Ruminococcus gnavus ameliorates atopic dermatitis by enhancing Treg cell and metabolites in BALB/c mice.

BACKGROUND: Ruminococcus gnavus (R. gnavus) are mucin-degrading gut bacteria that play a key role in the early colonization of the gut by serving as endogenous sources of nutrients. They can also influence immune development. We had previously reported a lower abundance of R. gnavus in infants with atopic dermatitis (AD) compared with that in healthy subjects. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of orally administered R. gnavus on antibiotic treatment-induced gut dysbiosis (and the underlying mechanism) in a mouse model of AD. METHODS: Four-week-old female BALB/C mice were administered antibiotic cocktails for 2 weeks. R. gnavus was orally administered throughout the study duration. At 6 weeks of age, AD was induced by epidermal sensitization with ovalbumin. AD phenotypes and systemic and gut immune responses were investigated. RESULTS: Orally administered R. gnavus significantly reduced AD-associated parameters (i.e., transepidermal water loss, clinical score, total serum immunoglobulin (Ig) E level, OVA-specific IgE level, and skin inflammation). R. gnavus treatment also resulted in significant downregulation of T helper 2-related cytokine mRNA and upregulation of interleukin (IL)-10 and Foxp3 in the skin. The population of CD4+ FOXP3+ T cells in mesenteric- and skin-draining lymph nodes and butyrate levels in the cecum increased in R. gnavus-administered AD mice. CONCLUSIONS: Immune modulation by orally administered R. gnavus may alleviate AD symptoms through the enhancement of regulatory T-cell counts and short-chain fatty acids production in AD mice.

Inducible spy Transcription Acts as a Sensor for Envelope Stress of Salmonella typhimurium.

Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella.

Valosin-containing protein is a novel autoantigen in patients with glaucoma.

PURPOSE: The purpose of this study was to identify novel autoantigens that react with specific serum autoantibodies in patients with glaucoma. METHODS: Sera from patients with glaucoma (n = 80) and healthy subjects without a known pathology (n = 20) were investigated by immunoblot performed with bovine optic nerve lysates and resolved by one- and two-dimensional electrophoresis. Proteins in the immunoreactive spots were selected and identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) data analysis. All the sera from subjects were assayed using enzyme-linked immunosorbent assay to identify autoantibodies. RESULTS: We selected two prominent bands with molecular weights of 100 and 220 kDa by 8% sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, and these two bands were only found in the glaucoma patients. Using one-dimensional electrophoresis and LC-MS/MS analyses, we identified these proteins to be valosin-containing protein (VCP) and fodrin, respectively, and using two-dimensional electrophoresis and LC-MS/MS analyses, VCP was identified to be a common target antigen. In patients with primary open angle glaucoma and normal tension glaucoma, the frequency of autoantibodies to recombinant human VCP was 42.0 and 23.3%, respectively (p < 0.002). In the enzyme-linked immunosorbent assay tests, autoantibody titers to recombinant human VCP were significantly higher than that in healthy controls (p < 0.025). CONCLUSIONS: VCP represents a potential candidate target for autoantibodies on the optic nerve in patients with glaucoma.

Bevacizumab accelerates corneal wound healing by inhibiting TGF-beta2 expression in alkali-burned mouse cornea.

This study investigated the effect of subconjunctival injections of bevacizumab, an anti-VEGF antibody, on processes involved in corneal wound healing after alkali burn injury. Mice were divided into three groups: Group 1 was the saline-treated control, group 2 received subconjunctival injection of bevacizumab 1 hr after injury and group 3 received bevacizumab 1 hr and 4 days after injury. Cornea neovascularization and opacity were observed using a slit lamp microscope. Corneal repair was assessed through histological analysis and immunostaining for CD31, alpha-SMA, collagen I, and TGF-beta2 7 days post-injury. In group 3, injection of bevacizumab significantly lowered neovascularization and improved corneal transparency. Immunostaining analysis demonstrated a reduction in CD31, alpha-SMA and TGF-beta2 levels in stroma compared to group 1. These results indicate that bevacizumab may be useful in reducing neovascularization and improving corneal transparency following corneal alkali burn injury by accelerating regeneration of the basement membrane.

Protective effect of heat shock proteins 70.1 and 70.3 on retinal photic injury after systemic hyperthermia.

PURPOSE: This study aimed to determine the relationship between the heat shock protein 70 from hsps70.1 and 70.3 on retinal photic injury after systemic hyperthermia. METHODS: Eight-week-old female C57BU6 mice were kept at a constant temperature of 41-42 degrees C for 25-30 minutes. After dark-adaptation for 8 hours, intense light of 11000 lux was maintained for 6 hours. Histology and immunohistochemistry for the inducible heat shock protein 70 (hsp70), the constitutive heat shock protein 70 (hsc70), and westem blot analysis, reverse transcriptase-polymerase chain reaction for hsp70.1 and hsp70.3 were performed just before photic injury and after 1, 4, 7, and 14 days. RESULTS: Light-induced retinal degeneration was prevented by thermotolerance. After hyperthermia, hsp70 was densely expressed in the inner segment of the photoreceptor layer on the photic injury. Hsp70 expression increased for 4 days after photic injury and slowly decreased thereafter. mRNA from hsp70.3 was induced earlier than that of hsp70.1. CONCLUSIONS: Retinal photic injury was prevented by hyperthermia-induced hsp70. Hsp70 from hsp70.3 may be a rapid and short-lived responder, and that from hsp70.1 is a slower and more sustained responder. Hsp70 from hsp70.3 may be an initial retinal chaperone while hsp70 from hsp70.1 may be a sustained chaperone.

Delay of photoreceptor cell degeneration in rd mice by systemically administered phenyl-N-tert-butylnitrone.

PURPOSE: To study the effect of systemic administration of phenyl-N-tert-butylnitrone (PBN) on the degeneration of photoreceptor cells in rd mice. METHODS: PBN was injected intraperitoneally into FVB/rd mice on postnatal days (P) 5 to 14 (group A), and P10 to 18 (group B). At days P14, 16, 18, 20 and 27, morphological changes and apoptosis were analyzed by staining with hematoxylin and eosin or DAPI. The effect of PBN on apoptosis was analyzed in retinal pigment epithelial (RPE) cells by the measurement of caspase-3 activity. RESULTS: In control and group B mice, the outer nuclear layer (ONL) of the retina was composed of 8-10 rows at P12, and rapidly decreased to one row at P18. In group A mice, the ONL was preserved with 5-7 rows at P18, and decreased to one row at P22. PBN inhibited caspase-3 activity in cultured RPE cells. CONCLUSIONS: PBN delayed, but did not block, the degeneration of photoreceptor cells in rd mice. PBN may exert its inhibitory effect during the early phase of photoreceptor cell degeneration.

Third cranial nerve palsy from midbrain neurocysticercosis: repeated exacerbation on tapering corticosteroids.

Third cranial nerve palsy is rare in neurocysticercosis and is usually caused by supratentorial or sub-arachnoid lesions with accompanying hydrocephalus or meningitis. We report a patient who presented with third cranial nerve palsy caused by neurocysticercosis involving the midbrain. The patient showed repeated exacerbation of symptoms on tapering corticosteroids. The experience with this patient indicates that tapering of corticosteroids should be performed very slowly in such cases.