Molecular and Biochemical Pathways of Catalpol in Alleviating Diabetes Mellitus and Its Complications

Catalpol isolated from Rehmannia glutinosa is a potent antioxidant and investigated against many disorders. This review appraises the key molecular pathways of catalpol against diabetes mellitus and its complications. Multiple search engines including Google Scholar, PubMed, and Science Direct were used to retrieve publications containing the keywords “Catalpol”, “Type 1 diabetes mellitus”, “Type 2 diabetes mellitus”, and “diabetic complications”. Catalpol promotes IRS-1/PI3K/AKT/GLUT2 activity and suppresses Phosphoenolpyruvate carboxykinase (PEPCK) and Glucose 6-phosphatase (G6Pase) expression in the liver. Catalpol induces myogenesis by increasing MyoD/MyoG/MHC expression and improves mitochondria function through the AMPK/PGC-1α/PPAR-γ and TFAM signaling in skeletal muscles. Catalpol downregulates the pro-inflammatory markers and upregulates the anti-inflammatory markers in adipose tissues. Catalpol exerts antioxidant properties through increasing superoxide dismutase (sod), catalase (cat), and glutathione peroxidase (gsh-px) activity in the pancreas and liver. Catalpol has been shown to have anti-oxidative, anti-inflammatory, anti-apoptosis, and anti-fibrosis properties that in turn bring beneficial effects in diabetic complications. Its nephroprotective effect is related to the modulation of the AGE/RAGE/NF-κB and TGF-β/smad2/3 pathways. Catalpol produces a neuroprotective effect by increasing the expression of protein Kinase-C (PKC) and Cav-1. Furthermore, catalpol exhibits a cardioprotective effect through the apelin/APJ and ROS/NF-κB/Neat1 pathway. Catalpol stimulates proliferation and differentiation of osteoblast cells in high glucose condition. Lastly, catalpol shows its potential in preventing neurodegeneration in the retina with NF-κB downregulation. Overall, catalpol exhibits numerous beneficial effects on diabetes mellitus and diabetic complications.

Dose-Dependent Effects of Resveratrol on Cisplatin-Induced Hearing Loss

Previous preclinical studies have demonstrated the otoprotective effects of resveratrol (RV) at low doses. This study aimed to investigate the dose-dependent effects of RV in rats with cisplatin (CXP)-induced hearing loss. Sprague-Dawley rats (8-weeks old) were divided into six treatment groups (n = 12/group) and treated as follows: control, 0.5 mg/kg RV, 50 mg/kg RV, CXP, 0.5 mg/kg RV + CXP), and 50 mg/kg RV + CXP groups. CXP (3 mg/kg) was intraperitoneally injected for 5 days. RV (0.5 or 50 mg/kg) was intraperitoneally injected for 10 days from the first day of CXP administration. Auditory brainstem response (ABR) thresholds were measured before and within 3 days at the end of the drug administration. Cochlear tissues were harvested, and the outer hair cells were examined using cochlear whole mounts. The mRNA expression of NFκB, IL6, IL1β, and CYP1A1, and protein levels of aryl hydrocarbon receptor (AhR) and cytosolic and nuclear receptor for advanced glycation endproducts (RAGE) were evaluated. The ABR threshold increased in the 50 mg/kg RV and CXP groups at 4, 8, 16, and 32 kHz. The 0.5 mg/kg RV + CXP group demonstrated decreased hearing thresholds at 4 and 32 kHz compared to the CXP group. Cochlear whole-mount analysis revealed loss of outer hair cells in the 50 mg/kg RV and CXP groups and partial prevention of these cells in the 0.5 mg/kg RV + CXP group. The mRNA expressions of NFκB, IL6, and IL1β were increased in the 50 mg/kg RV and CXP groups compared to the control group. In contrast, these levels were decreased in the 0.5 mg/kg RV + CXP group compared to the CXP group. The mRNA expression of CYP1A1 was increased in the CXP group, while it was decreased in the 0.5 mg/kg RV + CXP group compared to the control group. The protein levels of AhR and cytosolic RAGE decreased in the 0.5 mg/kg RV group. Low-dose RV had partial otoprotective effects on CXP ototoxicity. The otoprotective effects of RV may be mediated through anti-oxidative (CYP1A1 and RAGE) and anti-inflammatory (NFκB, IL6, and IL1β) responses. High-dose RV exerted an inflammatory response and did not ameliorate CXP-induced ototoxicity.

Evaluating the role of dithiolane rich fraction of Ferula asafoetida (apiaceae) for its antiproliferative and apoptotic properties: in vitro studies

Asafoetida resin has been reported for various biological activities but its use has been widely restricted owing to its pungent smell and pool water solubility.

AIM

In vitro study of the anticancer potential of microwave-extracted essential oil (EO) of Ferula asafoetida.

MATERIALS AND METHODS

The phytochemical investigation and in vitro cytotoxicity assessment was carried out in two human liver cancer cell lines. The expression of NFKB1, TGFB1, TNF, CASP3 was analyzed by reverse transcription polymerase chain reaction.

RESULTS

Ferula asafoetida EO contains high concentrations of dithiolane, which possess antiproliferative activity in human liver carcinoma cell lines (HepG2 and SK-Hep1) in a dose-dependent manner. The bioactive compounds in F. asafoetida are capable of induction of apoptosis and altered NF-kB and TGF-β signalling with increase in caspase-3 and TNF-α expression.

CONCLUSION

Further elucidation of bioactive molecules and underlying mechanisms could lead to potential intervention in liver cancer in animal models. The safety and efficacy as well as the mode of EO action in animal models would be highly crucial.

The PKC/NF-κB signaling pathway induces APOBEC3B expression in multiple human cancers

Overexpression of the antiviral DNA cytosine deaminase APOBEC3B has been linked to somatic mutagenesis in many cancers. Human papillomavirus infection accounts for APOBEC3B upregulation in cervical and head/neck cancers, but the mechanisms underlying nonviral malignancies are unclear. In this study, we investigated the signal transduction pathways responsible for APOBEC3B upregulation. Activation of protein kinase C (PKC) by the diacylglycerol mimic phorbol-myristic acid resulted in specific and dose-responsive increases in APOBEC3B expression and activity, which could then be strongly suppressed by PKC or NF-κB inhibition. PKC activation caused the recruitment of RELB, but not RELA, to the APOBEC3B promoter, implicating noncanonical NF-κB signaling. Notably, PKC was required for APOBEC3B upregulation in cancer cell lines derived from multiple tumor types. By revealing how APOBEC3B is upregulated in many cancers, our findings suggest that PKC and NF-κB inhibitors may be repositioned to suppress cancer mutagenesis, dampen tumor evolution, and decrease the probability of adverse outcomes, such as drug resistance and metastasis.

Buthionine sulfoximine, an inhibitor of glutathione biosynthesis, induces expression of soluble epoxide hydrolase and markers of cellular hypertrophy in a rat cardiomyoblast cell line: roles of the NF-κB and MAPK signaling pathways

Evidence suggests that upregulation of soluble epoxide hydrolase (sEH) is associated with the development of myocardial infarction, dilated cardiomyopathy, cardiac hypertrophy, and heart failure. However, the upregulation mechanism is still unknown. In this study, we treated H9C2 cells with buthionine sulfoximine (BSO) to explore whether oxidative stress upregulates sEH gene expression and to identify the molecular and cellular mechanisms behind this upregulatory response. Real-time PCR and Western blot analyses were used to measure mRNA and protein expression, respectively. We demonstrated that BSO significantly upregulated sEH at mRNA levels in a concentration- and time-dependent manner, leading to a significant increase in the cellular hypertrophic markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). Furthermore, BSO significantly increased the cytosolic phosphorylated IκB-α and translocation of NF-κB p50 subunits, as measured by Western blot analysis. This level of translocation was paralleled by an increase in the DNA-binding activity of NF-κB P50 subunits. Moreover, our results demonstrated that pretreatment with the NF-κB inhibitor PDTC significantly inhibited BSO-mediated induction of sEH and cellular hypertrophic marker gene expression in a dose-dependent manner. Additionally, mitogen-activated protein kinases (MAPKs) were transiently phosphorylated by BSO treatment. To understand further the role of MAPKs pathway in BSO-mediated induction of sEH mRNA, we examined the role of extracellular signal-regulated kinase (ERK), c-JunN-terminal kinase (JNK), and p38 MAPK. Indeed, treatment with the MEK/ERK signal transduction inhibitor, PD98059, partially blocked the activation of IκB-α and translocation of NF-κB p50 subunits induced by BSO. Moreover, pretreatment with MEK/ERK signal transduction inhibitors, PD98059 and U0126, significantly inhibited BSO-mediated induction of sEH and cellular hypertrophic marker gene expression. These results clearly demonstrated that the NF-κB signaling pathway is involved in BSO-mediated induction of sEH gene expression, and appears to be associated with the activation of the MAPK pathway. Furthermore, our findings provide a strong link between sEH-induced cardiac dysfunction and involvement of NF-κB in the development of cellular hypertrophy.

An obligatory role of NF-κB in mediating bone marrow derived endothelial progenitor cell recruitment and proliferation following endotoxemic multiple organ injury in mice

BACKGROUND

Recruitment of bone marrow derived endothelial progenitor cells (BMDEPCs) alleviates multiple organ injury (MOI) and improves outcomes. However, mechanisms mediating BMDEPC recruitment following septic MOI remain largely unknown. This study characterized the kinetics of BMDEPC recruitment and proliferation and defined the role of NF-κB in regulating BMDEPC recruitment and proliferation.

METHODS AND MAIN FINDINGS

Chimeric mice with an intact or disrupted NF-κB p50 gene and BMDEPC-restricted expression of green fluorescent protein were created and injected with LPS (2 mg/kg, i.p.). BMDEPC recruitment and proliferation in multiple organs were quantified. BMDEPC recruitment and proliferation are highly organ-dependent. Lungs had the highest number of BMDEPC recruitment, whereas heart, liver and kidney had only a small fraction of the number of BMDEPCs in lungs. Number of proliferating BMDEPCs was several-fold higher in lungs than in other 3 organs. Kinetically, BMDEPC recruitment into different organs showed different time course profiles. NF-κB plays obligatory roles in mediating BMDEPC recruitment and proliferation. Universal deletion of NF-κB p50 gene inhibited LPS-induced BMDEPC recruitment and proliferation by 95% and 69% in heart. However, the contribution of NF-κB to these regulations varies significantly between organs. In liver, universal p50 gene deletion reduced LPS-induced BMDEPC recruitment and proliferation only by 49% and 35%. NF-κB activities in different tissue compartments play distinct roles. Selective p50 gene deletion either in stromal/parenchymal cells or in BM/blood cells inhibited BMDEPC recruitment by a similar extent. However, selective p50 gene deletion in BM/blood cells inhibited, but in stromal/parenchymal cells augmented BMDEPC proliferation.

CONCLUSIONS

BMDEPC recruitment and proliferation display different kinetics in different organs following endotoxemic MOI. NF-κB plays obligatory and organ-dependent roles in regulating BMDEPC recruitment and proliferation. NF-κB activities in different tissue compartments play distinct roles in regulating BMDEPC proliferation.

Role of the exogenous HCV core protein in the interaction of human hepatocyte proliferation and macrophage sub-populations

BACKGROUND

The core protein of hepatitis C virus (HCV) is found in the cytoplasm and nuclei of infected cells, including hepatocytes and other cells in the liver. The core protein could be secreted as well. Resident liver macrophages are dependent on the tissue micro-environment and external stimuli to differentiate M1 and M2 hypotypes with distinct functions, and increased expression of the nuclear transcription factor STAT3 was seen in M2-polarized macrophages. In contrast to proinflammatory M1 macrophages, M2 macrophages serve beneficial roles in chronic inflammation, immunosuppression, and tumorigenesis.

METHODS

Monocyte-derived human macrophage line (mTHP-1) was treated with the exogenous HCV core protein. Next, the mTHP-1 culture supernatant or cell pellets were added to culture media of normal human liver cell line (L02).

RESULTS

Only the culture supernatant stimulated L02 cells proliferation, which was associated with phosphorylated ERK expression. Core protein activated mTHP-1 cells showed enhanced pro- and anti-inflammatory cytokines secretion, which was accompanied by high expression of phosphorylated NF-κB105 and NF-κB65. However, phosphorylated STAT1, and STAT3, which are normally associated with M1 and M2 macrophage polarization, and cell surface expression of CD206, CD14, CD16, and CD86, were unaltered. A transwell co-culture system showed that only in mTHP-1 co-cultured with L02 in the presence of exogenous core protein, were higher levels of phosphorylated STAT3 and CD206 seen.

CONCLUSIONS

We showed L02 cells proliferation was accelerated by the culture supernatant of mTHP-1 cells treated with the exogenous HCV core protein. The exogenous core protein mediated the interaction between macrophages and hepatocytes in co-culture, which enhanced the expression of phosphorylated STAT3 and CD206 in macrophages.

Lymphotoxin organizes contributions to host defense and metabolic illness from innate lymphoid cells

The lymphotoxin (LT)-pathway is a unique constituent branch of the Tumor Necrosis Superfamily (TNFSF). Use of LT is a critical mechanism by which fetal innate lymphoid cells regulate lymphoid organogenesis. Within recent years, adult innate lymphoid cells have been discovered to utilize this same pathway to regulate IL-22 and IL-23 production for host defense. Notably, genetic studies have linked polymorphisms in the genes encoding LTα to several phenotypes contributing to metabolic syndrome. The role of the LT-pathway may lay the foundation for a bridge between host immune response, microbiota, and metabolic syndrome. The contribution of the LT-pathway to innate lymphoid cell function and metabolic syndrome will be visited in this review.

Expression of NFkB1, GADD45A and JNK1 in salivary gland carcinomas of different histotypes

The class of salivary gland tumours is very heterogenous, both in a histopathological and clinical sense. Since they are uncommon lesions, their clinical management is still problematic. Molecular mechanisms underlying the development of these cancer types may be fundamental for the diagnosis, treatment and prognosis of this disease. In this study, the gene expression of nuclear factor-kappa B (NKkB1/p65), c-Jun N-terminal kinase (JNK1) and growth arrest and DNA damage (GADD45A), which all play an important role in inflammatory and cell survival mechanisms, was assessed in benign and malignant neoplasms of the salivary gland. The absolute mRNA content of paraffin embedded samples of salivary gland cancer was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using specific primers for NFkB1, GADD45A and JNK1. Expression values (relative to HPRT) were statistically evaluated. Among the detected alterations in gene expression, the only difference reaching statistical significance was in the case of NFkB1 in adenocystic carcinomas (p=0.05). Given the importance of these signalling mechanisms in the biology of tumorigenesis, these results may be implemented in further research and these genes might become targets for innovative diagnostic and therapeutic strategies.

NFκB signaling is important for growth of antiestrogen resistant breast cancer cells

Resistance to endocrine therapy is a major clinical challenge in current treatment of estrogen receptor-positive breast cancer. The molecular mechanisms underlying resistance are yet not fully clarified. In this study, we investigated whether NFκB signaling is causally involved in antiestrogen resistant cell growth and a potential target for re-sensitizing resistant cells to endocrine therapy. We used an MCF-7-derived cell model for antiestrogen resistant breast cancer to investigate dependence on NFκB signaling for antiestrogen resistant cell growth. We found that targeting NFκB preferentially inhibited resistant cell growth. Antiestrogen resistant cells expressed increased p50 and RelB, and displayed increased phosphorylation of p65 at Ser529 and Ser536. Moreover, transcriptional activity of NFκB after stimulation with tumor necrosis factor α was enhanced in antiestrogen resistant cell lines compared to the parental cell line. Inhibition of NFκB signaling sensitized tamoxifen resistant cells to the growth inhibitory effects of tamoxifen but was not sufficient to fully restore sensitivity of fulvestrant resistant cells to fulvestrant. In support of this, depletion of p65 with siRNA in tamoxifen resistant cells increased sensitivity to tamoxifen treatment. Our data provide evidence that NFκB signaling is enhanced in antiestrogen resistant breast cancer cells and plays an important role for antiestrogen resistant cell growth and for sensitivity to tamoxifen treatment in resistant cells. Our results imply that targeting NFκB might serve as a potential novel treatment strategy for breast cancer patients with resistance toward antiestrogen.

An additive interaction between the NFkappaB and estrogen receptor signalling pathways in human endometrial epithelial cells

BACKGROUND

Human embryo implantation is regulated by estradiol (E2), progesterone and locally produced mediators including interleukin-1beta (IL-1beta). Interactions between the estrogen receptor (ER) and NF kappa B (NFkappaB) signalling pathways have been reported in other systems but have not been detailed in human endometrium.

METHODS AND RESULTS

Real-time PCR showed that mRNA for the p65 and p105 NFkappaB subunits is maximally expressed in endometrium from the putative implantation window. Both subunits are localized in the endometrial epithelium throughout the menstrual cycle. Reporter assays for estrogen response element (ERE) activity were used to examine functional interactions between ER and NFkappaB in telomerase immortalized endometrial epithelial cells (TERT-EEC). E2 and IL-1beta treatment of TERT-EECs enhances ERE activity by a NFkappaB and ER dependent mechanism; this effect could be mediated by ERalpha or ERbeta. E2 and IL-1beta also positively interact to increase endogenous gene expression of prostaglandin E synthase and c-myc. This is a gene-dependent action as there is no additive effect on cyclin D1 or progesterone receptor expression.

CONCLUSION

In summary, we have established that NFkappaB signalling proteins are expressed in normal endometrium and report that IL-1beta can enhance the actions of E2 in a cell line derived from healthy endometrium. This mechanism may allow IL-1beta, possibly from the developing embryo, to modulate the function of the endometrial epithelium to promote successful implantation, for example by regulating prostaglandin production. Aberrations in the interaction between the ER and NFkappaB signalling pathways may have a negative impact on implantation contributing to pathologies such as early pregnancy loss and infertility.

Pioglitazone, a PPARgamma ligand, suppresses NFkappaB activation through inhibition of IkappaB kinase activation in cerulein-treated AR42J cells

BACKGROUND AND AIM

NFkappaB plays a major role in the immune and inflammation responses of pancreatitis. Recently, there is increasing evidence that the expression and activity of PPARgamma may participate in the activity of NFkappaB. Therefore, we investigated a putative relationship of the two transcription factors in cerulein-treated pancreatic acinar AR42J cells.

METHOD

AR42J were stimulated by cerulein with or without the presence of a PPARgamma activator pioglitazone or a PPARgamma antagonist GW9662.

RESULTS

Treatment of AR42J cells with pioglitazone attenuated cerulein induced p50 and p65 NFkappaB dimer activity in the nucleus as measured by transcription factor assay. Cytosolic expression of IkappaBalpha protein was reduced by cerulein, basal signalling was not influenced by the PPARgamma inhibitor GW9662 and pioglitazone. Adversely, the inhibitory effect of pioglitazone on NFkappaB activity induced by cerulein was almost reversed by GW9662.

CONCLUSION

These findings provide evidence for the involvement of the nuclear hormone receptors PPARgamma in the activity of NFkappaB in cerulein-treated AR42J cells.

Induction of activator protein-1 and nuclear factor-kappaB as a prerequisite for disease development in susceptible SJL/J mice after theiler murine encephalomyelitis

Theiler murine encephalomyelitis (TME) represents an important mouse model of multiple sclerosis. Activator protein and nuclear factor-kappaB proteins are interacting transcription factors controlling the expression of cytokines involved in the demyelination process. However, specific expression patterns of these transcription factors in susceptible and resistant mouse strains and their relationship to demyelination remains to be determined. The expression of activator protein-1 (c-fos and c-jun) and nuclear factor-kappaB (p50 and p65) genes, TME virus, tumor necrosis factor-alpha, and interferon-gamma was investigated in the spinal cord of TME virus (BeAn strain)-infected SJL/J and C57BL/6 mice until 196 days postinfection (dpi) using reverse transcription-quantitative polymerase chain reaction. Additionally, c-fos, c-jun, and p50 expression was examined by applying immunohistochemistry. In susceptible SJL/J mice, in contrast to resistant C57BL/6 mice, all investigated mRNA transcripts were upregulated in the early (0-7 days dpi) and late phases (28-196 days dpi) of TME. In addition, white matter lesions of SL/J mice were characterized by c-jun-positive astrocytes and p50-positive mononuclear immune cells. Upregulation of activator protein-1 and nuclear factor-kappaB in resident glial cells in the early phase followed by strong downstream tumor necrosis factor-alpha production might account for disease development in susceptible SJL/J mice. In the late phase, the formation of JUN/JUN homodimers in intralesional astrocytes might contribute to the sustained release of proinflammatory cytokines, thereby promoting disease progression.

Anti-beta2-glycoprotein I antibodies induce monocyte release of tumor necrosis factor alpha and tissue factor by signal transduction pathways involving lipid rafts

OBJECTIVE

To investigate the association of beta(2)-glycoprotein I (beta(2)GPI) with lipid rafts in monocytic cells and to evaluate the proinflammatory and procoagulant effects of anti-beta(2)GPI binding to its target antigen on the monocyte plasma membrane.

METHODS

Human monocytes were fractionated by sucrose density-gradient centrifugation and analyzed by Western blotting. Immunoprecipitation experiments were performed to analyze the association of beta(2)GPI with lipid rafts and the possible interaction of beta(2)GPI with annexin A2 and Toll-like receptor 4 (TLR-4). Monocytes were then stimulated with affinity-purified anti-beta(2)GPI antibodies from patients with the antiphospholipid syndrome (APS). Interleukin-1 receptor-associated kinase (IRAK) phosphorylation and NF-kappaB activation were evaluated by immunoprecipitation and transcription factor assay, respectively. Supernatants from monocytes were tested for tumor necrosis factor alpha (TNFalpha) and tissue factor (TF) levels by enzyme-linked immunosorbent assay.

RESULTS

We found beta(2)GPI and its putative receptor annexin A2 in lipid raft fractions of human monocytes. Moreover, there was an association between beta(2)GPI and TLR-4, suggesting that it was partially dependent on raft integrity. Triggering with anti-beta(2)GPI antibodies induced IRAK phosphorylation and consequent NF-kappaB activation, which led to the release of TNFalpha and TF.

CONCLUSION

Anti-beta(2)GPI antibodies react with their target antigen, likely in association with annexin A2 and TLR-4, in lipid rafts in the monocyte plasma membrane. Anti-beta(2)GPI binding triggers IRAK phosphorylation and NF-kappaB translocation, leading to a proinflammatory and procoagulant monocyte phenotype characterized by the release of TNFalpha and TF, respectively. These findings provide new insight into the pathogenesis of APS, improving our knowledge of valuable therapeutic targets.

Peripheral blood mononuclear cell NF-kappaB p105 mRNA decreases during asthmatic attacks

BACKGROUND

NF-kappaB is a transcription factor involved in expression of many inflammatory cytokines, chemical transmitters, and adhesion molecules. It has been reported to play a major role in the pathogenesis of asthma. NF-kappaB p50, which is the actual subunit that results from the cleavage of p105, is required for the induction of eosinophilia via IL-5 and chemokines.

METHODS

The subjects were 10 patients with a mean age of 59.3 years (14-82 years). NF-kappaB p105 mRNA in peripheral blood mononuclear cells during the presence or absence of asthmatic attacks was investigated. Total RNA was extracted from peripheral blood mononuclear cells. After cDNA was synthesized using random primers, NF-kappaB p105 mRNA level was measured by real-time polymerase chain reaction.

RESULTS

The NF-kappaB p105 mRNA level in peripheral blood mononuclear cells was lower during asthmatic attacks than in the absence of attacks, showing a significant difference (Wilcoxon's signed rank test: p<0.01).

CONCLUSIONS

A drop in NF-kappaB p105 during an asthma attack could result in increased NF-kappaB activity. There is a possibility that a change in the NF-kappaB p105 mRNA level might indicate some pathogenetic state in bronchial asthma attacks.

Nuclear factor kappa-B p50 and p65 subunits expression in dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia after Alzheimer's disease (AD). Parkinsonism in DLB is mainly caused by neuronal loss with Lewy bodies (LBs) in the substantia nigra, thereby inducing degeneration of the nigrostriatal dopaminergic pathway similar to that in Parkinson's disease (PD). To clarify the pathogenesis of DLB, it is important to investigate the mechanisms involved in the degenerative process of LB-bearing neurones. Several reports suggest a role for nuclear factor kappa-B (NFkappaB) in the manifestation of neurodegenerative conditions such as AD and PD. The aim of the present study was to investigate whether NFkappaB subunits are involved in the pathogenesis of neurodegeneration in DLB by measuring tyrosine hydroxylase (TH), NFkappaB p65 and p50 protein expression in frontal cortex and substantia nigra pars compacta of DLB and control human brains. An increase, although not statistically significant, in nigral TH expression in DLB cases was observed. There were no differences in the cortical and nigral expression levels of NFkappaB p65 subunit between control and DLB cases. Western blots of the frontal cortex showed no differences in the expression levels of NFkappaB p50 subunit. However, NFkappaB p50 levels were significantly decreased (P < 0.05) in the pars compacta of the substantia nigra in the DLB cases in comparison with controls. The decrease in the expression of the p50 subunit in the substantia nigra of DLB cases achieved in the present study may increase the vulnerability of the dopaminergic neurones to a possible neurotoxic effect of p65 subunit. Thus, normal levels of NFkappaB p65 might be toxic in neurones with a low expression of the NFkappaB p50 subunit.

NFKB1 is a direct target of the TAL1 oncoprotein in human T leukemia cells

We recently showed that a subset of human T acute lymphoblastic leukemia (T-ALL) cell lines expresses low basal levels of p50, a nuclear factor-kappaB (NF-kappaB)/Rel family member, resulting in their capacity to activate the atypical p65:cRel complex rather than the classic p50:p65 dimer. Here, we show that the transcription factor TAL1 (also known as SCL) binds to the promoter of the NFKB1 gene that encodes p50 and represses its transcription to set up this unique response in T-ALL cells. When TAL1 expression is reduced in CEM T leukemia cells, basal NFKB1 expression is increased, and the levels of p65:cRel complex and transcription of its target gene, such as intercellular adhesion molecule-1 (ICAM-1), are reduced in response to etoposide treatment. Moreover, a significant negative correlation between NFKB1 and TAL1 or LMO1 was found in primary human TAL1/LMO1 double-positive T-ALL samples previously described by Ferrando et al. Thus, TAL1 modulates NFKB1 expression and an NF-kappaB-dependent transcriptional program in a subset of human T-cell leukemia cells.

[The expression characteristics and biological significance of nuclear factor- kappa B in mice bone tissue of experimental osteoporosis models]

OBJECTIVE

To study the expression characteristics and biological significance of nuclear factor NF-kappaB p50 and NF-kappaB p65 in osteoporosis development. Adult mice were ovariectomized as models of experimental osteoporosis. In this way, we can explore the molecular mechanism of osteoporosis and understand the significance during the morbility of osteoporosis.

METHODS

Four-month female BALB/c mice were randomly divided into ovariectomized group and sham-operated group. 12 weeks after surgery, the mice were sacrificed after the measurement of bone mineral density (BMD). The NF-kappaB level in bone tissue were determined by immunohistochemistry and in situ hybridization techniques.

RESULTS

Compared with the sham-operated group, bone density, rarefaction of trabecula and the number of osteoblast decreased in the ovariectomized group, while the number of osteoclast increased in the ovariectomized group. The immunohistochemistry showed that NF-kappaB expressed in both groups. It mainly localized in the cytoplasm of osteoblast, osteocytes and marrow stroma cell. The expression level in the ovariectomized group was higher than that in the sham-operated group and was negatively correlated with the BMD (P < 0.01 or P < 0.05). In situ hybridization demonstrated that the expression levels of NF-kappaB 50mRNA and NF-kappaB 65mRNA in ovariectomized group were significantly higher than that of the sham-operated group (P < 0.05).

CONCLUSION

The expression level of NF-kappaB significantly increased in the bone tissue of ovariectomized mice, and its abnormal expression was significantly correlated with BMD.

[The effects of two TCM prescriptions, Tonifying Kidney and Strengthening Vital Energy, on NF-kappaB activing in aged mouse T cells]

AIM

The aim of the present study was to explore the immunologic mechanism of delaying senescence by Strengthening Vital Energy(SVE), Tonifying Kidney (TK) and combined TK and SVE.

METHODS

Mice of 20 months were used as senescence model. The effects of the prescriptions on anti-CD3 antibody-induced NF-kappaB activity and the expression of NF-kappaB in T cells from aged mice were analyzed by electrophoretic mobility shift assay (EMSA) and Western blot, respectively.

RESULTS

NF-kappaB activity in anti-CD3 antibody-induced T cells from the aged mice was lower than that from young ones. The three prescriptions raised the activity of NF-kappaB in the T cells from the aged mice to certain extent. Combined TK and SVE had no influence on p65 and p50 subunits expressions.

CONCLUSION

The increased NF-kappaB activity may be one of mechanisms underlying the improvement of immune response in aged mice by Chinese medicines.