Enhanced symbiotic seed germination of Cypripedium macranthos var. rebunense following inoculation after cold treatment

Cypripedium macranthos var. rebunense is a well-known wild orchid in Japan, and is considered to be a symbol for rare plant conservation. A fungus isolated from roots of C. macranthos var. rebunense induced symbiotic germination of the species in vitro. Cold treatment of the seeds at 4°C prior to fungal inoculation was required for the symbiotic germination. Changing the timing of inoculation of the fungus to the seeds greatly improved germination frequency. Maximum germination was attained after seeds were inoculated just after the cold treatment for 12 weeks, and approximately 20% of the seeds developed into protocorms more than 1 mm long. These results suggest that fungal inoculation takes place at the beginning of spring in nature, and the tough impervious seed coat may preserve the seed from the infection during autumn and winter seasons. The lengthy culture period of more than 16 weeks at 20°C on the same medium with the fungus caused gradual browning and rot of the protocorms. By elimination of the fungus with a fungicide and by transfer to a nutrient rich medium, approximately 20% of the protocorms developed into healthy plantlets. The methods obtained here appear to be applicable to symbiotic germination of many other threatened Cypripedium spp.     

Determination of oral mucosal Poisson’s ratio and coefficient of friction from in-vivo contact pressure measurements

Despite their considerable importance to biomechanics, there are no existing methods available to directly measure apparent Poisson’s ratio and friction coefficient of oral mucosa. This study aimed to develop an inverse procedure to determine these two biomechanical parameters by utilizing in vivo experiment of contact pressure between partial denture and beneath mucosa through nonlinear finite element (FE) analysis and surrogate response surface (RS) modelling technique. First, the in vivo denture–mucosa contact pressure was measured by a tactile electronic sensing sheet. Second, a 3D FE model was constructed based on the patient CT images. Third, a range of apparent Poisson’s ratios and the coefficients of friction from literature was considered as the design variables in a series of FE runs for constructing a RS surrogate model. Finally, the discrepancy between computed in silico and measured in vivo results was minimized to identify the best matching Poisson’s ratio and coefficient of friction. The established non-invasive methodology was demonstrated effective to identify such biomechanical parameters of oral mucosa and can be potentially used for determining the biomaterial properties of other soft biological tissues.     

Endocrine secretory granule production is caused by a lack of REST and intragranular secretory content and accelerated by PROX1

Journal of Molecular Histology - Endocrine secretory granules (ESGs) are morphological characteristics of endocrine/neuroendocrine cells and store peptide hormones/neurotransmitters. ESGs contain...     

Adenovirus vector expressing keratinocyte growth factor using CAG promoter impairs pulmonary function of mice with elastase‐induced emphysema

Pulmonary emphysema impairs quality of life and increases mortality. It has previously been shown that administration of adenovirus vector expressing murine keratinocyte growth factor (KGF) before elastase instillation prevents pulmonary emphysema in mice. We therefore hypothesized that therapeutic administration of KGF would restore damage to lungs caused by elastase instillation and thus improve pulmonary function in an animal model. KGF expressing adenovirus vector, which prevented bleomycin‐induced pulmonary fibrosis in a previous study, was constructed. Adenovirus vector (1.0 × 10⁹ plaque‐forming units) was administered intratracheally one week after administration of elastase into mouse lungs. One week after administration of KGF–vector, exercise tolerance testing and blood gas analysis were performed, after which the lungs were removed under deep anesthesia. KGF‐positive pneumocytes were more numerous, surfactant protein secretion in the airspace greater and mean linear intercept of lungs shorter in animals that had received KGF than in control animals. Unexpectedly, however, arterial blood oxygenation was worse in the KGF group and maximum running speed, an indicator of exercise capacity, had not improved after KGF in mice with elastase‐induced emphysema, indicating that KGF‐expressing adenovirus vector impaired pulmonary function in these mice. Notably, vector lacking KGF‐expression unit did not induce such impairment, implying that the KGF expression unit itself may cause the damage to alveolar cells. Possible involvement of the CAG promoter used for KGF expression in impairing pulmonary function is discussed.

     

Nicotinic acid adenine dinucleotide phosphate (NAADP) regulates autophagy in cultured astrocytes

Nicotinic acid adenine dinucleotide phosphate (NAADP) is a potent Ca(2+)-mobilizing messenger that in many cells releases Ca(2+) from the endolysosomal system. Recent studies have shown that NAADP-induced Ca(2+) mobilization is mediated by the two-pore channels (TPCs). Whether NAADP acts as a messenger in astrocytes is unclear, and downstream functional consequences have yet to be defined. Here, we show that intracellular delivery of NAADP evokes Ca(2+) signals from acidic organelles in rat astrocytes and that these signals are potentiated upon overexpression of TPCs. We also show that NAADP increases acidic vesicular organelle formation and levels of the autophagic markers, LC3II and beclin-1. NAADP-mediated increases in LC3II levels were reduced in cells expressing a dominant-negative TPC2 construct. Our data provide evidence that NAADP-evoked Ca(2+) signals mediated by TPCs regulate autophagy.     

Interstitial pneumonia in immunocompetent laboratory rats caused by natural infection with Pneumocystis carinii

Pneumocystis (P.) carinii is known to cause fatal pneumonia in immunocompromised rats. Cases of P. carinii interstitial pneumonia in immunocompetent rats have been shown histologically to present with perivascular lymphoid cuffs, which have previously been attributed to rat respiratory virus. This study aims to determine the prevalence and pathological characteristics of P. carinii in immunocompetent laboratory rats in experimental facilities in Japan. An epidemiological survey for this agent was performed using PCR to assess 1,981 immunocompetent rats from 594 facilities in Japan. We observed that 6 of the 1,981 rats (0.30%) from 4 out of 594 facilities (0.67%) were positive for P. carinii without infection of other known pathogens. Gross pulmonary lesions were found in 4 of the 6 affected rats. The lungs of these rats contained scattered dark red/gray foci. Histopathologically, the lungs exhibited interstitial pneumonia with lymphoid perivascular cuffs: Pneumocystis cysts were observed using Grocott’s methenamine silver stain. To our knowledge, this report is the first to reveal the prevalence of natural P. carinii infection in immunocompetent laboratory rats in Japan.     

Bcl-2 Modulates Endoplasmic Reticulum and Mitochondrial Calcium Stores in PC12 Cells

Endoplasmic reticulum (ER) and mitochondria are intracellular organelles and their interactions are directly involved in different processes such as Ca²⁺ signaling in cell survival and death mechanisms. Bcl-2 is an anti-apoptotic protein intrinsically related to ER and mitochondria, modulating Ca²⁺ content in these organelles. We investigated the effects of Bcl-2 overexpression on ER and mitochondrial Ca²⁺ dynamics in PC12 cells. Bcl-2 overexpressing and control cells were loaded with Fura 2/AM and stimulated with different drugs. Results showed that in Bcl-2 cells, ACh induced a lower Ca²⁺ response compared to control. Ca²⁺ release induced by TG was decreased in Bcl-2 cells, however, it was greater in Caff induced Ca²⁺ rise. In addition, FCCP induced a higher Ca²⁺ release in Bcl-2 cells. These results suggest that Bcl-2 overexpression modulate the ER Ca²⁺ pools differently and the release of ER Ca²⁺ may increase mitochondrial Ca²⁺ accumulation. These alterations of intracellular Ca²⁺ stores are important mechanisms for the control of Ca²⁺ signaling.     

Expression of retinoic acid-related orphan receptor alpha and its responsive genes in human endometrium regulated by cholesterol sulfate

Cholesterol sulfate (CS) is a major sterol sulfate in human plasma that is detected in the uterine endometrium. CS plays a role in steroidogenesis, cellular membrane stabilization, and regulation of the skin barrier. We previously reported that CS increased in rabbit endometrium during the implantation period. Recently, CS has been reported to be a ligand of retinoic acid receptor-related orphan receptor alpha (RORA). NR1D1 is one of the genes regulated by RORA. In the present study, we investigated the regulation of RORA and NR1D1 by CS in human endometrium. We determined the association-dissociation curves for the interaction of CS with RORA and the kinetic rates by surface plasmon resonance. Immunohistochemical staining and in situ hybridization revealed that RORA and NR1D1 were expressed in human endometrial stromal and epithelial cells. CS treatment significantly induced the mRNA expression of RORA and NR1D1 mRNA in ESCs. The results of a luciferase assay showed that RORA significantly activated the human NR1D1 promoter regardless of CS. Our results suggest that CS regulates the expression of RORA responsive genes in human endometrial cells but not as a ligand for RORA.