Enhanced expression of activity-regulated cytoskeleton-associated protein in the medial prefrontal cortex is involved in working memory performance.

Working memory (WM) is a cognitive function important for guiding the on-going or upcoming behavior. A memory-related protein Arc (activity-regulated cytoskeleton-associated protein) is implicated in long-term memory consolidation. Recent evidence further suggests the involvement of hippocampal Arc in spatial WM. The medial prefrontal cortex (mPFC) is a key brain region mediating WM. However, the role of mPFC Arc in WM is still uncertain. To investigate whether mPFC Arc protein is involved in WM performance, delayed non-match to sample (DNMS) T-maze task was performed in rats with or without blocking new synthesis of mPFC Arc. In DNMS task, a 10-s or 30-s delay between the sample run and the choice run was given to evaluate WM performance. To block new Arc protein synthesis during the DNMS task, Arc antisense oligodeoxynucleotides (ODNs) were injected to the bilateral mPFC. The results show that, in rats without surgery for cannula implantation and subsequent intracerebral injection of ODNs, WM was functioning well during the DNMS task with a delay of 10 s but not 30 s, which was accompanied with a significantly increased level of mPFC Arc protein, indicating a possible link between enhanced Arc protein expression and the performance of WM. After preventing the enhancement of mPFC Arc protein expression with Arc antisense ODNs, rat's WM performance was impaired. These findings support enhanced mPFC Arc protein expression playing a role during WM performance.

FGF23 ameliorates ischemia-reperfusion induced acute kidney injury via modulation of endothelial progenitor cells: targeting SDF-1/CXCR4 signaling.

The levels of fibroblast growth factor 23 (FGF23) rapidly increases after acute kidney injury (AKI). However, the role of FGF23 in AKI is still unclear. Here, we observe that pretreatment with FGF23 protein into ischemia-reperfusion induced AKI mice ameliorates kidney injury by promoting renal tubular regeneration, proliferation, vascular repair, and attenuating tubular damage. In vitro assays demonstrate that SDF-1 induces upregulation of its receptor CXCR4 in endothelial progenitor cells (EPCs) via a non-canonical NF-κB signaling pathway. FGF23 crosstalks with the SDF-1/CXCR4 signaling and abrogates SDF-1-induced EPC senescence and migration, but not angiogenesis, in a Klotho-independent manner. The downregulated pro-angiogenic IL-6, IL-8, and VEGF-A expressions after SDF-1 infusion are rescued after adding FGF23. Diminished therapeutic ability of SDF-1-treated EPCs is counteracted by FGF23 in a SCID mouse in vivo AKI model. Together, these data highlight a revolutionary and important role that FGF23 plays in the nephroprotection of IR-AKI.

Comparing the Protection Imparted by Different Fraction Extracts of Garlic (Allium sativum L.) against Der p-Induced Allergic Airway Inflammation in Mice.

Garlic (Allium sativum L.) has been used extensively as a food ingredient and medicinally, but the effect on asthmatic airway inflammation has not been studied in detail. We accordingly explored the protective effects exerted by various garlic fraction extracts against airway inflammation with Dermatophagoides pteronyssinus (Der p)-induced allergic asthma in vivo and in vitro. Garlic extraction was realized using n-hexane, dichloromethane, ethylacetate, n-butanol, and water in sequence to obtain different fraction extracts. Mice were orally administered different fractions (80 mg/kg) daily for four weeks. The histological results showed that the water fraction could ameliorate lung-based goblet cell hyperplasia, inflammatory cell infiltration, and mucus hypersecretion. The water fraction extracts decreased IgE and IgG1, and they decreased inflammatory cells as quantified in bronchoalveolar lavage fluid (BALF); however, they increased IgG2a in serum. Moreover, the water fraction extracts increased IFN-γ and IL-12 (both constituting Th1 cytokines) in BALF, but they reduced IL-13, -4, and -5 (all constituting Th2 cytokines), and also inhibited the expression of IL-1ß, IL-6, and TNF-α. The water fraction also inhibited the PI3K/Akt/NF-κB signal pathways in A549 cells. These findings suggest that water fraction extracts of garlic have a clear anti-inflammatory effect on Der p-induced allergic asthma.

Adaptation of Medical Students During Clinical Training: Effects of Holistic Preclinical Education on Clerkship Performance.

THEORY: Taiwan's medical undergraduate program at a university or medical center is a continuation of 12 years of compulsory citizenship education rooted in holistic philosophies. Students acquire both technical knowledge and nontechnical attributes, which are necessary for success in further work and life. The early clinical learning experiences of medical students are primarily acquired through clerkships. These clerkships require medical students to apply and extend what they learned during their preclinical education; however, previous studies have explored this issue through examining fragmentary factors such as preclinical course grades and traits but not undertaking comprehensive, whole-person investigations. HYPOTHESES: To account for the potential benefits of a holistic approach in medical students' learning, we propose three hypotheses: Medical students' preclinical performance on Taiwan's technical and nontechnical higher education assessments are positively associated with their clinical competence (Hypothesis 1) and psychological well-being (Hypothesis 2) during clerkships, and medical students' psychological well-being during clerkships is positively associated with their clinical competence (Hypothesis 3). METHOD: We studied a cohort of 65 medical students engaged in clerkships from September 2013 to April 2015. Their preclinical technical knowledge scores-formal curricular grades received from course instructors-were obtained from their medical school's archival dataset. Their nontechnical attributes-moral and social performance scores received from student mentors and physical performance scores received from course instructors-were also obtained from the school's archival data set. The medical students' competence in their 2-year clinical clerkships was measured using the objective structured clinical examination scores from the end of both clerkship years. The medical students' psychological well-being during their 2-year clerkships was measured according to burnout level, which was determined using routine online surveys that employed validated, structured, and self-administered questionnaires at each specialty rotation. Multiple regressions and linear mixed-effects model were employed for statistical analysis. RESULTS: Our study revealed that higher preclinical technical knowledge predicted superior clinical competence and a higher level of burnout during clerkships. By contrast, higher preclinical nontechnical attributes (i.e., higher preclinical moral, social, and physical performance) predicted lower level of burnout. However, no relationship was discovered between clerkship burnout and the clinical competence of the medical students. CONCLUSIONS: Our study verified the value of a holistic education that encompasses both technical knowledge and nontechnical attributes during the preclinical learning stage for medical students. Our findings can serve as a reference for medical educators designing preclinical educational programs for medical students.

Both PKMζ and KIBRA are closely related to reference memory but not working memory in a T-maze task in rats.

Protein kinase M zeta (PKMζ) and the kidney and brain protein (KIBRA) play important roles in various forms of memories. However, whether they are involved in performing the T-maze task is still unknown. In this study, the delayed nonmatch-to-sample (DNMS) task in a T-maze was given to rats. The percentage of correct choices denoting the performance accuracy was calculated and the protein levels of PKMζ and KIBRA in rat's prefrontal cortex were measured. The results showed significantly increased performance accuracy after the training phase, which was maintained on the next day in groups with a delay of 10 s but not 30 s, indicating that 30 s is too long for rats to maintain working memory. As for the expressions of PKMζ and KIBRA, significant increases were observed 1 day after the training phase, indicating that the formation of reference memory accompanies an increase in PKMζ and KIBRA. No significant difference was found among groups with various delay intervals, indicating that the expressions of PKMζ and KIBRA exert no effects on the performance of working memory. These results provide the first evidence that KIBRA as well as PKMζ is closely related to reference memory but not working memory in rats.