Failure of the functional pancreatic ␤-cell mass to expand in response to increased metabolic demand is a hallmark of type 2 diabetes. Lineage tracing studies indicate that replication of existing ␤-cells is important for ␤-cell proliferation in adult animals. In rat pancreatic ␤-cell lines (RIN5F), treatment with 100 nM thyroid hormone (triiodothyronine, T 3 ) enhances cell proliferation. This result suggests that T 3 is required for ␤-cell proliferation or replication. To identify the role of thyroid hormone receptor ␣ (TR␣) in the processes of ␤-cell growth and cell cycle regulation, we constructed a recombinant adenovirus vector, AdTR␣. Infection with AdTR␣ to RIN5F cells increased the expression of cyclin D1 mRNA and protein. Overexpression of the cyclin D1 protein in AdTR␣-infected cells led to activation of the cyclin D1/cyclin-dependent kinase/retinoblastoma protein/E2F pathway, along with cell cycle progression and cell proliferation following treatment with 100 nM T 3 . Conversely, lowering cellular cyclin D1 by small interfering RNA knockdown in AdTR␣-infected cells led to down-regulation of the cyclin D1/CDK/Rb/E2F pathway and inhibited cell proliferation. Furthermore, in immunodeficient mice with streptozotocin-induced diabetes, intrapancreatic injection of AdTR␣ led to the restoration of islet function and to an increase in the ␤-cell mass. These results support the hypothesis that liganded TR␣ plays a critical role in ␤-cell replication and in expansion of the ␤-cell mass during postnatal development. Thus, liganded TR␣ may be a target for therapeutic strategies that can induce the expansion and regeneration of ␤-cells.The pancreatic ␤-cell mass plays an essential role in determining the amount of insulin that is secreted to maintain blood glucose levels within a narrow range. Elucidation of the mechanisms that control the size of the ␤-cell mass is essential to allow development of regenerative therapy for both type 1 and type 2 diabetes, which are diseases characterized by an insufficient ␤-cell mass (1). Several mechanisms have been proposed to explain the process of adult ␤-cell mass expansion, including neogenesis from pancreatic duct cells or hematopoietic tissues, replication of highly active ␤-cell progenitors within the islets, and simple ␤-cell proliferation. The size of the ␤-cell mass is governed by the balance between the growth (differentiation and replication) and death (apoptosis) of these cells, but the mechanisms that sense the ␤-cell mass and maintain its homeostasis are largely unknown (2). Several recent reports have indicated that proliferation or replication of existing ␤-cells rather than differentiation of new ␤-cells from stem cells, is one mechanism involved in maintenance of the ␤-cell mass in adults (3, 4).To clarify the mechanisms involved in the replication of ␤-cells, we focused on molecular regulation of the cell cycle in mature pancreatic ␤-cells. Terminally differentiated cells often make the decision to replicate at the interface of the G 0 /G 1 phase of the cel...

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Knock-in mouse models have contributed tremendously to our understanding of human disorders. However, generation of knock-in animals requires a significant investment of time and effort. We addressed this problem by developing a novel knock-in system that circumvents several traditional challenges by establishing stem cells with acceptor elements enveloping a particular genomic target. Once established, these acceptor embryonic stem (ES) cells are efficient at directionally incorporating mutated target DNA using modified Cre/lox technology. This is advantageous, because knock-ins are not restricted to one a priori selected variation. Rather, it is possible to generate several mutant animal lines harboring desired alterations in the targeted area. Acceptor ES cell generation is the rate-limiting step, lasting approximately 2 months. Subsequent manipulations toward animal production require an additional 8 weeks, but this delimits the full period from conception of the genetic alteration to its animal incorporation. We call this system a “kick-in” to emphasize its unique characteristics of speed and convenience. To demonstrate the functionality of the kick-in methodology, we generated two mouse lines with separate mutant versions of the voltage-dependent potassium channel Kv7.2 (Kcnq2): p.Tyr284Cys (Y284C) and p.Ala306Thr (A306T); both variations have been associated with benign familial neonatal epilepsy. Adult mice homozygous for Y284C, heretofore unexamined in animals, presented with spontaneous seizures, whereas A306T homozygotes died early. Heterozygous mice of both lines showed increased sensitivity to pentylenetetrazole, possibly due to a reduction in M-current in CA1 hippocampal pyramidal neurons. Our observations for the A306T animals match those obtained with traditional knock-in technology, demonstrating that the kick-in system can readily generate mice bearing various mutations, making it a suitable feeder technology toward streamlined phenotyping.

Background During the perinatal period, suicides are more likely to occur in those with depression and who are not receiving active treatment at the time of death. Suicide is a common outcome in people with suicide ideation. We developed an intervention program taking care of comprehensive perinatal maternal mental healthcare to prevent suicide ideation. We hypothesized that our intervention program could reduce postnatal suicide ideation and improve maternal mental health. Methods We performed a controlled trial to examine the usual postnatal care plus a maternal suicide prevention program (the intervention group) compared with usual postnatal care alone, which comprised home visits by public health nurses without mental health screening (the control group) in Nagano city, Japan. In total, 464 women were included; 230 were allocated to the control group and 234 to the intervention group. The intervention had three components: 1) all the women received postnatal mental health screening by public health nurses who completed home visits during the neonatal period, 2) the intervention was administered by a multidisciplinary clinical network, and 3) systematic follow-up sheets were used to better understand bio–psycho–social characteristics of both the mothers and their infants and develop responsive care plans. We measured the participants’ mental health at 3–4 months postpartum (T1) and 7–8 months postpartum (T2) using the Japanese version of the Edinburgh Postnatal Depression Scale (EPDS). Results Suicidal ideation was significantly lower in the intervention group compared with the control group at T1 ( p = 0.014); however, this significant between-group difference did not continue to T2 ( p = 0.111). We measured the intervention effects on maternal mental health using the total score of the EPDS, which was significantly improved in the intervention group compared with the control group at T1. Here, the significant difference continued to T2 ( p = 0.049). Conclusions Our results indicate that our program may reduce maternal suicidal ideation at 3–4 months postnatally and improve women’s mental health during the postnatal periods of 3–4 to 7–8 months. Postnatal maternal mental healthcare, including services to reduce suicide ideation, should be included as an important component of general postnatal care. Trial registration Name of registry: A multidisciplinary intervention program for maternal mental health in perinatal periods. UMIN Clinical Trials Registry number: UMIN000033396 . Registration URL: https://upload.umin.ac.jp/cgibin/ctr/ctr_view_reg.cgi?recptno=R000038076 Registration date: July 15, 2018. Registration timing: retrospective.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors such as afatinib are used for nonsmall cell lung cancer (NSCLC) and show varying efficacy depending on EGFR gene mutation. Few studies have examined the relationship between EGFR gene mutations and the adverse events of afatinib in NSCLC. This retrospective study included 32 Japanese patients with NSCLC with EGFR gene mutation who were treated with afatinib between May 2014 and August 2018 at Kagawa University Hospital. Among the 32 Japanese patients with NSCLC treated with afatinib, 19 patients were positive for exon 19 deletion mutation (Del 19) and 13 patients were negative for Del 19. The incidence of grade ≥ 2 skin rash was slightly higher in patients positive for Del 19 (42.1% vs. 7.7%, P = 0.050). No significant differences were detected in other adverse events between the two patient groups. Patients positive for Del 19 also showed significantly longer median progression-free survival (288 vs. 84 days, P = 0.049). Our study indicates a higher incidence of skin rash associated with afatinib treatment in Japanese patients with NSCLC positive for Del 19 compared with patients without Del 19. The Del 19 positive patient group also showed better progression-free survival.