Local and downstream actions of proximal tubule angiotensin II signaling on Na+ transporters in the mouse nephron.

The renal nephron consists of a series of distinct cell types that function in concert to maintain fluid and electrolyte balance and blood pressure. The renin-angiotensin system (RAS) is central to Na+ and volume balance. We aimed to determine how loss of angiotensin II signaling in the proximal tubule (PT), which reabsorbs the bulk of filtered Na+ and volume, impacts solute transport throughout the nephron. We hypothesized that PT renin-angiotensin system disruption would not only depress PT Na+ transporters but also impact downstream Na+ transporters. Using a mouse model in which the angiotensin type 1a receptor (AT1aR) is deleted specifically within the PT (AT1aR PTKO), we profiled the abundance of Na+ transporters, channels, and claudins along the nephron. Absence of PT AT1aR signaling was associated with lower abundance of PT transporters (Na+/H+ exchanger isoform 3, electrogenic Na+-bicarbonate cotransporter 1, and claudin 2) as well as lower abundance of downstream transporters (total and phosphorylated Na+-K+-2Cl- cotransporter, medullary Na+-K+-ATPase, phosphorylated NaCl cotransporter, and claudin 7) versus controls. However, transport activities of Na+-K+-2Cl- cotransporter and NaCl cotransporter (assessed with diuretics) were similar between groups in order to maintain electrolyte balance. Together, these results demonstrate the primary impact of angiotensin II regulation on Na+ reabsorption in the PT at baseline and the associated influence on downstream Na+ transporters, highlighting the ability of the nephron to integrate Na+ transport along the nephron to maintain homeostasis.NEW & NOTEWORTHY Our study defines a novel role for proximal tubule angiotensin receptors in regulating the abundance of Na+ transporters throughout the nephron, thereby contributing to the integrated control of fluid balance in vivo.

Somatic Mosaicism in the Pathogenesis of de novo Cerebral Arteriovenous Malformations: A Paradigm Shift Implicating the RAS-MAPK Signaling Cascade.

Cerebral arteriovenous malformations (AVMs) are leading causes of lesional hemorrhagic stroke in both the pediatric and young adult population, with sporadic AVMs accounting for the majority of cases. Recent evidence has identified somatic mosaicism in key proximal components of the RAS-MAPK signaling cascade within endothelial cells collected from human sporadic cerebral AVMs, with early preclinical models supporting a potential causal role for these mutations in the pathogenesis of these malformations. Germline mutations that predispose to deregulation of the RAS-MAPK signaling axis have also been identified in hereditary vascular malformation syndromes, highlighting the key role of this signaling axis in global AVM development. Herein, we review the most recent genomic and preclinical evidence implicating somatic mosaicism in the RAS-MAPK signaling pathway in the pathogenesis of sporadic cerebral AVMs. Also, we review evidence for RAS-MAPK dysregulation in hereditary vascular malformation syndromes and present a hypothesis suggesting that this pathway is central for the development of both sporadic and syndrome-associated AVMs. Finally, we examine the clinical implications of these recent discoveries and highlight potential therapeutic targets within this signaling pathway.

Mice lacking three Loci encoding 14 glutathione transferase genes: a novel tool for assigning function to the GSTP, GSTM, and GSTT families.

Glutathione S-transferases (GSTs) form a superfamily defined by their ability to catalyze the conjugation of glutathione with electrophilic substrates. These enzymes are proposed to play a critical role in protection of cellular components from damage mediated by reactive metabolites. Twenty-two cytosolic GSTs, grouped into seven families, are recognized in mice. This complexity hinders the assignment of function to a subset or family of these genes. We report generation of a mouse line in which the locus encoding three GST gene families is deleted. This includes the four Gstt genes spanning 65 kb on chromosome 10 and the seven Gstm genes found on a 150 kb segment of DNA chromosome 3. In addition, we delete two Gstp genes on chromosome 19 as well as a third related gene located 15 kb telomeric to Gstp1 and Gstp2, which we identify as a potential new member of this gene family. We show that, despite the loss of up to 75% of total GST activity in some tissues from these animals, the mice are healthy and fertile, with normal life expectancy. The normal development and health of these animals make them an appropriate model for defining the role of these families in redox homeostasis and metabolism of drugs and environmental pollutants.

NLRP1-dependent pyroptosis leads to acute lung injury and morbidity in mice.

Acute inflammation in response to both exogenous and endogenous danger signals can lead to the assembly of cytoplasmic inflammasomes that stimulate the activation of caspase-1. Subsequently, caspase-1 facilitates the maturation and release of cytokines and also, under some circumstances, the induction of cell death by pyroptosis. Using a mouse line lacking expression of NLRP1, we show that assembly of this inflammasome in cells is triggered by a toxin from anthrax and that it initiates caspase-1 activation and release of IL-1ß. Furthermore, NLRP1 inflammasome activation also leads to cell death, which escalates over 3 d following exposure to the toxin and culminates in acute lung injury and death of the mice. We show that these events are not dependent on production of IL-1ß by the inflammasome but are dependent on caspase-1 expression. In contrast, muramyl dipeptide-mediated inflammasome formation is not dependent on NLRP1 but NLRP3. Taken together, our findings show that assembly of the NLRP1 inflammasome is sufficient to initiate pyroptosis, which subsequently leads to a self-amplifying cascade of cell injury within the lung from which the lung cannot recover, eventually resulting in catastrophic consequences for the organism.

Influenza enhances caspase-1 in bronchial epithelial cells from asthmatic volunteers and is associated with pathogenesis.

BACKGROUND: The leading cause of asthma exacerbation is respiratory viral infection. Innate antiviral defense pathways are altered in the asthmatic epithelium, yet involvement of inflammasome signaling in virus-induced asthma exacerbation is not known. OBJECTIVE: This study compared influenza-induced activation of inflammasome and innate immune signaling in human bronchial epithelial cells from volunteers with and without asthma and investigated the role of caspase-1 in epithelial cell antiviral defense. METHODS: Differentiated primary human bronchial epithelial cells from volunteers with and without asthma were infected with influenza A virus. An inflammasome-specific quantitative real-time polymerase chain reaction array was used to compare baseline and influenza-induced gene expression profiles. Cytokine secretion, innate immune gene expression, and viral replication were compared between human bronchial epithelial cells from volunteers with and without asthma. Immunofluorescence microscopy was used to evaluate caspase-1 and PYCARD colocalization. Tracheal epithelial cells from caspase-1-deficient or wild-type mice were infected with influenza and assessed for antiviral gene expression and viral replication. RESULTS: Human bronchial epithelial cells from asthmatic volunteers had altered influenza-induced expression of inflammasome-related and innate immune signaling components, which correlated with enhanced production of IL-1ß, IL-6, and TNF-α. Specifically, influenza-induced caspase-1 expression was enhanced and localization differed in human bronchial epithelial cells from asthmatic volunteers compared to volunteers without asthma. Influenza-infected tracheal epithelial cells from caspase-1-deficient mice had reduced expression of antiviral genes and viral replication. CONCLUSION: Caspase-1 plays an important role in the airway epithelial cell response to influenza infection, which is enhanced in asthmatic volunteers, and may contribute to the enhanced influenza-related pathogenesis observed in vivo.

Single-cell transcriptomes reveal a molecular link between diabetic kidney and retinal lesions.

The occurrence of diabetic nephropathy (DN) and diabetic retinopathy (DR) are closely associated in patients with diabetes. However, the cellular and molecular linkage of DN and DR has not been elucidated, and further revelations are needed to improve mutual prognostic decisions and management. Here, we generate and integrate single-cell RNA sequencing profiles of kidney and retina to explore the cellular and molecular association of kidney and retina in both physiological and pathological conditions. We find renal mesangial cells and retinal pericytes share molecular features and undergo similar molecular transitions under diabetes. Furthermore, we uncover that chemokine regulation shared by the two cell types is critical for the co-occurrence of DN and DR, and the chemokine score can be used for the prognosis of DN complicated with DR. These findings shed light on the mechanism of the co-occurrence of DN and DR and could improve the prevention and treatments of diabetic microvascular complications.

Mitochondria bridge HIF signaling and ferroptosis blockage in acute kidney injury.

Ferroptosis, a form of regulated cell death, plays an important role in acute kidney injury (AKI). Previous studies have shown that prolyl hydroxylase domain protein (PHD) inhibitors that activate HIF signaling provide strong protection against AKI, which is characterized by marked cell death. However, the relationship between PHD inhibition/HIF signaling and ferroptosis in AKI has not been elucidated. Here, we review recent studies to explore the issue. First, we will review the literature concerning the functions of HIF in promoting mitophagy, suppressing mitochondrial respiration and modulating redox homeostasis. Second, we will describe the current understanding of ferroptosis and its role in AKI, particularly from the perspective of mitochondrial dysfunction. Finally, we will discuss the possibility that mitochondria link PHD inhibition/HIF signaling and ferroptosis in AKI. In conclusion, we propose that HIF may protect renal cells against ferroptosis in AKI by reducing mitochondrial oxidative stress and damage.

[Effects of allitridin on transcription of immediate-early, early and late genes of human cytomegalovirus in vitro].

OBJECTIVE: The effect of allitridin on the transcription levels of immediate-early (ie), early(e) and late (1) genes of human cytomegalovirus (HCMV) was investigated in order to explore the mechanism of allitridin against HCMV. METHOD: Established the models of HCMV AD169 strain infected cells and AD169 strain infected cells treated with allitridin (9.6 mg x L(-1)), and they were compared with the appropriate dose(2.3 mg x L(-1)) of ganciclovir (GCV). All groups of cells were infected at 2.5 multiplicity of infection (MOI), using SYBR Green real-time PCR method to detect the dynamic change of ul122, ul123, ul54 and ul83 mRNA expression at 0.5, 2, 4, 6, 12, 24 h post-infection. RESULT: The mRNA levels of ul122 and ul123 in AD169 infected cells treated with allitridin at all time points were markedly lower than those of AD169 infected controls (P<0.05), but there were no significant difference of ul122 gene in AD169 infected cells treated with GCV and AD169 infected cells at 0.5-6 h post-infection. The inhibitory rates of allitridin to AD169 ul122 and ul123 mRNA reached 75.2% and 70.4% at 24 h post-infection, respectively. The expression of ul54 mRNA in two drug-treatment groups at all time points were lower than those of AD169 infected cells group (P<0.05). The inhibitory rates of alltridin and GCV to AD169 ul54 mRNA were 45.4% and 27.2% at 24 h post-infection,respectively. The expression of HCMV ul83 mRNA in all groups rapidly increased after 6 h of infection,which is most obvious in AD169 infected cells group. The inhibitory rates of alltridin and GCV to AD169 ul83 mRNA were 45.9% and 26.2% at 24 h post-infection, respectively. CONCLUSION: Allitridin could effectively suppress the transcription of ie genes (ul122 and ul123) of HCMV AD169 strain, led the expression of mRNA significantly lowerd. It was able to supress the transcription of egene (ul54) and l gene (ul83) too, indicating that HCMV ie genes may be the key target of allitridin against HCMV.

A novel method for ex-vivo latex angiography of the mouse brain.

INTRODUCTION: Latex perfusion is an effective tool to study cerebrovascular pathology in the animal brain. It provides, low-cost, high fidelity anatomical information on ex-vivo analysis, and can be utilized to study multiple, states. However, current methods of latex casting and tissue-clearance do not allow for immunohistochemical analysis following sample processing. This results in experiments that require increased numbers of animals to attain adequate data. NEW METHOD: In this paper, we present a modified latex perfusion and tissue processing protocol for ex-vivo analysis, of the cerebral vasculature. The method consists of injection of the arterial tree with liquid latex, followed by tissue clearance with a scale solution. RESULTS: Our results demonstrate effective and reliable perfusion of the murine cerebrovascular tree, rendering the arterial morphology of the brain in high detail, while allowing for post-perfusion, immunohistochemistry of the sample. COMPARISON WITH EXISTING METHOD: Our technique bypasses the limitations of previous latex angiography protocols by allowing for postperfusion, pathologic analysis of casted cerebrovascular tissue. CONCLUSION: This protocol provides a reliable, low-cost, method of cerebrovascular perfusion that reduces the number of animals required to generate robust data from latex-casted brain tissue.

Localization of Cell Receptor-Related Genes of SARS-CoV-2 in the Kidney through Single-Cell Transcriptome Analysis.

BACKGROUND: The new coronavirus (SARS-CoV-2), which has been responsible for the recent coronavirus disease 2019 (COVID-19) pandemic, uses the cell receptor angiotensin converting enzyme-2 (ACE2) for entry and the serine protease TMPRSS2 for spike (S) protein priming. Meanwhile, the presence of B0AT1 (SLC6A19) may prevent TMPRSS2 from accessing the cutting position on ACE2. Identifying the expression of these cell receptor-related genes of SARS-CoV-2 is critical for understanding the pathogenesis of SARS-CoV-2 in various tissues, especially in the kidney. METHODS: The single-cell transcription datasets of the human cell landscape (HCL) and other relevant single-cell transcription databases were used to analyze the expression of ACE2, TMPRSS2, and SLC6A19 in various organs and tissues, but mainly in the kidney. RESULTS: ACE2 was significantly expressed in the S1, S2, and S3 segments of proximal tubule (PT) cells. TMPRSS2 was widely expressed in several renal tubule populations extending from the PT cells to the collection system cell type, of which intercalated cells and the distal convoluted tubule cells showed more significant expression than PT cells. Unexpectedly, although expressed on various renal tubule populations, SLC6A19 was mainly enriched in PT cells, in line with ACE2 expression. Although alveolar-type (AT) 2 cells of the lung and intestinal epithelial cells expressed ACE2 as well as PT cells, AT 2 cells significantly expressed TMPRSS2 but not SLC6A19, while all 3 genes were significantly expressed in intestinal epithelial cells. CONCLUSIONS: ACE2 was widely expressed in specific cell subgroups of various human tissues, especially in intestinal epithelial cells, kidney PT cells, and also AT 2 cells of the lung. These 3 types of cells demonstrated significant differences in the distribution of the cell receptor-related genes of SARS-CoV-2, which may indicate the diversity of cell surface structures and differences in the affinity between SARS-CoV-2 and cells.

CpG oligodeoxynucleotide triggers the liver inflammatory reaction and abrogates spontaneous tolerance.

Liver allografts are spontaneously accepted in the liver transplantation mouse model; however, the basis for this tolerance and the conditions that abrogate spontaneous tolerance to liver allografts are incompletely understood. We examined the role of CpG oligodeoxynucleotide (ODN) in triggering the liver inflammatory reaction and allograft rejection. Bioluminescence imaging quantified the activation of nuclear transcriptional factor kappaB (NF-kappaB) at different time points post-transplantation. Intrahepatic lymphocyte subsets were analyzed by immunofluorescence assay and flow cytometry. The results showed that liver allografts survived for more than 100 days without a requirement for any immunosuppressive therapy. Donor-matched cardiac allografts were permanently accepted, whereas third-party cardiac grafts were rejected with delayed kinetics; this confirmed donor-specific tolerance. NF-kappaB activation in the liver allografts was transiently increased on day 1 and diminished by day 4; in comparison, it was elevated up to 10 days post-transplantation in the cardiac allografts. When CpG ODN was administered at a high dose (50 microg per mouse x 1) to the recipients on day 7 post-transplantation, it induced an acute liver inflammatory reaction with elevated NF-kappaB activation in both allogeneic and syngeneic liver grafts. Multiple doses of CpG ODN (10 microg per mouse x 3) elicited acute rejection of the liver allografts with significant T cell infiltration in the liver allografts, reduced T regulatory cells, and enhanced interferon gamma-producing cells in the intrahepatic infiltrating lymphocytes. These data demonstrate that CpG ODN initiates an inflammatory reaction and abrogates spontaneous tolerance in the liver transplantation mouse model. Liver Transpl 15:915-923, 2009. (c) 2009 AASLD.

CD4+ T cells are sufficient to elicit allograft rejection and major histocompatibility complex class I molecule is required to induce recurrent autoimmune diabetes after pancreas transplantation in mice.

BACKGROUND: We characterized the role of T cell subsets and major histocompatibility complex molecules in allograft rejection and recurrence of autoimmune diabetes. METHODS: Adoptive cell transfer and vascularized segmental pancreas transplantation were performed in mice. RESULTS: In an alloimmune response model, transfer of nondiabetic CD4, but not CD8 T cells, elicited pancreas allograft rejection in streptozotocin (STZ)-induced diabetic NOD/scid mice. Pancreas allografts were acutely rejected in STZ-induced diabetic NOD/beta2m mice (confirmed the absence of major histocompatibility complex [MHC] class I and CD8 T cells) and permanently accepted in NOD/CIIT mice (confirmed the absence of MHC class II and CD4 T cells). The results suggest that rejection of pancreas allograft is CD4-dependent and MHC class I-independent. In the autoimmune diabetes model, whole spleen cells obtained from diabetic NOD mice induced autoimmune diabetes in NOD/scid and NOD/CIIT mice, but the onset of diabetes was delayed in NOD/beta2m mice. However, the purified diabetic T cells failed to elicit autoimmune diabetes in NOD/beta2m mice. NOD/scid and NOD/CIIT pancreas grafts were acutely destroyed whereas four of six NOD/beta2m pancreas grafts were permanently accepted in autoimmune diabetic NOD mice. CONCLUSION: CD4 T cells are sufficient for the induction of allograft rejection, and MHC class I molecule is required to induce recurrent autoimmune diabetes after pancreas transplantation in mice.

Bioluminescence imaging visualizes activation of nuclear factor-kappaB in mouse cardiac transplantation.

BACKGROUND: The purpose of the current study was to evaluate the role of bioluminescence imaging (BLI) in the determination of nuclear factor (NF)-kappaB activation in cardiac allograft rejection and ischemia-reperfusion injury. METHODS: To visualize NF-kappaB activation, luciferase transgenic mice under the control of a mouse NF-kappaB promoter (NF-kappaB-Luc) were used as donors or recipients of cardiac grafts. Alternatively, NF-kappaB-Luc spleen cells were adoptively transferred into Rag2 -/- mice with or without cardiac allografts. BLI was performed posttransplantation to detect luciferase activity that represents NF-kappaB activation. RESULTS: The results show that luciferase activity was significantly increased in the cardiac allografts when NF-kappaB-Luc mice were used as recipients as well as donors. Luciferase activity was also elevated in the wild-type cardiac allografts in Rag2 -/- mice that were transferred with NF-kappaB-Luc spleen cells. CD154 monoclonal antibody (mAb) therapy inhibited luciferase activity and induced long-term survival of cardiac allografts. toll-like receptor-9 ligand, CpG DNA, enhanced luciferase activity and abrogated tolerance induction by CD154 mAb. Luciferase activity was also increased in ischemia-reperfusion injury of the cardiac grafts. CONCLUSION: BLI using Luc-NF-kappaB mice is a noninvasive approach to visualize the activation of NF-kappaB signaling in mouse cardiac allograft rejection and ischemia-reperfusion injury. CD154 mAb can inhibit NF-kappaB activation, which is reversed by toll-like receptor engagement.

Sequencing and characterization of leaf transcriptomes of six diploid Nicotiana species.

BACKGROUND: Nicotiana belongs to the Solanaceae family that includes important crops such as tomato, potato, eggplant, and pepper. Nicotiana species are of worldwide economic importance and are important model plants for scientific research. Here we present the comparative analysis of the transcriptomes of six wild diploid Nicotiana species. Wild relatives provide an excellent study system for the analysis of the genetic basis for various traits, especially disease resistance. RESULTS: Whole transcriptome sequencing (RNA-seq) was performed for leaves of six diploid Nicotiana species, i.e. Nicotiana glauca, Nicotiana noctiflora, Nicotiana cordifolia, Nicotiana knightiana, Nicotiana setchellii and Nicotiana tomentosiformis. For each species, 9.0-22.3 Gb high-quality clean data were generated, and 67,073-182,046 transcripts were assembled with lengths greater than 100 bp. Over 90 % of the ORFs in each species had significant similarity with proteins in the NCBI non-redundant protein sequence (NR) database. A total of 2491 homologs were identified and used to construct a phylogenetic tree from the respective transcriptomes in Nicotiana. Bioinformatic analysis identified resistance gene analogs, major transcription factor families, and alkaloid transporter genes linked to plant defense. CONCLUSIONS: This is the first report on the leaf transcriptomes of six wild Nicotiana species by Illumina paired-end sequencing and de novo assembly without a reference genome. These sequence resources hopefully will provide an opportunity for identifying genes involved in plant defense and several important quality traits in wild Nicotiana and will accelerate functional genomic studies and genetic improvement efforts of Nicotiana or other important Solanaceae crops in the future.

The effects of allitridin on the expression of transcription factors T-bet and GATA-3 in mice infected by murine cytomegalovirus.

This study was designed to investigate the effects of allitridin on the expression of transcription factors T-bet and GATA-3 in mice infected by murine cytomegalovirus (MCMV). A BALB/c mouse model system of MCMV infection was established. Twenty mice were allocated randomly into an allitridin-treated group (n = 10) and a placebo control group (n = 10). The same dose (25 mg/kg/day) and regimen of allitridin were used in the treated group in the 24 hours after virus infection; the same volume of saline solution was injected in placebo control mice. In an additional blank control group (n = 10), the same volume of saline solution was injected. The expression levels of the transcription factors T-bet and GATA-3 were measured by reverse transcription-polymerase chain reaction. The expression levels of the T helper (Th) 1 cytokine interferon-gamma (IFN-gamma) and the Th2 cytokine interleukin (IL)-10 in supernatant of spleen cell culture were measured by enzyme-linked immunosorbent assay. MCMV infection markedly down-modulated the expression of IFN-gamma and T-bet and significantly up-modulated the expression of IL-10 and GATA-3. Allitridin induced significantly (P < .01) increased expression of the transcription factor T-bet and the Th1 cytokine IFN-gamma and markedly (P < .01) decreased expression of the transcription factor GATA-3 and the Th2 cytokine IL-10. Thus MCMV infection could lead to disequilibrium of Th1/Th2 cytokine expression: The level of the Th1 cytokine IFN-gamma was decreased significantly, and Th2 cytokine IL-10 was overexpressed markedly. Allitridin could up-regulate the expression of T-bet and IFN-gamma and inhibit the expression of GATA-3 and IL-10 in MCMV-infected mice, indicating a Th1 dominant state, which should enhance the specific cellular immune reactions against cytomegalovirus (CMV) and be helpful for clearance of CMV from the host.

An improved method for directional differentiation and efficient production of neurons from embryonic stem cells in vitro.

To establish a method of directional differentiation and efficient production of neurons from embryonic stem cells (ES cells) in vitro, based on the 4-/4+ protocol described by Bain, a new method was established to induce ES cells differentiating into neurons by means of three-step differentiation using all-trans retinoic acid (ATRA) combined with astrocyte-conditioned medium (ACM) in Vitro. The totipotency of ES cells was identified by observation of cells' morphology and formations of teratoma in immunocompromised mice. The cells' differentiation was evaluated continuously by the detection of the specific cellular markers of neural stem cells, neurons and astrocytes, including nestin, NSE and GFAP using immunohistochemistry assay. The NSE positive cells' ratio of the differentiated cells was determined by flow cytometry. It was found that the transparent circular clusters surrounding embryoid bodies induced with combining induction protocol formed just after 24 h and gradually enlarged later. This phenomenon could not be observed in EBs induced only by ATRA. The NSE positive cells' ratio in the cells induced with ATRA and ACM was higher than that of the cells induced by ATRA at different time points of differentiation, and finally reached up to 73.5% among the total differentiated population. It was concluded that ES cells could be induced into neurons with high purity and yield by means of inducing method combining with ATRA and ACM.

[BALB/c mice model system of cytomegalovirus-induced myocarditis].

OBJECTIVE: To establish a BALB/c mice model system of cytomegalovirus-induced myocarditis. METHODS: Twenty five specific pathogen-free inbred female BALB/c mice (5 weeks old, 16 - 18 g, seronegative for MCMV) were infected with 1 x 10(4) PFU MCMV by the intraperitoneal (i.p.) route. All experimental mice were sacrificed at 3, 5, 7, 10, 14 days i.p. (n = 5 per time point). Hearts were removed under aseptic conditions, and were transected along the midline. One part of each heart was processed with Bouin's fixative for histological examination. The other part of each heart was immediately frozen in liquid nitrogen and stored at -80 degrees C until MCMV titre was determined by plaque assay. Serum cTnI level was assayed by ELISA. RESULTS: MCMV was detected in the hearts at extremely low levels on 3 days i.p. and could not be detected on 10 days i.p. A mixed cellular infiltrate composed of polymorphonuclear neutrophils and mononuclear lymphocytes was observed on 3 days, which reached a peak at 7 to 10 days after MCMV infection and was maintained for at least 3 - 4 months postinfection. Serum cTnI levels were elevated on 3 days i.p., reaching a peak at 7 to 10 days i.p.. CONCLUSIONS: These data highlight the possible therapeutic uses of antiviral drugs in viral myocarditis as well as further elucidating the pathogenic nature of the disease.

Allitridin inhibits human cytomegalovirus replication in vitro.

Human cytomegalovirus (HCMV) has been associated with a wide spectrum of diseases. There is currently no effective treatment for eliminating the virus. Garlic bulb extract has been reported to possess anti-viral efficacy. This study aimed to investigate the expression of the immediate­early (IE; ul122 and ul123), early (E; ul54) and late (L; ul83) genes of HCMV as well as the inhibitory effect of allitridin on the transcription levels of these genes. The results indicated that a HCMV gene expression cascade occurred, and that the deletion of IE72 had no influence on the transcription of the ul122 gene, while it led to significant reductions of ul54 and ul83 mRNA expression levels. Additionally, allitridin effectively suppressed the transcription of the HCMV IE, E and L genes; the inhibition rates of the transcription of the ul122 and ul123 genes were higher compared with those of ul54 and ul83 mRNA expression, while the expression of the IE genes was not significantly reduced by ganciclovir (GCV). Our results indicate that the HCMV IE72 deletion mutant strain affects the transcription of the virus downstream gene, allitridin inhibits HCMV infection in vitro, and that the IE genes may be the key target of allitridin in its action against HCMV.

Isolation and identification of chlorinated genistein from Actinoplanes sp. HBDN08 with antioxidant and antitumor activities.

A strain Actinoplanes sp. HBDN08 was screened by PCR-guided method using primers derived from conserved regions of halogenase genes. A new chlorinated isoflavone, 3',8-dichlorogenistein (1), along with 8-chlorogenistein (2) were isolated from the fermentation broth of Actinoplanes sp. HBDN08. Their structures were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS, ESI-MS, UV, and IR spectroscopic analyses. The origin of the two compounds was also investigated by high-performance liquid chromatography (HPLC) analysis. The results demonstrated that they were not biosynthesized but derived from the biotransformation of genistein by Actinoplanes sp. HBDN08. The antioxidant activities of the isolated compounds 1 and 2 were evaluated by using the lipid peroxidation assay. Their antitumor activities were calculated according to the inhibitory rate of cell proliferation against the human breast cancer cell line MDA-MB-231. The results indicated that compounds 1 (IC(50) = 5.2 microM) and 2 (IC(50) = 7.5 microM) showed stronger antioxidant activities than genistein (IC(50) = 13.6 microM). In comparison with the antitumor activities of genistein, those of compounds 1 and 2 increased 7.7- and 2.6-fold, respectively. These results suggest that the PCR-guided screening strategy is a rapid method for obtaining halometabolite-producing strains. Moreover, these results reveal that chlorination has significant effects on the bioactivities of genistein. This could be important information for studying the structure-activity relationships of genistein.

Deficiency of protein kinase C-theta facilitates tolerance induction.

BACKGROUND: Protein kinase C-theta (PKCtheta) mediates critical T-cell receptor signals required for T-cell activation. We have recently shown that PKCtheta knockout (PKCtheta, H-2b) T cells, when transferred into T/B cell-deficient mice, failed to reject fully allogeneic (H-2d) cardiac grafts and that transgenic expression of antiapoptotic Bcl-xL gene in PKCtheta T cells restored allograft rejection. METHODS: We used PKCtheta mice as recipients of cardiac allografts, compared with wild-type (WT) cardiac allograft transplantation. Anti-CD154 monoclonal antibody (MR1) and human CTLA4Ig were sued to induce donor-specific tolerance. T-cell proliferation, T-cell subsests, nuclear factor kappa B (NF-kappaB) activation, and Bax and Bcl-xL were analyzed. RESULTS: Although suboptimal anti-CD154 monoclonal antibody or human CTLA4Ig failed to delay cardiac allograft rejection in WT mice, the same therapy induced long-term survival of cardiac allografts in PKCtheta mice. Donor-type second cardiac allografts (H-2d) were accepted, and third-party heart allografts (H-2k) were rejected by tolerant PKCtheta mice. However, tolerance state could not be effectively transferred with T cells from tolerance PKCtheta mice. Compared with WT mice, reduced NF-kappaB activation, T-cell proliferation, and T-cell infiltration in PKCtheta spleens were observed. PKCtheta mice reveal reduced CD4/CD25/FoxP3, Th1/Th17 subsets, and mouse MHC class II (IE)-reactive CD4Vbeta11 T cells. Apoptotic molecule, Bax, was increased and antiapoptotic molecule, Bcl-xL, was reduced in PKCtheta spleen cells. CONCLUSION: We concluded that PKCtheta mice have a defected alloimmune response and are susceptible to tolerance induction, which is associated with a clonal deletion of T-cell subsets.