Individual experiences and issues in predictive genetic testing for untreatable hereditary neuromuscular diseases in Japan.

Predictive genetic testing (PT) for hereditary diseases that do not have effective treatment or prevention strategies places a psychological burden on parties and their families. There has been little research on the psychosocial aspects of PT in Japan, nor are there any guidelines. To address this gap, we conducted a questionnaire survey of parties at genetic risk for untreatable hereditary neuromuscular diseases, and the National Liaison Conference of Genetic Medicine Departments (GMDs). Of the 63 parties who responded to the survey, 10 (15.9%) had undergone PT. Of the 67 GMDs, only 18 facilities (26.9%) were conducting PT with written procedures. At least two of the six parties with such results felt that some follow-up would be helpful. One party had taken PT for preimplantation genetic testing for monogenic (PGT-M); four, who had no experience, provided free text responses indicating that PGT-M or prenatal genetic testing was chosen as a motivation. Eight were unaware of PT, and six were unaware of their blood relatives' diseases being "hereditary." The results highlighted the need to: 1) develop guidelines for PT in untreatable hereditary diseases; 2) provide access to PT information; and 3) share the "heritability" of diseases with family and relatives.

Significance of the Multi-gene Panel myRisk in Japan.

BACKGROUND/AIM: Hereditary tumors are estimated to account for approximately 5-10% of all tumors. In Europe and the United States, multi-gene panel testing (MGPT) is the standard method used for identifying potential causative genes. However, MGPT it is still not widely used in Japan. The aim of this study was to assess the risk of hereditary tumors in Japanese cancer patients using germline MGPT and provide an overview of MGPT in the Japanese medical system. PATIENTS AND METHODS: We used the myRiskTM, a 35-gene panel that determines the risk for eight hereditary cancers: breast, ovarian, gastric, colorectal, prostate, pancreatic, malignant melanoma, and endometrial cancers. RESULTS: From June 2019 to March 2020, 21 patients who were suspected to have hereditary tumors were included, based on their family or medical history. Pathogenic variants were found in 7 patients [BRCA1 (5), MSH6 (1), TP 53 (1)]. CONCLUSION: In this study, despite the small number of participants, we were able to show the significance of MGPT in Japan. Therefore, MGPT should be used for evaluating hereditary tumors in clinical practice.

Arabidopsis LBP/BPI related-1 and -2 bind to LPS directly and regulate PR1 expression.

Lipopolysaccharide (LPS) is a major constituent of the outer membrane of Gram-negative bacteria and acts as a pathogen-associated molecular pattern that triggers immune responses in both plants and animals. LPS-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI), which bind to LPS and play important roles in immunity of mammals, have been well studied. However, the molecule contributing to LPS binding in plants is mostly unknown. The Arabidopsis genome carries two genes encoding LBP/BPI-related proteins which we designated as AtLBP/BPI related-1 (AtLBR-1) and AtLBP/BPI related-2 (AtLBR-2). We found that their N-terminal domains were co-purified with cell wall-derived LPS when expressed in E. coli. Since this finding implied the direct binding of AtLBRs to LPS, we also confirmed binding by using LPS-free AtLBRs and purified LPS. AtLBRs directly bind to both rough and smooth types of LPS. We also demonstrated that LPS-treated atlbr mutant Arabidopsis exhibit a significant delay of induction of defence-related gene pathogenesis-related 1 (PR1) but no other PR genes. Furthermore, LPS-treated atlbr mutants showed defects in reactive oxygen species (ROS) generation. These results demonstrate that, as well as LBP and BPI of mammals, AtLBRs also play an important role in the LPS-induced immune response of plants.

Fetal Leydig Cells Persist as an Androgen-Independent Subpopulation in the Postnatal Testis.

Two distinct types of Leydig cells emerge during the development of eutherian mammals. Fetal Leydig cells (FLCs) appear shortly after gonadal sex differentiation, and play a crucial role in masculinization of male fetuses. Meanwhile, adult Leydig cells (ALCs) emerge after birth and induce the secondary male-specific sexual maturation by producing testosterone. Previous histological studies suggested that FLCs regress completely soon after birth. Furthermore, gene disruption studies indicated that androgen signaling is dispensable for FLC differentiation but indispensable for postnatal ALC differentiation. Here, we performed lineage tracing of FLCs using a FLC enhancer of the Ad4BP/SF-1 (Nr5a1) gene and found that FLCs persist in the adult testis. Given that postnatal FLCs expressed androgen receptor (AR) as well as LH receptor (LuR), the effects of AR disruption on FLCs and ALCs were analyzed by crossing AR knockout (KO) mice with FLC-specific enhanced green fluorescent protein (EGFP) mice. Moreover, to eliminate the influence of elevated LH levels in ARKO mice, LuRKO mice and AR/LuR double-KO mice were analyzed. The proportion of ALCs to postnatal FLCs was decreased in ARKO mice, and the effect was augmented in the double-KO mice, suggesting that androgen signaling plays important roles in ALCs, but not in FLCs. Finally, ARKO was achieved in an FLC-specific manner (FLCARKO mice), but the FLC number and gene expression pattern appeared unaffected. These findings support the conclusion that FLCs persist as an androgen-independent Leydig subpopulation in the postnatal testis.

Contribution of Leydig and Sertoli cells to testosterone production in mouse fetal testes.

Testosterone is a final product of androgenic hormone biosynthesis, and Leydig cells are known to be the primary source of androgens. In the mammalian testis, two distinct populations of Leydig cells, the fetal and the adult Leydig cells, develop sequentially, and these two cell types differ both morphologically and functionally. It is well known that the adult Leydig cells maintain male reproductive function by producing testosterone. However, it has been controversial whether fetal Leydig cells can produce testosterone, and the synthetic pathway of testosterone in the fetal testis is not fully understood. In the present study, we generated transgenic mice in which enhanced green fluorescence protein was expressed under the control of a fetal Leydig cell-specific enhancer of the Ad4BP/SF-1 (Nr5a1) gene. The transgene construct was prepared by mutating the LIM homeodomain transcription factor (LHX9)-binding sequence in the promoter, which abolished promoter activity in the undifferentiated testicular cells. These transgenic mice were used to collect highly pure fetal Leydig cells. Gene expression and steroidogenic enzyme activities in the fetal Leydig cells as well as in the fetal Sertoli cells and adult Leydig cells were analyzed. Our results revealed that the fetal Leydig cells synthesize only androstenedione because they lack expression of Hsd17b3, and fetal Sertoli cells convert androstenedione to testosterone, whereas adult Leydig cells synthesize testosterone by themselves. The current study demonstrated that both Leydig and Sertoli cells are required for testosterone synthesis in the mouse fetal testis.