidative stress levels, inhibited cell apoptosis, and promoted autophagy following SCI. Inhibiting autophagy reversed the effects of GPNMB. These findings suggest that GPNMB promotes neural injury repair after SCI, potentially through attenuating the inflammatory response, reducing oxidative stress, and inhibiting cell apoptosis.

GPNMB Ameliorates Neuroinflammation Via the Modulation of AMPK/NFκB Signaling Pathway After SAH in Mice

Glycoprotein non-metastatic melanoma protein B (GPNMB) got its name from the first discovery in a cell line of non-metastatic melanoma. Later studies found that GPNMB is widely expressed in various tissues and cells of the human body, most abundant in neural tissue, epithelial tissue, bone tissue, and monocyte-macrophage system. GPNMB has been shown to have anti-inflammatory effects in a variety of neurological diseases, however, it has not been reported in subarachnoid hemorrhage (SAH). Male CD-1 mice were used and intra-arterial puncture method was applied to establish the SAH model. Exogenous recombinant GPNMB (rGPNMB) was injected intracerebroventricularly 1 h after SAH. SAH grading, brain edema and blood-brain barrier (BBB) integrity were quantified, and neurobehavioral tests were performed to evaluate the effect of GPNMB on the outcome. Dorsomorphin, the selective inhibitor on AMPK was introduced to study the downstream signaling through which the GPNMB works. Furthermore, western blot, immunofluorescence staining and ELISA were utilized to confirm the signaling. After SAH, GPNMB expression increased significantly as a result of the inflammatory response. GPNMB was expressed extensively in mouse microglia, astrocytes and neurons. The administration of rGPNMB could alleviate brain edema, restore BBB integrity and improve the neurological outcome of mice with SAH. GPNMB treatment significantly magnified the expression of p-AMPK while p-NFκB, IL-1β, IL-6 and TNF-α were suppressed; in the meantime, the combined administration of GPNMB and AMPK inhibitor could decrease the intensity of p-AMPK and reverse the quantity of p-NFκB and the above inflammatory cytokines. GPNMB has the potential of ameliorating the brain edema and neuroinflammation, protecting the BBB and improving the neurological outcome, possibly via the AMPK/NFκB signaling pathway.

Peritoneal Gene Transfection of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand for Tumor Surveillance and Prophylaxis

Peritoneal metastasis is very common in gastrointestinal, reproductive, and genitourinary tract cancers in late stages or postsurgery, causing poor prognosis, so effective and nontoxic prophylactic strategies against peritoneal metastasis are highly imperative. Herein, we demonstrate the first gene transfection as a nontoxic prophylaxis preventing peritoneal metastasis or operative metastatic dissemination. Lipopolyplexes of TNF-related-apoptosis-inducing-ligand (TRAIL) transfected peritonea and macrophages to express TRAIL for over 15 days. The expressed TRAIL selectively induced tumor cell apoptosis while exempting normal tissue, providing long-term tumor surveillance. Therefore, tumor cells inoculated in the pretransfected peritoneal cavity quickly underwent apoptosis and, thus, barely formed tumor nodules, significantly prolonging the mouse survival time compared with chemotherapy prophylaxis. Furthermore, lipopolyplex transfection showed no sign of toxicity. Therefore, this peritoneal TRAIL-transfection is an effective and safe prophylaxis, preventing peritoneal metastasis.

Bazi Bushen capsule attenuates cognitive deficits by inhibiting microglia activation and cellular senescence

CONTEXT

Bazi Bushen capsule (BZBS) has anti-ageing properties and is effective in enhancing memory.

OBJECTIVE

To find evidence supporting the mechanisms and biomarkers by which BZBS functions.

MATERIALS AND METHODS

Male C57BL/6J mice were randomly divided into five groups: normal, ageing, β-nicotinamide mononucleotide capsule (NMN), BZBS low-dose (LD-BZ) and BZBS high-dose (HD-BZ). The last four groups were subcutaneously injected with d-galactose (d-gal, 100 mg/kg/d) to induce the ageing process. At the same time, the LD-BZ, HD-BZ and NMN groups were intragastrically injected with BZBS (1 and 2 g/kg/d) and NMN (100 mg/kg/d) for treatment, respectively. After 60 days, the changes in overall ageing status, brain neuron morphology, expression of p16^INK4a, proliferating cell nuclear antigen (PCNA), ionized calcium-binding adapter molecule 1 (Iba1), postsynaptic density protein 95 (PSD95), CD11b, Arg1, CD206, Trem2, Ym1 and Fizz1, and the senescence-associated secretory phenotype (SASP) factors were observed.

RESULTS

Compared with the mice in the ageing group, the HD-BZ mice exhibited obvious improvements in strength, endurance, motor coordination, cognitive function and neuron injury. The results showed a decrease in p16^INK4a, Iba1 and the upregulation of PCNA, PSD95 among brain proteins. The brain mRNA exhibited downregulation of Iba1 (p < 0.001), CD11b (p < 0.001), and upregulation of Arg1 (p < 0.01), CD206 (p < 0.05), Trem2 (p < 0.001), Ym1 (p < 0.01), Fizz1 (p < 0.05) and PSD95 (p < 0.01), as well as improvement of SASP factors.

CONCLUSIONS

BZBS improves cognitive deficits via inhibition of cellular senescence and microglia activation. This study provides experimental evidence for the wide application of BZBS in clinical practice for cognitive deficits.

Minocycline reverses developmental arsenic exposure-induced microglia activation and functional alteration in BALB/c mice

Arsenic activates microglia and exerts bystander effects on neuron. The present study is focused to test whether minocycline, a second generation antibiotic, can reverse the effect of developmental arsenic exposure on microglial activation and function. Pregnant Balb/c dams were gavaged with sodium arsenite (0.38 mg/kg bd wt) from gestational day 5 (GD5) till post natal day 21 (PND21) and then one group of pups continued till PND59 with arsenic gavage. Minocycline (33 mg/kg bd wt) was administered intraperitoneally two weeks till sacrifice, every alternate day. Mice were sacrificed on PND22 and PND60 and used for various assays. Primary microglial were isolated (ex vivo microglia) from experimental animals and used to measure reactive oxygen species (ROS), nitric oxide (NO), cytokine production and phagocytosis. The whole brain lysate was used for western blot analysis of microglial marker CD68 and synaptic marker, post synaptic density protein 95 (PSD95). For real-time PCR analysis of triggering receptor expressed on myeloid cells 2 (TREM2) and PSD95, RNA isolated from whole brain was used. The study reveals that minocycline administration reversed arsenic-induced increased expression of CD68, ROS, NO, cytokine production, phagocytosis and TREM2 expression. Arsenic-induced reduced expression of PSD95 protein was reversed by minocycline, although the mRNA of PSD95 was unaltered among different groups. Finally, we have checked the learning and memory response of the experimental animals using Y-maze test to correlate the arsenic-induced altered level of synaptic protein. Taken together, the present study finds minocycline to reduce arsenic-induced microglial activation and function which in turn reverses the arsenic-induced impaired learning and memory response.

Fibrin with Laminin-Nidogen Reduces Fibrosis and Improves Soft Palate Regeneration Following Palatal Injury

This study aimed to analyze the effects of fibrin constructs enhanced with laminin-nidogen, implanted in the wounded rat soft palate. Fibrin constructs with and without laminin-nidogen were implanted in 1 mm excisional wounds in the soft palate of 9-week-old rats and compared with the wounded soft palate without implantation. Collagen deposition and myofiber formation were analyzed at days 3, 7, 28 and 56 after wounding by histochemistry. In addition, immune staining was performed for a-smooth muscle actin (a-SMA), myosin heavy chain (MyHC) and paired homeobox protein 7 (Pax7). At day 56, collagen areas were smaller in both implant groups (31.25 ± 7.73% fibrin only and 21.11 ± 6.06% fibrin with laminin-nidogen)) compared to the empty wounds (38.25 ± 8.89%, p < 0.05). Moreover, the collagen area in the fibrin with laminin-nidogen group was smaller than in the fibrin only group (p ˂ 0.05). The areas of myofiber formation in the fibrin only group (31.77 ± 10.81%) and fibrin with laminin-nidogen group (43.13 ± 10.39%) were larger than in the empty wounds (28.10 ± 11.68%, p ˂ 0.05). Fibrin-based constructs with laminin-nidogen reduce fibrosis and improve muscle regeneration in the wounded soft palate. This is a promising strategy to enhance cleft soft palate repair and other severe muscle injuries.

A PSGL-1 glycomimetic reduces thrombus burden without affecting hemostasis

Events mediated by the P-selectin/PSGL-1 pathway play a critical role in the initiation and propagation of venous thrombosis by facilitating the accumulation of leukocytes and platelets within the growing thrombus. Activated platelets and endothelium express P-selectin, which binds P-selectin glycoprotein ligand-1 (PSGL-1) that is expressed on the surface of all leukocytes. We developed a pegylated glycomimetic of the N terminus of PSGL-1, PEG40-GSnP-6 (P-G6), which proved to be a highly potent P-selectin inhibitor with a favorable pharmacokinetic profile for clinical translation. P-G6 inhibits human and mouse platelet-monocyte and platelet-neutrophil aggregation in vitro and blocks microcirculatory platelet-leukocyte interactions in vivo. Administration of P-G6 reduces thrombus formation in a nonocclusive model of deep vein thrombosis with a commensurate reduction in leukocyte accumulation, but without disruption of hemostasis. P-G6 potently inhibits the P-selectin/PSGL-1 pathway and represents a promising drug candidate for the prevention of venous thrombosis without increased bleeding risk.

Interaction between a Novel Oligopeptide Fragment of the Human Neurotrophin Receptor TrkB Ectodomain D5 and the C-Terminal Fragment of Tetanus Neurotoxin

This article presents experimental evidence and computed molecular models of a potential interaction between receptor domain D5 of TrkB with the carboxyl-terminal domain of tetanus neurotoxin (Hc-TeNT). Computational simulations of a novel small cyclic oligopeptide are designed, synthesized, and tested for possible tetanus neurotoxin-D5 interaction. A hot spot of this protein-protein interaction is identified in analogy to the hitherto known crystal structures of the complex between neurotrophin and D5. Hc-TeNT activates the neurotrophin receptors, as well as its downstream signaling pathways, inducing neuroprotection in different stress cellular models. Based on these premises, we propose the Trk receptor family as potential proteic affinity receptors for TeNT. In vitro, Hc-TeNT binds to a synthetic TrkB-derived peptide and acts similar to an agonist ligand for TrkB, resulting in phosphorylation of the receptor. These properties are weakened by the mutagenesis of three residues of the predicted interaction region in Hc-TeNT. It also competes with Brain-derived neurotrophic factor, a native binder to human TrkB, for the binding to neural membranes, and for uptake in TrkB-positive vesicles. In addition, both molecules are located together in vivo at neuromuscular junctions and in motor neurons.

New generation of DNA-based immunotherapy induces a potent immune response and increases the survival in different tumor models

BACKGROUND

Strategies to increase nucleic acid vaccine immunogenicity are needed to move towards clinical applications in oncology. In this study, we designed a new generation of DNA vaccines, encoding an engineered vesicular stomatitis virus glycoprotein as a carrier of foreign T cell tumor epitopes (plasmid to deliver T cell epitopes, pTOP). We hypothesized that pTOP could activate a more potent response compared with the traditional DNA-based immunotherapies, due to both the innate immune properties of the viral protein and the specific induction of CD4 and CD8 T cells targeting tumor antigens. This could improve the outcome in different tumor models, especially when the DNA-based immunotherapy is combined with a rational therapeutic strategy.

METHODS

The ability of pTOP DNA vaccine to activate a specific CD4 and CD8 response and the antitumor efficacy were tested in a B16F10-OVA melanoma (subcutaneous model) and GL261 glioblastoma (subcutaneous and orthotopic models).

RESULTS

In B16F10-OVA melanoma, pTOP promoted immune recognition by adequate processing of both MHC-I and MHC-II epitopes and had a higher antigen-specific cytotoxic T cell (CTL) killing activity. In a GL261 orthotopic glioblastoma, pTOP immunization prior to tumor debulking resulted in 78% durable remission and long-term survival and induced a decrease of the number of immunosuppressive cells and an increase of immunologically active CTLs in the brain. The combination of pTOP with immune checkpoint blockade or with tumor resection improved the survival of mice bearing, a subcutaneous melanoma or an orthotopic glioblastoma, respectively.

CONCLUSIONS

In this work, we showed that pTOP plasmids encoding an engineered vesicular stomatitis virus glycoprotein, and containing various foreign T cell tumor epitopes, successfully triggered innate immunity and effectively promoted immune recognition by adequate processing of both MHC-I and MHC-II epitopes. These results highlight the potential of DNA-based immunotherapies coding for viral proteins to induce potent and specific antitumor responses.

Activation of Toll-like receptor 7 provides cardioprotection in septic cardiomyopathy-induced systolic dysfunction

BACKGROUND

As a pattern recognition receptor, Toll-like receptor 7 (TLR7) widely presented in the endosomal membrane of various cells. However, the precise role and mechanism of TLR7 in septic cardiomyopathy remain unknown. This study aims to determine the role of TLR7 in cardiac dysfunction during sepsis and explore the mechanism of TLR7 in septic cardiomyopathy.

METHODS

We generated a mouse model of septic cardiomyopathy by challenging with lipopolysaccharide (LPS). TLR7-knockout (TLR7-/- ), wild-type (WT) mice, cardiac-specific TLR7-transgenic (cTG-TLR7) overexpression, and littermates WT (LWT) mice were subjected to septic model. Additionally, to verify the role and mechanism of TLR7 in vitro, we transfected neonatal rat ventricular myocytes (NRVMs) with Ad-TLR7 and TLR7 siRNA before LPS administration. The effects of TLR7 were assessed by Ca2+ imaging, western blotting, immunostaining, and quantitative real-time polymerase chain reaction (qPCR).

RESULTS

We found that TLR7 knockout markedly exacerbated sepsis-induced systolic dysfunction. Moreover, cardiomyocytes isolated from TLR7-/- mice displayed weaker Ca2+ handling than that in WT mice in response to LPS. Conversely, TLR7 overexpression alleviated LPS-induced systolic dysfunction, and loxoribine (TLR7-specific agonist) improved LPS-induced cardiac dysfunction. Mechanistically, these optimized effects were associated with enhanced the adenosine (cAMP)-protein kinase A (PKA) pathway, which upregulated phosphorylate-phospholamban (p-PLN) (Ser16) and promoted sarco/endoplasmic reticulum Ca2+ ATPase (Serca) and Ryanodine Receptor 2 (RyR2) expression in the sarcoplasmic reticulum (SR), and ultimately restored Ca2+ handling in response to sepsis. While improved Ca2+ handling was abrogated after H89 (a specific PKA inhibitor) pretreatment in cardiomyocytes isolated from cTG-TLR7 mice. Consistently, TLR7 overexpression improved LPS-induced Ca2+ -handling decrement in NRVMs. Nevertheless, TLR7 knockdown showed a deteriorative phenotype.

CONCLUSIONS

Our data demonstrated that activation of TLR7 protected against sepsis-induced cardiac dysfunction through promoting cAMP-PKA-PLN pathway, and we revealed that TLR7 might be a novel therapeutic target to block the septic cardiomyopathy and support systolic function during sepsis.

Effect of Lactobacillus acidophilus CICC 6074 S-Layer Protein on Colon Cancer HT-29 Cell Proliferation and Apoptosis

The objective of this research was to investigate the effects of Lactobacillus acidophilus CICC 6074 S-layer protein on the viability, adhesion, cell cycle, and apoptosis of human colon cancer HT-29 cells and to explore their molecular mechanism of tumor suppression. The S-layer protein at doses of 0, 25, 50, and 100 mg/L significantly suppressed the proliferation of HT-29 cells. The S-layer protein exerts its cytotoxic activities against colon cancer HT-29 cells by arresting the cell cycle in the G1 phase through upregulating the expression of p53, p21, and p16 and downregulating the expression of CDK1 (cyclin-dependent kinases) and cyclin B. Morphological changes were further observed by transmission electron microscopy, and the cells treated with the S-layer protein showed obvious characteristic changes of apoptosis including chromatin condensation, nuclear fragmentation, vacuoles, and so on. Furthermore, our mechanism studies indicated that the S-layer protein may induce HT-29 cell apoptosis through the death receptor apoptotic pathway and mitochondrial pathway and impede cell invasion by inhibiting the synthesis of the PI3K/AKT pathway and FasL. These results demonstrated that the L. acidophilus CICC 6074 S-layer protein may be a potential anticarcinogenic agent.

Hhip inhibits proliferation and promotes differentiation of adipocytes through suppressing hedgehog signaling pathway

Adipogenesis, which directly control body fat mass, plays a crucial role in lipid metabolism and obesity-related diseases. Hedgehog interacting protein (Hhip) belongs to Hedgehog (Hh) signaling pathway. The Hh signaling pathway was already linked with adipogenesis in previous reports, however, the physiological functions of Hhip on lipid deposition are still poorly understood. In this study, the level of Hhip was down-regulated during the development of porcine adipose tissues. Recombinant Hedgehog interacting protein (rHhip) could down-regulate cell cycle related genes and cell numbers in S phage to inhibit cell proliferation. Moreover, rHhip could increase adipocytes differentiation by targeting canonical Hh signaling, indicated by the increase of lipid accumulation and up-regulation of Glut4 and PPARγ expression. Collectively, these findings illustrated the essential role of Hhip in the proliferation and differentiation of adipocytes, and provided a potential novel target for preventing obesity.

Lipopolysaccharide-binding protein (LBP) can reverse the amyloid state of fibrin seen or induced in Parkinson's disease

The thrombin-induced polymerisation of fibrinogen to form fibrin is well established as a late stage of blood clotting. It is known that Parkinson's Disease (PD) is accompanied by dysregulation in blood clotting, but it is less widely known as a coagulopathy. In recent work, we showed that the presence of tiny amounts of bacterial lipopolysaccharide (LPS) in healthy individuals could cause clots to adopt an amyloid form, and this could be observed via scanning electron microscopy (SEM) or via the fluorescence of thioflavin-T. This could be prevented by the prior addition of lipopolysaccharide-binding protein (LBP). We had also observed by SEM this unusual clotting in the blood of patients with Parkinson's Disease. We hypothesised, and here show, that this too can be prevented by LBP in the context of PD. This adds further evidence implicating inflammatory microbial cell wall products as an accompaniment to the disease, and may be part of its aetiology. This may lead to novel treatment strategies in PD designed to target microbes and their products.

Purification of Lactobacillus acidophilus surface-layer protein and its immunomodulatory effects on RAW264.7 cells

BACKGROUND

Surface-layer proteins (SLP) have been found in the outermost layer of the cell wall in many types of lactobacillus are considered to be an important factor with respect to intestinal immunity.

RESULTS

The present study compared the effects of SLP extracted by different concentrations of LiCl and carbamide, and subsequently identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, circular dichroism and differential scanning calorimetry. Furthermore, RAW 264.7 cells were used to evaluate the immunomodulatory effects of SLP. SLP were derived from Lactobacillus acidophilus CICC6074 with a molecular weight of 46 kDa, and consisted of 16.9% α-helix, 42.3% β-sheet, 20.8% β-turns and 22.5% random coils. SLP promoted NO secretion and higher quantities of NO were produced as the SLP concentrations increased. SLP concentrations over 50 µg mL^-1 significantly decreased the amount of tumor necrosis factor-α secreted by RAW264.7 cells.

CONCLUSION

SLP can trigger immunomodulatory effects in RAW 264.7 cells. This provides crucial information that will enable the further use of L. acidophilus in food, medicine and other products. © 2017 Society of Chemical Industry.

Spleen Tyrosine Kinase Is Involved in the CD38 Signal Transduction Pathway in Chronic Lymphocytic Leukemia

The survival and proliferation of CLL cells depends on microenvironmental contacts in lymphoid organs. CD38 is a cell surface receptor that plays an important role in survival and proliferation signaling in CLL. In this study we demonstrate SYK's direct involvement in the CD38 signaling pathway in primary CLL samples. CD38 stimulation of CLL cells revealed SYK activation. SYK downstream target AKT was subsequently induced and MCL-1 expression was increased. Concomitant inhibition of SYK by the SYK inhibitor R406 resulted in reduced activation of AKT and prevented upregulation of MCL-1. Moreover, short-term CD38 stimulation enhanced BCR-signaling, as indicated by increased ERK phosphorylation. CXCL12-dependent migration was increased after CD38 stimulation. Treating CLL cells with R406 inhibited CD38-mediated migration. In addition, we observed marked downregulation of CD38 expression for CLL cells treated with R406 compared to vehicle control. Finally, we observed a clear correlation between CD38 expression on CLL cells and SYK-inhibitor efficacy. In conclusion, our study provides deeper mechanistic insight into the effect of SYK inhibition in CLL.

The Regulation of Interleukin-6 Secretion by Prostanoids and Members of the Tumor Necrosis Factor Superfamily in Fresh Villous Fragments of Term Human Placenta

OBJECTIVE

To determine whether prostanoids, nonsteroidal anti-inflammatory drugs (NSAIDs), and members of the tumor necrosis factor superfamily can regulate placental secretion of interleukin-6 (IL-6) and whether labor influences any such effects.

METHODS

Villous fragments of term, human placenta were kept in culture for up to 4 hours, and IL-6 concentrations were measured in the supernatant. We assessed the effects of the following prostanoids: PGE(2), PGF(2alpha), thromboxane A(2) mimetic (U-46619), and carbacyclin, a stable prostacyclin analogue (all at 1 microM); NSAIDs: indomethacin (150 microM) or nimesulide (100 microM); and Fas ligand (5 ng/mL).

RESULTS

Secretion (mean +/- standard error) of IL-6 was, for control conditions, 1.92 +/- 0.28 fmol/mg wet weight per 3 hours; for PGE(2), 3.57 +/- 0.29 fmol/mg wet weight per 3 hours, P <.01; and for carbacyclin, 3.11 +/- 0.44 fmol/mg wet weight per 3 hours, P <.01. Incubation with PGF(2alpha) or the thromboxane A(2) analogue, U46619, had no effect on IL-6 secretion under these conditions. Fas ligand stimulated IL-6 secretion (3.06 +/- 0.38 fmol/mg wet weight per 3 hours, P <.05). Labor did not alter the effects of prostanoids or FasL. The effects of NSAIDs were assessed over 4 hours. Secretion (median, interquartile range) was, under control conditions 3.26, 2.83-6.23 fmol/mg wet weight per 4 hours, with indomethacin 1.4, 1.28-3.21 (P <.05), and with nimesulide 0.75, 0.50-1.56 fmol/mg wet weight per 4 hours. The magnitude of the effect of Fas ligand in the presence of NSAIDs depended on whether the placentas were delivered before or after labor.

CONCLUSION

Prostanoids, NSAIDs, and the Fas ligand regulate placental IL-6 secretion. Although the effects of individual agents did not vary with the presence or absence of labor, modulation of IL-6 secretion by labor became apparent when agents were combined.

Insulin-like growth factor-II mRNA binding protein-3 and podoplanin expression are associated with bone invasion and prognosis in oral squamous cell carcinoma

OBJECTIVE

This study aimed to evaluate the prognostic implications of insulin-like growth factor-II mRNA binding protein-3 (IMP3) and podoplanin (PDPN) as therapeutic targets against oral squamous cell carcinoma (OSCC) with bone invasion.

STUDY DESIGN

We elucidated the correlation of IMP3 and PDPN expression with bone invasion in 160 OSCC tissue specimens, and assessed a mouse calvarium xenograft model using an IMP3- and PDPN-depleted OSCC cell line.

RESULTS

The retrospective analysis revealed that the expression of IMP3 and PDPN is significantly correlated with T stage, lymph node metastasis, and the overall survival of OSCC patients. In addition, the dual expression of IMP3 and PDPN but not the single expression of either IMP3 or PDPN was associated with bone invasion and the number of osteoclasts in patients with OSCC. In support of these findings, IMP3 or PDPN depletion inhibited the invasive capacity of OSCC cells in a three-dimensional culture system, tumorigenesis, and regional bone destruction in a xenograft mouse model. In addition, IMP3 or PDPN depletion inhibited the expression of interleukin (IL)-6 and IL-8 in OSCC cells, and decreased the expression of receptor activator of NF-κB ligand (RANKL) in xenograft tumor tissues of OSCC.

CONCLUSIONS

These results suggest that IMP3 and PDPN may have strong influence on the pathogenesis of OSCC, especially in bone invasion, and may serve as novel therapeutic targets with prognostic implications for bone-invasive OSCC.

[Stable expression of recombinant human podoplanin in Chinese hamster ovary (CHO) cells]

OBJECTIVE

To construct podoplanin (PDPN) eukaryotic expression plasmid PDPN-pEGFP-N1, establish Chinese hamster ovary (CHO) cell line stably expressing recombinant human PDPN and investigate its biological activity.

METHODS

PDPN cDNA was cloned from HEK293 cells by reverse transcription PCR and recombinant DNA technology and inserted into plasmid pEGFP-N1 labeled by enhanced green fluorescent protein (EGFP). The recombinant vector was identified by PCR, restriction enzyme digestion and DNA sequencing, and then transfected into CHO cells. Recombinant PDPN-EGFP was observed by fluorescent microscopy and CHO cell line with the high expression of PDPN-EGFP was selected by flow cytometry. Recombinant PDPN was detected by Western blotting and the biological activity of the cell line was determined by platelet aggregation assay.

RESULTS

DNA sequencing and restriction enzyme digestion proved that the gene of PDPN was inserted successfully into pEGFP-N1 plasmid. After stable transfection of the recombinant plasmid into CHO cells, CHO with EGFP could be seen under a fluorescent microscope. The CHO cell line with the high expression of recombinant PDPN-EGFP was obtained after sorting by flow cytometry. Western blotting showed that the recombinant PDPN was expressed on the cell surface. The over-expressing PDPN-EGFP CHO cells were able to induce human platelet aggregation.

CONCLUSION

The CHO cell line with the stable and high expression of recombinant PDPN-EGFP has been constructed successfully, and it could induce platelet aggregation.

[A experiment research of beryllium oxide induced oxidative lung injury and the protective effects of LBP in rats]

OBJECTIVE

To explore beryllium oxide induced oxidative lung injury and the protective effects of LBP.

METHODS

Intoxication of animals were induced by once intratracheal injection and LBP intervention by intragastric administration. The content of HIF-1, VEGF and HO-1 of lung tissues were measured by kits. The pathological changes of lung tissue were showed by pathological section. The changes of lung ultrastructure were observed by electron microscope.

RESULTS

Pathological changes of the lung tissue in beryllium oxide exposure group rats were in line with the characteristics of beryllium disease in human. Compared with the control group, HO-1 was increased in beryllium oxide exposure 40 d group and low doses of LBP group, compared with the control group, HO-1 was increased in beryllium oxide exposure 80d group and LBP treatment groups (P < 0.05 or P < 0.01). Compared with the control group, HIF-1 was increased in beryllium oxide exposure 40 d group, LBP treatment groups, beryllium oxide exposure 60 d and 80 d groups (P < 0.05 or P < 0.01). Compared with the control group, VEGF was increased of all phases, especially in beryllium oxide exposure 40d and 80 groups, LBP treatment groups and beryllium oxide exposure 60 d (P < 0.05 or P < 0.01). The content of HO-1 of beryllium oxide exposure group was higher than the LBP treatment for 40d group but below LBP treatment for 80 d group (P < 0.05). The content of HIF1 of beryllium oxide exposure group was higher than high dose of LBP treatment for 60d group and LBP treatment for 80 d group (P < 0.01). The content of VEGF of beryllium oxide exposure group was higher than LBP treatment for 40 d group and high dose of LBP treatment for 60 d (P < 0.05 or P < 0.01).

CONCLUSIONS

BeO can cause abnormal expression of related genes of lung tissue in rats, LBP has protective effects on BeO caused lung injury.

rPSGL-1-Ig, a recombinant PSGL-1-Ig fusion protein, ameliorates LPS-induced acute lung injury in mice by inhibiting neutrophil migration

The binding of selectin to P&mdash;selectin glycoprotein ligand&mdash;1 (PSGL&mdash;1) mediates the tethering and rolling of leukocytes on the endothelium during leukocyte migration and inflammation. Recombinant human PSGL&mdash;1&mdash;Ig fusion protein (rPSGL&mdash;1&mdash;Ig) is a widely used selectin inhibitor that prevents neutrophil entry into inflamed or reperfused tissues. We hypothesized that rPSGL&mdash;1&mdash;Ig could be used to as a drug for the treatment of acute lung injury (ALI). We induced murine ALI by injecting mice with lipopolysaccharide (LPS) and then treated the mice with rPSGL&mdash;1&mdash;Ig. We determined the lung injury index, wet/dry ratio, and inflammatory cytokine level in differentially treated mice. The symptoms of LPS&mdash;induced lung injury were alleviated by rPSGL&mdash;1&mdash;Ig treatment. The histopathological index of LPS&mdash;induced lung injury improved after rPSGL&mdash;1&mdash;Ig treatment. rPSGL&mdash;1&mdash;Ig treatment also reduced the recruitment of inflammatory cells, including neutrophils, into the lung, as well as reducing the level of inflammatory cytokines. These data suggest that rPSGL&mdash;1&mdash;Ig protein has a therapeutic effect on LPS&mdash;induced lung injury.

Mutation of threonine 34 in mouse podoplanin-Fc reduces CLEC-2 binding and toxicity in vivo while retaining antilymphangiogenic activity

The lymphatic system plays an important role in cancer metastasis and inhibition of lymphangiogenesis could be valuable in fighting cancer dissemination. Podoplanin (Pdpn) is a small, transmembrane glycoprotein expressed on the surface of lymphatic endothelial cells (LEC). During mouse development, binding of Pdpn to the C-type lectin-like receptor 2 (CLEC-2) on platelets is critical for the separation of the lymphatic and blood vascular systems. Competitive inhibition of Pdpn functions with a soluble form of the protein, Pdpn-Fc, leads to reduced lymphangiogenesis in vitro and in vivo. However, the transgenic overexpression of human Pdpn-Fc in mouse skin causes disseminated intravascular coagulation due to platelet activation via CLEC-2. In the present study, we produced and characterized a mutant form of mouse Pdpn-Fc, in which threonine 34, which is considered essential for CLEC-2 binding, was mutated to alanine (PdpnT34A-Fc). Indeed, PdpnT34A-Fc displayed a 30-fold reduced binding affinity for CLEC-2 compared with Pdpn-Fc. This also translated into fewer side effects due to platelet activation in vivo. Mice showed less prolonged bleeding time and fewer embolized vessels in the liver, when PdpnT34A-Fc was injected intravenously. However, PdpnT34A-Fc was still as active as wild-type Pdpn-Fc in inhibiting lymphangiogenesis in vitro and also inhibited lymphangiogenesis in vivo. These data suggest that the function of Pdpn in lymphangiogenesis does not depend on threonine 34 in the CLEC-2 binding domain and that PdpnT34A-Fc might be an improved inhibitor of lymphangiogenesis with fewer toxic side effects.

Contribution of S-layer proteins to the mosquitocidal activity of Lysinibacillus sphaericus

Lysinibacillus sphaericus strains belonging the antigenic group H5a5b produce spores with larvicidal activity against larvae of Culex mosquitoes. C7, a new isolated strain, which presents similar biochemical characteristics and Bin toxins in their spores as the reference strain 2362, was, however, more active against larvae of Culex mosquitoes. The contribution of the surface layer protein (S-layer) to this behaviour was envisaged since this envelope protein has been implicated in the pathogenicity of several bacilli, and we had previously reported its association to spores. Microscopic observation by immunofluorescence detection with anti S-layer antibody in the spores confirms their attachment. S-layers and BinA and BinB toxins formed high molecular weight multimers in spores as shown by SDS-PAGE and western blot detection. Purified S-layer from both L. sphaericus C7 and 2362 strain cultures was by itself toxic against Culex sp larvae, however, that from C7 strain was also toxic against Aedes aegypti. Synergistic effect between purified S-layer and spore-crystal preparations was observed against Culex sp. and Aedes aegypti larvae. This effect was more evident with the C7 strain. In silico analyses of the S-layer sequence suggest the presence of chitin-binding and hemolytic domains. Both biochemical characteristics were detected for both S-layers strains that must justify their contribution to pathogenicity.

Bioluminescent imaging of TRAIL-induced apoptosis through detection of caspase activation following cleavage of DEVD-aminoluciferin

Apoptosis, the most common and well-defined form of programmed cell death (PCD), is often impaired in cancer and neurodegenerative diseases and can limit conventional therapy. Bioluminescent molecular imaging was employed to study apoptosis in human colon cancer cells that have been treated with various doses of the therapeutic agent TRAIL (tumor necrosis factor-related apoptosis inducing ligand). While monitoring therapeutic response through a proluminescent, caspase-activated DEVD-aminoluciferin reagent (Caspase-Glo 3/7) which produced strong, stable signals, alternate preparations of the reagent were explored for non-invasive imaging methods. Dissolving the lyophilized DEVD-aminoluciferin compound in Dulbecco's PBS instead of lysis buffer (along with heat inactivation of an accompanying exogenous luciferase protein by heating at 85 degrees C for 20 minutes) yielded a minimally invasive apoptosis detector, with maximum luminescence intensities 2.5-fold stronger than those produced by D-luciferin at a final concentration of 100 microg/mL. Bioluminescent imaging of cancer therapeutic response through minimally invasive detection of caspase activation may serve as an important tool in monitoring apoptosis in vivo and in vitro.

Lack of p38 MAP Kinase Activation in TRAIL-Resistant Cells is Not Related to the Resistance to TRAIL-Mediated Cell Death

Activation of MAP kinases is involved in various cellular processes, including immunoregulation, inflammation, cell growth, cell differentiation, and cell death. To investigate the role of p38 MAP kinase activation in the signaling pathway of TRAIL-mediated apoptosis, we compared TRAIL-mediated MAP kinase activation in TRAIL-susceptible human colon cancer cell line DLD1 and TRAIL-resistant DLD1/TRAIL-R cells. TRAIL-mediated activation of ERK occurred in both cell lines. In contrast, both DLD1 and DLD1/TRAIL-R cells showed no obvious JNK activation after treatment with TRAIL. Interestingly, TRAIL-mediated activation of p38 MAP kinases was observed in DLD1 cells but not in DLD1/TRAIL-R cells. However, activation of p38 MAP kinases was observed in both DLD1 and DLD1/TRAIL-R cells after treatment with anisomycin. Furthermore, inhibiting activated p38 MAP kinases with known inhibitors or with an adenovector expressing dominant negative p38alpha did not block TRAIL-mediated cell death in DLD1 cells. Moreover, activation of p38 MAP kinases by adenovectors expressing constitutive MKK3 or MKK6 (Ad/MKK3bE or Ad/MKK6bE) did not induce cell death in either DLD1 or DLD1/TRAIL-R cell lines. Our results suggest that activation of p38 MAP kinases does not play a major role in TRAIL-mediated apoptosis in DLD1 cells and that lack of TRAIL-mediated p38 MAP kinase activation may not be the mechanism of TRAIL-resistance in DLD1/TRAIL-R cells.

Endoplasmic reticulum oxidoreductin 1α mediates hepatic endoplasmic reticulum stress in homocysteine-induced atherosclerosis

Endoplasmic reticulum (ER) stress is emerging as an important modulator of different pathological process and as a mechanism contributing to homocysteine (Hcy)-induced hepar injury. However, the molecular event that Hcy-induced ER stress in the hepar under the atherosclerosis background is currently unknown. Endoplasmic reticulum oxidoreductin 1α (ERO1α) plays a crucial role in maintaining ER stress function. In this study, we determined the expression of ERO1α in the hepar in hyperhomocysteinemia and the effect of ERO1α in hepacytes ER stress in the presence of Hcy. HHcy model was established by feeding the methionine diet in apolipoprotein-E-deficient (ApoE-/-) mice, and the hepatocytes were incubated with folate and different concentrations of Hcy. Our results showed that Hcy triggered ER stress characterized by an increased contents of glucose-regulated protein 78 (GRP78), protein kinase RNA-like ER kinase (PERK), activating transcription factor (ATF) 6 and X-box binding protein-1 (XBP-1). The ERO1α expressions in HHcy mice and Hcy-treated hepatocytes were decreased compared with those in ApoE-/- group and control hepacytes (P < 0.05), respectively. Knocking-down the expression of ERO1α with small-interfering RNA significantly augmented Hcy-induced ER stress. Meanwhile, the expressions of ER stress-related factor including GRP78, PERK, ATF6 and XBP-1, were significantly decreased when the ERO1α gene was over-expressed in hepacytes. Our results suggested that ERO1α may be involved in Hcy-induced hepar ER stress, and the inhibition of ERO1α expression can accelerate this process.

Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections

Vertebrate females transfer antibodies via the placenta, colostrum and milk or via the egg yolk to protect their immunologically immature offspring against pathogens. This evolutionarily important transfer of immunity is poorly documented in invertebrates and basic questions remain regarding the nature and extent of parental protection of offspring. In this study, we show that a lipopolysaccharide binding protein/bactericidal permeability increasing protein family member from the invertebrate Biomphalaria glabrata (BgLBP/BPI1) is massively loaded into the eggs of this freshwater snail. Native and recombinant proteins displayed conserved LPS-binding, antibacterial and membrane permeabilizing activities. A broad screening of various pathogens revealed a previously unknown biocidal activity of the protein against pathogenic water molds (oomycetes), which is conserved in human BPI. RNAi-dependent silencing of LBP/BPI in the parent snails resulted in a significant reduction of reproductive success and extensive death of eggs through oomycete infections. This work provides the first functional evidence that a LBP/BPI is involved in the parental immune protection of invertebrate offspring and reveals a novel and conserved biocidal activity for LBP/BPI family members.

Vertebrate immune systems not only protect adult organisms against infections but also increase survival of offspring through parental transfer of innate and adaptive immune factors via the placenta, colostrum and milk or via the egg yolk. This maternal transfer of immunity is critical for species survival as embryos and neonates are immunologically immature and unable to fight off infections at early life stages. Parental immune protection is poorly documented in invertebrates and how the estimated 1.3 million of invertebrate species protect their eggs against pathogens remains an intriguing question. Here, we show that a fresh-water snail, Biomphalaria glabrata massively loads its eggs with a lipopolysaccharide binding protein/bactericidal permeability increasing protein (LBP/BPI) displaying expected antibacterial activities. Remarkably, this snail LBP/BPI also displayed a strong biocidal activity against water molds (oomycetes). This yet unsuspected activity is conserved in human BPI. Gene expression knock-down resulted in the reduction of snail reproductive success and massive death of eggs after water mold infections. This work reveals a novel and conserved biocidal activity for LBP/BPI family members and demonstrates that the snail LBP/BPI represents a major fitness-related protein transferred from parents to their clutches and protecting them from widespread and lethal oomycete infections.

Induction of regulatory T cells by high-dose gp96 suppresses murine liver immune hyperactivation

Immunization with high-dose heat shock protein gp96, an endoplasmic reticulum counterpart of the Hsp90 family, significantly enhances regulatory T cell (Treg) frequency and suppressive function. Here, we examined the potential role and mechanism of gp96 in regulating immune-mediated hepatic injury in mice. High-dose gp96 immunization elicited rapid and long-lasting protection of mice against concanavalin A (Con A)-and anti-CD137-induced liver injury, as evidenced by decreased alanine aminotransaminase (ALT) levels, hepatic necrosis, serum pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-6), and number of IFN-γ ⁺ CD4⁺ and IFN-γ ⁺ CD8⁺ T cells in the spleen and liver. In contrast, CD4⁺CD25⁺Foxp3⁺ Treg frequency and suppressive function were both increased, and the protective effect of gp96 could be generated by adoptive transfer of Treg cells from gp96-immunized mice. In vitro co-culture experiments demonstrated that gp96 stimulation enhanced Treg proliferation and suppressive function, and up-regulation of Foxp3, IL-10, and TGF-β1 induced by gp96 was dependent on TLR2- and TLR4-mediated NF-κB activation. Our work shows that activation of Tregs by high-dose gp96 immunization protects against Con A- and anti-CD137-induced T cell-hepatitis and provides therapeutic potential for the development of a gp96-based anti-immune hyperactivation vaccine against immune-mediated liver destruction.

MMPs and soluble ICAM-5 increase neuronal excitability within in vitro networks of hippocampal neurons

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that are released from neurons in an activity dependent manner. Published studies suggest their activity is important to varied forms of learning and memory. At least one MMP can stimulate an increase in the size of dendritic spines, structures which represent the post synaptic component for a large number of glutamatergic synapses. This change may be associated with increased synaptic glutamate receptor incorporation, and an increased amplitude and/or frequency of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) mini excitatory post-synaptic currents (EPSCs). An associated increase in the probability of action potential occurrence would be expected. While the mechanism(s) by which MMPs may influence synaptic structure and function are not completely understood, MMP dependent shedding of specific cell adhesion molecules (CAMs) could play an important role. CAMs are ideally positioned to be cleaved by synaptically released MMPs, and shed N terminal domains could potentially interact with previously unengaged integrins to stimulate dendritic actin polymerization with spine expansion. In the present study, we have used multielectrode arrays (MEAs) to investigate MMP and soluble CAM dependent changes in neuronal activity recorded from hippocampal cultures. We have focused on intercellular adhesion molecule-5 (ICAM-5) in particular, as this CAM is expressed on glutamatergic dendrites and shed in an MMP dependent manner. We show that chemical long-term potentiation (cLTP) evoked changes in recorded activity, and the dynamics of action potential bursts in particular, are altered by MMP inhibition. A blocking antibody to β₁ integrins has a similar effect. We also show that the ectodomain of ICAM-5 can stimulate β₁ integrin dependent increases in spike counts and burst number. These results support a growing body of literature suggesting that MMPs have important effects on neuronal excitability. They also support the possibility that MMP dependent shedding of specific synaptic CAMs can contribute to these effects.

A hexapeptide of the receptor-binding domain of SARS corona virus spike protein blocks viral entry into host cells via the human receptor ACE2

In vitro infection of Vero E6 cells by SARS coronavirus (SARS-CoV) is blocked by hexapeptide Tyr-Lys-Tyr-Arg-Tyr-Leu. The peptide also inhibits proliferation of coronavirus NL63. On human cells both viruses utilize angiotensin-converting enzyme 2 (ACE2) as entry receptor. Blocking the viral entry is specific as alpha virus Sindbis shows no reduction in infectivity. Peptide ⁴³⁸YKYRYL⁴⁴³ is part of the receptor-binding domain (RBD) of the spike protein of SARS-CoV. Peptide libraries were screened by surface plasmon resonance (SPR) to identify RBD binding epitopes. ⁴³⁸YKYRYL⁴⁴³ carries the dominant binding epitope and binds to ACE2 with K_D = 46 μM. The binding mode was further characterized by saturation transfer difference (STD) NMR spectroscopy and molecular dynamic simulations. Based on this information the peptide can be used as lead structure to design potential entry inhibitors against SARS-CoV and related viruses.

Alterations in nuclear pore architecture allow cancer cell entry into or exit from drug-resistant dormancy

Phenotypic diversity arises in tumors just as it does in developing organisms, and tumor recurrence frequently manifests from the selective survival of divergent drug-resistant cells. Although the expanding tumor cell population may be successfully targeted, drug-resistant cells may persist and sustain the tumor or enter dormancy before igniting a future relapse. Herein, we show that partial knockdown of nucleoporin p62 (NUP62) by small-interfering RNA confers cisplatin resistance to cultured high-grade ovarian carcinoma cells. Treatment with NUP62 small-interfering RNA and cisplatin leaves resistant cells in a state of dormancy; some dormant cells can be induced to proliferate by transient induction of NUP62 expression from an ectopic expression construct. In addition to suggesting functional links between nuclear pore complex architecture and cancer cell survival, the culture system provides a novel experimental window into the dynamics of tumor cell drug resistance and dormancy.

Congenital absence of vasopressin and age-dependent changes in ACTH and corticosterone stress responses in rats

The hypothalamic components of the hypothalamo-pituitary-adrenal axis (HPA) are corticotropin-releasing hormone (CRH) and vasopressin. To test the hypothesis that HPA regulation changes with age, we compared ether and bacterial lipopolysaccharide (LPS) injection induced stress reactions in adult and 10-day-old Brattleboro rats, which naturally lack vasopressin owing to mutation of the gene (di/di). The LPS stimulus was used also with V(1b) receptor antagonist pretreatment (SSR149415). In adult di/di or V(1b) pretreated rats, we observed normal pituitary and adrenocortical secretory responses, while in all 10-day-old rats stress-induced serum corticosterone increases were marked, but adrenocorticotropin (ACTH) increases were significantly smaller. Compared to control pups the adenohypophysis of the 10-day-old di/di rats responded normally to CRH, but their adrenal glands were hyper-responsive to ACTH, while in adults there was greater secretion at both levels with no difference between the genotypes. The serum transcortin level was higher in adults than pups, with the di/di pups having higher transcortin levels than controls. Hence, using the same stressors in adults and pups with both a genetic model and pharmacological pretreatment, we have shown that the role of vasopressin in ACTH regulation is more important during the neonatal period than in adulthood. Blunted hypophysial sensitivity to CRH and similar adrenal gland sensitivity to ACTH in the pups compared to adults suggest that hypothalamic factors could be responsible for the neonatal stress hyporesponsive period.

A family of helminth molecules that modulate innate cell responses via molecular mimicry of host antimicrobial peptides

Over the last decade a significant number of studies have highlighted the central role of host antimicrobial (or defence) peptides in modulating the response of innate immune cells to pathogen-associated ligands. In humans, the most widely studied antimicrobial peptide is LL-37, a 37-residue peptide containing an amphipathic helix that is released via proteolytic cleavage of the precursor protein CAP18. Owing to its ability to protect against lethal endotoxaemia and clinically-relevant bacterial infections, LL-37 and its derivatives are seen as attractive candidates for anti-sepsis therapies. We have identified a novel family of molecules secreted by parasitic helminths (helminth defence molecules; HDMs) that exhibit similar biochemical and functional characteristics to human defence peptides, particularly CAP18. The HDM secreted by Fasciola hepatica (FhHDM-1) adopts a predominantly α-helical structure in solution. Processing of FhHDM-1 by F. hepatica cathepsin L1 releases a 34-residue C-terminal fragment containing a conserved amphipathic helix. This is analogous to the proteolytic processing of CAP18 to release LL-37, which modulates innate cell activation by classical toll-like receptor (TLR) ligands such as lipopolysaccharide (LPS). We show that full-length recombinant FhHDM-1 and a peptide analogue of the amphipathic C-terminus bind directly to LPS in a concentration-dependent manner, reducing its interaction with both LPS-binding protein (LBP) and the surface of macrophages. Furthermore, FhHDM-1 and the amphipathic C-terminal peptide protect mice against LPS-induced inflammation by significantly reducing the release of inflammatory mediators from macrophages. We propose that HDMs, by mimicking the function of host defence peptides, represent a novel family of innate cell modulators with therapeutic potential in anti-sepsis treatments and prevention of inflammation.

[Effects of elicitors on accumulation of phenolic acids and tanshinones in Salvia miltiorrhiza hairy root]

OBJECTIVE

To observe the effects of a biotic elicitor fungal hyphae extract, an abiotic elicitor methyl jasmonate and their synergistic action on the accumulation of phenolic acids and tanshinones in Salvia miltiorrhiza hairy root.

METHOD

Different elicitors were added to S. miltiorrhiza hairy root, which was subcultured for 21 days, the dry weight and contents of phenolic acids and tanshinones were determined at different harvest-time.

RESULT

S. miltiorrhiza hairy root growth was significantly inhibited by all three treatments and the accumulation of cryptotanshinone and dihydrotanshinone were promoted by each elicition. As for the accumulation of phenolic acids, there were differences between fungal elicitor and methyl jasmonate treatments, they were promoted by methyl jasmonate while inhibited in a certain extent by fungal hyphae extract.

CONCLUSION

Fungal elicitor, methyl jasmonate and their synergistic action have significant influence on accumulation of components in S. miltiorrhiza hairy root, and the effect varies between phenolic acids and tanshinones. There is no correlation between production of water-soluble ingredients and fat-soluble components on the whole under three different treatments.

Effects of glucose-regulated protein94 (Grp94) on Ig secretion from human blood mononuclear cells

Grp94 is the main endoplasmic reticulum-resident heat shock protein (HSP) that besides chaperoning native proteins, displays important modulatory effects on both the innate and adaptive immune response. Since the knowledge of a direct influence of Grp94 on the humoral response is lacking, in this work we tested the effect of Grp94 on Ig secretion from peripheral blood mononuclear cells (PBMCs) of five normal volunteers. The concentration of Ig secreted in the medium after incubation of 15 days was found increased in a dose-dependent manner in the presence of Grp94, used at the final concentrations of 10 and 100 ng/ml. However, by measuring the Ig secretion at different incubation times, it was apparent that maximal percent stimulation by Grp94 occurred at 7 days, decreasing thereafter. In addition, the pattern of Ig secretion in time significantly differed in the presence of Grp94 with respect to that of control PBMCs. Grp94 also stimulated in a dose-dependent manner the PBMC proliferation, an effect that preceded the Ig secretion and was accompanied by morphological changes of cells similar to those induced by the pokeweed mitogen. Effects of Grp94 on PBMCs were mediated by an intense activation of the MEK-ERK1/2 pathway and by an increased expression of HSP90. Results indicate that Grp94 can activate the humoral response by a cytokine-like, cell-mediated mechanism that leads to an accelerated process of B cell maturation and differentiation.

Induction of systemic resistance in different varieties of Solanum tuberosum by pure and crude elicitor treatment

A 10 kD elicitor protein (infestin) produced by Phytopthora infestans was purified and its efficacy for induction of systemic resistance in resistant and susceptible varieties of Solanum tuberosum was studied. Culture filtrates from P. infestans with and without purified elicitor (infestin) were used as elicitors to understand the effect of purified elicitor (infestin) on development of systemic resistance. Culture filtrate and purified elicitor (infestin) were found to induce hypersensitive reaction on the leaves of resistant varieties, but not on susceptible varieties after 48 h. Culture filtrate devoid of purified elicitor (infestin) did not induce any necrotic spots even on resistant variety. Purified elicitor (infestin) was found to induce glucose oxidase, NADPH oxidase, superoxide dismutase, glutathione reductase, catalase and peroxidase enzymes in resistant S. tuberosum plants, however the induction of these enzymes was low in susceptible varieties. The oxidative enzymes were found to induce earlier than antioxidative enzymes and there was negative correlation between these two groups of enzymes. Levels of salicylic acid, phenylalanine ammonia lyase (PAL), beta-1, 3 glucanase and chitinase activities were also found higher in resistant than in susceptible varieties. It was observed that purified elicitor (infestin) was superior to crude culture filtrate, but was not capable of inducing systemic resistance in susceptible varieties.

An ancient molecule with novel function: Alanine aminotransferase as a lipopolysaccharide binding protein with bacteriocidal activity

Alanine aminotransaminase (ALT) has been identified from bacteria to plants to animals including humans. The increase in serum ALT is regarded as an index for clinical diagnosis of liver function in humans. However, ALT elevation is also reported in non-liver injury conditions and in apparently healthy people, suggesting it may play a fundamental role physiologically. Herein we isolated an alt homolog, Amphialt, from Branchiostoma japonicus, an intermediatary species from invertebrates to vertebrates, which encoded a polypeptide of 500 amino acids with more than 62 and 52% sequence identity to vertebrate and invertebrate ALT isoenzymes, respectively. It was constitutively expressed in many tissues including the hepatic caecum, the precursor of liver, and its expression in the caecum was significantly up-regulated by challenge with lipopolysaccharides (LPS). Strikingly, recombinant AmphiALT, with a specific activity of 0.114±0.02U/mg, was capable of specifically binding to the Gram-negative bacteria Escherichia coli and Aeromonas hydrophila and to their conserved molecule LPS, as well as inhibiting the growth of E. coli and causing its lysis. In contrast, AmphiALT did not bind to the Gram-positive bacteria Staphyloccocus aureus and Bacillus subtilis as well as their conserved molecule LTA. In addition, a high homology noted between amphioxus and mammalian ALT sequences suggested a functional conservation of ALT evolutionarily, hinting at the clue that mammalian ALT may also play an antibacterial role similar to that of AmphiALT. Taken together, it is proposed that AmphiALT is an immune-relevant molecule capable of identifying LPS and causing damage to Gram-negative bacteria like E. coli and A. hydrophila. It also bolsters the notion that the hepatic caecum of amphioxus is the precursor of vertebrate liver, acting as a major tissue in acute phase response.

[Immunogenicity of protective antigen extracted from asporogenic recombinant strain Bacillus anthracis]

AIM

To study the ability of recombinant protective antigen (PA) to stimulate adaptive immune response in laboratory animals.

MATERIALS AND METHODS

Vaccine, recombinant, and reference strains of Bacillus anthracis were used in the study. Laboratory animals were immunized subcutaneously with two doses of antigenic preparation or one dose of B. anthracis strain. After inoculation with reference strain of B. anthracis, measurement of LD50 as well as indexes of immunity was performed by specified methods.

RESULTS

It was revealed that asporogenic recombinant strain has stable biological characteristics during passages in vitro and is effective producer of PA. Using 2-stage chromatography, highly purified protein was obtained. Experiments on different biomodels--BALB/c mice, guinea pigs, and rabbits--demonstrated high protective activity of PA obtained from asporogenic producer. Increase of immunity index was noted when EA1 protein from S-layer was added to preparation for immunization.

CONCLUSION

Immunity indexes determined in experiments on laboratory animals point to high protective efficacy of recombinant PA. Further studies of its interaction with macroorganism's innate and adaptive immunity systems are promising.

Immunosuppression involving soluble CD83 induces tolerogenic dendritic cells that prevent cardiac allograft rejection

BACKGROUND

Dendritic cells (DCs) are crucial regulators of immunity and important in inducing and maintaining tolerance. Here, we investigated the potential of a novel DC-immunomodulating agent, soluble CD83 (sCD83), in inducing transplant tolerance.

METHODS

We used the C3H-to-C57BL/6 mouse cardiac transplantation model that exhibits a combination of severe cell-mediated rejection and moderate antibody-mediated rejection and investigated whether sCD83 could augment a combination therapy consisting of Rapamycin (Rapa) and anti-CD45RB monoclonal antibody (α-CD45) to prolong allograft survival.

RESULTS

Monotherapies consisting of Rapa and α-CD45 were incapable of preventing rejection. However, all treatments involving sCD83 were capable of (1) down-modulating expression of various DC surface molecules, such as major histocompatibility complex class II and costimulatory molecules, (2) reducing the allogeneic stimulatory capacity of the DCs, and (3) significantly inhibiting antidonor antibody responses. Most striking results were observed in the triple therapy-treated group, sCD83Rapaα-CD45, where cell-mediated rejection and antibody-mediated rejection were abrogated for over 100 days. Donor-specific tolerance was achieved in long-term surviving recipients, because donor skin transplants were readily accepted for an additional 100 days, whereas third-party skin grafts were rejected. Success of triple therapy treatment was accompanied by enhancement of tolerogenic-DCs that conferred antigen-specific protection on adoptive transfer to recipients of an allogeneic heart graft.

CONCLUSIONS

Our study revealed that sCD83 is capable of attenuating DC maturation and function, and inducing donor-specific allograft tolerance, in the absence of toxicity. Thus, sCD83 seems to be a safe and valuable counterpart to current DC-modulating agents.

Conserved high activity binding peptides from the Plasmodium falciparum Pf34 rhoptry protein inhibit merozoites in vitro invasion of red blood cells

Rhoptries are specialized secretory organelles found in all members of the genus Plasmodium whose proteins have been considered as promising vaccine candidates due to their involvement in cell invasion and the formation of the parasitophorous vacuole (PV). The Plasmodium falciparum Pf34 protein was recently identified as a rhoptry-neck protein located in detergent-resistant microdomains (DRMs) that is expressed in mature intraerythrocytic parasite stages, but its biological function is still unknown. Receptor-ligand assays carried out in this study found that peptides 36,051 ((101)DKKFSESLKAHMDHLKILNN(120)Y), 36,053 ((141)KKYIIKEIQNNKYLNKEKKS(160)), 36,055 ((181)WLESVNNIEEKSNILKNIKS(200)Y) and 36,056 ((201)QLLNNIASLNHTLSEEIKNI(220)Y), located in the central portion of Pf34, were found to establish protease-sensitive interactions of high affinity and specificity with receptors on the surface of red blood cell (RBCs). In vitro assays showed that Pf34 high activity binding peptides (HABPs) inhibit invasion of RBCs by P. falciparum merozoites, therefore suggesting that Pf34 could act as an adhesin during invasion and supporting the inclusion of Pf34 HABPs in further studies to develop antimalarial control methods.

Expression of Scophthalmus maximus CD83 correlates with bacterial infection and antigen stimulation

CD83 is a transmembrane glycoprotein of the immunoglobulin (Ig) superfamily and a surface marker for fully matured dendritic cells (DCs) in humans and mice. In teleosts, DC-like cells and their molecular markers are largely unknown. In this report, we described the identification and expressional analysis of a CD83 homologue, SmCD83, from turbot Scophthalmus maximus. The open reading frame of SmCD83 is 639 bp, which is preceded by a 5'-untranslated region (UTR) of 87 bp and followed by a 3'-UTR of 1111 bp. The SmCD83 gene is 4716 bp in length, which contains five exons and four introns. The deduced amino acid sequence of SmCD83 shares 40-50% overall identities with the CD83 of several fish species. Like typical CD83, SmCD83 possesses an Ig-like extracellular domain, a transmembrane domain, and a cytoplasmic domain. The conserved disulfide bond-forming cysteine residues and the N-linked glycosylation sites that are preserved in CD83 are also found in SmCD83. Expressional analysis showed that constitutive expression of SmCD83 was high in gill, blood, spleen, muscle, and kidney and low in heart and liver. Bacterial infection and poly(I:C) treatment enhanced SmCD83 expression in kidney in time-dependent manners. Likewise, bacterial challenge caused significant induction of SmCD83 expression in cultured macrophages. Vaccination of turbot with a bacterin and a purified recombinant subunit vaccine-induced significant SmCD83 expression during the first week following vaccination. These results demonstrate that SmCD83 expression correlates with microbial challenge and antigen stimulation, which suggests the possibility that there may exist in turbot DC-like antigen-presenting cells that express SmCD83 upon activation by antigen uptake. In addition, these results also suggest that SmCD83 may serve as a marker for activated macrophages in turbot.

Eukaryotic expression of functionally active recombinant soluble CD83 from HEK 293T cells

The cell surface protein CD83 belongs to the immunoglobulin super family and is highly expressed on mature dendritic cells (DCs). A membrane bound and a soluble form of CD83 (sCD83) have been described. Previously, the isolation of a purified recombinant sCD83 molecule from bacterial cultures using high pressure liquid chromatography was reported. This recombinant protein reduced DC-mediated T cell proliferation in vitro and displayed an inhibitory effect in the experimental autoimmune encephalomyelitis (EAE) model. When purifying sCD83 from bacteria, however, a lipopolysaccharide fraction is frequently co-isolated with the recombinant sCD83 protein. Moreover, the subsequent separation of sCD83 from contaminating LPS is usually accompanied by a considerable loss of soluble CD83. A further disadvantage of soluble CD83 expression in prokaryotic cells is the lack of functional glycosylation. To overcome these problems, we developed an alternative strategy to express sCD83 in eukaryotic human embryonic kidney (HEK) 293 T cells. Using this system, we showed that recombinant sCD83 was LPS-free and effectively glycosylated with all three asparagine residues at least partially involved. The functionality of the expressed sCD83 protein was examined using the mixed lymphocyte reaction (MLR) assay, demonstrating a reduced DC-mediated T cell proliferation as previously reported for the sCD83 protein purified from E. coli. Thus, a new protocol for efficient eukaryotic expression and purification of sCD83 was established, which might have several advantages compared to prokaryotic expression systems.

[Effects of S-layer proteins from lactobacillus against Salmonella typhimurium adhesion and invasion on Caco-2 cells]

OBJECTIVE

S-layer proteins of Lactobacillus acidophilus were extracted and purified, then the effect of Lactobacillus acidophilus and its S-layer proteins against the adhesion and invasion of salmonella typhimurium to caco-2 cells were investigated.

METHODS

S-layer proteins were purified by anion-exchange column {diethylaminoethyl (DEAE) DE52}, and the inhibition of Lactobacillus acidophilus and its S-layer proteins were studied against the adhesion and invasion of salmonella typhimurium on Caco-2 cells.

RESULTS

S-layer proteins exhibited strongly inhibitory effects of adhesive and invading properties of Salmonella typhimurium. In the adhesive experiments (competitive, exclusive and displacement), Salmonella typhimurium adhesion was reduced by S-layer proteins and the ability of adherence to Caco-2 cells were 1.17% +/- 5.97%, 8.71% +/- 1.36% and 10.56% +/- 0.92%, respectively (P < 0.01). The influence to inhibit the competitive adhesion of Salmonella typhimurium was optimal. Furthermore, the S-layer proteins showed a stronger effect than Lactobacillus acidophilus to inhibit Salmonella typhimurium adhesion on Caco-2 monolayers (P < 0.01). Moreover, invasion of Salmonella typhimurium to Caco-2 monolayers was inhibited by S-layer proteins.

CONCLUSION

S-layer proteins inhibited adherence and invasion of Salmonella typhimurium. The result can merit a highlight for preventive or probiotic therapy in human or animals with disease caused by Salmonella typhimurium.

Effect of yeast mannoproteins and grape polysaccharides on the growth of wine lactic acid and acetic acid bacteria

Polysaccharides constitute one of the main groups of wine macromolecules, and the difficulty in separating and purifying them has resulted in them being less studied than other wine macromolecules. In this study, the biological activity of a number of polysaccharide fractions obtained from yeast lees, must, and wine has been analyzed against a large collection of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) of enological origin. Results showed that a high proportion of AAB strains (60-88%) was inhibited by concentrations lower than 50 mg/L polysaccharide fractions containing intermediate- (6-22 kD) and small-molecular-weight (<6 kD) mannoproteins and oligosaccharide fragments derived from cellulose and hemicelluloses. Results also showed that, in contrast, yeast mannoproteins in concentrations up to 200 mg/L activated the growth of 23-48% of the studied LAB strains when ethanol was present in the culture broth. Specially, yeast commercial mannoproteins of intermediate molecular weight (6-22 kD) were active in increasing Oenococcus oeni growth (81.5% of the studied O. oeni strains) in the presence of ethanol in the culture broth. These effects of wine polysaccharides on bacterial growth provide novel and useful information for microbiological control of wines and winemaking biotechnology.

Recombinant human ZP3-induced sperm acrosome reaction: evidence for the involvement of T- and L-type voltage-gated calcium channels

For successful fertilization mammalian spermatozoa must undergo the acrosome reaction (AR), an exocytotic event that allows this cell to penetrate the outer layer of the oocyte, the zona pellucida (ZP). Four glycoproteins (ZP1-ZP4) compose the human ZP, being ZP3 the physiological inductor of the AR. This process requires changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) involving not fully understood mechanisms. Even in mouse sperm, the pharmacologically documented participation of voltage-gated Ca(2+) (Ca(V)) channels and store-operated channels (SOCs) in the ZP-induced AR is being debated. The situation in human sperm is even less clear due to the limited availability of human ZP. Here, we used recombinant human ZP3 (rhZP3) produced in baculovirus-infected Sf9 cells to investigate the involvement of Ca(V) channels in the human sperm AR. Our findings showed that Ni(2+) and mibefradil at concentrations that block T-type or Ca(V)3 channels, and nimodipine and diltiazem that block L-type or Ca(V)1 channels, significantly inhibited the rhZP3-initiated AR. On the other hand, the AR was insensitive to concentrations of omega-Agatoxin IVA, omega-Conotoxin GVIA and SNX-482 that block P/Q, N and R-type channels, respectively (Ca(V)2 channels). Our overall findings suggest that Ca(V)1 and Ca(V)3 channels participate in human sperm AR. Consistent with this, we detected in human sperm transcripts for the Ca(V)1 auxiliary subunits, alpha(2)delta, beta(1), beta(2) and beta(4), but not the neuronal specific isoforms beta(3) and gamma(2).

The human cancer antigen mesothelin is more efficiently presented to the mouse immune system when targeted to the DEC-205/CD205 receptor on dendritic cells

To develop a tumor vaccine directly targeting tumor antigen to dendritic cells in situ, we engineered human mesothelin (MSLN) into an antibody specific for mouse DEC-205, a receptor for antigen presentation. We then characterized both T cell and humoral responses to human MSLN and compared immunizing efficacy of DEC-205-targeted MSLN to nontargeted protein after a single-dose immunization. Targeting human MSLN to DEC-205 receptor induced stronger CD4(+) T-cell responses compared to high doses of mesothelin protein. Approximately 0.5% CD4(+) T cells were primed to produce IFN-gamma, tumor necrosis factor-alpha, and IL-2 via intracellular cytokine staining, and the T cells also could proliferate rapidly. The immune response exhibited breadth because the primed CD4(+) T cells responded to at least three epitopes in the H-2(b) background. Targeting MSLN protein to DEC-205 receptor also resulted in cross-presentation to CD8(+) T cells. Antibody responses against human MSLN were also detected in serum from primed mice by ELISA assays. In summary, targeting of MSLN to DEC-205 improves the induction of CD4(+) and CD8(+) T-cell immunity accompanied by an antibody response. DEC-205-targeting could be valuable for enhancing immunity to MSLN in cancers where this nonmutated protein is expressed.

A Comparative Analysis of Immunorestoration and Recovery with Conventional and Immunotherapeutic Protocols in Canine Generalized Demodicosis: A Newer Insight of Immunotherapeutic Efficacy of T11TS

Demodex canis is a natural inhabiting mite of canine skin. Immunological disorder or genetic disorder induces the Demodex population to proliferate vigorously resulting in generalized demodicosis with consequent chronic immunosuppression. Signs of generalized demodicosis include alopecia, crysting, erythema, secondary pyoderma etc. Amitraz, an acaricide, is used conventionally for the treatment of generalized demodicosis. In many instances, the disease relapses due to the residual immunosuppression. The need of an immunorestorative therapy has been urged in generalized demodicosis. Two immunorestorative drugs, namely, Immuplus, a herbal drug, and T11TS, a sheep erythrocyte surface glycoprotein, has been used in two separate groups of dogs having generalized demodicosis and receiving Amitraz treatment. It was observed that though Amitraz treated group responded to the therapy showing increased E-rosettes and nonspecific cytotoxic efficacy of T-lymphocytes and decrease in phagocytic potential of macrophages, the groups treated with the immunotherapeutics like Immuplus and T11TS, responded better. However, the group treated with T11TS showed best recovery. These results emphasize the need for an immunorestorative therapy in generalized demodicosis and provide data in favor of T11TS as a better immunomodulator in comparison to Immuplus.

LTB4 Can Directly Stimulate Human Osteoclast Formation from PBMC Independent of RANKL

Leukotriene B4, as a kind of 5-lipoxygenase metabolite of arachidonic acid, is known to influence osteoclast formation and bone resorption. In order to determine whether Leukotriene B4 could directly stimulate human osteoclast differentiation and activation independent of RANKL (ODF), three different concentrations of Leukotriene B4 (10(-9)M, 10(-8)M, 10(-7)M) were added to the culture of CD14+ monocyte fraction of peripheral blood mononuclear cell (PBMC) in the presence of macrophage colony-stimulating factor (M-CSF). Under these conditions, Leukotriene B4 could induce multinucleated cells, which were positive for Tartrate-resistant acidic phosphatase (TRAP) staining and capable of bone resorption. Addition of osteoprotegerin (OPG) to PBMC cultures does not abrogate osteoclast formation induced by LTB4. Osteoclastogenesis induced by Leukotriene B4 were dose-dependently increased and weaker than that of RANKL. These results indicated that Leukotriene B4, elevated in many inflammatory diseases, is directly capable of inducing osteoclast formation by a RANKL-independent mechanism.

The Potential of the Tumor Microenvironment to Influence Apo2L/TRAIL Induced Apoptosis

Apo2L/TRAIL ligation of specific cell surface receptors (DR4 and DR5) induces apoptosis of many malignant cells with little effect on normal cells. This anti-tumor capability has been demonstrated using cell lines of many tumor types, both in vitro and in vivo when the cells are grown as xenografts. We have extended these studies to investigate the efficacy of Apo2L/TRAIL against patient tumor xenografts in SCID mice and found that the growth of many tumors, both of primary and metastatic origin, can be inhibited by Apo2L/TRAIL. The basis of resistance to Apo2L/TRAIL induced apoptosis in malignant cells and normal cells is not completely understood, but it is known that a variety of factors including hypoxia, MMPs and cytokines present in the tumor microenvironment can influence the response of malignant cells to Apo2L/TRAIL. Currently, the clinical potential of several molecules targeting the Apo2L/TRAIL receptors DR4 and DR5 is being investigated. Our goal in this review is to provide a brief overview of a number of factors that have potential to influence the response of patient tumors to Apo2L/TRAIL.