Subunit nanovaccine elicited T cell functional activation controls Trypanosoma cruzi mediated maternal and placental tissue damage and improves pregnancy outcomes in mice

This study investigated a candidate vaccine effect against maternal Trypanosoma cruzi (Tc) infection and improved pregnancy outcomes. For this, TcG2 and TcG4 were cloned in a nanoplasmid optimized for delivery, antigen expression, and regulatory compliance (nano2/4 vaccine). Female C57BL/6 mice were immunized with nano2/4, infected (Tc SylvioX10), and mated 7-days post-infection to enable fetal development during the maternal acute parasitemia phase. Females were euthanized at E12-E17 (gestation) days. Splenic and placental T-cell responses were monitored by flow cytometry. Maternal and placental/fetal tissues were examined for parasites by qPCR and inflammatory infiltrate by histology. Controls included age/immunization-matched non-pregnant females. Nano2/4 exhibited no toxicity and elicited protective IgG2a/IgG1 response in mice. Nano2/4 signaled a splenic expansion of functionally active CD4+ effector/effector memory (Tem) and central memory (Tcm) cells in pregnant mice. Upon challenge infection, nano2/4 increased the splenic CD4+ and CD8+T cells in all mice and increased the proliferation of CD4+Tem, CD4+Tcm, and CD8+Tcm subsets producing IFNγ and cytolytic molecules (PRF1, GZB) in pregnant mice. A balanced serum cytokines/chemokines response and placental immune characteristics indicated that pregnancy prevented the overwhelming damaging immune response in mice. Importantly, pregnancy itself resulted in a significant reduction of parasites in maternal and fetal tissues. Nano2/4 was effective in arresting the Tc-induced tissue inflammatory infiltrate, necrosis, and fibrosis in maternal and placental tissues and improving maternal fertility, placental efficiency, and fetal survival. In conclusion, we show that maternal nano2/4 vaccination is beneficial in controlling the adverse effects of Tc infection on maternal health, fetal survival, and pregnancy outcomes.

Acute muscle mass loss was alleviated with HMGB1 neutralizing antibody treatment in severe burned rats

Burn injury is associated with muscle wasting, though the involved signaling mechanisms are not well understood. In this study, we aimed to examine the role of high mobility group box 1 (HMGB1) in signaling hyper-inflammation and consequent skeletal muscle impairment after burn. Sprague Dawley rats were randomly assigned into three groups: (1) sham burn, (2) burn, (3) burn/treatment. Animals in group 2 and group 3 received scald burn on 30% of total body surface area (TBSA) and immediately treated with chicken IgY and anti-HMGB1 antibody, respectively. Muscle tissues and other samples were collected at 3-days after burn. Body mass and wet/dry weights of the hind limb muscles (total and individually) were substantially decreased in burn rats. Acute burn provoked the mitochondrial stress and cell death and enhanced the protein ubiquitination and LC3A/B levels that are involved in protein degradation in muscle tissues. Further, an increase in muscle inflammatory infiltrate associated with increased differentiation, maturation and proinflammatory activation of bone marrow myeloid cells and αβ CD4+ T and γδ T lymphocytes was noted in in circulation and spleen of burn rats. Treatment with one dose of HMGB1 neutralizing antibody reduced the burn wound size and preserved the wet/dry weights of the hind limb muscles associated with a control in the markers of cell death and autophagy pathways in burn rats. Further, anti-HMGB1 antibody inhibited the myeloid and T cells inflammatory activation and subsequent dysregulated inflammatory infiltrate in the muscle tissues of burn rats. We conclude that neutralization of HMGB1-dependent proteolytic and inflammatory responses has potential beneficial effects in preventing the muscle loss after severe burn injury.

Platelets, Macrophages, and Thromboinflammation in Chagas Disease

Chagas disease (CD) is a major health problem in the Americas and an emerging health problem in Europe and other nonendemic countries. Several studies have documented persistence of the protozoan parasite Trypanosoma cruzi, and oxidative and inflammatory stress are major pathogenic factor. Mural and cardiac thrombi, cardiac arrhythmias, and cardiomyopathy are major clinical features of CD. During T. cruzi infection, parasite-released factors induce endothelial dysfunction along with platelet (PLT) and immune-cell activation. PLTs have a fundamental role in maintaining hemostasis and preventing bleeding after vascular injury. Excessive activation of PLTs and coagulation cascade can result in thrombosis and thromboembolic events, which are recognized to occur in seropositive individuals in early stages of CD when clinically symptomatic heart disease is not apparent. Several host and parasite factors have been identified to signal hypercoagulability and increase the risk of ischemic stroke in early phases of CD. Further, PLT interaction with immune cells and their role in host defense against pathogens and inflammatory processes have only recently been recognized and evolving. In the context of parasitic diseases, PLTs function in directly responding to T. cruzi infection, and PLT interactions with immune cells in shaping the proinflammatory or immunoregulatory function of monocytes, macrophages, and neutrophils remains elusive. How T. cruzi infection alters systemic microenvironment conditions to influence PLT and immune-cell interactions is not understood. In this review, we discuss the current literature, and extrapolate the mechanistic situations to explain how PLT and innate immune cell (especially monocytes and macrophages) interactions might be sustaining hypercoagulability and thromboinflammation in chronic CD.

Prognostic Performance of Peripheral Blood Biomarkers in Identifying Seropositive Individuals at Risk of Developing Clinically Symptomatic Chagas Cardiomyopathy

Biomarkers for prognosis-based detection of Trypanosoma cruzi-infected patients presenting no clinical symptoms to cardiac Chagas disease (CD) are not available. In this study, we examined the performance of seven biomarkers in prognosis and risk of symptomatic CD development. T. cruzi-infected patients clinically asymptomatic (C/A; n = 30) or clinically symptomatic (C/S; n = 30) for cardiac disease and humans who were noninfected and healthy (N/H; n = 24) were enrolled (1 - β = 80%, α = 0.05). Serum, plasma, and peripheral blood mononuclear cells (PBMCs) were analyzed for heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), vimentin, poly(ADP-ribose) polymerase (PARP1), 8-hydroxy-2-deoxyguanosine (8-OHdG), copeptin, endostatin, and myostatin biomarkers by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Secreted hnRNPA1, vimentin, PARP1, 8-OHdG, copeptin, and endostatin were increased by 1.4- to 7.0-fold in CD subjects versus N/H subjects (P < 0.001) and showed excellent predictive value in identifying the occurrence of infection (area under the receiver operating characteristic [ROC] curve [AUC], 0.935 to 0.999). Of these, vimentin, 8-OHdG, and copeptin exhibited the best performance in prognosis of C/S (versus C/A) CD, determined by binary logistic regression analysis with the Cox and Snell test (R2C&S = 0.492 to 0.688). A decline in myostatin and increase in hnRNPA1 also exhibited good predictive value in identifying C/S and C/A CD status, respectively. Furthermore, circulatory 8-OHdG (Wald χ2 = 15.065), vimentin (Wald χ2 = 14.587), and endostatin (Wald χ2 = 17.902) levels exhibited a strong association with changes in left ventricular ejection fraction and diastolic diameter (P = 0.001) and predicted the risk of cardiomyopathy development in CD patients. We have identified four biomarkers (vimentin, 8-OHdG, copeptin, and endostatin) that offer excellent value in prognosis and risk of symptomatic CD development. Decline in these four biomarkers and increase in hnRNPA1 would be useful in monitoring the efficacy of therapies and vaccines in halting CD. IMPORTANCE There is a lack of validated biomarkers for diagnosis of T. cruzi-infected individuals at risk of developing heart disease. Of the seven potential biomarkers that were screened, vimentin, 8-OHdG, copeptin, and endostatin exhibited excellent performance in distinguishing the clinical severity of Chagas disease. A decline in these four biomarkers can also be used for monitoring the therapeutic responses of infected patients to established or newly developed drugs and vaccines and precisely inform the patients about their progress. These biomarkers can easily be screened using the readily available plasma/serum samples in the clinical setting by an ELISA that is inexpensive, fast, and requires low-tech resources at the facility, equipment, and personnel levels.

Oxidative stress implications for therapeutic vaccine development against Chagas disease

INTRODUCTION

Pathogenesis of Chagas disease (CD) caused by the protozoan parasite Trypanosoma cruzi (T. cruzi) involves chronic oxidative and inflammatory stress. In this review, we discuss the research efforts in therapeutic vaccine development to date and the potential challenges imposed by oxidative stress in achieving an efficient therapeutic vaccine against CD.

AREAS COVERED

This review covers the immune and nonimmune mechanisms of reactive oxygen species production and immune response patterns during T. cruzi infection in CD. A discussion on immunotherapy development efforts, the efficacy of antigen-based immune therapies against T. cruzi, and the role of antioxidants as adjuvants is discussed to provide promising insights to developing future treatment strategies against CD.

EXPERT OPINION

Administration of therapeutic vaccines can be a good option to confront persistent parasitemia in CD by achieving a rapid, short-lived stimulation of type 1 cell-mediated immunity. At the same time, adjunct therapies could play a critical role in the preservation of mitochondrial metabolism and cardiac muscle contractility in CD. We propose combined therapy with antigen-based vaccine and small molecules to control the pathological oxidative insult would be effective in the conservation of cardiac structure and function in CD.

Acute monocyte pro inflammatory response predicts higher positive to negative acute phase reactants ratio and severe hemostatic derangement in dengue fever

PURPOSE

The present study was intended to investigate whether monocyte immune activation shapes plasma positive to negative acute phase reactants (APRs) ratio and predicts disease severity in dengue infection.

METHODS

Serum level of ferritin, ceruloplasmin and transferrin was measured by means of electrochemiluminescence and immunoturbidimetry, respectively. Gene expression and plasma level for TNF-α, IL-6 and IL1-β was measured by means of RT-qPCR and ELISA.

RESULTS

A significant increased serum ferritin to transferrin [6.6 (3-11.7) vs 3.4 (1.9-6.1)] and ceruloplasmin to transferrin ratio [0.48 (0.21-0.87) vs 0.22 (0.13-0.43)] has been detected among the subjects with secondary dengue infection (SDENI) compared to primarily infected (PDENI) subjects (P < 0.001). Significant increased expression for CD14⁺ monocyte TNF-α, IL-6 and IL-1β has been detected in SDENI patients (vs PDENI and control, P < 0.001). Plasma ferritin to transferrin ratio was found in a significant association with high level of plasma TNF-α [ρ = 0.6522, 95% CI (0.4714-0.7805)], IL-6 [ρ = 0.6181, 95% CI (0.4257-0.7571)] and IL- 1β [ρ = 0.4119, 95% CI (0.1689-0.6077)] level among SDENI patients at 5th day time point after progression of the disease, with significantly low platelet [P < 0.001] and prolonging prothrombin time [P < 0.001] compared to control and PDENI subjects, respectively.

CONCLUSION

Acute proinflammatory cytokine response is significantly associated with increased positive to negative APRs ratio in SDENI patients, which predicts intense immune activation, and renders SDENI patients extremely susceptible to hemostatic derangement.

Chronic inflammation in polycystic ovary syndrome: A case-control study using multiple markers

Background

Polycystic ovary syndrome (PCOS) is associated with insulin resistance and elevated risk of cardiovascular disease and diabetes. Chronic inflammation has been observed in PCOS in several studies but there is also opposing evidence and a dearth of research in Indians.

Objective

To estimate chronic inflammation in PCOS and find its relationship with appropriate anthropometric and biochemical parameters.

Materials and Methods

Chronic inflammation was assessed in 30 women with PCOS (Group A) and 30 healthy controls (Group B) with highly sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), tumour necrosis factor alpha (TNFα), and platelet microparticles (PMP). In group A, the relationship of chronic inflammation with insulin resistance, waist hip ratio (WHR) serum testosterone, and serum glutamate pyruvate transaminase (SGPT) were examined.

Results

In group A, the hsCRP, TNFα, and PMP were significantly elevated compared to group B. However, IL-6 level was similar between the groups. In group A, PMP showed a significant positive correlation with waist-hip ratio and serum testosterone. IL-6 showed a significant positive correlation with insulin sensitivity and significant negative correlation with insulin resistance and serum glutamate pyruvate transaminase.

Conclusion

PCOS is associated with chronic inflammation and PMP correlates positively with central adiposity and biochemical hyperandrogenism in women with PCOS.

Associations of insulin-induced lipodystrophy in children, adolescents, and young adults with type 1 diabetes mellitus using recombinant human insulin: a cross-sectional study

OBJECTIVE

Insulin-induced lipodystrophy is of two types, lipohypertrophy and lipoatrophy. Lipodystrophy often leads to worsening of glycemic control in type 1 diabetes mellitus. Our objective was to identify the clinical, immunological, and other factor(s) associated with the development of lipodystrophy.

METHODS

In this observational cross-sectional hospital-based study, 95 children, adolescents, and young adults with type 1 diabetes mellitus were observed for the development of lipodystrophy. Injection technique, insulin dose, and glycemic parameters were noted. Serum TNF-α, IL-1β, and anti-insulin antibody levels were measured. Histopathological examination of the lipodystrophic area was done in a small number of people.

RESULTS

Among the participants, 45.2% of participants had lipohypertrophy and 4.2% had lipoatrophy exclusively; 3.1% of participants had coexisting lipohypertrophy and lipoatrophy. Improper injection site rotation technique was more common in participants with lipohypertrophy in comparison to those without lipodystrophy. The age of onset of diabetes, duration of insulin use, and the number of times of needle reuse were not significantly different between the lipohypertrophy and nonlipodystrophy groups. Serum TNF-α, IL-1β, and anti-insulin antibody levels; HbA_1c; rate of hypoglycemia; and body weight-adjusted dose requirement were higher among the participants with lipohypertrophy. On histopathology, scant, or no inflammatory infiltrate was found in lipoatrophic and lipohypertrophic areas, respectively.

CONCLUSION

Improper insulin injection technique and higher levels of proinflammatory cytokines and anti-insulin antibody are associated with lipodystrophy in type 1 diabetes mellitus. HbA_1c and rate of hypoglycemia are higher in people with lipodystrophy.

Mitochondrial Regulation of Macrophage Response Against Pathogens

Innate immune cells play the first line of defense against pathogens. Phagocytosis or invasion by pathogens can affect mitochondrial metabolism in macrophages by diverse mechanisms and shape the macrophage response (proinflammatory vs. immunomodulatory) against pathogens. Besides β-nicotinamide adenine dinucleotide 2'-phosphate, reduced (NADPH) oxidase, mitochondrial electron transport chain complexes release superoxide for direct killing of the pathogen. Mitochondria that are injured are removed by mitophagy, and this process can be critical for regulating macrophage activation. For example, impaired mitophagy can result in cytosolic leakage of mitochondrial DNA (mtDNA) that can lead to activation of cGAS-STING signaling pathway of macrophage proinflammatory response. In this review, we will discuss how metabolism, mtDNA, mitophagy, and cGAS-STING pathway shape the macrophage response to infectious agents.

PARP1-cGAS-NF-κB pathway of proinflammatory macrophage activation by extracellular vesicles released during Trypanosoma cruzi infection and Chagas disease

Trypanosoma cruzi (T. cruzi) is the etiological agent of Chagas cardiomyopathy. In the present study, we investigated the role of extracellular vesicles (Ev) in shaping the macrophage (Mφ) response in progressive Chagas disease (CD). We purified T. cruzi Ev (TcEv) from axenic parasite cultures, and T. cruzi-induced Ev (TEv) from the supernatants of infected cells and plasma of acutely and chronically infected wild-type and Parp1-/- mice. Cultured (Raw 264.7) and bone-marrow Mφ responded to TcEV and TEv with a profound increase in the expression and release of TNF-α, IL-6, and IL-1β cytokines. TEv produced by both immune (Mφ) and non-immune (muscle) cells were proinflammatory. Chemical inhibition or genetic deletion of PARP1 (a DNA repair enzyme) significantly depressed the TEv-induced transcriptional and translational activation of proinflammatory Mφ response. Oxidized DNA encapsulated by TEv was necessary for PARP1-dependent proinflammatory Mφ response. Inhibition studies suggested that DNA-sensing innate immune receptors (cGAS>>TLR9) synergized with PARP1 in signaling the NFκB activation, and inhibition of PARP1 and cGAS resulted in >80% inhibition of TEv-induced NFκB activity. Histochemical studies showed intense inflammatory infiltrate associated with profound increase in CD11b+CD68+TNF-α+ Mφ in the myocardium of CD wild-type mice. In comparison, chronically infected Parp1-/- mice exhibited low-to-moderate tissue inflammation, >80% decline in myocardial infiltration of TNF-α+ Mφ, and no change in immunoregulatory IL-10+ Mφ. We conclude that oxidized DNA released with TEv signal the PARP1-cGAS-NF-κB pathway of proinflammatory Mφ activation and worsens the chronic inflammatory pathology in CD. Small molecule antagonists of PARP1-cGAS signaling pathway would potentially be useful in reprogramming the Mφ activation and controlling the chronic inflammation in CD.

Antigen-Based Nano-Immunotherapy Controls Parasite Persistence, Inflammatory and Oxidative Stress, and Cardiac Fibrosis, the Hallmarks of Chronic Chagas Cardiomyopathy, in A Mouse Model of Trypanosoma cruzi Infection

Chagas cardiomyopathy is caused by Trypanosoma cruzi (Tc). We identified two candidate antigens (TcG2 and TcG4) that elicit antibodies and T cell responses in naturally infected diverse hosts. In this study, we cloned TcG2 and TcG4 in a nanovector and evaluated whether nano-immunotherapy (referred as nano2/4) offers resistance to chronic Chagas disease. For this, C57BL/6 mice were infected with Tc and given nano2/4 at 21 and 42 days post-infection (pi). Non-infected, infected, and infected mice treated with pcDNA3.1 expression plasmid encoding TcG2/TcG4 (referred as p2/4) were used as controls. All mice responded to Tc infection with expansion and functional activation of splenic lymphocytes. Flow cytometry showed that frequency of splenic, poly-functional CD4⁺ and CD8⁺ T cells expressing interferon-γ, perforin, and granzyme B were increased by immunotherapy (Tc.nano2/4 > Tc.p2/4) and associated with 88%–99.7% decline in cardiac and skeletal (SK) tissue levels of parasite burden (Tc.nano2/4 > Tc.p2/4) in Chagas mice. Subsequently, Tc.nano2/4 mice exhibited a significant decline in peripheral and tissues levels of oxidative stress (e.g., 4-hydroxynonenal, protein carbonyls) and inflammatory infiltrate that otherwise were pronounced in Chagas mice. Further, nano2/4 therapy was effective in controlling the tissue infiltration of pro-fibrotic macrophages and established a balanced environment controlling the expression of collagens, metalloproteinases, and other markers of cardiomyopathy and improving the expression of Myh7 (encodes β myosin heavy chain) and Gsk3b (encodes glycogen synthase kinase 3) required for maintaining cardiac contractility in Chagas heart. We conclude that nano2/4 enhances the systemic T cell immunity that improves the host’s ability to control chronic parasite persistence and Chagas cardiomyopathy.

Origin of Monocytes/Macrophages Contributing to Chronic Inflammation in Chagas Disease: SIRT1 Inhibition of FAK-NFκB-Dependent Proliferation and Proinflammatory Activation of Macrophages

BACKGROUND

Trypanosoma cruzi (Tc) causes Chagas disease (CD) that is the most frequent cause of heart failure in Latin America. TNF-α+ monocytes/macrophages (Mo/Mφ) are associated with inflammatory pathology in chronic CD. In this study, we determined the progenitor lineage of Mo/Mφ contributing to inflammation and examined the regulatory role of SIRT1 in modulating the Mo/Mφ response in Chagas disease.

METHODS AND RESULTS

C57BL/6 mice were infected with Tc, treated with SIRT1 agonist (SRT1720) after control of acute parasitemia, and monitored during chronic phase (150 days post-infection). Flow cytometry studies showed an increase in maturation of bone marrow hematopoietic stem cell (HSC)-derived Mo of proinflammatory and anti-inflammatory phenotype in acutely- and chronically-infected mice; however, these cells were not increased in splenic compartment of infected mice. Instead, yolk-sac-derived CD11b+ F4/80+ Mo/Mφ were increased in sinusoidal compartment of Chagas mice. The splenic CD11b+ F4/80+ Mo/Mφ of Chagas (vs. control) mice exhibited increased mRNA, protein, and surface expression of markers of proinflammatory phenotype (CD80+/CD64+ > CD200+/CD206+) associated with proinflammatory cytokines response (IL-6+TNF-α >> Arg-1+IL-10), and these were also detected in the myocardium of chronically infected mice. Infected mice treated with SRT1720 (vs. infected/untreated) exhibited decreased splenic expansion and myocardial infiltration of proinflammatory Mo/Mφ. SRT1720 did not alter the inherent capability of splenic Mo/Mφ of Chagas mice to respond to pathogen stimulus. Instead, SRT1720 dampened the Tc-induced increase in the expression and/or phosphorylation of focal adhesion kinase (FAK) and downstream transcription factors (Pu.1, c-Myb, and Runx1) involved in Mφ proliferation and migration and Notch1 involved in functional activation. Studies in cultured Mφ confirmed the agonistic effects of SIRT1 in controlling the Tc-induced, FAK-dependent increase in the expression of transcription factors and showed that SIRT1 agonist and FAK inhibitor abrogated the NF-κB transcriptional activity and inflammatory cytokine gene expression in Tc-infected Mφ.

CONCLUSIONS

The proinflammatory Mo/Mφ of yolk sac origin drive the splenic and tissue inflammatory response in chronic CD. SRT1720 reprogrammed the Tc-induced FAK-dependent transcription factors involved in Mφ proliferation and proinflammatory activation in Chagas disease.

DETERIORARON OF OVARIAN FUNCTION AFTER TOTAL ABDOMINAL HYSTERECTOMY WITH PRESERVARON OF OVARIES

OBJECTIVE

To evaluate ovarian function after total abdominal hysterectomy in premenopausal women.

METHODS

In the present cross-sectional study, we enrolled 52 healthy female subjects having normal menstrual cycle as controls and 37 female patients (age <45 years) who had undergone total abdominal hysterectomy (TAH) with preservation of at least one ovary for the evaluation of ovarian function. Serum antimüllerian hormone (AMH) and follicle-stimulating hormone (FSH) were measured by enzyme-linked immunosorbent assay in both groups. Transvaginal Doppler ultrasonography was done to measure ovarian stromal blood flow indices (resistive index [RI] and pulsatility index [PI]). The means obtained from different sample groups were compared using the nonparametric Mann-Whitney U test, and correlations between two variables were evaluated using the Spearman nonparametric correlation test. A value of P<.05 was considered statistically significant.

RESULTS

Mean postoperative duration of patients who had undergone hysterectomy was 2.5 years. Mean serum AMH level was 7.68 ± 6.70 ng/mL in the cases, significantly lower than the level in controls (10.98 ± 7.83 ng/mL) (P = .016). Serum FSH level in controls was 12.01 ± 6.27 μIU/mL, which was significantly higher in the cases (20.27 ± 12.91 μIU/mL) (P = .001). An inverse correlation between serum AMH and FSH was observed (P = .0006; r = -0.4583). However, the ovary RI and PI values in both groups were similar.

CONCLUSION

TAH affects ovarian function, despite normal ovarian blood supply.

ABBREVIATIONS

AMH = antimüllerian hormone FSH = follicle-stimulating hormone RI = resistive index PI = pulsatility index TAH = total abdominal hysterectomy.

Association of Genital Chlamydia trachomatis Infection with Female Infer-tility, Study in a Tertiary Care Hospital in Eastern India

BACKGROUND

Chlamydia trachomatis is recognized as one of the most common sexually transmitted pathogen in the world. 50-80% of infected females are asymptomatic. These untreated women are at risk of developing chronic sequelae leading to tubal pathology causing infertility. Infertility is defined as 1 year of unprotected intercourse without pregnancy. It may be primary or secondary. Aim : To find out the association of genital Chlamydia trachomatis infection with female infertility. Materials and Methodology : This case control study has been carried out in collaboration with R. G. Kar Medical College and Institute of Post Graduate Medical Education &amp; Research, India, between July 2012 and June 2013. 40 infertile and 40 pregnant women were enrolled by purposive sampling as per inclusion and exclusion criteria. ELISA test was performed to detect serum IgG and IgA antibody against recombinant analogs of MOMP and 3 different PCR assays were done targeting MOMP and rRNA DNA from DNA extracted from first void urine. Results : IgG seropositivity was significantly higher (15% vs 0%, P=.0255) in cases than controls, though there was no significant difference in the proportion of IgA seropositivity among 2 groups (12.5% vs 2.5%, P=0.2007). Out of 80 samples 2 samples showed the production of amplicons with R1 - R2 primers. Only 1 sample gave positive result with production of amplicons with all the 3 primers used (R1 - R2, CT0005 - CT06 and JM15 - JM16). Conclusion : Persistent C. trachomatis infection must be recognized as a risk factor of infertility in this region of India. The low PCR positivity in FVU sample helps to conclude the diagnostic utility of serological tests in screening of infertile women.

Role of NF-κB activation and VEGF gene polymorphisms in VEGF up regulation in non-proliferative and proliferative diabetic retinopathy

The present study was aimed to investigate the relation between nuclear factor kappa beta (NFκB) activation and downstream up-regulation of vascular endothelial growth factor (VEGF) in diabetic retinopathy (DR). Moreover the study was intended to evaluate the role of VEGF gene single nucleotide polymorphisms (SNPs) in DR occurrence and to investigate the functional relevance of VEGF gene SNPs in terms of VEGF expression in DR. Serum level of VEGF, VEGF R1 (receptor 1), VEGF R 2 (receptor 2) and NFκB (p50/65) activity was measured by enzyme linked immune sorbent assay. Genotyping and allelic composition of different SNPs i.e., rs2010963, rs3025039, rs1570360 and rs 2071559 were investigated by Taqman SNP genotyping assay. VEGF, NFκB p50/p65, and VEGF R1 & R2 gene expressions were quantified by real time quantitative polymerase chain reaction. Increased NFκB p50/p65 activity and expressions were observed in non proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) subjects compared to type 2 diabetes mellitus without retinopathy (DNR) group. Significantly elevated levels of serum VEGF and highest VEGF expression were found among PDR subjects compared to DNR or NPDR subjects. CC genotype and C allele of rs2010963 and TT genotype and T allele of rs3025039 were significantly over represented among PDR subjects compared to DNR group. Increased activation of NFκβ in NPDR and PDR subjects might involve increased up regulation of VEGF. VEGF SNPs i.e., rs2010963 C allele and rs3025039 T allele might be associated with PDR occurrence and in turn regulates VEGF expression among PDR subjects.

Alteration of serum inflammatory cytokines in active pulmonary tuberculosis following anti-tuberculosis drug therapy

Active pulmonary tuberculosis (APTB) is associated with a failure of the host immune system to control the invading Mycobacterium tuberculosis (Mtb). The objective of this study was to quantify and assess the role of serum inflammatory cytokines in active pulmonary tuberculosis patients following anti-tuberculosis drug (ATD) therapy. Blood samples were collected from APTB patients and normal healthy subjects (NHS) (total n=204) at baseline and 2, 4 and 6 months post-therapy and the abundance of serum inflammatory cytokines were measured by cytokine specific ELISA. Compared to NHS, APTB patients at baseline had higher levels of serum pro-inflammatory cytokines IL-12p40 (P<0.001), IFN-γ (P<0.001), TNF-α (P<0.01), IL-1β (P<0.001) and IL-6 (P<0.001) and anti-inflammatory cytokines IL-10 (P<0.001) and TGF-β1 (P<0.001) while there was no change in the level of IL-4. In APTB patients, the serum levels of IFN-γ, TNF-α, IL-6 and TGF-β1 directly relate to the bacterial load while the TNF-α, IL-1β, IL-6 and TGF-β1 relate to radiological severity. At baseline, the IL-6 level in NHS and APTB patients differed most and following ATD therapy, this level rapidly decreased and stabilized by 4-month in APTB patients. It is concluded that a subtle reduction in the serum level of IL-6 of the APTB patients following ATD therapy might play a vital role in immune-protection of the host against Mtb infection and hence the serum IL-6 level can be a useful marker to diagnose the effectiveness of therapy in the patients.

Urinary albumin : creatinine ratio predicts prediabetes progression to diabetes and reversal to normoglycemia: role of associated insulin resistance, inflammatory cytokines and low vitamin D

BACKGROUND

The relationship between albumin : creatinine ratio (ACR), insulin resistance (IR), cytokines, dyslipidemia, and 25-hydroxy vitamin D (25-OHD) in individuals with prediabetes (IPD) was investigated to evaluate their role in predicting future risk of progression to diabetes.

METHODS

The aforementioned parameters were evaluated in 147 IPD with persistent impaired fasting glucose and/or impaired glucose tolerance over two oral glucose tolerance tests, who were then followed up at 3-monthly intervals for progression to diabetes or reversal to normoglycemia.

RESULTS

Data were analyzed for 137 IPD with at least 1-year follow-up. Forty-three IPD reversed to normoglycemia (Group I), 69 continued with prediabetes (Group II), and 25 progressed to diabetes (Group III) over a mean follow-up period of 28.36 ± 8.19 months. Baseline fasting blood glucose levels (BGLs), 2-h post-glucose BGLs, and ACR were lowest in Group I and highest in Group III. Of the 137 IPD, 54.75% (n = 75) had microalbuminuria. The IPD in the lowest ACR quartile had the highest reversal to normoglycemia. Cox regression revealed that baseline IL-6 was predictive of progression to diabetes (P = 0.03) and ACR was an independent predictor of reversal to normoglycemia (P = 0.007). Kaplan-Meier analysis showed higher reversal to normoglycemia in IPD without microalbuminuria (P < 0.001).

CONCLUSION

An increased ACR is associated with higher creatinine, IR, and cytokine levels and lower 25-OHD levels in IPD. Microalbuminuria is associated with decreased reversal to normoglycemia and increased progression to diabetes. Low 25-OHD may be associated with increased progression to diabetes, perhaps via modulation of the ACR.

Vitamin-D supplementation in prediabetes reduced progression to type 2 diabetes and was associated with decreased insulin resistance and systemic inflammation: an open label randomized prospective study from Eastern India

Vitamin-D supplementation in vitamin-D insufficient/deficient prediabetes individuals is associated with significantly lower progression to diabetes (6/55 vs. 13/49; p=0.04) and higher reversal to normoglycemia (23/55 vs. 10/49; p=0.02), associated with decreased insulin resistance and systemic inflammation (TNFα and IL6). Baseline vitamin-D and 2h blood glucose independently predicted progression to diabetes.

Association of hyperglycemia mediated increased advanced glycation and erythrocyte antioxidant enzyme activity in different stages of diabetic retinopathy

AIM

This study aimed to evaluate whether hyperglycemia mediated increased formation of advanced glycation end products (AGEs) was associated with erythrocyte antioxidant enzyme activity in subjects with different stages of diabetic retinopathy (DR).

METHODS

Serum level of AGEs was determined by enzyme linked immunosorbent assay. Erythrocyte superoxide dismutase (SOD), glutathione reductase (GR) and catalase activity were estimated by enzymatic reaction based spectrophotometric assay in patients with type 2 diabetes with proliferative diabetic retinopathy (PDR), non-proliferative diabetic retinopathy (NPDR) and no retinopathy (DNR) and also in healthy non-diabetic controls (HC).

RESULT

Erythrocyte SOD and GR activity was significantly lower among NPDR (p=0.024, 0.0017, respectively) and PDR (p=0.0003, 0.0001, respectively) subjects compared with DNR individuals. A significant inverse correlation was observed between serum AGEs and erythrocyte SOD or GR activity in DNR (p=0.0019; r=-0.3033, p=0.0021; r=-0.3015, respectively), NPDR (p=0.0001; r=-0.4602, p=0.0003; r=-0.4161, respectively), and PDR (p<0.0001; r=-0.6753, p<0.0001; r=-0.5854, respectively) individuals.

CONCLUSION

Poor glycemia may be the key factor enhancing AGE formation, which may be associated with lower erythrocyte SOD and GR activity along with increased catalase activity in DR.

Tumor necrosis factor alpha -238G/A (rs 361525) gene polymorphism predicts progression to type-2 diabetes in an Eastern Indian population with prediabetes

Prediabetes (IPD; n=122) and normoglycemic individuals (n=100) underwent assessment of polymorphisms of TNFα (-238, -308) and IL6 (-174). After 27.25±5.64 months, 16 IPD had reverted to normoglycemia and 18 progressed to diabetes. TNFα -238AA/GA genotypes were significantly more common in IPD, had higher TNFα, higher progression to diabetes and lower reversal.

A molecular approach to identification and profiling of first-line-drug-resistant mycobacteria from sputum of pulmonary tuberculosis patients

Conventional and molecular techniques were applied to detect and characterize drug resistance of mycobacteria in the sputum samples of clinically confirmed tuberculosis. The sensitivities of mycobacterium detection by ZN staining, culture, multiplex PCR, and restriction fragment length polymorphism (RFLP) were 27.7%, 19.9%, 92.9%, and 95.7%, respectively, but all were 100% specific. The conventional and multiple-allele-specific PCR (MAS-PCR) methods enabled establishment of the drug resistance in 19.3% and 86.9% cases, respectively. We demonstrated that molecular techniques have potential in the accurate diagnosis of tuberculosis.

Impact of interleukin-6 promoter polymorphism and serum interleukin-6 level on the acute inflammation and neovascularization stages of patients with Eales' disease

PURPOSE

To evaluate the role of interleukin-6 (IL-6) in the inflammatory and proliferative stages of Eales' disease (ED) and to determine the influence of IL-6-174G/C polymorphism in the IL-6 and IL-6-regulated protein expression, as well as the development of ED.

METHODS

One hundred and twenty-one patients diagnosed with ED, 223 matched healthy controls, and 16 control patients with macular holes were recruited from the eastern Indian population. Serum and vitreous levels of IL-6 and vascular endothelial growth factors (VEGF) were measured by enzyme-linked immunosorbent assay. Serum levels of high-sensitivity C-reactive protein (hsCRP) were measured by enzyme immunoassay. Subjects were genotyped for the IL-6-174G/C polymorphism (rs1800795) by a custom TaqMan single-nucleotide polymorphism (SNP) Genotyping Assays system.

RESULTS

Serum IL-6 (p<0.0001), hsCRP (p<0.0001), and VEGF (p=0.0031) levels were significantly higher in the inflammatory stage of ED than in healthy controls. Serum IL-6 also significantly correlated with hsCRP (Spearman's correlation coefficient; r=0.4992, p=0.0009), but not with VEGF in this stage in ED patients. At the proliferative stage of ED, significantly higher levels of vitreous IL-6 (p=<0.0001) and VEGF (p=<0.0001) were found compared with the vitreous of patients with macular holes. A significant correlation was observed between vitreous IL-6 and VEGF in ED patients (Spearman's correlation coefficient; r=0.5834, p=0.0087). A statistically significant association was found between the -174GG genotype (p=0.006) and occurrence of ED. Mean serum and vitreous concentrations of IL-6 were also higher in the subjects with the GG genotype than in those with the GC or CC genotype in this population.

CONCLUSIONS

IL-6 expression, regulated by the allelic distribution of -174 loci and the enhanced level of IL-6, modulates CRP and VEGF concentration depending respectively on the acute inflammatory stimulation at the initial stage and angiogenic stimulation at the advanced stage of ED.

Genomic organization and tissue-specific expression of splice variants of mouse organic anion transporting polypeptide 2

cDNAs that code for mouse organic anion transporting polypeptide 2 (oatp2) have been cloned. At least three forms of mouse oatp2 cDNAs containing the same coding sequence were isolated. The common coding sequence is for a protein of 670 amino acids with 12 putative transmembrane domains. The deduced amino acid sequence of the mouse oatp2 shares 89% identity with the reported rat oatp2. Cloning and analysis of mouse oatp2 gene indicates that these isoforms are alternatively spliced products from the same gene. Heterogeneity was observed in the 5'-untranslated region of the cDNAs. Two of the three isoforms lacked the noncoding exon 3 sequence. Northern-blot hybridization analysis using the exon 3-specific probes demonstrated that mouse oatp2 mRNA containing exon 3 sequence is expressed in heart and lung, whereas exon 1-, 2-, and 17-specific probes detected mRNA only in brain and liver. The mouse oatp2 gene consists of 17 exons, including three noncoding exons, and 16 introns. All of the introns are flanked by GT-AG splice sequences except for intron 10 that is flanked by GC-AG splice sequence.

Cloning, expression, and ontogeny of mouse organic anion-transporting polypeptide-5, a kidney-specific organic anion transporter

The full-length coding sequence of mouse organic anion-transporting polypeptide (designated mouse Oatp-5) has been cloned from mouse kidney cDNA library. Analysis of the 5'-untranslated region (5'-UTR) of Oatp-5 cDNA through capsite cloning reveals two possible transcription start sites that are 4-bp apart. The 3'-untranslated region (3'-UTR) of Oatp-5 cDNA contains an early polyadenylation signal, indicating the possibility that mRNAs with different 3'-UTR lengths may coexist. Deduced amino acid sequence of mouse Oatp-5 protein contains 670 amino acids and has 10 putative transmembrane domains, multiple potential glycosylation and phosphorylation sites. Tissue-specific expression studies indicate that mouse Oatp-5 is expressed only in kidney. Studies on the developmental expression reveal that there is no significant expression of Oatp-5 mRNA in mouse kidney for at least 3 weeks after birth, and adult levels of Oatp-5 mRNA expression are attained more than 6 weeks after birth. Phylogenetic analysis reveals that mouse Oatp-5 is an ortholog of rat Oatp-5.

Cloning of the full-length coding sequence of rat liver-specific organic anion transporter-1 (rlst-1) and a splice variant and partial characterization of the rat lst-1 gene

The full-length coding sequence of rat liver-specific organic anion transporter-1 (lst-1) and its splice variant have been cloned. The full-length rat lst-1 (designated rlst-1a) encodes a protein containing 687 amino acids and has 12-putative transmembrane domains, multiple potential N-glycosylation and phosphorylation sites. Therefore, rat lst-1a has 35 additional amino acid residues compared to the previously reported rat lst-1. A splice variant (designated rlst-1c) reported in this communication encodes a protein containing 654 amino acids and has 10-putative transmembrane domains. PCR analysis suggests that rlst-1a is the most abundant form in liver. Phylogenetic analysis reveals that rat lst-1a is an ortholog of human LST-1 (hLST-1) and mouse lst-1 (mlst-1). The rlst-1 gene is composed of 15 exons and 14 introns. Analysis of exon-intron boundary reveals that the splice variant rlst-1c lacks the entire exon 7, while the previously reported rat lst-1 (designated herein as rlst-1b) lacks approximately half of exon 10, and the splicing has occurred through alternative usage of a splice donor site within exon 10.

Full-length cDNA cloning and genomic organization of the mouse liver-specific organic anion transporter-1 (lst-1)

We have cloned a cDNA that codes for mouse liver-specific transporter-1, mouse lst-1. The cDNA is comprised of 3296 base pairs and it contains a coding sequence for a protein of 689 amino acids with 12 putative transmembrane domains. The deduced amino acid sequence of the mouse lst-1 shares 64 and 77% identities with the reported human and rat lsts, respectively. Northern blot analysis demonstrates that mouse lst-1 mRNA is expressed exclusively in liver. We also report here the structural organization of the mouse lst-1 gene as the first evidence for the structure of a gene encoding an lst. The mouse lst-1 gene spans approximately 60 kbp in length and consists of 16 exons, including two noncoding exons. All the introns are flanked by GT-AG consensus splice sequences. 5'-Rapid Amplification of cDNA Ends (RACE) analyses demonstrate three splice variant mRNAs involving the noncoding exon 2 and exon 3. The 5'-flanking region of the gene contains consensus CAAT and TATA boxes and several potential binding sites for transcription factors for CAAT enhancer binding protein (C/EBP) and hepatocyte nuclear factors (HNF-3beta, HFH-1, and HFH-2), transcription factors important for liver-specific gene expression.

Induction of hepatic xenobiotic metabolizing enzymes in female Fischer-344 rats following repeated inhalation exposure to decamethylcyclopentasiloxane (D5)

Decamethylcyclopentasiloxane (D5) is a cyclic siloxane with a wide range of commercial applications. The present study was designed to investigate the effects of D5 on the expression and activity of selected rat hepatic phase I and phase II metabolizing enzymes. Female Fischer-344 rats were exposed to 160 ppm D5 vapors (6 h/day, 7 days/week, for 28 days) by whole-body inhalation. Changes in the activity and relative abundance of hepatic microsomal cytochromes P450 (CYP1A, CYP2B, CYP3A, and CYP4A), epoxide hydrolase, and UDP-glucuronosyltransferase (UDPGT) were measured. Repeated inhalation exposure of rats to D5 increased liver size by 16% relative to controls by day 28. During a 14-day post-exposure period, liver size in D5-exposed animals showed significant recovery. Exposure to D5 did not change total hepatic P450, but increased the activity of hepatic NADPH-cytochrome c reductase by 1.4-fold. An evaluation of cytochrome P450 (CYP) enzymes in hepatic microsomes prepared from D5-exposed rats revealed a slight (1.8-fold) increase in 7-ethoxyresorufin O-deethylase (EROD) activity, but no change in immunoreactive CYP1A1/2 protein. A moderate increase (4.2-fold) in both 7-pentoxyresorufin O-depentylase (PROD) activity and immunoreactive CYP2B1/2 protein (3.3-fold) was observed. Testosterone 6beta-hydroxylase activity was also increased (2.4-fold) as was CYP3A1/2 immunoreactive protein. Although a small increase in 11- and 12-hydroxylation of lauric acid was detected, no change in immunoreactive CYP4A levels was measured. Liver microsomal epoxide hydrolase activity and immunoreactive protein increased 1.7- and 1.4-fold, respectively, in the D5-exposed group. UDPGT activity toward chloramphenicol was induced 1.8-fold, while no change in UDPGT activity toward 4-nitrophenol was seen. These results suggest that the profile for enzyme induction following inhalation exposure of female Fischer-344 rats to D5 vapors is similar to that reported for phenobarbital, and therefore D5 may be described as a weak "phenobarbital-like" inducer.

Metallothionein: an intracellular protein to protect against cadmium toxicity

Metallothioneins (MT) are low-molecular-weight, cysteine-rich, metal-binding proteins. MT genes are readily induced by various physiologic and toxicologic stimuli. Because the cysteines in MT are absolutely conserved across species, it was suspected that the cysteines are necessary for function and MT is essential for life. In attempts to determine the function(s) of MT, studies have been performed using four different experimental paradigms: (a) animals injected with chemicals known to induce MT; (b) cells adapted to survive and grow in high concentrations of MT-inducing toxicants; (c) cells transfected with the MT gene; and (d) MT-transgenic and MT-null mice. Most often, results from studies using the first three approaches have indicated multiple functions of MT in cell biology: MT (a) is a "storehouse" for zinc, (b) is a free-radical scavenger, and (c) protects against cadmium (Cd) toxicity. However, studies using MT-transgenic and null mice have not strongly supported the first two proposed functions but strongly support its function in protecting against Cd toxicity. Repeated administration of Cd to MT-null mice results in nephrotoxicity at one tenth the dose that produces nephrotoxicity in control mice. Human studies indicate that 7% of the general population have renal dysfunction from Cd exposure. Therefore, if humans did not have MT, "normal" Cd exposure would be nephrotoxic to humans. Thus, it appears that during evolution, the ability of MT to protect against Cd toxicity might have taken a more pivotal role in the maintenance of life processes, as compared with its other proposed functions (i.e. storehouse for zinc and free radical scavenger).

ROLE OF ASCORBIC ACID ON TRANSAMINASE ACTIVITIES IN SOME METABOLICALLY ACTIVE TISSUES OF ASPIRIN TREATED RATS

Aspartate amino transferase (GOT) and alanine amino transferase (GPT) activities were studied in plasma, liver and kidney of aspirin treated and ascorbic acid supplemented groups for a period of seven days. GOT and GPT activities were increased in plasma but decreased significantly in liver and kidney in aspirin treated animals. Ascorbic acid supplemented groups showed no significant change of GOT and GPT in plasma and liver. In case of kidney, GOT activity remained unchange but GPT activity showed significant change in ascorbic acid supplemented group. The results clearly indicate that aspirin is a potent hepatotoxic and nephrotoxic drug but supplementation of ascorbic acid in High doses to rats fed aspirin can restore enzyme activities to the normal level.

Evaluation of octamethylcyclotetrasiloxane (D4) as an inducer of rat hepatic microsomal cytochrome P450, UDP-glucuronosyltransferase, and epoxide hydrolase: a 28-day inhalation study

Repeated inhalation exposure to octamethylcyclotetrasiloxane (D4) produces a reversible and dose-related hepatomegaly and proliferation of hepatic endoplasmic reticulum in rats. However, the effects of D4 on the expression of cytochrome P450 enzymes have not been evaluated. In the present study, the time course for changes in hepatic microsomal cytochrome P450 enzyme expression following repeated inhalation exposure to D4 vapors was determined in male and female Fischer 344 rats. Animals were exposed to D4 vapor at concentrations of 70 and 700 ppm, via whole body inhalation for 6 h/day, 5 days/week for 4 weeks. Specified animals were euthanized on exposure days 3, 7, 14, 21, and 28. Microsomal fractions were prepared from fresh liver by differential centrifugation. Enzyme activity as well as immunoreactive protein levels of several cytochrome P450 enzymes (CYP), epoxide hydrolase, and UDP-glucuronosyltransferase (UDPGT) were evaluated. The time course for enzyme induction was monitored by measuring 7-ethoxyresorufin O-deethylase (EROD) and 7-pentoxyresorufin O-depentylase (PROD) activities on days 3, 7, 14, 21, and 28. CYP1A1/2 activity, as determined by EROD activity, was increased approximately 2- to 3-fold over the exposure period. However, an examination of immunoreactive protein revealed no induction of CYP1A1 and a suppression of CYP1A2 in the 700 ppm D4 group. In comparison, CYP2B1/2 enzyme activity, as determined by PROD, was significantly increased as early as day 3 in both the 70 and 700 ppm D4 groups of male and female rats. Overall, PROD activity on day 28 was induced more than 10-fold in the 70 ppm D4 groups and more than 20-fold in the 700 ppm D4 groups. The increase in PROD activity was paralleled by a comparable increase in CYP2B1/2 immunoreactive protein. There was a modest (2- to 3-fold) increase in CYP3A1/2 activity and immunoreactive protein, as determined by 6 beta-hydroxylation of testosterone and Western blot analysis. Expression of CYP enzymes was at or near maximum by day 14 and remained relatively constant throughout the exposure period. On day 28, epoxide hydrolase activity and immunoreactive protein were induced (2- to 3-fold) in a dose-dependent manner. Only slight changes in the expression and activity of UDPGT were detected, and these did not appear to be dose related. Thus, repeated inhalation exposure to D4 induces CYP enzymes and epoxide hydrolase in a manner similar to that observed for phenobarbital (PB). Therefore, D4 can be described as a "PB-like" inducer of hepatic microsomal enzymes in the Fischer 344 rat.

Cadmium accumulation and metallothionein expression in brain of mice at different stages of development

Cadmium accumulation and metallothionein (MT) expression were studied in brains of adult mice as well as at different stages of development. MT expression was also studied in the eye of adult mice as well as at different stages of development. Using northern blot analysis with total RNA, MT mRNAs were not detected in day 16 through day 18 embryos or in postnatal animals up to day 14. Detectable expression of MT-I, -II, and -III mRNAs was obtained in brains of 30- and 60-day-old-mice. The expression of MT-III mRNA appeared to be much stronger in adults (12 weeks old or more) than in 30- and 60-day-old animals. In contrast, there was similar expression of MT-I and -II in 30- and 60-day-old mice. Cd distribution to brain was found to decrease with age; the brains of 7-day-old mice contained about 4-times more Cd than that of adult mice. Thus, an inverse correlation was observed between MT expression and Cd accumulation in brain.

Induction of metallothionein mRNA and protein in murine astrocyte cultures

Astrocytes are known to express metallothionein (MT) and were studied in culture to determine whether MT could be directly induced and which isoforms are induced. Primary astrocyte cultures were established from neonatal CF-1 mice. Both concentration-response and time-course analyses for MT induction at the protein level were determined. At the mRNA level, induction of MT-I, -II, and -III was examined 6 hr following the addition of the inducing agents. Dexamethasone (Dex), cadmium (Cd), mercury (Hg), or zinc (Zn) increased (three- to fourfold) MT protein in the astrocytes, whereas methyl mercury, lead, and interleukin-1 and -6 were ineffective. Cadmium was the most potent inducer, but was not more effective than Hg or Zn in inducing MT protein. All effective inducers increased MT protein by 24 hr. After 48 hr, Hg caused cell death, but all other effective inducers increased the MT protein examined over the 5 days. Cadmium induction of MT protein reached a peak at 96 hr, whereas the other effective inducers stimulated maximal MT protein at 24-48 hr. The effects of Dex, Cd, and Zn, on MT-I, -II, and -III mRNAs were also examined. Cadmium, Zn, and Dex stimulated increases in both MT-I and MT-II mRNA, with Dex producing the greatest effect (2.0- and 3.5-fold for MT-I and -II mRNA, respectively). Metallothionein-III mRNA was relatively unresponsive to induction. Therefore, Cd, Zn, and Dex induced MT-I and -II mRNA but not MT-III mRNA in astrocytes. These results demonstrate that MT-I and -II are directly induced in mouse astrocyte primary cultures.

Differential regulation of cytochrome P450 3A1 and P450 3A2 in rat liver following dexamethasone treatment

Induction of P450 3A1 and P450 3A2 was studied in adult rat liver following treatment with a single high dose of dexamethasone (DEX). The increase of both P450 3A1 and 3A2 occurred at the level of mRNA as well as protein. P450 3A isozymes thus induced were catalytically active. No constitutive expression of P450 3A1 mRNA or protein was observed in males or females. Constitutive expression of P450 3A2 mRNA and protein was observed in males but not in females. Additionally, in females, P450 3A2 was almost nondetectable compared to that in males, at any dose of DEX. A time course study following DEX treatment showed that P450 3A1 mRNA and protein were detectable in both sexes at 12 hours, increased until 48 hours, and then declined. The decline was more rapid in males. P450 3A2 mRNA and protein increased as early as 3 hours, increased further up to 48 hours, and slowly declined thereafter. A dose-response study indicated that P450 3A1 mRNA and protein progressively increased in both sexes from a dose of 30 mg/kg. In contrast, P450 3A2 mRNA and protein in males did not increase up to a dose of 30 mg/kg but increased at higher doses. Total P450 content and P450 3A catalytic activity were also found to increase with time and dose.

Induction of "male-specific" cytochrome P450 isozymes in female rats by oxandrolone

Oxandrolone (OXA) (5 alpha-androstan-2-oxa-17 alpha-methyl-17 beta-ol-3-one) is a clinically useful, synthetic, anabolic androgen steroid hormone. OXA was administered to rats orally twice daily for 3 days at 75 mg/kg to study the effect on hepatic cytochrome P450 (P450) isozymes. Western blots were performed on the hepatic microsomal fraction and probed with isozyme-specific monoclonal antibodies. Microsomes were also tested for catalytic activity in a testosterone metabolism assay. Data from Western blots revealed that, in female rats, there were increased levels of two male-specific isozymes, P4502C11 and P4503A2, as well as P4503A1. In contrast, male rats showed little or no change in expression of these P450 isozymes after OXA treatment. The 6 beta-hydroxylation of testosterone, which is catalyzed predominantly by P4503A1 and P4503A2, increased approximately 10-fold in female rats after treatment with OXA (from 0.05 +/- 0.01 to 0.52 +/- 0.05 nmol/min/mg protein), but only relatively small changes were seen in the male rats (from 1.02 +/- 0.05 to 1.38 +/- 0.07 nmol/min/mg protein). To investigate if the changes seen in P4503A1 and P4503A2 protein and activity were caused, at least in part, by an increase in mRNA levels, Northern blot analysis was performed. P4503A2 mRNA was increased dramatically in the female rat liver after OXA treatment, but only small increases in P4503A1 mRNA were seen. This data indicate that OXA induces P450 isozymes in the female but not in the male rat liver, probably through transcriptional activation, and some of these induced isozymes are male-specific.

Constitutive expression of metallothionein genes in mouse brain

Metallothioneins (MTs) are ubiquitous low-molecular-weight proteins that are induced by a variety of inducers, including metals, lipopolysaccharides (LPS), cytokines, oxidative stress, etc., and are thought to play a protective role against various toxic insults. The constitutive level of metallothionein is an important determinant of a tissue's susceptibility to toxic insults. In the present study, we report the constitutive expression of MT mRNAs in adult mouse brain. Analysis of total RNA from whole brain by Northern blot and solution hybridization showed that mRNAs for all three MT isoforms (I, II, III) were constitutively expressed in mouse brain, and there was no remarkable difference in their expression. However, in quantitative terms the order of expression was MT-I > MT-III > MT-II. The expression of MT-III and MT-II was about 70 and 50% of that of MT-I, respectively. Examination of their constitutive expression in different brain regions revealed that the three isoforms were expressed in all seven brain regions studied (olfactory bulb, cortex, caudate, hippocampus, thalamus, cerebellum, and brain stem), and there was only about a twofold difference in MT mRNA expression from one region of the brain to another. However, olfactory bulb had the highest mRNA expression for all three isoforms, as revealed by slot blot analysis. Constitutive expression of MT-I and -II mRNA, but not MT-III mRNA, was high in cerebellum. In order to study the cellular localization of MT mRNA, in situ hybridization of MT-I and MT-III mRNA was performed. For comparison, LPS was used to enhance MT-I mRNA signal because LPS is a good inducer of MT-I mRNA expression in mouse brain. In situ hybridization revealed that certain brain regions had distinctly localized high levels of expression of MT mRNAs. In brains of untreated mice, the constitutive expression of MT-I mRNA was high in the ependymal cell layer lining the lateral ventricles and in the Purkinje cell layer of cerebellum. The signal in the Purkinje cell layer was not on the Purkinje cells themselves, but was on locations consistent with that of glial cells. In LPS-treated mice, the signal in cerebellum was higher, and distinct signal appeared in the choroid plexus. However, signal in ependyma was similar to that in untreated mice. Pia mater in LPS-treated, but not in untreated, mouse brain showed enhanced signal for MT-I mRNA.(ABSTRACT TRUNCATED AT 400 WORDS)

Species variation in hepatic metallothionein

Metallothionein (MT) is a low-molecular-weight protein involved in the homeostasis of endogenous metals and in the detoxication of heavy metals. In humans, the levels of hepatic MT have been shown to be up to 100 times the levels found in rat and mouse liver. In order to further investigate this species difference in hepatic MT levels, hepatic MT was quantified in 15 species (human, monkey, dog, cat, cow, pig, sheep, goat, rabbit, chicken, hamster, rat, mice, guinea pig, and frog). Fresh liver was obtained from each species and MT was quantified by 2 different metal-saturation assays. Results from the Cd-heme and Ag-heme assays showed that human, dog, cat, pig, and goat had the highest hepatic MT levels (400-700 micrograms/g liver). Monkey, cow, and sheep had moderate hepatic MT levels (about 200 micrograms/g liver), while rodents (mouse, rat, hamster, guinea pig, and rabbit) had low hepatic MT levels (2-10 micrograms/g liver). Hepatic MT levels in non-mammals (chick and frog) were slightly higher than rodents (about 20 micrograms/g liver). Sephadex G-75 column elution volumes ranged from 1.7 to 1.8, which implies that MT from all species had approximately the same molecular weight and similar structure. Copper and zinc concentration in the cytosols were measured by atomic absorption spectrophotometry. Dog and cat had the highest levels of Cu (86 and 50 micrograms/g liver, respectively), and pig and hamster were lowest (about 10 micrograms/g liver). Human, dog, cat, and goat had the highest levels of zinc (approximately 40-50 micrograms/g liver) while hamster and guinea pig were lowest (approximately 15 micrograms/g liver). The results show that there is a marked species difference in hepatic MT concentrations with dog, cat, and human having the highest levels.

In vitro and in vivo studies on the degradation of metallothionein

Degradation of metallothionein (MT) from rat liver was examined. Degradation of apo-MT by liver homogenate was greater than that by cytosol. At pH 5.5, degradation by homogenate was more than that at pH 7.2. These findings suggest that proteases that function at acidic pH are probably involved in MT degradation. Because lysosomes are the principal subcellular organelles that contain acid proteases (cathepsins), we compared the degradation of apo-MT by lysosomes and cytosol. Apo-MT was degraded about 400 times faster by lysosomal fraction than by cytosolic fraction. To determine the relative importance of different cathepsins, we used different inhibitors. Leupeptin, which inhibits cathepsins B and L, inhibited the degradation of apo-MT by 80%, implying that cathepsins B and/or L might be very important in the intracellular turnover of MT. Cathepsin D appeared to be the least significant, because apo-MT degradation was reduced by about 20% by inhibiting cathepsin D. When we extended this study with purified cathepsins, we obtained the same answer, i.e., the ability of different cathepsins to degrade apo-MT was in the following order: cathepsin B >> cathepsin C > cathepsin D. While apo-MT was susceptible to degradation, ZnMT and CdMT were highly resistant to degradation. Coincubation of ZnMT or CdMT with either lysosomal extract or purified cathepsins did not result in any appreciable degradation even after 16 hr. However, longer incubations did result in some degradation, especially by purified cathepsin B. Interestingly, CdMT degraded little faster than ZnMT by both lysosomal extract as well as purified cathepsin B.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of metallothionein by superantigenic bacterial exotoxin: probable involvement of the immune system

Metallothionein (MT) can be induced in mouse liver by a bacterial exotoxin, toxic shock syndrome toxin-1 (TSST-1). Hepatic MT was induced by TSST-1 in a dose-dependent manner from 100 micrograms/kg through 3 mg/kg in CF-1 mice, and by 6 h the induction was almost maximal. The increase of hepatic MT occurred at the mRNA level, also, and both MT-I and II mRNAs increased coordinately. Because TSST-1 is a superantigen, it was investigated whether TSST-1 induces MT through cytokines as a consequence of immunostimulation. In low-cytokine-producing mice (C3H/HeJ), up to a dose of 1 mg/kg of TSST-1, there was only 2- to 3-fold increase of hepatic MT. In contrast, in normal-cytokine-producing mice (C3Heb/FeJ), TSST-1 increased MT in a dose-dependent manner, and at a dose of 1 mg/kg, there was a 25-fold increase in hepatic MT. This suggests that activation of the immune system is probably involved in the induction of MT by TSST-1. Studies on the role of specific hepatic cytokines (IL-1, TNF-alpha, and IL-6) in TSST-mediated hepatic MT induction showed that TSST-1 did not increase hepatic IL-1 or TNF-alpha significantly over controls in any of the mouse strains studied. In contrast, TSST-1 induced hepatic IL-6 in all three strains of mice. However, in CF-1 and C3Heb/FeJ mice (normal-cytokine-producing) IL-6 induction preceded MT mRNA induction, but in C3H/HeJ mice (low-cytokine-producing), IL-6 induction did not precede MT mRNA induction.

Induction of metallothionein by alpha-hederin

alpha-Hederin (alpha-Hed) is a triterpenoid saponin that has been shown to protect against some hepatotoxicants. This study examined the protective effect of alpha-Hed against cadmium (Cd) hepatotoxicity and the mechanism of protection. alpha-Hed pretreatment (100 mumol/kg, sc) dramatically decreased Cd (3.7 mg/kg, iv) hepatotoxicity as indicated by a reduction of serum alanine aminotransferase and sorbitol dehydrogenase, as well as by histopathological examination. alpha-Hed did not produce protection by decreasing the distribution of Cd to the liver, as higher amounts of Cd were found in the liver of alpha-Hed-pretreated mice. However, there was a marked alteration in subcellular distribution of Cd in the alpha-Hed-pretreated mice, with much less Cd distributing to nuclei, mitochondria, and microsomes and more in the cytosol. The increased cytosolic Cd was found primarily bound to a low-molecular-weight protein, metallothionein (MT). alpha-Hed (10-300 mumol/kg, sc) produced a dose-dependent increase in hepatic MT with a 100-fold increase over controls 24 hr after a single injection of 100 mumol/kg, as determined by the Cd/hemoglobin assay. The hepatic MT increase produced by alpha-Hed is relatively long lasting, in that it is still eight times control values 6 days after a single administration. The induction of MT was also relatively specific for the liver, as little or no increase in MT was observed in other tissues. Furthermore, alpha-Hed increased both hepatic MT-I and MT-II levels. Northern blot analysis revealed that alpha-Hed rapidly increased MT mRNA levels. In conclusion, alpha-Hed decreases the hepatotoxicity of Cd by inducing MT, which binds Cd in the cytosol, and thus reduces the amount of Cd in the critical cellular organelles. alpha-Hed is an effective inducer of both MT-I and MT-II in liver, and this effect is associated with an increase in MT mRNA.

Oleanolic acid protects against cadmium hepatotoxicity by inducing metallothionein

Oleanolic acid (OA) is a triterpenoid compound that has been shown to protect against some hepatotoxicants and is used in China to treat hepatitis. This study was conducted to examine the protective effects of OA against cadmium (Cd)-induced liver injury in mice and the mechanism of protection. OA (100 mg/kg x 3 days) pretreatment dramatically decreased Cd (3.7 mg/kg i.v.)-induced liver injury as indicated by decreased serum activities of alanine aminotransferase and sorbitol dehydrogenase, as well as by histopathological observation. To examine the mechanism of protection, the distribution of Cd to major organs and the hepatic subcellular distribution of Cd were determined 2 hr after 109Cd injection (3.5 mg/kg of Cd and 10 microCi/mg of Cd i.v.). OA did not reduce the amount of Cd in liver, but significantly altered the hepatic subcellular distribution of Cd, with more Cd in hepatic cytosol bound to metallothionein (MT), and with less Cd in other organelles and proteins. OA produced an approximately 30-fold increase in hepatic MT, but had no appreciable effects on MT levels of five other organs. Furthermore, OA increased both hepatic MT-I and MT-II levels, as determined by high-performance liquid chromatography/atomic absorption spectrophotometry. Northern blot analysis revealed that OA increases MT mRNA expression. In summary, OA pretreatment protects against Cd-induced hepatotoxicity by inducing MT. MT bound Cd in the cytosol, and thus decreased the amount of Cd in other critical organelles and proteins. OA is a hepatic MT inducer for both MT-I and MT-II isoforms, and this effect is due, at least in part, to an increased MT mRNA accumulation.

Differential expression of the metallothionein gene in liver and brain of mice and rats

Expression of the metallothionein I (MT-I) gene was studied in liver and brain of control mice and rats, as well as following administration of Cd and lipopolysaccharide (LPS). Time-course studies revealed that MT mRNA reached a maximum in liver of both mice and rats 6 hr following treatment with Cd or LPS. MT mRNA from control and Cd- and LPS-treated rat brains could not be detected by Northern-blot analysis of total RNA, but Northern analysis with poly(A)-enriched RNA revealed that induction of MT mRNA in rat brain does occur with both Cd and LPS treatment. In contrast, mouse brain MT mRNA was easily detected by Northern-blot analysis of total RNA. It was also clear from Northern-blot analyses of both mouse and rat brain that LPS induced more MT mRNA than did Cd. Quantitation of MT mRNA by solution hybridization revealed that Cd and LPS induced similar amounts of MT mRNA in livers of mice (about 0.64 fmol/micrograms total RNA by Cd and 0.68 by LPS) and rats (about 0.23 fmol/micrograms total RNA by Cd and 0.21 by LPS). Therefore, both inducers increased MT mRNA about threefold more in mouse liver than in rat liver. In mouse and rat brain, LPS induced about twice as much MT mRNA as did Cd (about 0.08 fmol/micrograms total RNA by Cd and 0.16 by LPS in mice and about 0.006 fmol/micrograms total RNA by Cd and 0.008 by LPS in rats). However, the actual amount of MT mRNA induced in rat brain by either inducer was minimal compared to that in mouse brain. In fact, Cd induced 13 times more MT mRNA in mouse brain than in rat brain, and LPS induced about 20 times more MT mRNA in mouse brain than in rat brain. Cd distribution to liver was similar in both mice and rats, but the Cd concentration in mouse brain was about 60% more than that in rat brain. Distribution of LPS was also similar in mouse and rat livers, as well as in mouse and rat brains. Therefore, there exists a difference in the expression of MT gene in both liver and brain of mice and rats, the expression in mice being higher than that in rats. These findings suggest that such differential expression of the MT gene cannot be entirely accounted for by the difference in the tissue distribution of inducers. Other tissue-specific and species-specific factors controlling MT gene expression appear to be involved.

In vitro degradation of apo-, zinc-, and cadmium-metallothionein by cathepsins B, C, and D

Metallothionein (MT) has been extensively studied over the past several years because of its probable role in endogenous metal homeostasis and cellular protection. A large body of knowledge now exists describing the physicochemical properties of MT as well as the mechanisms involved in MT induction. It has been well established that MT protects tissues from metal toxicity by chelating metals that would otherwise be available to interact with and disrupt vital cell functions. Information on the degradation of metal-saturated MT and the fate of the metals associated with it would be extremely important in predicting metal toxicity. Lysosomes have been targeted as a possible subcellular site for the turnover of MT; however, the susceptibility of MT to degradation by specific acidic proteases (i.e., cathepsins) has not been described. Therefore, the purpose of the present study was to examine the relative abilities of cathepsins B, C, and D to degrade Zn7-MT, Cd7-MT, and apo-MT in vitro. In so doing, the effects of metal species, degree of metal saturation, and pH on the degradation processes were evaluated. Time course experiments revealed that apo-MT was rapidly degraded by all three cathepsins. Cathepsin B degraded apo-MT approximately 36-fold more rapidly than cathepsin C and 45-fold more rapidly than cathepsin D. Therefore, under the in vitro conditions used in this study, the relative potency of the cathepsins tested was cathepsin B much much greater than cathepsin C greater than cathepsin D. In comparison, metal-saturated MT was more than 1000-fold more resistant to degradation by the cathepsins tested. In order to determine how much metal was needed to protect MT against degradation, apo-MT was reconstituted with increasing molar equivalents of Zn2+. The results suggest that as metal to apo-MT ratios increase, less apo-MT substrate is available to the protease and degradation decreases.

Role of hepatic lysosomes in the degradation of metallothionein

The degradation of metallothionein (MT) by rat liver was examined. Degradation of MT by liver homogenate was greater than by cytosol. In addition, MT degradation by the homogenate at pH 5.5 was more than that at pH 7.2. Because lysosomal proteases function at acidic pH, these findings suggest the importance of lysosomes in MT degradation. The degradation by the lysosomal fraction was about 400-fold greater than that by the cytosol. Because cathepsins are the principal lysosomal proteases, we used cathepsin-specific inhibitors, such as leupeptin, E-64 and pepstatin, to determine the relative importance of different cathepsins in degrading MT. The study reveals that cathepsin B and/or L is (are) probably the most important enzyme(s) in degrading hepatic MT, because leupeptin, which blocks cathepsin B and L activity, inhibited the degradation of apo-MT by about 80%. Cathepsin D appears to be of least importance in MT degradation, because inhibition of this enzyme by pepstatin reduced degradation by only 20%. Studies on the degradation of apo-MT, ZnMT, and CdMT indicated that apo-MT is about 1500-fold more sensitive to degradation than ZnMT and CdMT. These data suggest that metals protect MT from degradation. This is further supported by a reconstitution experiment, which shows that with a progressive decrease of MT: metal ratio following titration of apo-MT by metals, there is a concomitant reduction in degradation. At a lysosomal pH of around 4.7, about 60% of Zn and 20% of Cd are displaced from MT, thereby making it susceptible to degradation. We propose, therefore, that lysosomes are probably important for MT degradation in vivo and that metal release is a prerequisite for degradation. With the release of metals, MT becomes susceptible to degradation, which is probably accomplished by the lysosomal cathepsins, in particular cathepsins B and L.