Pulmonary responses to subacute ozone exposure in obese vs. lean mice.

The purpose of this study was to determine whether obesity affects pulmonary responses following a 3-day ozone exposure. Obese db/db and lean wild-type mice were exposed to ozone (0.3 ppm) for 72 h.

Diet-induced obesity causes innate airway hyperresponsiveness to methacholine and enhances ozone-induced pulmonary inflammation.

We previously reported that genetically obese mice exhibit innate airway hyperresponsiveness (AHR) and enhanced ozone (O(3))-induced pulmonary inflammation. Such genetic deficiencies in mice are rare in humans, and they may not be representative of human obesity. Thus the purpose of this study was to determine the pulmonary phenotype of mice with diet-induced obesity (DIO), which more closely mimics the cause of human obesity.

Pulmonary responses to acute ozone exposure in fasted mice: effect of leptin administration.

Leptin is a satiety hormone that also has proinflammatory effects, including augmentation of ozone-induced pulmonary inflammation. The purpose of this study was to determine whether reductions in endogenous levels of leptin can attenuate pulmonary responses to ozone. To reduce serum leptin, we fasted mice overnight before ozone exposure.

Adiponectin attenuates allergen-induced airway inflammation and hyperresponsiveness in mice.

Background: Epidemiologic data indicate an increased incidence of asthma in the obese.

Objective: Because serum levels of the insulin-sensitizing and anti-inflammatory adipokine adiponectin are reduced in obese individuals, we sought to determine whether exogenous adiponectin can attenuate allergic airway responses.

Methods: We sensitized and challenged BALB/cJ mice with ovalbumin (OVA).

Increased pulmonary responses to acute ozone exposure in obese db/db mice.

Epidemiological studies indicate the incidence of asthma is increased in obese and overweight humans. Responses to ozone (O(3)), an asthma trigger, are increased in obese (ob/ob) mice lacking the satiety hormone leptin. The long form of leptin receptor (Ob-R(b)) is required for satiety; mice lacking this receptor (db/db mice) are also substantially obese.

Prolonged cold ischemia in rat cardiac allografts promotes ischemia-reperfusion injury and the development of graft coronary artery disease in a linear fashion.

Background: Prolonged cold ischemia is thought to exacerbate ischemia-reperfusion injury and graft coronary artery disease (GCAD). We investigated the effect of varying lengths of cold ischemia on inflammation and apoptosis during ischemia-reperfusion injury and correlated this with the degree of GCAD in rat cardiac allografts.

Methods: PVG rat (RT1c) hearts subjected to 30, 60, 90, 120, or 150 minutes of cold ischemia were heterotopically transplanted into ACI rats (RT1a).

Progression of alloresponse and tissue-specific immunity during graft coronary artery disease.

Chronic rejection remains the major obstacle for long-term transplant survival. Both indirect alloresponse and tissue-specific autoimmunity have been implicated in its pathogenesis. The interrelationship between these two types of host anti-graft response remains poorly understood.

Inhibition of heart transplant injury and graft coronary artery disease after prolonged organ ischemia by selective protein kinase C regulators.

Objective: Transplanted hearts subjected to prolonged ischemia develop ischemia-reperfusion injury and graft coronary artery disease. To determine the effect of delta-protein kinase C and -protein kinase C on ischemia-reperfusion injury and the resulting graft coronary artery disease induced by prolonged ischemia, we used a delta-protein kinase C-selective inhibitor peptide and an -protein kinase C-selective activator peptide after 30 or 120 minutes of ischemia.

Methods: Hearts of piebald viral glaxo (PVG) rats were heterotopically transplanted into allogeneic August Copenhagen Irish (ACI) rats.

Overexpression of human copper/zinc superoxide dismutase (SOD1) suppresses ischemia-reperfusion injury and subsequent development of graft coronary artery disease in murine cardiac grafts.

Background: Ischemia-reperfusion injury is an important risk factor for graft coronary artery disease (GCAD). We hypothesized that overexpression of SOD1 in donor hearts would suppress ischemia-reperfusion injury and thereby reduce GCAD.

Methods And Results: In one series, donor hearts of C57BL/6 (H-2b) transgenic mice overexpressing human SOD1 or C57BL/6 wild-type mice were heterotopically transplanted into C57BL/6 recipients and procured after 4 hours of reperfusion (n=6 each).

Suppression of graft coronary artery disease by a brief treatment with a selective epsilonPKC activator and a deltaPKC inhibitor in murine cardiac allografts.

Background: Inhibiting delta protein kinase C (deltaPKC) during reperfusion and activating epsilon PKC (epsilonPKC) before ischemia each limits cardiac ischemic injury. Here, we examined whether limiting ischemia-reperfusion injury inhibits graft coronary artery disease (GCAD) and improves murine cardiac allografting.

Methods And Results: Hearts of FVB mice (H-2q) were transplanted into C57BL/6 mice (H-2b).

Cardiomyocyte-specific Bcl-2 overexpression attenuates ischemia-reperfusion injury, immune response during acute rejection, and graft coronary artery disease.

After cardiac transplantation, graft damage occurs secondary to ischemia-reperfusion injury and acute rejection. This damage ultimately leads to the development of graft coronary artery disease (GCAD), which limits long-term graft survival. Apoptosis is directly involved in graft injury, contributing to the development of GCAD.