Gauthaman Kalamegam

Dr. Gauthaman Kalamegam


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2016 in Methods
Verified
Journal Article
Open access
SRStephen M Richardson
Stephen M Richardson
GKGauthaman Kalamegam
Gauthaman Kalamegam
PPPeter Pushparaj
Peter Pushparaj
CMCsaba Matta
Csaba Matta
Adnan MemicAdnan Memic
Adnan Memic
Ali MobasheriAli Mobasheri
Ali Mobasheri
Musculoskeletal disorders represent a major cause of disability and morbidity globally and result in enormous costs for health and social care systems. Development of cell-based therapies is rapidly proliferating in a number of disease areas, including musculoskeletal disorders. Novel biological therapies that can effectively treat joint and spine degeneration are high priorities in regenerative medicine. Mesenchymal stem cells (MSCs) isolated from bone marrow (BM-MSCs), adipose tissue (AD-MSCs) and umbilical cord (UC-MSCs) show considerable promise for use in cartilage and intervertebral disc (IVD) repair. This review article focuses on stem cell-based therapeutics for cartilage and IVD repair in the context of the rising global burden of musculoskeletal disorders. We discuss the biology MSCs and chondroprogenitor cells and specifically focus on umbilical cord/Wharton's jelly derived MSCs and examine their potential for regenerative applications. We also summarize key components of the molecular machinery and signaling pathways responsible for the control of chondrogenesis and explore biomimetic scaffolds and biomaterials for articular cartilage and IVD regeneration. This review explores the exciting opportunities afforded by MSCs and discusses the challenges associated with cartilage and IVD repair and regeneration. There are still many technical challenges associated with isolating, expanding, differentiating, and pre-conditioning MSCs for subsequent implantation into degenerate joints and the spine. However, the prospect of combining biomaterials and cell-based therapies that incorporate chondrocytes, chondroprogenitors and MSCs leads to the optimistic view that interdisciplinary approaches will lead to significant breakthroughs in regenerating musculoskeletal tissues, such as the joint and the spine in the near future.

22 August 2017 in BMC Complementary and Alternative Medicine
Verified
Journal Article
Open access
PDF file
FKFazal Khan
Fazal Khan
TKTARIQ Khan
TARIQ Khan
GKGauthaman Kalamegam
Gauthaman Kalamegam
PPPeter Pushparaj
Peter Pushparaj
ACAdeel Chaudhary
Adeel Chaudhary
MAMohammed H. Al-Qahtani
Mohammed H. Al-Qahtani
Hepatocellular carcinoma (HCC) accounts for major cancer-related deaths despite current advanced therapies. Treatment and prognosis of HCC is better in patients with preserved liver function. Many natural products including ajwa dates (Phoenix dactylifera L.), are claimed to have hepatoprotective and HCC inhibitory effects, but most lack scientific validation. To prove our hypothesis, we attempted to evaluate the HCC inhibitory effects, and other beneficial properties of the aqueous extract of ajwa dates (ADE) in a rat model of diethylnitrosamine (DEN) induced liver cancer. Thirty-two male rats were divided into four groups of eight each as follows, Group A: untreated control; Group B: DEN control (180 mg/kg bw), Group C: DEN + ADE 0.5 g/kg bw; and Group D: DEN +1.0 g/kg bw. Rats from all groups were assessed for liver cancer progression or inhibition by evaluating histological, biochemical, antioxidant enzyme status, cytokines and gene expression profiles. DEN treatment Groups (B, C, D) showed histological features of HCC and in rats treated with ADE (Groups C, D) partial to complete reversal of normal liver architecture was observed. Antioxidant enzymes such as superoxide dismutase (SOD), glutathione reductase (GR), glutatione peroxidase (GPx) and catalase (CAT) were increased, while the liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels and lipid peroxidation were significantly decreased in Group C and Group D compared to Group B. Pro-inflammatory cytokines such as interleukin (IL)-1α, IL-1β,, GM-CSF) were increased in the serum of rats in Group B while the anti-tumor cytokines (IL-2, IL-12) were increased in ADE treated Groups (C, D). In addition, Alpha-Feto Protein (AFP) and IL-6 gene expression levels were upregulated in Group B, while they were significantly downregulated in ADE treated Groups (C, D). ADE helped in the reversal of DEN damaged liver towards normal. Restoration of anti-oxidant enzymes, liver enzymes, cytokines balance and gene expression to normal levels following ADE treatment indicates that ADE improves liver function and inhibits HCC. ADE can, therefore, be used together with conventional therapeutics for HCC.

21 July 2016 in PLOS ONE
Verified
Journal Article
Open access
PDF file
FKFazal Khan
Fazal Khan
Farid AhmedFarid Ahmed
Farid Ahmed
PPPeter Pushparaj
Peter Pushparaj
AAAdel Abuzenadah
Adel Abuzenadah
TKTaha Kumosani
Taha Kumosani
GKGauthaman Kalamegam
Gauthaman Kalamegam
Phoenix dactylifera L (Date palm) is a native plant of the Kingdom of Saudi Arabia (KSA) and other Middle Eastern countries. Ajwa date has been described in the traditional and alternative medicine to provide several health benefits including anticholesteremic, antioxidant, hepatoprotective and anticancer effects, but most remains to be scientifically validated. Herein, we evaluated the anticancer effects of the Methanolic Extract of Ajwa Date (MEAD) on human breast adenocarcinoma (MCF7) cells in vitro. MCF7 cells were treated with various concentrations (5, 10, 15, 20 and 25 mg/ml) of MEAD for 24, 48 and 72 h and changes in cell morphology, cell cycle, apoptosis related protein and gene expression were studied. Phase contrast microscopy showed various morphological changes such as cell shrinkage, vacuolation, blebbing and fragmentation. MTT (2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay demonstrated statistically significant dose-dependent inhibitions of MCF7 cell proliferation from 35% to 95%. Annexin V-FITC and TUNEL assays showed positive staining for apoptosis of MCF7 cells treated with MEAD (15 mg and 25 mg for 48 h). Flow cytometric analyses of MCF7 cells with MEAD (15 mg/ml and 20 mg/ml) for 24 h demonstrated cell cycle arrest at 'S' phase; increased p53, Bax protein expression; caspase 3activation and decreased the mitochondrial membrane potential (MMP). Quantitative real time PCR (qRT-PCR) analysis showed up-regulation of p53, Bax, Fas, and FasL and down-regulation of Bcl-2. MEAD inhibited MCF7 cells in vitro by the inducing cell cycle arrest and apoptosis. Our results indicate the anticancer effects of Ajwa dates, which therefore may be used as an adjunct therapy with conventional chemotherapeutics to achieve a synergistic effect against breast cancer.

29 May 2020 in Polymers
Verified
Journal Article
Open access
PDF file
Turdimuhammad AbdullahTurdimuhammad Abdullah
Turdimuhammad Abdullah
GKGauthaman Kalamegam
Gauthaman Kalamegam
AHAhmed Hammad
Ahmed Hammad
Kasturi Joshi-NavareKasturi Joshi-Navare
Kasturi Joshi-Navare
AAAhmed A. Alshahrie
Ahmed A. Alshahrie
Adnan MemicAdnan Memic
Adnan Memic
Lack of suitable auto/allografts has been delaying surgical interventions for the treatment of numerous disorders and has also caused a serious threat to public health. Tissue engineering could be one of the best alternatives to solve this issue. However, deficiency of oxygen supply in the wounded and implanted engineered tissues, caused by circulatory problems and insufficient angiogenesis, has been a rate-limiting step in translation of tissue-engineered grafts. To address this issue, we designed oxygen-releasing electrospun composite scaffolds, based on a previously developed hybrid polymeric matrix composed of poly(glycerol sebacate) (PGS) and poly(ε-caprolactone) (PCL). By performing ball-milling, we were able to embed a large percent of calcium peroxide (CP) nanoparticles into the PGS/PCL nanofibers able to generate oxygen. The composite scaffold exhibited a smooth fiber structure, while providing sustainable oxygen release for several days to a week, and significantly improved cell metabolic activity due to alleviation of hypoxic environment around primary bone-marrow-derived mesenchymal stem cells (BM-MSCs). Moreover, the composite scaffolds also showed good antibacterial performance. In conjunction to other improved features, such as degradation behavior, the developed scaffolds are promising biomaterials for various tissue-engineering and wound-healing applications.

23 July 2020 in Frontiers in Cell and Developmental Biology
Verified
Journal Article
Open access
GKGauthaman Kalamegam
Gauthaman Kalamegam
SASaadiah M. Alfakeeh
Saadiah M. Alfakeeh
ABAfnan Omar Bahmaid
Afnan Omar Bahmaid
EAEtimad A. AlHuwait
Etimad A. AlHuwait
MGMamdouh A. Gari
Mamdouh A. Gari
PPPeter Natesan Pushparaj
Peter Natesan Pushparaj
Chronic inflammation is a common underlying factor in osteoarthritis (OA) and most age-related degenerative diseases. As conventional therapies help only in partial alleviation of symptoms in OA, stem cell-based therapies and herbal supplements are being widely explored. Thymoquinone (TQ), an active ingredient of Nigella sativa is reported to have immunomodulatory, anti-inflammatory and antioxidant properties. We evaluated the effects of TQ on bone marrow MSCs (BM-MSCs) derived from OA patients and its interrelated pathways in inflammation and age-related degenerative diseases using Ingenuity Pathway Analysis (IPA) as well as possible molecular targets using SwissTargetPrediction. BM-MSCs were derived from OA patients and their stemness properties were characterized by studying the MSCs related CD surface marker expression and differentiation into adipocytes, osteoblasts, and chondrocytes. Treatment with TQ (100 nM–5 μM) demonstrated cell death, especially at higher concentrations. MTT assay demonstrated a significant concentration-dependent decrease in cell viability which ranged from 20.04% to 69.76% with higher doses (300 nM, 1 μM, and 5 μM), especially at 48h and 72h. Additional cell viability testing with CellTiter-Blue also demonstrated a significant concentration-dependent decrease in cell viability which ranged from 27.80 to 73.67% with higher doses (300 nM, 1 μM, 3 μM, and 5 μM). Gene expression analysis following treatment of BM-MSCs with TQ (1 and 3 μM) for 48h showed upregulation of the anti-inflammatory genes IL-4 and IL-10. In contrast, the pro-inflammatory genes namely IFN-γ, TNF-α, COX-2, IL-6, IL-8, IL-16, and IL-12A although were upregulated, compared to the lower concentration of TQ (1 μM) they were all decreased at 3 μM. The pro-apoptotic BAX gene was downregulated while the SURVIVIN gene was upregulated. IPA of the molecular interaction of TQ in inflammation and age-related degenerative diseases identified canonical pathways directly related to synaptogenesis, neuroinflammation, TGF-β, and interleukin signaling. Further screening led to the identification of 36 molecules that are involved in apoptosis, cell cycle regulation, cytokines, chemokines, and growth factors. SwissTargetPrediction of TQ identified potential molecular targets with high probability. TQ exerted anti-inflammatory effects and therefore can be a useful adjuvant along with conventional therapies against inflammation in OA and other age-related degenerative diseases.

20 July 2016 in BMC Genomics
Verified
Journal Article
Open access
JSJerry W. Shay
Jerry W. Shay
NHNoriko Homma
Noriko Homma
RZRuyun Zhou
Ruyun Zhou
MNMuhammad Imran Naseer
Muhammad Imran Naseer
ACAdeel Chaudhary
Adeel Chaudhary
SBSaleh Binsaleh
Saleh Binsaleh
O1 Regulation of genes by telomere length over long distances