Novel SPEF2 Variant in a Japanese Patient with Primary Ciliary Dyskinesia: A Case Report and Literature Review.

Primary ciliary dyskinesia (PCD) is a genetic and congenital disease associated with an abnormal ciliary ultrastructure and function and is estimated to affect 1 in 15,000-20,000 individuals. A PCD diagnosis can be achieved by genotyping. Here, we performed whole-exome analysis for the diagnosis of PCD and described the detailed clinical characteristics of the case. A 39-year-old Japanese woman with sinusitis and bronchiectasis without situs inversus had had upper and lower respiratory symptoms since childhood and had received long-term macrolide therapy without an accurate diagnosis. A moderate deterioration of cilia function was observed by high-speed video microscopy analysis; additionally, the number of cells with moving cilia was fewer than that in patients without PCD. Electron microscopy revealed no apparent structural abnormalities. We performed whole-exome analysis and identified novel biallelic variants of SPEF2 in the homozygous state (c.1860_1861insCT). We confirmed the absence of SPEF2 protein expression in the cilia of the nasal mucosa using fluorescent immunostaining. Accordingly, she was diagnosed as having PCD with the SPEF2 variant. The present case suggests that the deterioration of cilia function is moderate, the number of respiratory cells with moving cilia might be reduced, and the respiratory condition could be severe in patients with PCD with the SPEF2 variant.

Increased In Vitro Intercellular Barrier Function of Lung Epithelial Cells Using Adipose-Derived Mesenchymal Stem/Stromal Cells.

With the emergence of coronavirus disease-2019, researchers have gained interest in the therapeutic efficacy of mesenchymal stem/stromal cells (MSCs) in acute respiratory distress syndrome; however, the mechanisms of the therapeutic effects of MSCs are unclear. We have previously reported that adipose-derived MSCs (AD-MSCs) strengthen the barrier function of the pulmonary vessels in scaffold-based bioengineered rat lungs. In this study, we evaluated whether AD-MSCs could enhance the intercellular barrier function of lung epithelial cells in vitro using a transwell coculture system. Transepithelial electrical resistance (TEER) measurements revealed that the peak TEER value was significantly higher in the AD-MSC coculture group than in the AD-MSC non-coculture group. Similarly, the permeability coefficient was significantly decreased in the AD-MSC coculture group compared to that in the AD-MSC non-coculture group. Immunostaining of insert membranes showed that zonula occuldens-1 expression was significantly high at cell junctions in the AD-MSC coculture group. Moreover, cell junction-related gene profiling showed that the expression of some claudin genes, including claudin-4, was upregulated in the AD-MSC coculture group. Taken together, these results showed that AD-MSCs enhanced the barrier function between lung epithelial cells, suggesting that both direct adhesion and indirect paracrine effects strengthened the barrier function of lung alveolar epithelium in vitro.

An axonemal alteration in apical endometria of human adenomyosis.

STUDY QUESTION: Is there any change in the distribution of microvilli and microtubules in the apical endometria of women with adenomyosis? SUMMARY ANSWER: We observed microvilli damage in the apical endometria and an axonemal alteration characterized by abnormal distribution of longitudinal bundles of microtubules within microvilli in women with adenomyosis. WHAT IS KNOWN ALREADY: Human adenomyosis has a negative impact on female fertility. Abnormal utero-tubal sperm transport, tissue inflammation and toxic effect of chemical mediators have been proposed as contributing factors. Inflammation-induced damage of mucosal cilia in the Fallopian tube has been reported. However, information on inflammation-induced damage of microvilli on the apical endometrial cells and its core bundles of microtubules in adenomyosis remains unknown. STUDY DESIGN, SIZE, DURATION: This is a prospective cohort study with subjects undergoing laparoscopic surgery or hysterectomy for clinical indication and evaluations of endometrial biopsy samples in two academic university hospitals. During the period between March 2015 and December 2018, endometrial biopsy samples were prospectively collected from 15 control women and 45 women with adenomyosis for immunohistochemical analysis and a separate cohort of 10 control women with cervical intraepithelial neoplasia Grade 3 (CIN3) and 20 women with adenomyosis for analysis by immunohistochemistry and transmission electron microscopy (TEM). PARTICIPANTS/MATERIALS, SETTING, METHODS: For immunohistochemical study, endometrial biopsy samples were prospectively collected from 15 control women with fibroids, 25 women with focal adenomyosis and 20 women with diffuse adenomyosis after surgery. The diagnosis of fibroid and adenomyosis was made clinically by transvaginal ultrasonography and magnetic resonance imaging and confirmed by histology. Immunohistochemical analysis was performed retrospectively using antibody against CD68 (marker of macrophages) in endometrial biopsy specimens of women with and without adenomyosis. TEM was performed with the apical endometria collected from a separate cohort of 10 control women with CIN3 and 20 women with focal and diffuse adenomyosis for the identification of any change in the distribution of microvilli and longitudinal bundles of microtubules within microvilli. MAIN RESULTS AND ROLE OF CHANCE: Comparing to control endometria and contralateral side, tissue infiltration of macrophages (Mφ) in the endometria was significantly higher on the ipsilateral side of focal adenomyosis (P = 0.02 and P = 0.03, respectively) and anterior/posterior walls of diffuse adenomyosis (P = 0.01 for both). In a subgroup analysis of patients with focal adenomyosis with and without symptoms, the endometria of symptomatic women displayed a tendency of higher Mφ infiltration on the ipsilateral side than in asymptomatic women (P = 0.07). Comparing to contralateral side endometria of symptomatic women, Mφ infiltration was significantly higher in the endometria of symptomatic women collected from the ipsilateral side of focal adenomyosis (P = 0.03). We found a significantly less tissue infiltration of Mφ in the endometria of women with CIN3 than that in endometria of women with focal adenomyosis. TEM analysis showed that number of microvilli in the endometria was significantly decreased on the ipsilateral side (P = 0.003) comparing to that on the contralateral side of focal adenomyosis. The Chi-squared test indicated that cases with abnormal (disruption in the normal arrangement of 9 peripheral pairs + 1 central pair) microtubules (MT) were significantly higher in women with adenomyosis than in cases with normal patterns (P = 0.0016). While contralateral side displayed significantly less abnormal MT (P = 0.0002), ipsilateral side of focal adenomyosis showed significantly higher abnormal MT (P = 0.0164) comparing to normal patterns. Cases with symptomatic adenomyosis showed significantly higher abnormal MT than normal MT (P = 0.0004). An axonemal alteration characterized by abnormal structural distribution of microtubules within microvilli in the apical endometria in response to endometrial inflammation may be involved in adverse reproductive outcome in women with adenomyosis. LIMITATIONS, REASONS FOR CAUTION: The average age of women in this study was high that may be associated with overall decline in fertility regardless of the presence or absence of adenomyosis or endometriosis. We collected endometrial biopsy samples from two completely separate cohorts of women for analysis by immunohiostochemistry and TEM. We need future follow-up study with increased sample size and from the same patients to precisely clarify the mechanistic link between axonemal alteration and negative fertility outcome. WIDER IMPLICATIONS OF THE FINDINGS: Our current findings may have some biological implication to better understand the endometrial epithelial biology and pathology in women with adenomyosis and may open the avenue for future study in other reproductive diseases. The ultra-structural abnormalities of microvilli and microtubules in the apical endometria in response to tissue inflammatory reaction may clarify the possible association between negative fertility outcome and adenomyosis. Our findings may be clinically useful during counseling with symptomatic patients with adenomyosis desiring pregnancy. STUDY FUNDING/COMPETING INTEREST (S): This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Sports, Culture, Science and Technology of Japan. There is no conflict of interest related to this study. TRIAL REGISTRATION NUMBER: N/A.

Roles of Elm1 in antifungal susceptibility and virulence in Candida glabrata.

Elm1 is a serine/threonine kinase involved in multiple cellular functions, including cytokinesis, morphogenesis, and drug resistance in Saccharomyces cerevisiae; however, its roles in pathogenic fungi have not been reported. In this study, we created ELM1-deletion, ELM1-reconstituted, ELM1-overexpression, and ELM1-kinase-dead strains in the clinically important fungal pathogen Candida glabrata and investigated the roles of Elm1 in cell morphology, stress response, and virulence. The elm1Δ strain showed elongated morphology and a thicker cell wall, with analyses of cell-wall components revealing that this strain exhibited significantly increased chitin content relative to that in the wild-type and ELM1-overexpression strains. Although the elm1Δ strain exhibited slower growth than the other two strains, as well as increased sensitivity to high temperature and cell-wall-damaging agents, it showed increased virulence in a Galleria mellonella-infection model. Moreover, loss of Elm1 resulted in increased adhesion to agar plates and epithelial cells, which represent important virulence factors in C. glabrata. Furthermore, RNA sequencing revealed that expression levels of 30 adhesion-like genes were elevated in the elm1Δ strain. Importantly, all these functions were mediated by the kinase activity of Elm1. To our knowledge, this is the first report describing the functional characterization of Elm1 in pathogenic fungi.

Initial human T-cell leukemia virus type 1 infection of the salivary gland epithelial cells requires a biofilm-like structure.

The initial phase of the human T cell leukemia virus-1 (HTLV-1) infection of salivary gland epithelial cells (SGECs) was examined. SGECs of patients with Sjögren's syndrome (SS) and non-SS subjects were co-cultured with the HTLV-1-infected cell line HCT-5 or MOLT-4, then immunofluorescence (IF), scanning and transmission electron microscopy (SEM/TEM) were employed. The extracellular matrix and linker proteins galectin-3, agrin, and tetherin were expressed on the surfaces of both HCT-5 and MOLT-4 cells. HTLV-1 Gag-positive spots were observed on adjacent SGECs after 1 h of co-culture with HCT-5. Both in subjects with and those without SS, agrin and tetherin were co-expressed with HTLV-1 Gag on SGECs after co-culture with HCT-5, although no polarization of HTLV-1 Gag and relevant molecules was observed. SEM showed HTLV-1 virions that were found on HCT-5 were observed in the interfaces between HCT-5 cells and SGECs. TEM imaging showed that HTLV-1 virions were transmitted to SGECs at the interface with thin film-like structure, while HTLV-1 virions were released from the surface of HCT-5 cells. No endogenous retroviruses were observed. These results showed that the initial phase of HTLV-1 infection toward SGECs of SS was mediated not by viral synapses, but by biofilm-like components.

Distinct Roles of Zmynd17 and PGC1α in Mitochondrial Quality Control and Biogenesis in Skeletal Muscle.

Maintaining skeletal muscle mitochondrial quality is important not only for muscle activity but also for systemic metabolism. Exercise has long been recognized to have a positive impact on muscle mitochondrial quality. Although exercise triggers various changes in the mitochondrial dynamics, its molecular basis remains to be elucidated. We have previously reported that inactivation of the muscle-specific protein, zinc finger MYND domain-containing protein 17 (Zmynd17), results in mitochondrial abnormalities. To investigate the link between Zmynd17 activity and exercise-induced mitochondrial maintenance, we observed the effect of consecutive exercise on the mitochondrial quality in Zmynd17-deficient muscles. Zmynd17-deficient mice displayed abnormal mitochondrial morphology in limb muscles, which remarkably improved upon voluntary exercise. Interestingly, morphological abnormalities in mitochondria were even more apparent when PGC1α, a regulator of exercise-induced mitochondrial biogenesis, was overexpressed in Zmynd17-KO limb muscle. These abnormalities were also ameliorated by voluntary exercise. Our results show that neither the effect of consecutive exercise on mitochondrial quality nor PGC1α-induced mitochondrial biogenesis are mediated through Zmynd17 activity, thereby suggesting the existence of a complex mechanism of mitochondrial quality control in muscles.

Increased expression and altered localization of cathepsin Z are associated with progression to jaundice stage in primary biliary cholangitis.

Our recent genome-wide association study found that the NELFCD/CTSZ locus was significantly associated with progression of primary biliary cholangitis (PBC) to jaundice stage in the Japanese population. In this study, we investigated the role of cathepsin Z in the etiology and pathology of PBC. Serum cathepsin Z levels were measured using enzyme-linked immunosorbent assay. The expression and localization of cathepsin Z in liver specimens were analyzed by western blotting and immunohistochemistry. In PBC patients, serum cathepsin Z levels were significantly increased with disease progression. In addition, its levels were positively correlated with alanine transaminase, aspartate transaminase and total bilirubin, and were negatively correlated with platelet count and albumin. Cathepsin Z expression was markedly increased in hepatocytes at later stages of PBC, and its localization was altered from the peri-bile canaliculus to the cytoplasm, where a fraction was no longer colocalized with endosomal/lysosomal vesicles. Similar altered expression of cathepsin Z was observed in end-stage of other cholestatic liver diseases including sepsis, obstructive jaundice, and Alagille syndrome. Our results indicate that altered expression and localization of cathepsin Z in hepatocytes are characteristic features of PBC and other cholestatic liver diseases, and are implicated in the progression of PBC.

Sodium hydroxide based non-detergent decellularizing solution for rat lung.

Lung transplantation is the last option for the treatment of end stage chronic lung disorders. Because the shortage of donor lung organs represents the main hurdle, lung regeneration has been considered to overcome this hurdle. Recellularization of decellularized organ scaffold is a promising option for organ regeneration. Although detergents are ordinarily used for decellularization, other approaches are possible. Here we used high alkaline (pH12) sodium hydroxide (NaOH)-PBS solution without detergents for lung decellularization and compared the efficacy on DNA elimination and ECM preservation with detergent based decellularization solutions CHAPS and SDS. Immunohistochemical image analysis showed that cell components were removed by NaOH solution as well as other detergents. A Collagen and GAG assay showed that the collagen reduction of the NaOH group was comparable to that of the CHAPS and SDS groups. However, DNA reduction was more significant in the NaOH group than in other groups (p < 0.0001). The recellularization of HUVEC revealed cell attachment was not inferior to that of the SDS group. Ex vivo functional analysis showed 100% oxygen ventilation increased oxygen partial pressure as artificial hemoglobin vesicle-PBS solution passed through regenerated lungs in the SDS or NaOH group. It was concluded that the NaOH-PBS based decellularization solution was comparable to ordinal decellularizaton solutions and competitive in cost effectiveness and residues in the decellularized scaffold negligible, thus providing another potential option to detergent for future clinical usage.

Zmynd17 controls muscle mitochondrial quality and whole-body metabolism.

Muscle mitochondria are crucial for systemic metabolic function, yet their regulation remains unclear. The zinc finger MYND domain-containing protein 17 (Zmynd17) was recently identified as a muscle-specific gene in mammals. Here, we investigated the role of Zmynd17 in mice. We found Zmynd17 predominantly expressed in skeletal muscle, especially in fast glycolytic muscle. Genetic Zmynd17 inactivation led to morphologic and functional abnormalities in muscle mitochondria, resulting in decreased respiratory function. Metabolic stress induced by a high-fat diet upregulated Zmynd17 expression and further exacerbated muscle mitochondrial morphology in Zmynd17-deficient mice. Strikingly, Zmynd17 deficiency significantly aggravated metabolic stress-induced hepatic steatosis, glucose intolerance, and insulin resistance. Furthermore, middle-aged mice lacking Zmynd17 exhibited impaired aerobic exercise performance, glucose intolerance, and insulin resistance. Thus, our results indicate that Zmynd17 is a metabolic stress-inducible factor that maintains muscle mitochondrial integrity, with its deficiency profoundly affecting whole-body glucose metabolism.-Fujita, R., Yoshioka, K., Seko, D., Suematsu, T., Mitsuhashi, S., Senoo, N., Miura, S., Nishino, I., Ono, Y. Zmynd17 controls muscle mitochondrial quality and whole-body metabolism.

Ventilation-Based Decellularization System of the Lung.

The demand for donated organs greatly exceeds the availability. Alternatives to organ donation, such as laboratory-engineered organs, are therefore being developed. One approach is to decellularize the organ and reseed it with selected cells, ideally from the organ recipient. Organ decellularization has typically been attempted by the administration of detergents into vessels such as the portal vein in the liver. However, in the case of the lung, the airway provides another potential administration route, because it has a wide contact area between cells and detergents in the tracheal tree and alveoli. In the present study, we introduce a novel ventilation-based decellularization system for the lung and compare its efficacy to ordinary decellularization systems administering detergent through the pulmonary artery. Rat lungs were decellularized using 500 mL of 3-[(3-cholamidopropyl) dimethylammonio]-1-Propanesulfonate (CHAPS) decellularization solution administrated through the pulmonary artery (vessel group) or through the trachea (airway group). The vessel group was infused CHAPS solution using a gravitational pressure head of 20 cmH2O. The airway group was infused with the detergent using negative pressure and positive end-expiratory pressure, for a volume 10cc with each inspiration in a bioreactor. Pathological and immunohistochemical findings indicated that components of the extracellular matrix (ECM), including proteoglycans, elastic fibers, fibronectin, and laminin, were more decreased in the airway group than in the vessel group. Western blot analysis showed that MHC class I antigen and ß-actin were not detected in both decellularized groups. A collagen assay showed that collagen was 70% preserved in both groups compared to native lung. Glycosaminoglycan (GAG) and DNA assays showed that GAG and DNA contents were strongly diminished in both decellularized groups, but those contents were smaller in the airway group than in the vessel group. Accordingly, the alveolar wall was thinner on electron microscopy, and DNA remnants were not observed in the airway group. Infusion of red blood cells indicated that capillary walls were preserved without blood leakage in both groups. In conclusion, we describe a novel approach for decellularization through the airway that represents a more stringent method for both DNA and ECM removal, with capillary wall preservation.

Vascularized subcutaneous human liver tissue from engineered hepatocyte/fibroblast sheets in mice.

Subcutaneous liver tissue engineering is an attractive and minimally invasive approach used to curative treat hepatic failure and inherited liver diseases. However, graft failure occurs frequently due to insufficient infiltration of blood vessels (neoangiogenesis), while the maintenance of hepatocyte phenotype and function requires in vivo development of the complex cellular organization of the hepatic lobule. Here we describe a subcutaneous human liver construction allowing for rapidly vascularized grafts by transplanting engineered cellular sheets consisting of human primary hepatocytes adhered onto a fibroblast layer. The engineered hepatocyte/fibroblast sheets (EHFSs) showed superior expression levels of vascularization-associated growth factors (vascular endothelial growth factor, transforming growth factor beta 1, and hepatocyte growth factor) in vitro. EHFSs developed into vascularized subcutaneous human liver tissues contained glycogen stores, synthesized coagulation factor IX, and showed significantly higher synthesis rates of liver-specific proteins (albumin and alpha 1 anti-trypsin) in vivo than tissues from hepatocyte-only sheets. The present study describes a new approach for vascularized human liver organogenesis under mouse skin. This approach could prove valuable for establishing novel cell therapies for liver diseases.

Fragments of Target Cells are Internalized into Retroviral Envelope Protein-Expressing Cells during Cell-Cell Fusion by Endocytosis.

Retroviruses enter into host cells by fusion between viral and host cell membranes. Retroviral envelope glycoprotein (Env) induces the membrane fusion, and also mediates cell-cell fusion. There are two types of cell-cell fusions induced by the Env protein. Fusion-from-within is induced by fusion between viral fusogenic Env protein-expressing cells and susceptible cells, and virions induce fusion-from-without by fusion between adjacent cells. Although entry of ecotropic murine leukemia virus (E-MLV) requires host cell endocytosis, the involvement of endocytosis in cell fusion is unclear. By fluorescent microscopic analysis of the fusion-from-within, we found that fragments of target cells are internalized into Env-expressing cells. Treatment of the Env-expressing cells with an endocytosis inhibitor more significantly inhibited the cell fusion than that of the target cells, indicating that endocytosis in Env-expressing cells is required for the cell fusion. The endocytosis inhibitor also attenuated the fusion-from-without. Electron microscopic analysis suggested that the membrane fusion resulting in fusion-from-within initiates in endocytic membrane dents. This study shows that two types of the viral cell fusion both require endocytosis, and provides the cascade of fusion-from-within.

Coexpression of ang1 and tie2 in odontoblasts of mouse developing and mature teeth-a new insight into dentinogenesis.

Angiopoietin-1 regulates vascular angiogenesis and stabilization, and is reported to promote bone formation by facilitating angiogenesis. To estimate the role of Ang1 in odontogenesis, we explored the distribution of Ang1 and the receptor, Tie2 in the mouse developing and mature first molar of the mandible. At embryonic day 18, when differentiation of odontoblasts begins, immunosignals for Ang1 were intensely detected in the basement membrane and the distal side, which faced the basement membrane of odontoblasts. In situ hybridization revealed that Ang1 was expressed in odontoblasts and ameloblasts facing the basement membrane. Tie2 was localized in the distal side of odontoblasts. After birth, Ang1 was detected in the predentin, whereas both Ang1 and Tie2 were colocalized in odontoblasts and odontoblast processes. These distributions were retained up to 8 weeks. In contrast to odontoblasts, ameloblasts, cementoblasts and osteoblasts expressed Ang1 but did not express Tie2. Colocalization of Ang1 and Tie2 in odontoblasts and selective expression of Tie2 in odontoblasts among cells responsible for calcified tissue formation suggested the involvement of autocrine signals of Ang1-Tie2 in dentinogenesis.

Characterization of dsRNA-induced pancreatitis model reveals the regulatory role of IFN regulatory factor 2 (Irf2) in trypsinogen5 gene transcription.

Mice deficient for interferon regulatory factor (Irf)2 (Irf2(-/-) mice) exhibit immunological abnormalities and cannot survive lymphocytic choriomeningitis virus infection. The pancreas of these animals is highly inflamed, a phenotype replicated by treatment with poly(I:C), a synthetic double-stranded RNA. Trypsinogen5 mRNA was constitutively up-regulated about 1,000-fold in Irf2(-/-) mice compared with controls as assessed by quantitative RT-PCR. Further knockout of IFNα/ß receptor 1(Ifnar1) abolished poly(I:C)-induced pancreatitis but had no effect on the constitutive up-regulation of trypsinogen5 gene, indicating crucial type I IFN signaling to elicit the inflammation. Analysis of Ifnar1(-/-) mice confirmed type I IFN-dependent transcriptional activation of dsRNA-sensing pattern recognition receptor genes MDA5, RIG-I, and TLR3, which induced poly(I:C)-dependent cell death in acinar cells in the absence of IRF2. We speculate that Trypsin5, the trypsinogen5 gene product, leaking from dead acinar cells triggers a chain reaction leading to lethal pancreatitis in Irf2(-/-) mice because it is resistant to a major endogenous trypsin inhibitor, Spink3.

Magnifying endoscopic observation with narrow band imaging for specialized intestinal metaplasia in barrett's esophagus with special reference to light blue crests.

AIM: Barrett's esophagus (BE) with specialized intestinal metaplasia (SIM) is at high risk of esophageal adenocarcinoma. Magnified endoscopy with narrow band imaging (ME-NBI) can be useful for detecting this condition. In addition to pit patterns, light blue crests (LBC), blue-whitish patchy areas on the metaplastic epithelia of the stomach, can predict SIM in BE under ME-NBI observation. METHODS: A total of 54 patients with BE underwent ME-NBI to identify IM pits (tubular and villous pits) and LBC. Biopsy samples were taken for histological evaluation of IM, immunohistochemical staining for CD10, MUC2 and MUC5AC antigen, transmission electron microscopy and real-time polymerase chain reaction (RT-PCR) analysis of CD10 mRNA expression. RESULTS: IM pit pattern with ME-NBI for the diagnosis of IM yielded acceptable sensitivity, specificity and accuracy at 92%, 77% and 83%, respectively. However, the sensitivity, specificity and accuracy of LBC with ME-NBI for IM were comparably high at 79%, 97% and 89%, respectively. Upon immunohistochemistry, all 19 metaplastic epithelia of LBC-positive BE showed immunoreactivity against anti-MUC2 antibody, whereas CD10 antigen was identified in 11 of the 19 LBC-positive BE. Brush borders were seen on IM epithelia using electron microscopy. On real-time PCR analysis, CD10 mRNA levels in the LBC-positive BE were higher compared to those in the LBC-negative BE. CONCLUSION: The appearance of LBC can be an accurate sign to predict SIM in BE and may be associated with high CD10 expression, possibly along with brush borders.

Anti-Clostridium difficile potential of tetramic acid derivatives from Pseudomonas aeruginosa quorum-sensing autoinducers.

We have examined the potential bactericidal activities of several tetramic acids derived from Pseudomonas autoinducers against Clostridium difficile, a cause of antibiotic-associated pseudomembranous colitis. Clinical isolates of C. difficile (n=4) were incubated in broth with a chemically synthesized Pseudomonas autoinducer and its tetramic acid derivatives. The structure-activity relationship and the mechanisms of action were examined by a time-killing assay and by determination of the morphological/staining characteristics. The use of some tetramic acids derived from N-3-oxododecanoyl L-homoserine lactone resulted in more than 3-log reductions in the viability of C. difficile within 30 min at 30 microM. The outer membrane was suggested to be one of the targets for the bactericidal activity of tetramic acid, because disturbance of the bacterial outer surface was demonstrated by alteration of the Gram-staining characteristic and electron microscopy. The data for the tetramic acid derivatives demonstrate that the keto-enol structure and the length of the acyl side chain of tetramic acid may be essential for the antibacterial activity of this molecule. These results suggest the potential for tetramic acid derivatives to be novel agents with activity against C. difficile.

Decreased cellular membrane expression of gap junctional protein, connexin 43, in rat detrusor muscle with chronic partial bladder outlet obstruction.

OBJECTIVES: To investigate alterations in gap junctional protein, connexin-43 (Cx-43), in the rat detrusor muscle with partial bladder outlet obstruction (P-BOO). Muscle cell actions, such as detrusor contractions, are thought to be synchronized by way of gap junctional intercellular communication. Gap junctions may play an important role in voiding, and P-BOO is a common medical problem. METHODS: A total of 33 female Wistar rats (12 weeks old) were divided into a P-BOO group and a sham-operated control group and were killed at 2, 4, and 8 weeks after surgery. Cystometric investigation, the alteration of gap junction, and Cx-43 protein expression, which compose the gap junction, were examined. RESULTS: The number of gap junctions was decreased in the P-BOO rat bladder. Furthermore, decreased cellular membrane expression of Cx-43 proteins was detected in rat detrusor muscle cells more than 4 weeks after surgery. The gap junctions of the detrusor muscle cell membranes were significantly fewer in number in the P-BOO rats with no detrusor contractions. CONCLUSIONS: These data suggest that the normal signals that contribute to voiding function could be transported directly through the gap junctions. Voiding dysfunction may be caused by the disruption of gap junctional intercellular communication.

Critical roles of interferon regulatory factor 4 in CD11bhighCD8alpha- dendritic cell development.

IFN regulatory factors (IRFs) are a family of transcription factors that play an essential role in the homeostasis and function of immune systems. Recent studies indicated that IRF-8 is critical for the development of CD11b(low)CD8alpha(+) conventional dendritic cells (DCs) and plasmacytoid DCs. Here we show that IRF-4 is important for CD11b(high)CD8alpha(-) conventional DCs. The development of CD11b(high) DCs from bone marrow of IRF-4(-/-) mice was severely impaired in two culture systems supplemented with either GM-CSF or Flt3-ligand. In the IRF-4(-/-) spleen, the number of CD4(+)CD8alpha(-) DCs, a major subset of CD11b(high) DCs, was severely reduced. IRF-4 and IRF-8 were expressed in the majority of CD11b(high)CD4(+)CD8alpha(-) DCs and CD11b(low)CD8alpha(+) DCs, respectively, in a mutually exclusive manner. These results imply that IRF-4 and IRF-8 selectively play critical roles in the development of the DC subsets that express them.