Tomoaki Imai

A type I DnaJ homolog, DjA1, regulates androgen receptor signaling and spermatogenesis

Two type I DnaJ homologs DjA1 (DNAJA1; dj2, HSDJ/hdj‐2, rdj1) and DjA2 (DNAJA2; dj3, rdj2) work similarly as a cochaperone of Hsp70s in protein folding and mitochondrial protein import in vitro. To study the in vivo role of DjA1, we generated DjA1‐mutant mice. Surprisingly, loss of DjA1 in mice led to severe defects in spermatogenesis that involve aberrant androgen signaling. Transplantation experiments with green fluorescent protein‐labeled spermatogonia into DjA1−/− mice revealed a primary defect of Sertoli cells in maintaining spermiogenesis at steps 8 and 9. In Sertoli cells of DjA1−/− mice, the androgen receptor markedly accumulated with enhanced transcription of several androgen‐responsive genes, including Pem and testin. Disruption of Sertoli–germ cell adherens junctions was also evident in DjA1−/− mice. Experiments with DjA1−/− fibroblasts and primary Sertoli cells indicated aberrant androgen receptor signaling. These results revealed a critical role of DjA1 in spermiogenesis and suggest that DjA1 and DjA2 are not functionally equivalent in vivo.

In vivo and in vitro constant expression of GATA-4 in mouse postnatal Sertoli cells

In the mammalian postnatal testis, the biochemical and structural features of Sertoli cells change, depending on developmental stage and spermatogenic cycle, to support efficient spermatogenesis. Consequently, basic transcription factors that determine fundamental properties should be strictly maintained in postnatal Sertoli cells. We have confirmed that GATA-4 expression is kept at a constant level in mouse Sertoli cells during postnatal development, and is also maintained at a constant level in primary cultures, independent of treatment with hormones or the addition of germ cell fractions. In transient transfection assays with the testicular cell line TM3, established from Leydig cells, GATA-4 induced several Sertoli cell-specific genes. In the Sertoli cell line TM4, and in Sertoli cells in primary culture, GATA-4 slightly up-regulated these genes. These results suggest that GATA-4 plays an important role in the regulation of Sertoli cell function, and is exactly regulated in these cells.

Bilateral multiple spindle cell lipomas of the tongue

Spindle cell lipoma (SCL) typically occurs in elderly men as a solitary lesion in the posterior neck and back, but less commonly also involves the oral cavity. Here, we describe a rare case of bilateral multiple SCLs of the tongue. The patient was a 72-year-old Japanese man with multiple painless soft nodules in the bilateral margins of the tongue. The patient was not obese, and had used alcohol moderately for more than 40 years. A clinical diagnosis of multiple tongue lipomas was made. The tumors were resected surgically, and they exhibited the histopathological features of SCL, composed of mature fat cells, collagen-forming CD34-positive spindle cells, and sparse mast cells. This suggests that differential diagnosis of intraoral multiple lipomatous nodules should include not only lipomatosis but also multiple SCLs, notwithstanding the rare incidence of the latter.

A novel fusogenic herpes simplex virus for oncolytic virotherapy of squamous cell carcinoma

BackgroundR849 is a neurovirulent γ134.5 gene-deficient form of herpes simplex virus type 1 (HSV-1) and has LacZ genes at the deleted sites of the γ134.5 gene. HF is a spontaneously occurring, fusogenic HSV-1 strain. The purpose of this work was to generate a virus that has the syncytial character of HF, while preserving the γ134.5 gene inactivation profile of R849 virus.ResultsVero cells were infected with R849 and HF simultaneously and two viruses, RH1 and RH2, expressing the LacZ gene and inducing extensive cell fusion were selected. A polymerase chain reaction (PCR)-based analysis suggested that one copy of the γ134.5 gene is lost in RH1, whereas both copies are lost in RH2, and that the γ134.5 gene is replaced by a R849-derived DNA fragment with the LacZ gene. These viruses produced larger plaques and more progeny than the parental viruses. Infection with RH2 decreased the viability of oral squamous cell carcinoma (SCC) cells most strongly. When RH2 was injected into xenografts of oral SCC in nude mice, multinucleated cells were produced and the growth of the tumors was suppressed significantly.ConclusionThese results indicate that novel oncolytic HSV-1 vectors can be produced with the genetic background of the oncolytic HSV-1 HF, and that RH2 is deficient in γ134.5 genes and shows extensive cytopathic effects in oral SCC cells. RH2 may be useful in oncolytic virotherapy for oral SCC.

Immunogenic cell death by oncolytic herpes simplex virus type 1 in squamous cell carcinoma cells

Molecules essential for the induction of immunogenic cell death (ICD) are called damage-associated molecular patterns (DAMPs). The effects of oncolytic herpes simplex virus type 1 (HSV-1) on the production of DAMPs were examined in squamous cell carcinoma (SCC) cells. The cytopathic effects of HSV-1 RH2 were observed in mouse SCCVII cells infected at a high multiplicity of infection (MOI), and the amounts of viable cells were decreased. After being infected with RH2, ATP and high mobility group box 1 (HMGB1) were released extracellulary, while calreticulin (CRT) translocated to the cell membrane. A flow-cytometric analysis revealed an increase in the number of annexin-V and propidium iodide (PI)-stained cells; and the amount of cleaved poly (ADP-ribose) polymerase (PARP) was increased. The killing effect of RH2 was reduced by pan-caspase inhibitor z-VAD-fmk and the caspase-1 inhibitor z-YVAD-fmk, suggesting the involvement of apoptosis and pyroptosis. In C3H mice bearing synergic SCCVII tumors, the growth of tumors injected with the supernatant of RH2-infected cells was less than that of tumors injected with phosphate-buffered saline (PBS). These results indicate that oncolytic HSV-1 RH2 produces DAMPs from SCC cells to induce cell death. This may contribute to the enhancement of tumor immunity by oncolytic HSV-1.

C-arm-guided reduction of zygomatic fractures revisited.

BACKGROUND Anatomic reduction of the zygomatic arch, a key surgical landmark for midfacial width and projection, is essential for the treatment of combined fractures of the zygomaticomaxillary complex and zygomatic arch. Reduction control in surgery for this common facial fracture would be facilitated by intraoperative real-time assessment using widely available and reliable equipment. Although C-arm fluoroscopy is routinely used in the repair of orthopedic fractures, its use in the maxillofacial region, particularly for combined zygomatic fractures, has been scarcely reported. METHODS We prospectively evaluated C-arm-guided reduction in 38 patients of combined zygomatic fracture without concurrent craniofacial fractures. Patients were classified according to the presence or absence of bone contact in the displaced zygomatic arch, namely as conserved (C) and loss (L) types, respectively. Reduction status was determined by the degree of recovery of the malar prominence and arch shape. RESULTS In all cases, C-arm imaging clearly displayed the displaced zygomatic arch and body in a single image. Cumulative fluoroscopic time was a few minutes in all cases. Total reduction status was excellent in 21 patients and good in 17. No case was classified as fair or poor. Repair was significantly more favorable in type C than in type L cases (p = 0.0016). CONCLUSIONS In combined zygomatic fractures, the C-arm technique provides easy, flexible, and time-efficient adjustment. Its comprehensive imaging for zygomatic arch shape and body contour markedly facilitates the control of fracture reduction and protects against unexpected, unsatisfactory outcomes.

Necrotizing sialometaplasia in a patient with an eating disorder: palatal ulcer accompanied by dental erosion due to binge-purging.

This report describes a case of necrotizing sialometaplasia (NS) accompanied by significant dental erosion of the maxillary teeth of the palatal surfaces owing to chronic self-induced vomiting. This observation contributed to the determination of an immediate and appropriate provisional diagnosis of NS in a patient with an eating disorder, which subsequently was confirmed histopathologically as NS. The diagnostic challenges presented by NS associated with eating disorders and its management are discussed.

Ultrasound as a method to enhance antitumor ability of oncolytic herpes simplex virus for head and neck cancer

Low-intensity ultrasound is a useful method to enhance the delivery of drugs to target cells via a range of mechanisms including the transient formation of micropores in the cell membrane, a process known as sonoporation. The effect of ultrasound on oncolytic herpes simplex virus type-1 (HSV-1) infection in oral squamous cell carcinoma (SCC) was examined. Human SCC cell line SAS and oncolytic HSV-1 RH2, which was deficient in the neurovirulent γ134.5 gene and exhibited cell fusion actions, were used. Cells grown in multi-well plates were infected with HSV-1 and exposed to ultrasound in the presence or absence of microbubbles after an adsorption period. The number of plaques was significantly greater than that of the untreated control. SAS cells were inoculated subcutaneously into nude mice and tumors were produced. Tumors were injected with HSV-1 RH2 with or without microbubbles and then exposed to ultrasound through the covering skin. The amount of the virus in tumor tissues 3 days after the injection was higher in tumors treated with HSV-1 RH2 and ultrasound than in tumors treated with RH2 only. The expression of the HSV-1 antigen was also increased by ultrasound and microbubbles. Tumor growth was suppressed with HSV-1 RH2 in combination with ultrasound, especially with microbubbles. These results indicated that ultrasound increased the efficiency of the HSV-1 infection in SAS cells and nude mouse tumors. This method can potentially be useful to enhance the antitumor effects of oncolytic HSV-1 on head and neck cancer treatment.

Anterior dislocation of the intact mandibular condyle caused by fracture of the articular eminence: an unusual fracture of the temporomandibular joint apparatus.

i t d t Maxillofacial injuries often involve fractures of the temporomandibular joint (TMJ) apparatus, which occur predominantly in the condylar process of the mandible. Fractures of the temporal bone portion of the TMJ, such as the glenoid fossa or articular eminence, are another important group of injuries dealt with by maxillofacial specialists. Fractures of the glenoid fossa are occasionally revealed by imaging for serious head injuries or mandibular trauma. A notable manifestation of glenoid fossa fractures is dislocation of the mandibular condyle into the middle cranial fossa, of which approximately 50 cases have een reported. Reports on articular eminence fractures are scarce, however, possibly because of their rare occurrence or often-obscured presentation in the presence of other more serious injuries. Reported cases have been treated conservatively or by surgical intervention only after an incidental finding during operative wound repair. This report presents an unusual type f articular eminence fracture exhibiting a disturance of mouth closing and anterior dislocation of the

Autophagy as a Survival Mechanism for Squamous Cell Carcinoma Cells in Endonuclease G-Mediated Apoptosis.

Safingol, L- threo-dihydrosphingosine, induces cell death in human oral squamous cell carcinoma (SCC) cells through an endonuclease G (endoG) -mediated pathway. We herein determined whether safingol induced apoptosis and autophagy in oral SCC cells. Safingol induced apoptotic cell death in oral SCC cells in a dose-dependent manner. In safingol-treated cells, microtubule-associated protein 1 light chain 3 (LC3)-I was changed to LC3-II and the cytoplasmic expression of LC3, amount of acidic vesicular organelles (AVOs) stained by acridine orange and autophagic vacuoles were increased, indicating the occurrence of autophagy. An inhibitor of autophagy, 3-methyladenine (3-MA), enhanced the suppressive effects of safingol on cell viability, and this was accompanied by an increase in the number of apoptotic cells and extent of nuclear fragmentation. The nuclear translocation of endoG was minimal at a low concentration of safingol, but markedly increased when combined with 3-MA. The suppressive effects of safingol and 3-MA on cell viability were reduced in endoG siRNA- transfected cells. The scavenging of reactive oxygen species (ROS) prevented cell death induced by the combinational treatment, whereas a pretreatment with a pan-caspase inhibitor z-VAD-fmk did not. These results indicated that safingol induced apoptosis and autophagy in SCC cells and that the suppression of autophagy by 3-MA enhanced apoptosis. Autophagy supports cell survival, but not cell death in the SCC cell system in which apoptosis occurs in an endoG-mediated manner.