Structural basis of antiviral activity of caffeic acid against severe fever with thrombocytopenia syndrome virus

Caffeic acid (CA), a coffee-related natural compound, has various beneficial biological effects, including antiviral effects. Our former studies demonstrated that the CA dose-dependently inhibited the in vitro infection with Dabie bandavirus, which was previously named as severe fever with thrombocytopenia syndrome virus (SFTSV), mainly at the step of virus attachment. Therefore, we studied the structural basis of CA for conferring anti-SFTSV activity to clarify the mechanism of action of CA against SFTSV. In this study, the anti-SFTSV activity of nine CA analogs were examined. The treatment of SFTSV with the 3,4-dihydroxyhydrocinnamic acid (DHCA) as well as CA inhibited the SFTSV infection in a dose-dependent manner, whereas other CA analogs did not. Both CA and DHCA only possessed the o-dihydroxybenzene backbone. When SFTSV was treated with catechol (o-dihydroxybenzene), SFTSV infection was also dose-dependently inhibited. Additionally, four compounds having the o-dihydroxybenzene backbone; CA phenethyl ester, methyl CA, 3,4-dihydroxyphenylacetic acid, and 3,4-dihydroxybenzoic acid, dose-dependently inhibited the viral infection, although these compounds were more toxic or less effective than CA. In conclusion, the o-dihydroxybenzene backbone in CA and its analogs was a critical structure for the anti-SFTSV activity. Based on these findings, modifications of the o-dihydroxybenzene backbone with various other residues might improve the antiviral effect and cytotoxicity for SFTSV.     

Factors predictive of relapse and spontaneous remission of autoimmune pancreatitis patients treated/not treated with corticosteroids

Background

Relapse and spontaneous remission (SR) are characteristic features of autoimmune pancreatitis (AIP).

Aim and methods

We conducted a study to determine if the predictive factors might be potentially related to the relapse in 70 consecutive AIP patients. Regarding SR, we studied the data of patients without corticosteroid treatment (CST).

Results

CST was administered to 60% (42/70) of the patients; however, relapse was noted in 45.2% (19/42) of these patients. In 95% (18/19) of the AIP patients developing relapse, the relapse occurred within 3?years. The relapse rate was 80% (12/15) in the AIP patients administered CST for less than 12?months and 25.9% (7/27) in those administered CST for over 12?months (p?p?p?=?0.0422) and the presence of jaundice (OR 6.945, p?=?0.0174) are significant independent factors predictive of relapse in AIP patients. SR was recognized in 65.0% (13/20) of AIP patients without CST.?The results of univariate analysis revealed that SR was associated with IgG4 seropositivity (p?p?=?0.0092) as a significant independent factor predictive of SR in these cases.

Conclusion

AIP patients with IgG4 seropositivity and jaundice are at a higher risk of relapse and they could therefore be candidates for over 3?years of maintenance CST. AIP patients with IgG4 seronegativity have a high likelihood of SR.     

A rare case of infectious colitis with ulcers in the cecum caused by Mycobacterium gordonae

A 69-year-old female complained of persistent abdominal pain, and annular ulcers and ulcer scars were detected endoscopically in the cecum. Pathological findings included caseous granulomas with some Langhans giant cells, and Ziehl-Neelsen staining was negative. Mycobacterium gordonae (M. gordonae) was identified by the DNA-DNA hybridization method and culture (Ogawa medium) of biopsy samples from ulcerous cecal lesions. After 6 months of antibiotic therapy, ulcerous cecal lesions were healed, and no acid-fast bacteria were detected by culture of biopsy samples from scar tissue. We believe this is the first report of M. gordonae infection in the alimentary tract.     

Clinical and genetic features of 20 Japanese patients with vascular‐type Ehlers–Danlos syndrome

Background Vascular‐type Ehlers–Danlos syndrome (vEDS) is a severe autosomal dominant inherited disorder resulting from mutations within the α1 type III collagen gene (COL3A1). The majority of published mutations are base changes leading to the substitution of single glycine residues within the triple‐helical domain of type III collagen. Although clinical characteristics and mutations in the COL3A1 gene have been analysed for some patients from Europe and America, similar analyses have not yet been performed for Japanese patients with vEDS. Objectives To analyse the genetic and phenotypic findings in Japanese patients with vEDS. Methods We analysed the clinical features of 20 unrelated individuals with vEDS. To quantify type III collagen production, the fibroblasts were cultured with ³H‐proline, and the radiolabelled collagenous proteins were analysed using sodium dodecyl sulphate–polyacrylamide gel electrophoresis and fluorography. Mutations in COL3A1 were detected by sequence analysis of cDNA from patients’ fibroblasts and subsequently by a genomic DNA sequence analysis. Results Thin and translucent skin with extensive bruising and hypermobility of the small joints were observed in about 90% of the patients, whereas the prevalence of serious clinical findings such as rupture/dissection/aneurysm of the arteries (30%) or rupture of the gastrointestinal tract (25%) was relatively low. Sequence analyses of the COL3A1 gene demonstrated heterozygous point mutations leading to glycine substitution in only nine patients (45%), while heterozygous splice‐site mutations at the junction of the triple‐helical exons were observed in the remaining 11 patients (55%). The average type III collagen production level in the cultured dermal fibroblasts was 14·6% of the normal value. The types of complication were not associated with specific mutations in COL3A1. Conclusion The analysis in the present series revealed a low frequency of patients presenting with serious clinical findings such as arterial rupture/arterial dissection/aneurysm and perforation or rupture of the gastrointestinal tract, and revealed a higher prevalence of splice‐site mutations at the junction of the triple‐helical exons than of glycine substitution mutations in COL3A1.     

Case of diffuse cutaneous systemic sclerosis with anti‐Ku and anti‐centromere antibodies

We report the case of a 58‐year‐old man who had an ulcer on the right middle finger that was cured by surgery 4 years before consultation with our department. A few years after the surgery, he noticed recurrence of the ulcer and sclerosis of the skin. At the initial examination, skin sclerosis was observed from the fingers to the upper arms and from the feet to the thighs. Pitting scars on the fingertips and punctured hemorrhages of the nail‐fold capillaries were also present. Gastroscopy showed slight reflex esophagitis. Laboratory findings were positive for antinuclear antibody (ANA; 1:640) with a speckled and discrete speckled pattern. Anti‐topoisomerase I (anti‐topo I) antibody and anti‐RNA polymerase III were negative, but anti‐centromere antibody was positive in an enzyme‐linked immunosorbent assay. Anti‐Ku antibody was positive in an immunoprecipitation assay using extracts of the leukemia cell line K562. Therefore, the patient was diagnosed with diffuse cutaneous systemic sclerosis with anti‐Ku and anti‐centromere antibodies. Treatment with an oral antiplatelet agent, vitamin E, a proton pump inhibitor, and i.v. lipoprostaglandin E1 were started. Subsequently, there has been repeated recurrence of finger ulcers, but no muscle involvement has been detected since his first visit. This is the first reported case of systemic sclerosis with anti‐Ku and anti‐centromere antibodies.     

Participation of autophagy in storage of lysosomes in neurons from mouse models of neuronal ceroid-lipofuscinoses (Batten disease)

In cathepsin D-deficient (CD-/-) and cathepsins B and L double-deficient (CB-/-CL-/-) mice, abnormal vacuolar structures accumulate in neurons of the brains. Many of these structures resemble autophagosomes in which part of the cytoplasm is retained but their precise nature and biogenesis remain unknown. We show here how autophagy contributes to the accumulation of these vacuolar structures in neurons deficient in cathepsin D or both cathepsins B and L by demonstrating an increased conversion of the molecular form of MAP1-LC3 for autophagosome formation from the cytosolic form (LC3-I) to the membrane-bound form (LC3-II). In both CD-/- and CB-/-CL-/- mouse brains, the membrane-bound LC3-II form predominated whereas MAP1-LC3 signals accumulated in granular structures located in neuronal perikarya and axons of these mutant brains and were localized to the membranes of autophagosomes, evidenced by immunofluorescence microscopy and freeze-fracture-replica immunoelectron microscopy. Moreover, as in CD-/- neurons, autofluorescence and subunit c of mitochondrial ATP synthase accumulated in CB-/-CL-/- neurons. This suggests that not only CD-/- but also CB-/-CL-/- mice could be useful animal models for neuronal ceroid-lipofuscinosis/Batten disease. These data strongly argue for a major involvement of autophagy in the pathogenesis of Batten disease/lysosomal storage disorders.     

Regulation of fungal infection by a combination of amphotericin B and peptide 2, a lactoferrin peptide that activates neutrophils

To establish a novel strategy for the control of fungal infection, we examined the antifungal and neutrophil-activating activities of antimicrobial peptides. The duration of survival of 50% of mice injected with a lethal dose of Candida albicans (5 x 10(8) cells) or Aspergillus fumigatus (1 x 10(8) cells) was prolonged 3 to 5 days by the injection of 10 microg of peptide 2 (a lactoferrin peptide) and 10 microg of alpha-defensin 1 for five consecutive days and was prolonged 5 to 13 days by the injection of 0.1 microg of granulocyte-monocyte colony-stimulating factor (GM-CSF) and 0.5 microg of amphotericin B. When mice received a combined injection of peptide 2 (10 microg/day) with amphotericin B (0.5 microg/day) for 5 days after the lethal fungal inoculation, their survival was greatly prolonged and some mice continued to live for more than 5 weeks, although the effective doses of peptide 2 for 50 and 100% suppression of Candida or Aspergillus colony formation were about one-third and one-half those of amphotericin B, respectively. In vitro, peptide 2 as well as GM-CSF increased the Candida and Aspergillus killing activities of neutrophils, but peptides such as alpha-defensin 1, beta-defensin 2, and histatin 5 did not upregulate the killing activity. GM-CSF together with peptide 2 but not other peptides enhanced the production of superoxide (O2-) by neutrophils. The upregulation by peptide 2 was confirmed by the activation of the O2- -generating pathway, i.e., activation of large-molecule guanine binding protein, phosphatidyl-inositol 3-kinase, protein kinase C, and p47phox as well as p67phox. In conclusion, different from natural antimicrobial peptides, peptide 2 has a potent neutrophil-activating effect which could be advantageous for its clinical use in combination with antifungal drugs.