title: Aging-associated changes in microRNA expression profile of internal anal sphincter smooth muscle: Role of microRNA-133a.
abstract: A comprehensive genomic and proteomic, computational, and physiological approach was employed to examine the (previously unexplored) role of microRNAs (miRNAs) as regulators of internal anal sphincter (IAS) smooth muscle contractile phenotype and basal tone. miRNA profiling, genome-wide expression, validation, and network analyses were employed to assess changes in mRNA and miRNA expression in IAS smooth muscles from young vs. aging rats. Multiple miRNAs, including rno-miR-1, rno-miR-340-5p, rno-miR-185, rno-miR-199a-3p, rno-miR-200c, rno-miR-200b, rno-miR-31, rno-miR-133a, and rno-miR-206, were found to be upregulated in aging IAS. qPCR confirmed the upregulated expression of these miRNAs and downregulation of multiple, predicted targets (Eln, Col3a1, Col1a1, Zeb2, Myocd, Srf, Smad1, Smad2, Rhoa/Rock2, Fn1, Tagln v2, Klf4, and Acta2) involved in regulation of smooth muscle contractility. Subsequent studies demonstrated an aging-associated increase in the expression of miR-133a, corresponding decreases in RhoA, ROCK2, MYOCD, SRF, and SM22α protein expression, RhoA-signaling, and a decrease in basal and agonist [U-46619 (thromboxane A2analog)]-induced increase in the IAS tone. Moreover, in vitro transfection of miR-133a caused a dose-dependent increase of IAS tone in strips, which was reversed by anti-miR-133a. Last, in vivo perianal injection of anti-miR-133a reversed the loss of IAS tone associated with age. This work establishes the important regulatory effect of miRNA-133a on basal and agonist-stimulated IAS tone. Moreover, reversal of age-associated loss of tone via anti-miR delivery strongly implicates miR dysregulation as a causal factor in the aging-associated decrease in IAS tone and suggests that miR-133a is a feasible therapeutic target in aging-associated rectoanal incontinence.
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Jagmohan
authors.initials: J
authors.lastname: Singh
authors.affiliation: Center for Translational Medicine, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Ettickan
authors.initials: E
authors.lastname: Boopathi
authors.affiliation: Kimmel Cancer Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Sankar
authors.initials: S
authors.lastname: Addya
authors.affiliation: Department of Surgery, Division of Colorectal Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania; and.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Phillips
authors.affiliation: Computational Medicine Center, Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Isidore
authors.initials: I
authors.lastname: Rigoutsos
authors.affiliation: Center for Translational Medicine, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Raymond B
authors.initials: RB
authors.lastname: Penn
authors.affiliation: Department of Medicine, Division of Gastroenterology & Hepatology, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Satish
authors.identifier: 0000-0001-6731-6980
authors.initials: S
authors.lastname: Rattan
mesh_terms: D000375:Aging / Q000235:genetics / Q000378:metabolism*; D001003:Anal Canal / Q000378:metabolism*; D000818:Animals; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D000090062:Kruppel-Like Factor 4; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D015398:Signal Transduction / Q000502:physiology
chemical_list: C000715469:Klf4 protein, rat; D000090062:Kruppel-Like Factor 4; C549446:MIRN133 microRNA, rat; D035683:MicroRNAs
keywords: RhoA/ROCK downregulation; aging-associated changes; microRNA-133a; rectoanal incontinence