Publications by authors named "Dhanesh Amarnani"

Messenger RNA (mRNA)-based therapies are a promising approach to medical treatment. Except for infectious diseases, no other disease has mRNA-based therapies available. The eye is an ideal model for mRNA therapeutic development because it requires limited dosing.

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We characterized the world's second case with ascertained extreme resilience to autosomal dominant Alzheimer's disease (ADAD). Side-by-side comparisons of this male case and the previously reported female case with ADAD homozygote for the APOE3 Christchurch (APOECh) variant allowed us to discern common features. The male remained cognitively intact until 67 years of age despite carrying a PSEN1-E280A mutation.

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Purpose: To test the efficacy of runt-related transcription factor 1 (RUNX1) inhibition with topical nanoemulsion containing Ro5-3335 (eNano-Ro5) in experimental ocular neovascularization.

Design: Preclinical experimental study.

Participants: In vitro primary culture human retinal endothelial cell (HREC) culture.

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Pulmonary fibrosis (PF) can arise from unknown causes, as in idiopathic PF, or as a consequence of infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current treatments for PF slow, but do not stop, disease progression. We report that treatment with a runt-related transcription factor 1 (RUNX1) inhibitor (Ro24-7429), previously found to be safe, although ineffective, as a Tat inhibitor in patients with HIV, robustly ameliorates lung fibrosis and inflammation in the bleomycin-induced PF mouse model.

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Choroidal neovascularization (CNV) is a prevalent cause of vision loss in patients with age-related macular degeneration. Runt-related transcription factor 1 (RUNX1) has been identified as an important mediator of aberrant retinal angiogenesis in proliferative diabetic retinopathy and its modulation has proven to be effective in curbing pathologic angiogenesis in experimental oxygen-induced retinopathy. However, its role in CNV remains to be elucidated.

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Article Synopsis
  • Proliferative vitreoretinopathy (PVR) is the main reason for failures in retinal detachment surgery, and there's currently no effective medical treatment available.
  • Researchers have identified the gene RUNX1 as being significantly expressed in PVR cases and linked to a process called epithelial to mesenchymal transition (EMT), which contributes to the formation of problematic membranes in the eye.
  • The created inhibitor Ro5-3335, delivered as a topical treatment, showed promise in reducing cell proliferation and slowing PVR progression in a rabbit model, indicating that targeting RUNX1 could be a viable strategy for treating this condition.
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Runt-related transcription factor 1 (RUNX1) acts as a mediator of aberrant retinal angiogenesis and has been implicated in the progression of proliferative diabetic retinopathy (PDR). Patients with PDR, retinopathy of prematurity (ROP), and wet age-related macular degeneration (wet AMD) have been found to have elevated levels of Tumor Necrosis Factor-alpha (TNF-α) in the eye. In fibrovascular membranes (FVMs) taken from patients with PDR RUNX1 expression was increased in the vasculature, while in human retinal microvascular endothelial cells (HRMECs), TNF-α stimulation causes increased RUNX1 expression, which can be modulated by RUNX1 inhibitors.

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Purpose: Acute orbital inflammation can lead to irreversible vision loss in serious cases. Treatment thus far has been limited to systemic steroids or surgical decompression of the orbit. An animal model that mimics the characteristic features of acute orbital inflammation as found in thyroid eye disease can be used to explore novel treatment modalities.

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We identified a PSEN1 (presenilin 1) mutation carrier from the world's largest autosomal dominant Alzheimer's disease kindred, who did not develop mild cognitive impairment until her seventies, three decades after the expected age of clinical onset. The individual had two copies of the APOE3 Christchurch (R136S) mutation, unusually high brain amyloid levels and limited tau and neurodegenerative measurements. Our findings have implications for the role of APOE in the pathogenesis, treatment and prevention of Alzheimer's disease.

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Purpose: The purpose of this study was to develop a method for isolating, culturing, and characterizing cells from patient-derived membranes in proliferative vitreoretinopathy (PVR) to be used for drug testing.

Methods: PVR membranes were obtained from six patients with grade C PVR. Membrane fragments were analyzed by gross evaluation, fixed for immunohistologic studies to establish cell identity, or digested with collagenase II to obtain single cell suspensions for culture.

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Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a neurological syndrome characterized by small vessel disease (SVD), stroke, and vascular cognitive impairment and dementia caused by mutations in No therapies are available for this condition. Loss of mural cells, which encompass pericytes and vascular smooth muscle cells, is a hallmark of CADASIL and other SVDs, including diabetic retinopathy, resulting in vascular instability. Here, we showed that Notch3 signaling is both necessary and sufficient to support mural cell coverage in arteries using genetic rescue in Notch3 knockout mice.

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Proliferative diabetic retinopathy (PDR) is a common cause of blindness in the developed world's working adult population and affects those with type 1 and type 2 diabetes. We identified Runt-related transcription factor 1 (RUNX1) as a gene upregulated in CD31 vascular endothelial cells obtained from human PDR fibrovascular membranes (FVMs) via transcriptomic analysis. In vitro studies using human retinal microvascular endothelial cells (HRMECs) showed increased RUNX1 RNA and protein expression in response to high glucose, whereas RUNX1 inhibition reduced HRMEC migration, proliferation, and tube formation.

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Purpose: Accumulation of oxidized phospholipids/lipoproteins with age is suggested to contribute to the pathogenesis of AMD. We investigated the effect of oxidized LDL (ox-LDL) on human RPE cells.

Methods: Primary human fetal RPE (hf-RPE) and ARPE-19 cells were treated with different doses of LDL or ox-LDL.

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Purpose: The human orbit is an environment that is vulnerable to inflammation and edema in the setting of autoimmune thyroid disease. Our study investigated the tenet that orbital adipose tissue lacks lymphatic vessels and analyzed the clinicopathologic differences between patients with acute and chronic thyroid eye disease (TED). The underlying molecular mediators of blood and lymphatic vessel formation within the orbital fat also were evaluated.

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Purpose: Epiretinal fibrovascular membranes (FVMs) are a hallmark of proliferative diabetic retinopathy (PDR). Surgical removal of FVMs is often indicated to treat tractional retinal detachment. This potentially informative pathological tissue is usually disposed of after surgery without further examination.

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Diabetes can lead to vision loss because of progressive degeneration of the neurovascular unit in the retina, a condition known as diabetic retinopathy. In its early stages, the pathology is characterized by microangiopathies, including microaneurysms, microhemorrhages, and nerve layer infarcts known as cotton-wool spots. Analyses of postmortem human retinal tissue and retinas from animal models indicate that degeneration of the pericytes, which constitute the outer layer of capillaries, is an early event in diabetic retinopathy; however, the relative contribution of specific cellular components to the pathobiology of diabetic retinopathy remains to be defined.

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Purpose: To evaluate the mechanism of tamoxifen-induced cell death in human cultured RPE cells, and to investigate concurrent cell death mechanisms including pyroptosis, apoptosis, and necroptosis.

Methods: Human RPE cells were cultured until confluence and treated with tamoxifen; cell death was measured by detecting LDH release. Tamoxifen-induced cell death was further confirmed by 7-aminoactinomycin D (7-AAD) and annexin V staining.

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