Expression and physiological role of CCN4/Wnt-induced secreted protein 1 mRNA splicing variants in chondrocytes

CCN4/Wnt-induced secreted protein 1 (WISP1) is one of the CCN (CTGF/Cyr61/Nov) family proteins. CCN members have typical structures composed of four conserved cysteine-rich modules and their variants lacking certain modules, generated by alternative splicing or gene mutations, have been described in various pathological conditions. Several previous reports described a CCN4/WISP1 variant (WISP1v) lacking the second module in a few malignancies, but no information concerning the production of WISP1 variants in normal tissue is currently available. The expression of CCN4/WISP1 mRNA and its variants were analyzed in a human chondrosarcoma-derived chondrocytic cell line, HCS-2/8, and primary rabbit growth cartilage (RGC) chondrocytes. First, we found WISP1v and a novel variant of WISP1 (WISP1vx) to be expressed in HCS-2/8, as well as full-length WISP1 mRNA. This new variant was lacking the coding regions for the second and third modules and a small part of the first module. To monitor the expression of CCN4/WISP1 mRNA along chondrocyte differentiation, RGC cells were cultured and sampled until they were mineralized. As a result, we identified a WISP1v ortholog in normal RGC cells. Interestingly, the WISP1v mRNA level increased dramatically along with terminal differentiation. Furthermore, overexpression of WISP1v provoked expression of an alkaline phosphatase gene that is a marker of terminal differentiation in HCS-2/8 cells. These findings indicate that WISP1v thus plays a critical role in chondrocyte differentiation toward endochondral ossification, whereas HCS-2/8-specific WISP1vx may be associated with the transformed phenotypes of chondrosarcomas.     

Homologs of the sexually induced gene 1 (sig1) product constitute the stramenopile mastigonemes

The tripartite tubular mastigoneme on the anterior flagellum is a morphological feature that characterizes the stramenopiles. Mastigonemes are significant and potentially informative structures not only from the viewpoint of systematics, but also of cell biology. Nevertheless, few biochemical studies have been reported on stramenopile mastigonemes. The flagella of Scytosiphon lomentaria (Phaeophyceae) were successfully isolated and analyzed using SDS-PAGE followed by protein sequencing. The partial amino acid sequence of one flagellar protein (115kDa) showed high similarity with the sexually induced gene 1 (sig1) product of centric diatoms. A polyclonal antibody against the 115-kDa protein reacted not only to the shaft of mastigonemes in Scytosiphon lomentaria, but also another distinctly different stramenopile flagellate, Sulcochrysis biplastida (Dictyochophyceae). Therefore, we propose that the 115-kDa protein (i.e. Sig1 homologs) is a constituent of the tubular shaft of the mastigoneme.     

Emerging role of podocyte autophagy in the progression of diabetic nephropathy

Glomerular podocytes are pivotal in maintaining glomerular filtration barrier function. As severe podocyte injury results in proteinuria in patients with diabetic nephropathy, determining the pathogenesis of podocyte injury may contribute to the development of new treatments. We recently showed that autophagy is involved in the pathogenesis of diabetes-related podocyte injury. Insufficient podocyte autophagy and podocyte loss are observed in diabetic patients with massive proteinuria. Podocyte loss and massive proteinuria occur in high-fat diet-induced diabetic mice with podocyte-specific autophagy deficiency, with podocytes of these mice and of diabetic rats having huge damaged lysosomes. Sera from diabetic patients and from rodents with massive proteinuria cause autophagy insufficiency, resulting in lysosome dysfunction and apoptosis of cultured podocytes. These findings suggest the importance of autophagy in maintaining lysosome homeostasis in podocytes under diabetic conditions. Impaired autophagy may be involved in the pathogenesis of podocyte loss, leading to massive proteinuria in diabetic nephropathy.     

A novel proapoptotic gene PANO encodes a post-translational modulator of the tumor suppressor p14ARF

The protein p14ARF is a known tumor suppressor protein controlling cell proliferation and survival, which mainly localizes in nucleoli. However, the regulatory mechanisms that govern its activity or expression remain unclear. Here, we report that a novel proapoptotic nucleolar protein, PANO, modulates the expression and activity of p14ARF in HeLa cells. Overexpression of PANO enhances the stability of p14ARF protein by protecting it from degradation, resulting in an increase in p14ARF expression levels. Overexpression of PANO also induces apoptosis under low serum conditions. This effect is dependent on the nucleolar localization of PANO and inhibited by knocking-down p14ARF. Alternatively, PANO siRNA treated cells exhibit a reduction in p14ARF protein levels. In addition, ectopic expression of PANO suppresses the tumorigenicity of HeLa cells in nude mice. These results indicate that PANO is a new apoptosis-inducing gene by modulating the tumor suppressor protein, p14ARF, and may itself be a new candidate tumor suppressor gene.     

Dietary zinc status reversibly alters both the feeding behaviors of the rats and gene expression patterns in diencephalon

Nutritional status influences feeding behaviors, food preferences, and taste sensations. For example, zinc-deficient rats have been reported to show reduced and cyclic food intake patterns with increased preferences for NaCl. Although some impairments of the central nervous and endocrine systems have been speculated to be involved in these phenomena, the effects of short-term zinc deficiency on the brain have not been well examined to date. In this study, we performed a comprehensive analysis of the gene expression patterns in the rat diencephalon, which is a portion of the brain that includes the hypothalamus and thalamus, after short-term zinc deficiency and also during zinc recovery. The rats showed reduced and cyclic food intake patterns with increased salt preferences after a 10-day dietary zinc deficiency. A comparative analysis of their diencephalons using cDNA microarrays revealed that approximately 1% of the genes expressed in the diencephalons showed significantly altered expression levels. On the other hand, a 6-day zinc supplementation following the deprivation allowed for the recovery to initial food intake behaviors and salt preferences. The expression levels of most of the genes that had been altered by exposure to zinc deficient conditions were also recovered. These results show that feeding behaviors, taste preferences and gene expression patterns in the diencephalon respond quickly to changing zinc levels.     

Effects of systemic sitafloxacin on periodontal infection control in elderly patients

doi: 10.1111/j.1741‐2358.2011.00605.x
Effects of systemic sitafloxacin on periodontal infection control in elderly patients Objective: To evaluate the microbiological and clinical effects of the systemic administration of sitafloxacin (STFX) on periodontal pockets in elderly patients receiving supportive periodontal therapy (SPT). Background: Periodontitis is a risk factor for atherosclerosis. Better periodontal health contributes to reduce atherosclerosis‐related diseases in elderly population. Materials and methods: Forty‐four patients undergoing SPT were randomly assigned to two groups: a test group took 100 mg/day of STFX for five consecutive days, or a control group received scaling and root planing (SRP) under local anaesthesia. Microbiological and clinical parameters were examined at baseline and at 1 and 3 months after therapy. Results: The presence of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia was significantly reduced at 1 month after treatment in both groups. The median reductions of the bacteria between the baseline and 1 month were 3.08 and 2.54% in the STFX‐ and SRP‐treated groups, respectively. Both treatments significantly decreased the probing depth at 1 and 3 months compared to the baseline. Conclusion: The systemic administration of STFX is effective at improving periodontal health during SPT and could be an alternative to SRP for elderly patients who cannot undergo anaesthesia or are at risk of tissue injury.