Publications by authors named "Arjunan Pachiappan"

Fascinatingly, the immune-privileged healthy eye has a small unique population of microbiota. The human microbiome project led to continuing interest in the ocular microbiome. Typically, ocular microflorae are commensals of low diversity that colonize the external and internal sites of the eye, without instigating any disorders.

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DNA damage, induced by either chemical carcinogens or environmental pollutants, plays an important role in the initiation of colorectal cancer. DNA repair processes, however, are involved in both protecting against cancer formation, and also contributing to cancer development, by ensuring genomic integrity and promoting the efficient DNA repair in tumor cells, respectively. Although DNA repair pathways have been well exploited in the treatment of breast and ovarian cancers, the role of DNA repair processes and their therapeutic efficacy in colorectal cancer is yet to be appreciably explored.

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Article Synopsis
  • Emerging research highlights a connection between age-related macular degeneration (AMD) and periodontal disease (PD), but the exact biological mechanisms behind this link and the role of oral health are still not well-defined.
  • To investigate this further, researchers created a new animal model that simulates both AMD and PD, which allowed them to examine how periodontal infections contribute to AMD-related eye issues.
  • Findings showed significant changes in the eyes of the mice, including inflammation, reduced retinal thickness, and increased blood vessel leakage, indicating that periodontal infections may worsen AMD symptoms.
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Mouth and associated structures were regarded as separate entities from the rest of the body. However, there is a paradigm shift in this conception and oral health is now considered as a fundamental part of overall well-being. In recent years, the subject of oral-foci of infection has attained a resurgence in terms of systemic morbidities while limited observations denote the implication of chronic oral inflammation in the pathogenesis of eye diseases.

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Recent epidemiological  studies link Periodontal disease(PD) to age-related macular degeneration (AMD). We documented earlier that Porphyromonas gingivalis(Pg), keystone oral-pathobiont, causative of PD, efficiently invades human gingival epithelial and blood-dendritic cells. Here, we investigated the ability of dysbiotic Pg-strains to invade human-retinal pigment epithelial cells(ARPE-19), their survival, intracellular localization, and the pathological effects, as dysfunction of RPEs leads to AMD.

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Chronic periodontitis (CP) is a microbial dysbiotic disease linked to increased risk of oral squamous cell carcinomas (OSCCs). To address the underlying mechanisms, mouse and human cell infection models and human biopsy samples were employed. We show that the 'keystone' pathogen Porphyromonas gingivalis, disrupts immune surveillance by generating myeloid-derived dendritic suppressor cells (MDDSCs) from monocytes.

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VEGF-B was discovered a long time ago. However, unlike VEGF-A, whose function has been extensively studied, the function of VEGF-B and the mechanisms involved still remain poorly understood. Notwithstanding, drugs that inhibit VEGF-B and other VEGF family members have been used to treat patients with neovascular diseases.

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Diabetic retinopathy (DR) is a leading cause of blindness among working-age adults. Increased iron accumulation is associated with several degenerative diseases. However, there are no reports on the status of retinal iron or its implications in the pathogenesis of DR.

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Purpose: Hemochromatosis, an iron-overload disease, occurs as adult and juvenile types. Mutations in hemojuvelin (HJV), an iron-regulatory protein and a bone morphogenetic protein (BMP) coreceptor, underlie most of the juvenile type. Hjv(-/-) mice accumulate excess iron in retina and exhibit aberrant vascularization and angiomas.

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Mammary stem/progenitor cells (MaSCs) maintain self-renewal of the mammary epithelium during puberty and pregnancy. DNA methylation provides a potential epigenetic mechanism for maintaining cellular memory during self-renewal. Although DNA methyltransferases (DNMTs) are dispensable for embryonic stem cell maintenance, their role in maintaining MaSCs and cancer stem cells (CSCs) in constantly replenishing mammary epithelium is unclear.

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A normal cornea is clear of vascular tissues. However, blood vessels can be induced to grow and survive in the cornea when potent angiogenic factors are administered (1). This uniqueness has made the cornea pocket assay one of the most used models for angiogenesis studies.

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Injury to the optic nerve can lead to axonal degeneration, followed by a gradual death of retinal ganglion cells (RGCs), which results in irreversible vision loss. Examples of such diseases in human include traumatic optic neuropathy and optic nerve degeneration in glaucoma. It is characterized by typical changes in the optic nerve head, progressive optic nerve degeneration, and loss of retinal ganglion cells, if uncontrolled, leading to vision loss and blindness.

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The importance of identifying VEGF-independent pathways in pathological angiogenesis is increasingly recognized as a result of the emerging drug resistance to anti-VEGF therapies. PDGF-CC is the third member of the PDGF family discovered after more than two decades of studies on PDGF-AA and PDGF-BB. The biological function of PDGF-CC and the underlying cellular and molecular mechanisms remain largely unexplored.

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Platelet-derived growth factor CC (PDGF-CC) is the third member of the PDGF family discovered after more than two decades of studies on the original members of the family, PDGF-AA and PDGF-BB. The biological function of PDGF-CC remains largely to be explored. We report a novel finding that PDGF-CC is a potent neuroprotective factor that acts by modulating glycogen synthase kinase 3beta (GSK3beta) activity.

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Platelet-derived growth factor-DD (PDGF-DD) is a recently discovered member of the PDGF family. The role of PDGF-DD in pathological angiogenesis and the underlying cellular and molecular mechanisms remain largely unexplored. In this study, using different animal models, we showed that PDGF-DD expression was up-regulated during pathological angiogenesis, and inhibition of PDGF-DD suppressed both choroidal and retinal neovascularization.

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Article Synopsis
  • Study Focus
  • : The research investigates the inhibitory effects of the phospholipase inhibitor PIP-18 peptide on inflammation in rheumatoid arthritis by examining its mechanism in synovial fibroblasts and its impact in a mouse model of arthritis.
  • Methodology
  • : The study uses techniques like real-time PCR, ELISA, and histological analysis to assess how PIP-18 affects gene and protein expression related to inflammation and cartilage degradation when compared to existing treatments like celecoxib and methotrexate.
  • Key Findings
  • : PIP-18 effectively reduces the production of inflammatory markers and enzymes associated with RA, showing promise in decreasing symptoms like synovitis and bone erosion in the treated mouse
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Despite its early discovery and high sequence homology to the other VEGF family members, the biological function of VEGF-B remained debatable for a long time, and VEGF-B has received little attention from the field thus far. Recently, we and others have found that (1) VEGF-B is a potent survival factor for different types of cells by inhibiting apoptosis via suppressing the expression of BH3-only protein and other apoptotic/cell death-related genes. (2) VEGF-B has a negligible role in inducing blood vessel growth in most organs.

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The mechanistic understanding of low-level sarin-induced neurotoxicity after single or repeated doses has yet to be explored at a cellular level. Using the microarray (Affymetrix-GeneChips) transcription profiling approach, the present study examined gene expression in human SH-SY5Y cells exposed to single (3 and 24 h) or repeated (2 x 24 h) doses of sarin (5 microg/mL) to delineate the possible mechanism. Two hundred twenty-four genes whose expression was significantly (P < 0.

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VEGF-B, a homolog of VEGF discovered a long time ago, has not been considered an important target in antiangiogenic therapy. Instead, it has received little attention from the field. In this study, using different animal models and multiple types of vascular cells, we revealed that although VEGF-B is dispensable for blood vessel growth, it is critical for their survival.

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GeneChip microarray is a cutting-edge technology being used to study the expression patterns of genes with in a particular cell type. In this study, the Affymetrix RAE230A platform was used to profile stably expressed mRNA transcripts from PC12 cells at passage 5 and 15. The whole-cell PC12 transcriptome revealed that a total of 7,531 stable transcripts (P < 0.

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Secretory phospholipase A2 (sPLA2) and matrix metallopreoteinases (MMPs) are key enzymes involved in rheumatoid arthritis (RA), and their modulation thus represents a potential therapeutic option. On the basis of Escherichia coli radioassay, synthetic peptides were designed and screened for sPLA2 inhibition. The linear peptide, 10f (PIP-18), inhibited the recombinant human synovial sPLA2 activity with an IC50 of 1.

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Heat induced complications cause an increase in a large number of proteins which play a role in diverse pathways during heat shock. A detailed characterization of these proteins is essential for understanding the molecular mechanisms involved in heat stroke. In this report, the proteins present in rat liver were compared at 37 degrees C (control) and at core temperature (Tc) 42 degrees C (heat stress) by 1D PAGE and MALDI/MS/MS.

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