Publications by authors named "Difernando Vanegas"

Unlabelled: Cryptococcosis, caused by fungi of the genus , manifests in a broad range of clinical presentations, including severe pneumonia and disease of the central nervous system (CNS) and other tissues (bone and skin). Immune deficiency or development of overexuberant inflammatory responses can result in increased susceptibility or host damage, respectively, during fungal encounters. Leukotrienes help regulate inflammatory responses against fungal infections.

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Diabetic retinopathy (DR) affects over 140 million people globally. The mechanisms that lead to blindness are still enigmatic but there is evidence that sustained inflammation and hypoxia contribute to vascular damage. Despite efforts to understand the role of inflammation and microglia in DR's pathology, the contribution of astrocytes to hypoxic responses is less clear.

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Diabetic retinopathy (DR)-associated vision loss is a devastating disease affecting the working-age population. Retinal pathology is due to leakage of serum components into retinal tissues, activation of resident phagocytes (microglia), and vascular and neuronal damage. While short-term interventions are available, they do not revert visual function or halt disease progression.

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Diabetic retinopathy (DR) affects about 200 million people worldwide, causing leakage of blood components into retinal tissues, leading to activation of microglia, the resident phagocytes of the retina, promoting neuronal and vascular damage. The microglial receptor, CX3CR1, binds to fractalkine (FKN), an anti-inflammatory chemokine that is expressed on neuronal membranes (mFKN), and undergoes constitutive cleavage to release a soluble domain (sFKN). Deficiencies in CX3CR1 or FKN showed increased microglial activation, inflammation, vascular damage, and neuronal loss in experimental mouse models.

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Vascular congestion and coagulopathy have been shown to play a role in human and experimental cerebral malaria (eCM), but little is known about the role of microglia, or microglia-vascular interactions and hypercoagulation during disease progression in this fatal infection. Recent studies show microglia bind to fibrinogen, a glycoprotein involved in thrombosis. An eCM model of Plasmodium chabaudi infection in mice deficient in the regulatory cytokine IL-10 manifests neuropathology, including hypercoagulation with extensive fibrin(ogen) deposition and neuroinflammation.

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Diabetic retinopathy, a microvascular disease characterized by irreparable vascular damage, neurodegeneration and neuroinflammation, is a leading complication of diabetes mellitus. There is no cure for DR, and medical interventions marginally slow the progression of disease. Microglia-mediated inflammation in the diabetic retina is regulated CX3CR1-FKN signaling, where FKN serves as a calming signal for microglial activation in several neuroinflammatory models.

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Microglia, the resident phagocytes of the retina, are believed to influence the development of retinopathy, but their exact contributions to vascular integrity and neuronal loss are unknown. Therefore, utilizing two models of microglia depletion, we aimed to deplete and repopulate microglia to clarify the contribution of microglia to neuronal loss and vascular damage in the diabetic retina in an STZ-induced model of hyperglycemia. Here, we report that 2 weeks exposure to diphtheria toxin (DTx) in diabetic CX3CR1:R26 transgenic mice induced a 62% increase in Iba1 microglia associated with an increase in TUJ1 axonal density and prevention of NeuNRBPMS neuronal loss.

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Diabetic human and murine retinas revealed pronounced microglial morphological activation and vascular abnormalities associated with inflammation. Pharmacological fibrinogen depletion using ancrod dampened microglial morphology alterations, resolved fibrinogen accumulation, rescued axonal integrity, and reduced inflammation in the diabetic murine retina.

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Microglia have been implicated in multiple sclerosis (MS) pathogenesis. The fractalkine receptor CX3CR1 limits the activation of pathogenic microglia and the human polymorphic CX3CR1 (hCX3CR1 ) variant increases disease progression in models of MS. However, the role of hCX3CR1 variant on microglial activation and central nervous system repair mechanisms remains unknown.

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Infections triggered by pathogenic fungi cause a serious threat to the public health care system. In particular, an increase of antifungal drug-resistant fungi has resulted in difficulty in treatment. A limited variety of antifungal drugs available to treat patients has left us in a situation where we need to develop new therapeutic approaches that are less prone to development of resistance by pathogenic fungi.

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CASP2/caspase 2 plays a role in aging, neurodegeneration, and cancer. The contributions of CASP2 have been attributed to its regulatory role in apoptotic and nonapoptotic processes including the cell cycle, DNA repair, lipid biosynthesis, and regulation of oxidant levels in the cells. Previously, our lab demonstrated CASP2-mediated modulation of autophagy during oxidative stress.

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Objective: Metabolic stress primes monocytes for accelerated chemokine-mediated adhesion, migration, and recruitment into vascular lesions by increasing actin remodeling. The mechanism linking metabolic stress to accelerated actin turnover and enhanced monocyte migration was not known. We tested the hypothesis that in metabolically primed monocytes, the acceleration of monocyte chemoattractant protein-1-induced chemotaxis is mediated by the hyperactivation of cofilin.

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Osteoporosis is a silent disease, characterized by a porous bone micro-structure that enhances risk for fractures and associated disabilities. Senile, or age-related osteoporosis (SO), affects both men and women, resulting in increased morbidity and mortality. However, cellular and molecular mechanisms underlying senile osteoporosis are not fully known.

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Objective: CD36 has been shown to play a role in atherosclerosis in the apolipoprotein E-knockout (apoE(o)) mouse. We observed no difference in aortic lesion area between Western diet (WD)-fed LDLR(o) and LDLR(o)/CD36(o) mice. The objective was to understand the mechanism of CD36-dependent atherogenesis.

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Aims: The role of scavenger receptors in atherogenesis is controversial as a result of conflicting reports and a recent hypothesis suggesting that scavenger receptor absence would enhance the pro-inflammatory, pro-atherogenic milieu. This study addresses the effect of combined absence of scavenger receptors CD36 and SRA I/II on atherosclerosis lesion development in the apolipoprotein E knock-out (apoE degrees ) model.

Methods: We created background-related strains of apoE degrees , scavenger receptor A I/II knock-out (SRA degrees )/apoE degrees , CD36 knock-out (CD36 degrees )/apoE degrees , and CD36 degrees /SRA degrees /apoE degrees mice that were >99% C57Bl/6.

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The prion protein (PrP) level in muscle has been reported to be elevated in patients with inclusion-body myositis, polymyositis, dermatomyositis, and neurogenic muscle atrophy, but it is not clear whether the elevated PrP accumulation in the muscles is sufficient to cause muscle diseases. We have generated transgenic mice with muscle-specific expression of PrP under extremely tight regulation by doxycycline, and we have demonstrated that doxycycline-induced overexpression of PrP strictly limited to muscles leads to a myopathy characterized by increased variation of myofiber size, centrally located nuclei, and endomysial fibrosis, in the absence of intracytoplasmic inclusions, rimmed vacuoles, or any evidence of a neurogenic disorder. The PrP-induced myopathy correlates with accumulation of an N-terminal truncated PrP fragment in the muscle, and the muscular PrP displayed consistent mild resistance to protease digestion.

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Chronic wasting disease (CWD), a prion disease affecting free-ranging and captive cervids (deer and elk), is widespread in the United States and parts of Canada. The large cervid population, the popularity of venison consumption, and the apparent spread of the CWD epidemic are likely resulting in increased human exposure to CWD in the United States. Whether CWD is transmissible to humans, as has been shown for bovine spongiform encephalopathy (the prion disease of cattle), is unknown.

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