Effects of long-term rapamycin treatment on glial scar formation after cryogenic traumatic brain injury in mice.

Glial scar impedes axon regeneration and functional recovery following traumatic brain injury (TBI). Although it has been shown that rapamycin (a specific inhibitor of mammalian target of rapamycin) can reduce astrocyte reactivation in the early stage of TBI, its effect on glial scar formation has not been characterized in TBI and other acute brain injury models. To test this, ICR mice received daily administration of rapamycin (0.

Postconditioning attenuates coronary perivascular and interstitial fibrosis through modulating angiotensin II receptors and angiotensin-converting enzyme 2 after myocardial infarction.

Background: Postconditioning (Postcon) is known to reduce infarct size. This study tested the hypothesis that Postcon attenuates the perivascular and interstitial fibrosis after myocardial infarction through modulating angiotensin II-activated fibrotic cascade.

Materials And Methods: Male Sprague-Dawley rats were subjected to 45-min coronary occlusion followed by 1 and 6 wk of reperfusion.

Angiotensin II AT1 receptor alters ACE2 activity, eNOS expression and CD44-hyaluronan interaction in rats with hypertension and myocardial fibrosis.

Aim: This study tested the hypothesis that angiotensin II (Ang II) AT1 receptor is involved in development of hypertension and cardiac fibrosis via modifying ACE2 activity, eNOS expression and CD44-hyaluronan interaction.

Main Methods: Male Sprague-Dawley rats were subjected to Ang II infusion (500ng/kg/min) using osmotic minipumps up to 4weeks and the AT1 receptor blocker, telmisartan was administered by gastric gavage (10mg/kg/day) during Ang II infusion.

Key Findings: Our results indicated that Ang II enhances AT1 receptor, downregulates AT2 receptor, ACE2 activity and eNOS expression, and increases CD44 expression and hyaluronidase activity, an enzyme for hyaluronan degradation.

Attenuation of myocardial fibrosis with curcumin is mediated by modulating expression of angiotensin II AT1/AT2 receptors and ACE2 in rats.

Curcumin is known to improve cardiac function by balancing degradation and synthesis of collagens after myocardial infarction. This study tested the hypothesis that inhibition of myocardial fibrosis by curcumin is associated with modulating expression of angiotensin II (Ang II) receptors and angiotensin-converting enzyme 2 (ACE2). Male Sprague Dawley rats were subjected to Ang II infusion (500 ng/kg/min) using osmotic minipumps for 2 and 4 weeks, respectively, and curcumin (150 mg/kg/day) was fed by gastric gavage during Ang II infusion.

Preservation of Glucagon-Like Peptide-1 Level Attenuates Angiotensin II-Induced Tissue Fibrosis by Altering AT1/AT 2 Receptor Expression and Angiotensin-Converting Enzyme 2 Activity in Rat Heart.

Purpose: The glucagon-like peptide-1 (GLP-1) has been shown to exert cardioprotective effects in animals and patients. This study tests the hypothesis that preservation of GLP-1 by the GLP-1 receptor agonist liraglutide or the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin is associated with a reduction of angiotensin (Ang) II-induced cardiac fibrosis.

Methods And Results: Sprague-Dawley rats were subjected to Ang II (500 ng/kg/min) infusion using osmotic minipumps for 4 weeks.

Dual ACE-inhibition and angiotensin II AT1 receptor antagonism with curcumin attenuate maladaptive cardiac repair and improve ventricular systolic function after myocardial infarctionin rat heart.

Curcumin has been shown to improve cardiac function by reducing degradation of extracellular matrix and inhibiting synthesis of collagen after ischemia. This study tested the hypothesis that attenuation of maladaptive cardiac repair with curcumin is associated with a dual ACE-inhibition and angiotensin II AT1 receptor antagonism after myocardial infarction. Sprague-Dawley rats were subjected to 45min ischemia followed by 7 and 42 days of reperfusion, respectively.

Attenuation of inflammatory response and reduction in infarct size by postconditioning are associated with downregulation of early growth response 1 during reperfusion in rat heart.

Early growth response 1 (EGR-1) works as a master regulator that plays a key role in triggering inflammation-induced tissue injury after ischemia and reperfusion. This study tested the hypothesis that postconditioning (Postcon) or anti-inflammatory compound, curcumin, ameliorates inflammatory responses and further reduces infarct size by normalizing EGR-1 expression during reperfusion. In the control group, male Sprague-Dawley rats were subjected to 30-min ischemia and 180-min reperfusion.

Postconditioning promotes the cardiac repair through balancing collagen degradation and synthesis after myocardial infarction in rats.

Postconditioning (Postcon) reduces infarct size. However, its role in modulation of cardiac repair after infarction is uncertain. This study tested the hypothesis that Postcon inhibits adverse cardiac repair by reducing degradation of extracellular matrix (ECM) and synthesis of collagens via modulating matrix metalloproteinase (MMP) activity and transforming growth factor (TGF) β1/Smad signaling pathway.