miRNA-27a is essential for bone remodeling by modulating p62-mediated osteoclast signaling.

The ability to simultaneously modulate a set of genes for lineage-specific development has made miRNA an ideal master regulator for organogenesis. However, most miRNA deletions do not exhibit obvious phenotypic defects possibly due to functional redundancy. miRNAs are known to regulate skeletal lineages as the loss of their maturation enzyme Dicer impairs bone remodeling processes. Therefore, it is important to identify specific miRNA essential for bone homeostasis. We report the loss of MIR27a causing severe osteoporosis in mice. MIR27a affects osteoclast-mediated bone resorption but not osteoblast-mediated bone formation during skeletal remodeling. Gene profiling and bioinformatics further identify the specific targets of MIR27a in osteoclast cells. MIR27a exerts its effects on osteoclast differentiation through modulation of Squstm1/p62 whose mutations have been linked to Paget's disease of bone. Our findings reveal a new MIR27a-p62 axis necessary and sufficient to mediate osteoclast differentiation and highlight a therapeutic implication for osteoporosis.

Nonmedical prescription stimulant use among a sample of college students: relationship with psychological variables.

OBJECTIVE: To further investigate use and potential misuse of prescription stimulants (e.g., Ritalin, Adderall, Concerta) among a sample of college students and to explore the relationship between psychological variables and nonmedical stimulant use. METHOD: The sample consisted of 390 college students (71.6% female, 28.4% male). Participants were asked to complete five questionnaires concerning demographic information, prescription stimulant use, internal restlessness, sensation seeking, and psychological distress. RESULTS: The study findings revealed that, regarding nonprescribed stimulants, 7.5% reported use within the past 30 days; 60% reported knowing students who misused stimulants; and 50% agreed or strongly agreed that prescription stimulants were "easy to get on this campus." Findings further revealed a relationship between stimulant use and degree of psychological distress and internal restlessness. CONCLUSIONS: Continued research regarding psychological variables, specific group membership (e.g., fraternity, sorority, athletics), and stimulant acquisition is suggested. Effective prevention and education efforts are needed to help address the nonmedical use of prescription stimulants on college campuses.