Jacek M Kwiecien's research while affiliated with McMaster University and other places

Publications (74)

Article
Elevated liver de novo lipogenesis contributes to non-alcoholic steatohepatitis (NASH) and can be inhibited by targeting acetyl-CoA carboxylase (ACC). However, hypertriglyceridemia limits the use of pharmacological ACC inhibitors as a monotherapy. ATP-citrate lyase (ACLY) generates acetyl-CoA and oxaloacetate from citrate, but whether inhibition is...
Article
Introduction: Radiation therapy increases the risk of secondary malignancy and morbidity in cancer survivors. The role of obesity and exercise training in modulating this risk is not well-understood. As such, we used a preclinical model of radiation-induced malignancy to investigate whether diet-induced obesity and/or endurance exercise training a...
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Traumatic injuries of the brain and spinal cord are a significant source of mortality and long-term disability. A recent systematic study in a rat model of spinal cord injury (SCI) indicates severe, destructive, and very protracted inflammation as the key mechanism initiated by the massive injury involving the white matter. Although the severe infl...
Article
The spinal cord injury (SCI) initiates an extraordinarily protracted disease with 3 phases; acute, inflammatory and resolution that are restricted to the cavity of injury (COI) or arachnoiditis by a unique CNS reaction against the severity of destructive inflammation. While the severity of inflammation involving the white matter is fueled by a pote...
Chapter
Severe inflammatory disease initiated by neurotrauma and stroke is of primary concern in these intractable pathologies as noted in recent studies and understanding of the pathogenesis of spinal cord injury (SCI) in the rat model. Successful anti-inflammatory treatments should result in neuroprotection and limit the loss of neurological function to...
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Spinal cord injury (SCI) initiates a severe, destructive inflammation with pro-inflammatory, CD68+/CD163−, phagocytic macrophages infiltrating the area of necrosis and hemorrhage by day 3 and persisting for the next 16 weeks. Inhibition of macrophage infiltration of the site of necrosis that is converted into a cavity of injury (COI) during the fir...
Article
A massive localized trauma to the spinal cord results in complex pathologic events driven by necrosis and vascular damage which in turn leads to hemorrhage and edema. Severe, destructive and very protracted inflammatory response is characterized by infiltration by phagocytic macrophages of a site of injury which is converted into a cavity of injury...
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Spinal cord injury (SCI) results in massive secondary damage characterized by a prolonged inflammation with phagocytic macrophage invasion and tissue destruction. In prior work, sustained subdural infusion of anti-inflammatory compounds reduced neurological deficits and reduced pro-inflammatory cell invasion at the site of injury leading to improve...
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Tumor-targeted chimeric antigen receptor (CAR)-engineered T cells (CAR-T cells) have demonstrated striking clinical success, but their use has been associated with a constellation of toxicities. A better understanding of the pathogenesis of these toxicities is required to improve the safety profile of CAR-T cells. Herein, we describe a xenograft mo...
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Viruses are widely used as a platform for the production of therapeutics. Vaccines containing live, dead and components of viruses, gene therapy vectors and oncolytic viruses are key examples of clinically-approved therapeutic uses for viruses. Despite this, the use of virus-derived proteins as natural sources for immune modulators remains in the e...
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The pathogenesis of spinal cord injury (SCI) remains poorly understood and treatment remains limited. Emerging evidence indicates that post-SCI inflammation is severe but the role of reactive astrogliosis not well understood given its implication in ongoing inflammation as damaging or neuroprotective. We have completed an extensive systematic study...
Preprint
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The pathogenesis of spinal cord injury (SCI) remains poorly understood and treatment remains limited. Emerging evidence indicates the severity of post-SCI inflammation and an ongoing controversy in the roles of astrocytes with studies identifying astrocytes as associated both with ongoing inflammation and damage as well as potentially having a prot...
Article
The availability of solid organs for transplantation remains low and there is a substantial need for methods to preserve the viability of grafted tissues. Suppression of solid-organ transplant rejection has traditionally focused on highly effective T cell inhibitors that block host immune lymphocyte responses. However, persistent and destructive in...
Article
Spinal cord injury (SCI)-initiated inflammation was treated with anti-inflammatory reagents. We compared local spinal cord or intraperitoneal infusion of two Myxoma virus derived immune modulating proteins, Serp-1 and M-T7, with dexamethasone (DEX). Hemorrhage and necrosis after SCI initiate a complex pathogenesis dominated by early, severe and h...
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Background: Previous studies have implicated white-matter-related changes in the pathophysiology of bipolar disorder. However, most of what is known is derived from in vivo subcortical white-matter imaging or postmortem studies. In this study, we investigated whole-brain intracortical myelin (ICM) content in people with bipolar disorder type I and...
Article
Chemically cross-linked cellulose nanocrystal (CNC) aerogels possess many properties beneficial for bone tissue scaffolding applications. CNCs were extracted using sulfuric acid or phosphoric acid, to produce CNCs with sulfate and phosphate half-ester surface groups, respectively. Hydrazone cross-linked aerogels fabricated from the two types of CNC...
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Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor, representing 20% of newly diagnosed childhood central nervous system malignancies. Although advances in multimodal therapy yielded a 5-year survivorship of 80%, MB still accounts for the leading cause of childhood cancer mortality. In this work, we describe the epigenetic re...
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Evidence suggests that there are both nociceptive and neuropathic components of cancer-induced pain (CIP). We have observed that changes in intrinsic membrane properties and excitability of normally non-nociceptive Aβ sensory neurons are consistent in rat models of peripheral neuropathic pain (NEP) and CIP. This has prompted a comparative investiga...
Chapter
As the systematic work on the pathogenesis of the white matter injury in the spinal cord models progresses, it becomes obvious that a severe and extraordinarily protracted, destructive inflammation follows the initial injury. Appropriate anti-inflammatory therapies of sufficient duration should not only inhibit but also lead to the elimination of t...
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Engineering T cells with chimeric antigen receptors (CARs) is an effective method for directing T cells to attack tumors, but may cause adverse side effects such as the potentially lethal cytokine release syndrome. Here the authors show that the T cell antigen coupler (TAC), a chimeric receptor that co-opts the endogenous TCR, induces more efficien...
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In this pilot study, a 3D printed Grade V titanium dental implant with a novel dual-stemmed design was investigated for its biocompatibility in vivo. Both dual-stemmed ( n = 12) and conventional stainless steel conical ( n = 4) implants were inserted into the tibial metaphysis of New Zealand white rabbits for 3 and 12 weeks and then retrieved with...
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The metastatic activity of breast carcinomas results from complex genetic changes in epithelial tumor cells and accounts for 90% of deaths in affected patients. Although the invasion of the local lymphatic vessels and veins by malignant breast tumor cells and their subsequent metastasis to the lung, has been recognized, the mechanisms behind the me...
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Kynurenic acid (KYNA) is an end stage product of tryptophan metabolism with a variety of functions in the human body, both in the central nervous system (CNS) and in other organs. Although its activity in the human brain has been widely studied and effects on neural cells were emphasized, the effect of KYNA on oligodendroglial cells remains unknown...
Article
White matter injury: a systematic study - Volume 44 Issue S1 - JM Kwiecien
Article
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Medulloblastoma (MB), the most common malignant paediatric brain tumor, is currently treated using a combination of surgery, craniospinal radiotherapy and chemotherapy. Owing to MB stem cells (MBSCs), a subset of MB patients remains untreatable despite standard therapy. CD133 is used to identify MBSCs although its functional role in tumorigenesis h...
Article
A model of dysmyelination, the Long Evans Shaker (les) rat, was used to study the contribution of myelin to MR tissue properties in white matter. A large region of white matter was identified in the deep cerebellum and was used for measurements of the MR relaxation rate constants, R1 = 1/T1 and R2 = 1/T2 , at 7 T. In this study, R1 of the les deep...
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Triple-negative breast cancers (TNBCs) represent a subset of breast tumors that are highly aggressive and metastatic, and are responsible for a disproportionate number of breast cancer-related deaths. Several studies have postulated a role for the epithelial-to-mesenchymal transition (EMT) program in the increased aggressiveness and metastatic prop...
Article
Streptococcus pneumoniae is a leading cause of invasive bacterial infections, with nasal colonization an important first step for disease. While cigarette smoking is a strong risk factor for invasive pneumococcal disease, underlying mechanisms remain unknown. This is partly due to a lack of clinically relevant animal models investigating nasal pneu...
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Background: Kynurenic acid (KYNA) is the end stage metabolite of tryptophan produced mainly by astrocytes in the central nervous system (CNS). It has neuroprotective activities but can be elevated in the neuropsychiatric disorders. Toxic effects of KYNA in the CNS are unknown. The aim of this study was to assess the effect of the subdural KYNA inf...
Article
Current therapies to limit the neural tissue destruction following the spinal cord injury are not effective. Our recent studies indicate that the injury to the white matter of the spinal cord results in a severe inflammatory response where macrophages phagocytize damaged myelin and the fluid-filled cavity of injury extends in size with concurrent a...
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Ligands for the NKG2D receptor are overexpressed on tumors, making them interesting immunotherapy targets. To assess the tumoricidal properties of T cells directed to attack NKG2D ligands, we engineered murine T cells with 2 distinct NKG2D-based chimeric antigen receptors (CARs): 1) a fusion between the NKG2D receptor and the CD3ζ chain and 2) a co...
Article
Quantitative T2 (qT2), diffusion tensor imaging (DTI), and histology were used to investigate a cervical model of spinal cord injury (SCI) in the rat. While quantitative MRI can significantly increase the specificity in the presence of pathology, it must be validated for each type of injury or disease. In the case of traumatic SCI most models are d...
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Trauma in spinal cord injury often results in massive damage to the white matter and in damage to myelin that results in a severe phagocyte-rich infiltration apparently directed at removing immunologically toxic myelin debris. In the epidural balloon crush injury to the rat cranial thoracic spinal cord, the dorsal column was crushed, which at one w...
Article
Background The most commonly used animal models of spinal cord injury (SCI) involve surgical exposure of the dorsal spinal cord followed by transection, contusion or compression. This high level of invasiveness often requires significant post-operative care and can limit post-operative imaging, as the surgical incision site can interfere with coil...
Article
Cellular mechanisms of regeneration after the white matter injury are difficult to study because of severe, inflammatory response to massively damaged myelin. Myelin-lacking CNS of the adult Long Evans Shaker (LES) rat supplies a model where neuroregeneration can be studied conveniently. The crush site in the dorsal spinal column in LES rats implan...
Article
Background: Thirty minutes has been considered as the thresholdfor tolerable warm ischemic time (WIT). Recent reports demonstraterecovery of renal function after longer WIT. We assessed renalhistology according to different WIT in a 2-kidney porcine model.Methods: Twelve female pigs were randomized to an open orlaparoscopic group. Each pig was furt...
Article
Schizophrenia is a mental illness characterized by a breakdown in cognition and emotion. Over the years, drug treatment for this disorder has mainly been compromised of orthosteric ligands that antagonize the active site of the dopamine D2 receptor. However, these drugs are limited in their use and often lead to the development of adverse movement...
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The master regulatory gene Bmi1 modulates key stem cell properties in neural precursor cells (NPCs), and has been implicated in brain tumorigenesis. We previously identified a population of CD133+ brain tumor cells possessing stem cell properties, known as brain tumor initiating cells (BTICs). Here, we characterize the expression and role of Bmi1 i...
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Bmi1 is a key stem cell regulatory gene implicated in the pathogenesis of many aggressive cancers, including medulloblastoma. Overexpression of Bmi1 promotes cell proliferation and is required for hedgehog (Hh) pathway-driven tumorigenesis. This study aimed to determine if Sonic hedgehog (Shh) modulates the key stem cell regulatory gene Bmi1 in chi...
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Thirty minutes has been considered as the threshold for tolerable warm ischemic time (WIT). Recent reports demonstrate recovery of renal function after longer WIT. We assessed renal histology according to different WIT in a 2-kidney porcine model. Twelve female pigs were randomized to an open or laparoscopic group. Each pig was further randomized w...
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Health problems in some animal models remain unexplained, rendering in vivo studies ethically challenging, especially when experimental animals are prone to sudden death. Over the last 3 decades, the myelin-deficient (md) rat, a strain with severe dysmyelination due to mutant proteolipid protein, has been key to important discoveries in mechanisms...
Article
Loss or absolute lack of myelin in the CNS results in remarkable compensation at the cellular level. In this study on the natural progression of neuropathology in the CNS in 2 related but distinct long-lived dysmyelinated rats, total lack of myelin was associated with remarkable glial cell proliferation and ineffective myelinating activity througho...
Article
Studies of regeneration of transected adult central nervous system (CNS) axons are difficult due to lack of appropriate in vivo models. In adult rats, we described filum terminale (FT), a caudal slender extension of the sacral spinal cord and an integral part of the central nervous system (CNS), to use it as a model of spinal cord injury. FT is mor...
Article
Regeneration within or into the CNS is thwarted by glial inhibition at the site of a spinal cord injury and at the dorsal root entry zone (DREZ), respectively. At the DREZ, injured axons and their distal targets are separated by degenerating myelin and an astrocytic glia limitans. The different glial barriers to regeneration following dorsal rhizot...
Article
Functional re-innervation of target neurons following neurological damage such as spinal cord injury is an essential requirement of potential therapies. There are at least two avenues by which this can be achieved: (a) through the regeneration of injured axons and (b) through promoting plasticity of those spared by the initial insult. There are sev...
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Diets rich in marine organisms or their oils are known to suppress solid tumor development in humans and rodents, but the potential for marine foods to affect hematopoietic system cancers is not well understood. As part of a toxicology study, we fed groups of mice three different diets for 10 weeks: marine fish, 58% homogenized Atlantic smelt and h...
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Abnormal formation or loss of myelin is a distinguishing feature of many neurological disorders and contributes to the pathobiology of neurotrauma. In this study we characterize the functional and molecular changes in CNS white matter in Long Evans Shaker (LES) rats. These rats have a spontaneous mutation of the gene encoding myelin basic protein w...
Article
The goal of this study was to determine the contribution of the distal nerve sheath to sensory protection. Following tibial nerve transection, rats were assigned to one of the following groups: (1) saphenous-to-tibial nerve neurorrhaphy; (2) saphenous-to-gastrocnemius neurotization; (3) unprotected controls (tibial nerve transection); or (4) immedi...
Article
Myelin-derived molecules inhibit axonal regeneration in the CNS. The Long-Evans Shaker rat is a naturally occurring dysmyelinated mutant, which although able to express the components of myelin lacks functional myelin in adulthood. Given that myelin breakdown exposes axons to molecules that are inhibitory to regeneration, we sought to determine whe...
Article
An alternative approach to somatic gene therapy is to deliver a therapeutic protein by implanting "universal" recombinant cells that are immunologically protected from graft rejection with alginate microcapsules. This strategy has proved successful in reversing pathologic conditions in several rodent models of human disease (dwarfism, lysosomal sto...
Article
Myelin in the central nervous system (CNS) is hypothesized to help guide the growth of developing axons by inhibiting sprouting of aberrant neurites. Previous studies using animal models lacking CNS myelin have reported that increasing capacity for sprouting axons is negatively correlated with the degree of myelination. In the present study, we inv...
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Spontaneous animal mutants affected by abnormal formation of myelin in the central nervous system (CNS) are useful in studies on myelinogenesis and remyelination leading to better understanding of cellular and molecular interactions involved in myelin repair. A novel rat mutant, Bouncer Long Evans (LE-bo) is severely dysmyelinated, but with excepti...
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Our understanding of myelination has been greatly enhanced via the study of spontaneous mutants that harbor a defect in a gene encoding one of the major myelin proteins (myelin mutants). In this study, we describe a unique genetic defect in a new myelin mutant called the Long Evans shaker (les) rat that causes severe dysmyelination of the CNS. Myel...
Article
The Long Evans shaker (les) rat is a recently identified CNS myelin mutant with an autosomal recessive mode of inheritance. Although scattered myelin sheaths are present in some areas of the CNS, most notably the ventral spinal cord in the young neonatal rat, this myelin is gradually lost, and 8-12 weeks little myelin is present throughout the CNS....
Article
To determine the protective effects of perindopril treatment in the prevention of stroke and the relation between preventive effects and the histopathology of the brain and kidneys in male stroke-prone spontaneously hypertensive rats (SHRSP). Prospective animal study. Beginning at 6 weeks of age, SHRSP were treated with either distilled water (cont...