Therapeutic Potential of Targeting p27kip1 in Plaque Vulnerability

Atherosclerosis, a critical contributor to coronary artery diseases, involves the accumulation of cholesterol, fibrin, and lipids within arterial walls, inciting inflammatory reactions culminating in plaque formation. This multifaceted interplay encompasses excessive fibrosis, fatty plaque development, vascular smooth muscle cell (VSMC) proliferation, and leukocyte migration in response to inflammatory pathways. While stable plaques demonstrate resilience against complications, vulnerable ones, with lipid-rich cores, necrosis, and thin fibrous caps, lead to thrombosis, myocardial infarction, stroke, and acute cerebrovascular accidents. The nuanced phenotypes of VSMCs, modulated by gene regulation and environmental cues, remain pivotal. Essential markers like alpha-SMA, myosin heavy chain, and calponin regulate VSMC migration and contraction, exhibiting diminished expression during VSMC de-differentiation and proliferation. p27kip, a CDK inhibitor, shows promise in regulating VSMC proliferation and appears associated with TNF-α-induced pathways impacting unstable plaques. Oncostatin M (OSM), an IL-6 family cytokine, correlates with MMP upregulation and foam cell formation, influencing plaque development. Efforts targeting mammalian target of rapamycin (mTOR) inhibition, notably using rapamycin and its analogs, demonstrate potential but pose challenges due to associated adverse effects. Exploration of the impact of p27kip impact on plaque macrophages presents promising avenues, yet its complete therapeutic potential remains untapped. Similarly, while OSM has exhibited potential in inducing cell cycle arrest via p27kip, direct links necessitate further investigation. This critical review discusses the role of mTOR, p27kip, and OSM in VSMC proliferation and differentiation followed by the therapeutic potential of targeting these mediators in atherosclerosis to attenuate plaque vulnerability.

Research Note: Bovine lactoferrin in chickens: an investigation into its viability as an antibiotic alternative

Finding effective antibiotic alternatives is crucial to managing the re-emerging health risk of Clostridium perfringens (CP) type A/G-induced avian necrotic enteritis (NE), a disease that has regained prominence in the wake of governmental restrictions on antibiotic use in poultry. Known for its antimicrobial and immunomodulatory effects, the use of bovine lactoferrin (bLF) in chickens is yet to be fully explored. In this study, we hypothesized that bLF can accumulate in the small intestines of healthy chickens through gavage and intramuscular supplementation and serves as a potential antibiotic alternative. Immunohistochemistry located bLF in various layers of the small intestines and ELISA testing confirmed its accumulation. Surprisingly, sham-treated chickens also showed the presence of bLF, prompting a western blotting analysis that dismissed the notion of cross-reactivity between bLF and the avian protein ovotransferrin. Although the significance of the route of administration remains inconclusive, this study supports the hypothesis that bLF is a promising and safe antibiotic alternative with demonstrated resistance to the degradative environment of the chicken intestines. Further studies are needed to determine its beneficial pharmacological effects in CP-infected chickens.

Modulation of Inflammatory Response by Electromagnetic Field Stimulation in Traumatic Brain Injury in Yucatan Swine

Traumatic brain injury is a leading cause of disability and death worldwide and represents a high economic burden for families and national health systems. After mechanical impact to the head, the first stage of the damage comprising edema, physical damage, and cell loss gives rise to a second phase characterized by glial activation, increased oxidative stress and excitotoxicity, mitochondrial damage, and exacerbated neuroinflammatory state, among other molecular calamities. Inflammation strongly influences the molecular events involved in the pathogenesis of TBI. Therefore, several components of the inflammatory cascade have been targeted in experimental therapies. Application of Electromagnetic Field (EMF) stimulation has been found to be effective in some inflammatory conditions. However, its effect in the neuronal recovery after TBI is not known. In this pilot study, Yucatan miniswine were subjected to TBI using controlled cortical impact approach. EMF stimulation via a helmet was applied immediately or two days after mechanical impact. Three weeks later, inflammatory markers were assessed in the brain tissues of injured and contralateral non-injured areas of control and EMF-treated animals by histomorphometry, immunohistochemistry, RT-qPCR, Western blot, and ELISA. Our results revealed that EMF stimulation induced beneficial effect with the preservation of neuronal tissue morphology as well as the reduction of inflammatory markers at the transcriptional and translational levels. Immediate EMF application showed better resolution of inflammation. Although further studies are warranted, our findings contribute to the notion that EMF stimulation could be an effective therapeutic approach in TBI patients.

Increased Oxidative Stress and Decreased Sirtuin-3 and FOXO3 Expression Following Carotid Artery Intimal Injury in Hyperlipidemic Yucatan Microswine

Hypercholesterolemia is a major risk factor for atherosclerosis as oxidized-low-density lipoproteins (ox-LDL) contribute to the formation of foam cells and inflammation. Increased immune cell infiltration and oxidative stress induce instability of a plaque. Rupture of the unstable plaque precipitates adverse ischemic events. Since reactive oxygen species (ROS) play a critical role in plaque formation and vulnerability, regulating ROS generation may have therapeutic potential. Sirtuins, specifically sirtuin-3 (SIRT3), are antigenic molecules that can reduce oxidative stress by reducing mitochondrial ROS production through epigenetic modulation. Lack of SIRT3 expression is associated with dysregulation of ROS and endothelial function following high-fat high-cholesterol diet. SIRT3 deacetylates FOXO3a (Forkhead transcription factor O subfamily member 3a) and protects mitochondria against oxidative stress which can lead to even further protective anti-oxidizing properties. This study was designed to investigate the association between hyperlipidemia, intimal injury, chronic inflammation, and the expression of NAD-dependent deacetylase SIRT-3, FOXO3, antioxidant genes, and oxidative stress in carotid arteries of hypercholesterolemic Yucatan microswine. We found that intimal injury in hypercholesterolemic state led to increased expression of oxidative stress, inflammation, neointimal hyperplasia, and plaque size and vulnerability, while decreasing anti-oxidative regulatory genes and mediators. The findings suggest that targeting the SIRT3-FOXO3a-oxidative stress pathway will have therapeutic significance.

Role of sirtuins in attenuating plaque vulnerability in atherosclerosis

Atherosclerosis is characterized by the development of intimal plaque, thrombosis, and stenosis of the vessel lumen causing decreased blood flow and hypoxia precipitating angina. Chronic inflammation in the stable plaque renders it unstable and rupture of unstable plaques results in the formation of emboli leading to hypoxia/ischemia to the organs by occluding the terminal branches and precipitate myocardial infarction and stroke. Such delibitating events could be controlled by the strategies that prevent plaque development or plaque stabilization. Despite the use of statins to stabilize plaques, there is a need for novel targets due to continuously increasing cases of cardiovascular events. Sirtuins (SIRTs), a family of signaling proteins, are involved in sustaining genome integrity, DNA damage response and repair, modulating oxidative stress, aging, inflammation, and energy metabolism. SIRTs play a critical role in modulating inflammation and involves in the development and progression of atherosclerosis. The role of SIRTs in relation to atherosclerosis and plaque vulnerability is scarcely discussed in the literature. Since SIRTs regulate oxidative stress, inflammation, and aging, they may also regulate plaque progression and vulnerability as these molecular mechanisms underlie the pathogenesis of plaque development, progression, and vulnerability. This review critically discusses the role of SIRTs in plaque progression and vulnerability and the possibility of targeting SIRTs to attenuate plaque rupture, focusing on the highlights in genomics, molecular pathways, and cell types involved in the underlying pathophysiology.

miRNA profiling of esophageal adenocarcinoma using transcriptome analysis

Esophageal adenocarcinoma (EAC) occurs following a series of histological changes through epithelial-mesenchymal transition (EMT). A variable expression of normal and aberrant genes in the tissue can contribute to the development of EAC through the activation or inhibition of critical molecular signaling pathways. Gene expression is regulated by various regulatory factors, including transcription factors and microRNAs (miRs). The exact profile of miRs associated with the pathogenesis of EAC is largely unknown, though some candidate miRNAs have been reported in the literature. To identify the unique miR profile associated with EAC, we compared normal esophageal tissue to EAC tissue using bulk RNA sequencing. RNA sequence data was verified using qPCR of 18 selected genes. Fourteen were confirmed as being upregulated, which include CDH11, PCOLCE, SULF1, GJA4, LUM, CDH6, GNA12, F2RL2, CTSZ, TYROBP, and KDELR3 as well as the downregulation of UGT1A1. We then conducted Ingenuity Pathway Analysis (IPA) to analyze for novel miR-gene relationships through Causal Network Analysis and Upstream Regulator Analysis. We identified 46 miRs that were aberrantly expressed in EAC compared to control tissues. In EAC tissues, seven miRs were associated with activated networks, while 39 miRs were associated with inhibited networks. The miR-gene relationships identified provide novel insights into potentially oncogenic molecular pathways and genes associated with carcinogenesis in esophageal tissue. Our results revealed a distinct miR profile associated with dysregulated genes. The miRs and genes identified in this study may be used in the future as biomarkers and serve as potential therapeutic targets in EAC.

Mitochondrial Biogenesis as a Therapeutic Target for Rotator Cuff Tendon Tears

Rotator Cuff Injuries (RCI) are highly prevalent and characterized by shoulder pain, restricted shoulder movement, and difficulty with overhead activity, radiating pain in the deltoid muscle, and atrophy of the rotator cuff muscles. Increasing age, hand dominance, smoking, hypertension, hyperlipidemia, and obesity are common risk factors. Chronic inflammation plays a critical role in the underlying pathogenesis. RCI accounts for massive healthcare expenditure costing about $15,000 per repair, and over 4.5 million physician visits per year, however, there is still no therapeutic target to improve clinical outcomes. Mitochondrial biogenesis in response to inflammatory stimuli supports increased cellular energy requirements, cell proliferation, and differentiation. This suggests that mitochondrial biogenesis may play a role in healing RCI by serving as a protective factor against free oxygen species and promoting homeostasis within the rotator cuff. There is evidence highlighting the potential therapeutic benefits of mitochondrial biogenesis in various inflammatory diseases, but no study explored the role of mitochondrial biogenesis in rotator cuff tears. Since hypercholesterolemia is a risk factor for RCI, we investigated the effects of hypercholesterolemia on the expression of PGC-1α, a marker of mitochondrial biogenesis, in rotator cuff muscle. The findings revealed an increased gene and protein expression of inflammatory mediators and PGC-1α, suggesting enhanced inflammation and increased mitochondrial biogenesis due to hypercholesterolemia. Additional studies are warranted to further investigate the chronic effect of hyperlipidemia induced RCI to elucidate the cause of insufficient mitochondrial biogenesis unable to protect the rotator cuff and the therapeutic effect of promoting mitochondrial biogenesis.

Role of oncostatin-M in ECM remodeling and plaque vulnerability

Atherosclerosis is a multifactorial inflammatory disease characterized by the development of plaque formation leading to occlusion of the vessel and hypoxia of the tissue supplied by the vessel. Chronic inflammation and altered collagen expression render stable plaque to unstable and increase plaque vulnerability. Thinned and weakened fibrous cap results in plaque rupture and formation of thrombosis and emboli formation leading to acute ischemic events such as stroke and myocardial infarction. Inflammatory mediators including TREM-1, TLRs, MMPs, and immune cells play a critical role in plaque vulnerability. Among the other inflammatory mediators, oncostatin-M (OSM), a pro-inflammatory cytokine, play an important role in the development and progression of atherosclerosis, however, the role of OSM in plaque vulnerability and extracellular matrix remodeling (ECM) is not well understood and studied. Since ECM remodeling plays an important role in atherosclerosis and plaque vulnerability, a detailed investigation on the role of OSM in ECM remodeling and plaque vulnerability is critical. This is important because the role of OSM has been discussed in the context of proliferation of vascular smooth muscle cells and regulation of cytokine expression but the role of OSM is scarcely discussed in relation to ECM remodeling and plaque vulnerability. This review focuses on critically discussing the role of OSM in ECM remodeling and plaque vulnerability.

COVID-19 and Kidney: The Importance of Follow-Up and Long-Term Screening

Renal involvement and kidney injury are common in COVID-19 patients, and the symptoms are more severe if the patient already has renal impairment. Renal involvement in COVID-19 is multifactorial, and the renal tubule is mainly affected, along with podocyte injury during SARS-CoV-2 infection. Inflammation, complement activation, hypercoagulation, and crosstalk between the kidney and lungs, brain, and heart are contributory factors. Kidney injury during the acute phase, termed acute kidney injury (AKI), may proceed to chronic kidney disease if the patient is discharged with renal impairment. Both AKI and chronic kidney disease (CKD) increase mortality in COVID-19 patients. Further, COVID-19 infection in patients suffering from CKD is more severe and increases the mortality rate. Thus, it is important to address both categories of patients, either developing AKI or CKD after COVID-19 or previously having CKD, with proper management and treatment. This review discusses the pathophysiology involved in AKI and CKD in COVID-19 infection, followed by management and treatment of AKI and CKD. This is followed by a discussion of the importance of screening and treatment of CKD patients infected with COVID-19 and future perspectives to improve treatment in such patients.

A Review of Hematological Complications and Treatment in COVID-19

COVID-19, caused by SARS-CoV-2, and its variants have spread rapidly across the globe in the past few years, resulting in millions of deaths worldwide. Hematological diseases and complications associated with COVID-19 severely impact the mortality and morbidity rates of patients; therefore, there is a need for oversight on what pharmaceutical therapies are prescribed to hematologically at-risk patients. Thrombocytopenia, hemoglobinemia, leukopenia, and leukocytosis are all seen at increased rates in patients infected with COVID-19 and become more prominent in patients with severe COVID-19. Further, COVID-19 therapeutics may be associated with hematological complications, and this became more important in immunocompromised patients with hematological conditions as they are at higher risk of hematological complications after treatment. Thus, it is important to understand and treat COVID-19 patients with underlying hematological conditions with caution. Hematological changes during COVID-19 infection and treatment are important because they may serve as biomarkers as well as to evaluate the treatment response, which will help in changing treatment strategies. In this literature review, we discuss the hematological complications associated with COVID-19, the mechanisms, treatment groups, and adverse effects of commonly used COVID-19 therapies, followed by the hematological adverse events that could arise due to therapeutic agents used in COVID-19.

Novel mediators regulating angiogenesis in diabetic foot ulcer healing

A non-healing diabetic foot ulcer (DFU) is a debilitating clinical problem amounting to socioeconomic and psychosocial burdens. DFUs increase morbidity due to prolonged treatment and mortality in the case of non-treatable ulcers resulting in gangrene and septicemia. The overall amputation rate of the lower extremity with DFU ranges from 3.34% to 42.83%. Wound debridement, antibiotics, applying growth factors, negative pressure wound therapy, hyperbaric oxygen therapy, topical oxygen, and skin grafts are common therapies for DFU. However, recurrence and nonhealing ulcers are still major issues. Chronicity of inflammation, hypoxic environment, poor angiogenesis, and decreased formation of the extracellular matrix (ECM) are common impediments leading to nonhealing patterns of DFUs. Angiogenesis is crucial for wound healing since proper vessel formation facilitates nutrients, oxygen, and immune cells to the ulcer tissue to help in clearing out debris and facilitate healing. However, poor angiogenesis due to decreased expression of angiogenic mediators and matrix formation results in nonhealing and ultimately amputation. Multiple proangiogenic mediators and vascular endothelial growth factor (VEGF) therapy exist to enhance angiogenesis, but the results are not satisfactory. Thus, there is a need to investigate novel pro-angiogenic mediators that can either alone or in combination enhance the angiogenesis and healing of DFUs. In this article, we critically reviewed the existing pro-angiogenic mediators followed by potentially novel factors that might play a regulatory role in promoting angiogenesis and wound healing in DFUs.

Oxidized Low-density Lipoproteins and Lipopolysaccharides Augment Carotid Artery Plaque Vulnerability in Hypercholesterolemic Microswine

Atherosclerosis is a chronic inflammatory disease and hypercholesterolemia is a risk factor. This study aims to compare the potency of lipopolysaccharide (LPS) and oxidized low-density lipoproteins (oxLDL) to induce plaque formation and increase plaque vulnerability in the carotid artery of hypercholesterolemic Yucatan microswine. Atherosclerotic lesions at the common carotid artery junction and ascending pharyngeal artery were induced in hypercholesterolemic Yucatan microswine at 5-6 months of age with balloon angioplasty. LPS or oxLDL were administered intraluminally at the site of injury after occluding the arterial flow temporarily. Pre-intervention ultrasound (US), angiography, and optical coherence tomography (OCT) were done at baseline and just before euthanasia to assess post-op parameters. The images from the US, OCT, and angiography in the LPS and the oxLDL-treated group showed increased plaque formation with features suggestive of unstable plaque, including necrotic core, thin fibrous caps, and a signal poor region more with oxLDL compared to LPS. Histomorphology of the carotid artery tissue near the injury corroborated the presence of severe lesions in both LPS and oxLDL-treated pigs but more in the oxLDL group. Vascular smooth muscle and endothelial cells treated with LPS and oxLDL showed increased folds changes in mRNA transcripts of the biomarkers of inflammation and plaque vulnerability compared to untreated cells. Collectively, the results suggest that angioplasty-mediated intimal injury of the carotid arteries in atherosclerotic swine with local administration of LPS or ox-LDL induces vulnerable plaques compared to angioplasty alone and oxLDL is relatively more potent than LPS in inducing vulnerable plaque.

Biomarkers to monitor the prognosis, disease severity, and treatment efficacy in coronary artery disease

INTRODUCTION

Coronary Artery Disease (CAD) is a prevalent condition characterized by the presence of atherosclerotic plaques in the coronary arteries of the heart. The global burden of CAD has increased significantly over the years, resulting in millions of deaths annually and making it the leading health-care expenditure and cause of mortality in developed countries. The lack of cost-effective strategies for monitoring the prognosis of CAD warrants a pressing need for accurate and efficient markers to assess disease severity and progression for both reducing health-care costs and improving patient outcomes.

AREA COVERED

To effectively monitor CAD, prognostic biomarkers and imaging techniques play a vital role in risk-stratified patients during acute treatment and over time. However, with over 1,000 potential markers of interest, it is crucial to identify the key markers with substantial utility in monitoring CAD progression and evaluating therapeutic interventions. This review focuses on identifying and highlighting the most relevant markers for monitoring CAD prognosis and disease severity. We searched for relevant literature using PubMed and Google Scholar.

EXPERT OPINION

By utilizing the markers discussed, health-care providers can improve patient care, optimize treatment plans, and ultimately reduce health-care costs associated with CAD management.

Role of Transcription Factors and MicroRNAs in Regulating Fibroblast Reprogramming in Wound Healing

Non-healing diabetic foot ulcer, a chronic inflammatory disease, is a sizable clinical and economic burden to healthcare systems around the world. Chronic inflammation plays a critical role in the nonhealing pattern due to the arrest of the cellular response during wound healing in the inflammatory phase without progressing to the proliferative and remodeling phase. Fibroblasts play a critical role in all three phases of wound healing. Activation of fibroblasts in the presence of cytokines results in the formation of myofibroblast that contributes to extracellular matrix formation. Additionally, few studies documented the presence of inflammatory, angiogenic, and angiostatic fibroblast subpopulation during wound healing. Various studies have discussed the role of transcription factors and microRNA in regulating the transdifferentiation of fibroblast to myofibroblast, however, what factors regulate the reprogramming of fibroblast to inflammatory, angiogenic, and angiostatic phenotypes have not been clearly addressed in the literature. This critical review article addresses the role of transcription factors and microRNAs in regulating fibroblast to myofibroblast transdifferentiation followed by the prediction of transcription factors and microRNAs, based on the bioinformatics analysis, in regulating transdifferentiation of fibroblasts to inflammatory, angiogenic, and angiostatic subtypes. The results of in-silico networking revealed multiple new transcription factors and microRNAs and their interaction with specific markers on other fibroblasts suggesting their role in the regulation of fibroblast reprogramming.

Oncostatin M, Serpins, and Oxidative Stress in Extracellular Matrix Remodeling and Arteriovenous Fistula Maturation

End-stage renal disease is a crippling diagnosis that generally requires dialysis to prolong life. To facilitate filtration of patient's blood in dialysis, surgical formation of an arteriovenous fistula (AVF) is commonly performed. Maturation of the AVF is required to allow for successful dialysis. However, AVFs commonly fail to mature, leading to the fistula closure, the necessity for another fistula site, and markedly increased morbidity and mortality. The current literature concerning molecular mechanisms associated with AVF maturation failure supports the role of inflammatory mediators involving immune cells and inflammatory cytokines. However, the role of oncostatin M (OSM), an inflammatory cytokine, and its downstream targets are not well investigated. Through inflammation, oxidative stress, and hypoxic conditions, the vascular tissue surrounding the AVF undergoes fibrosis, stenosis, and wall thickening, leading to complete occlusion and nonfunctional. In this report, first we critically review the existing literature on the role of OSM in the most common causes of early AVF failure - vascular inflammation, thrombosis, and stenosis. We next consider the potential of using OSM as a therapeutic target, and finally discuss therapeutic agents targeting inflammatory mediators involved in OSM signaling to potentiate successful maturation of the AVF.

Cholesterol: An Important Determinant of Muscle Atrophy in Astronauts

Since cholesterol is not routinely measured in astronauts before and after their return from space, there is no data on the role of blood cholesterol level in muscle atrophy and microgravity. Since the first moon landing, aerospace medicine became outdated and has not pushed boundaries like its rocket engineering counterpart. Since the 2019 astronaut twin study, there has yet to be another scientific breakthrough for aerospace medicine. Microgravity-induced muscle atrophy is the most known consequence of spaceflight. Yet, so far, there is no therapeutic solution to prevent it or any real efforts in understanding it on a cellular or molecular level. The most obvious reason to this unprecedented level of research is due to the small cohort of astronauts. With the establishment of private space industries and exponential recruitment of astronauts, there is more reason to push forward spaceflight-related health guidelines and ensure the safety of the brave humans who risk their lives for the progression of mankind. Spaceflight is considered the most challenging job and the failure to prevent injury or harm should be considered reckless negligence by the institutions that actively prevented sophistication of aerospace medicine. In this critical review, role of cholesterol is analyzed across the NASA-established parameters of microgravity-induced muscle atrophy with a focus on potential therapeutic targets for research.

Mitochondrial Metabolism in Pancreatic Ductal Adenocarcinoma: From Mechanism-Based Perspectives to Therapy

Pancreatic ductal adenocarcinoma (PDAC), the fourteenth most common malignancy, is a major contributor to cancer-related death with the utmost case fatality rate among all malignancies. Functional mitochondria, regardless of their complex ecosystem relative to normal cells, are essential in PDAC progression. Tumor cells' potential to produce ATP as energy, despite retaining the redox potential optimum, and allocating materials for biosynthetic activities that are crucial for cell growth, survival, and proliferation, are assisted by mitochondria. The polyclonal tumor cells with different metabolic profiles may add to carcinogenesis through inter-metabolic coupling. Cancer cells frequently possess alterations in the mitochondrial genome, although they do not hinder metabolism; alternatively, they change bioenergetics. This can further impart retrograde signaling, educate cell signaling, epigenetic modifications, chromatin structures, and transcription machinery, and ultimately satisfy cancer cellular and nuclear demands. To maximize the tumor microenvironment (TME), tumor cells remodel nearby stromal cells and extracellular matrix. These changes initiate polyclonality, which is crucial for growth, stress response, and metastasis. Here, we evaluate all the intrinsic and extrinsic pathways drawn by mitochondria in carcinogenesis, emphasizing the perspectives of mitochondrial metabolism in PDAC progression and treatment.

Role of fibroblast plasticity and heterogeneity in modulating angiogenesis and healing in the diabetic foot ulcer

Chronic diabetic foot ulcers (DFUs) are an important clinical issue faced by clinicians despite the advanced treatment strategies consisting of wound debridement, off-loading, medication, wound dressings, and keeping the ulcer clean. Non-healing DFUs are associated with the risk of amputation, increased morbidity and mortality, and economic stress. Neo-angiogenesis and granulation tissue formation are necessary for physiological DFU healing and acute inflammation play a key role in healing. However, chronic inflammation in association with diabetic complications holds the ulcer in the inflammatory phase without progressing to the resolution phase contributing to non-healing. Fibroblasts acquiring myofibroblasts phenotype contribute to granulation tissue formation and angiogenesis. However, recent studies suggest the presence of five subtypes of fibroblast population and of changing density in non-healing DFUs. Further, the association of fibroblast plasticity and heterogeneity with wound healing suggests that the switch in fibroblast phenotype may affect wound healing. The fibroblast phenotype shift and altered function may be due to the presence of chronic inflammation or a diabetic wound microenvironment. This review focuses on the role of fibroblast plasticity and heterogeneity, the effect of hyperglycemia and inflammatory cytokines on fibroblasts, and the interaction of fibroblasts with other cells in diabetic wound microenvironment in the perspective of DFU healing. Next, we summarize secretory, angiogenic, and angiostatic phenotypes of fibroblast which have been discussed in other organ systems but not in relation to DFUs followed by the perspective on the role of their phenotypes in promoting angiogenesis in DFUs.

Future applications of exosomes delivering resolvins and cytokines in facilitating diabetic foot ulcer healing

Type 2 diabetes mellitus (T2DM) increases the risk of many lethal and debilitating conditions. Among them, foot ulceration due to neuropathy, vascular disease, or trauma affects the quality of life of millions in the United States and around the world. Physiological wound healing is stalled in the inflammatory phase by the chronicity of inflammation without proceeding to the resolution phase. Despite advanced treatment, diabetic foot ulcers (DFUs) are associated with a risk of amputation. Thus, there is a need for novel therapies to address chronic inflammation, decreased angiogenesis, and impaired granulation tissue formation contributing to the non-healing of DFUs. Studies have shown promising results with resolvins (Rv) and anti-inflammatory therapies that resolve inflammation and enhance tissue healing. But many of these studies have encountered difficulty in the delivery of Rv in terms of efficiency, tissue targetability, and immunogenicity. This review summarized the perspective of optimizing the therapeutic application of Rv and cytokines by pairing them with exosomes as a novel strategy for targeted tissue delivery to treat non-healing chronic DFUs. The articles discussing the T2DM disease state, current research on Rv for treating inflammation, the role of Rv in enhancing wound healing, and exosomes as a delivery vehicle were critically reviewed to find support for the proposition of using Rv and exosomes in combination for DFUs therapy. The literature reviewed suggests the beneficial role of Rv and exosomes and exosomes loaded with anti-inflammatory agents as promising therapeutic agents in ulcer healing.

Regulation of Collagen I and Collagen III in Tissue Injury and Regeneration

The structure of connective tissues including cartilage, tendons, and ligaments as well as many organs, like the skin, heart, liver, kidney, lungs, blood vessels, and bones, depend on collagen. The bulk of the network of structural proteins that make up the extracellular matrix of the heart is composed of collagen type I and type III, which provide structural support for the muscle cells and are crucial for cardiac function. The prognosis and progression of a disease or diseased state may be significantly impacted by the upregulation or downregulation of the collagen types, particularly Col I and Col III. For example, increasing Col I protein levels may impose increasing myocardial stiffness, impairing the diastolic and systolic function of the myocardium. Collagen I is a stiff fibrillar protein that gives tensile strength, whereas Col III produces an elastic network that stores kinetic energy as an elastic rebound. These two collagen proteins have distinct physical properties in nature. Therefore, the control of Col I and Col III as well as the potential relevance of the Col I/Col III ratio in many biological processes serve as the foundation for this comprehensive review article.

Increased Population of CD40+ Fibroblasts Is Associated with Impaired Wound Healing and Chronic Inflammation in Diabetic Foot Ulcers

Despite the advancement in the treatment, nonhealing diabetic foot ulcers (DFUs) are an important clinical issue accounting for increased morbidity and risk of amputation. Persistent inflammation, decreased granulation tissue formation, decreased neo-angiogenesis, and infections are common underlying causes of the nonhealing pattern. Fibroblasts play a critical role in granulation tissue formation and angiogenesis and mediate wound healing how fibroblasts regulate inflammation in nonhealing DFUs is a question to ponder. This study aims to investigate the expression of a de-differentiated subpopulation of fibroblasts which are CD40+ (secretory fibroblasts) and increased secretion of IL-6 and IL-8 but have never been reported in DFUs. We characterized 11 DFU tissues and nearby clean tissues histologically and for the presence of inflammation and CD40+ fibroblasts using immunohistochemistry and RT-PCR. The results revealed significantly increased density of CD40+ fibroblasts and differential expression of mediators of inflammation in DFU tissues compared to clean tissue. Increased expression of IL-6, IL-1β, and TNF-α in DFU tissues along with CD40+ fibroblast suggest that CD40+ fibroblasts in DFUs contribute to the chronicity of inflammation and targeting fibroblasts phenotypic switch to decrease secretory fibroblasts may have therapeutic significance to promote healing.

Rotator Cuff Health, Pathology, and Repair in the Perspective of Hyperlipidemia

Rotator Cuff Injuries (RCI) are prevalent cause of shoulder pain affecting over 20% of the population in the USA. Surgical repair of the torn rotator cuff helps in relieving the pressure on the rotator cuff tendon and from symptoms, however tendon-to-bone healing after rotator cuff surgery still has a high failure rate. Hyperlipidemia has been strongly associated with RCI although the cellular and molecular mechanisms are largely unknown. The focus of this critical review is to further explore the role of hyperlipidemia in RCI and rotator cuff tissue repair to determine its implication as a risk factor for tears, repair, and retears. A literature review was conducted to elucidate the role of hyperlipidemia as an inflammatory mediator and catalyst for structural instability within the shoulder. The results from various studies were critically reviewed to summarize the relationship between hyperlipidemia and rotator cuff pathology. Hyperlipidemia induces LDL-particle entrapment within the dense regular collagen of rotator cuff tendons resulting in foam cell aggregation and macrophage recruitment. Subsequent inflammatory pathways including the JAK2/STAT3 pathway and NLRP3 inflammasome pathway led to persistent inflammation and Extracellular Matrix (ECM) degradation within the rotator cuff. While arthroscopic repair remains the most common treatment modality, nonsurgical treatment including statins, vitamin D, and targeting miRNA are also of therapeutic benefit. Hyperlipidemia interferes with arthroscopic repairs by inducing inflammation and stiffness within tendons and increases the risk of retears. Most notably, targeting underlying mechanisms influencing inflammation has large therapeutic value as a novel treatment strategy for the management of rotator cuff pathology.

Targeting the Crosstalk of Immune Response and Vascular Smooth Muscle Cells Phenotype Switch for Arteriovenous Fistula Maturation

Plaque formation, thrombosis, and embolism are the underlying causes of acute cardiovascular events such as myocardial infarction and stroke while early thrombosis and stenosis are common pathologies for the maturation failure of arteriovenous fistula (AVF). Chronic inflammation is a common underlying pathogenesis mediated by innate and adaptive immune response involving infiltration of immune cells and secretion of pro- and anti-inflammatory cytokines. Impaired immune cell infiltration and change in vascular smooth muscle cell (VSMC) phenotype play a crucial role in the underlying pathophysiology. However, the change in the phenotype of VSMCs in a microenvironment of immune cell infiltration and increased secretion of cytokines have not been investigated. Since change in VSMC phenotype regulates vessel remodeling after intimal injury, in this study, we investigated the effect of macrophages and pro-inflammatory cytokines, IL-6, IL-1β, and TNF-α, on the change in VSMC phenotype under in vitro conditions. We also investigated the expression of the markers of VSMC phenotypes in arteries with atherosclerotic plaques and VSMCs isolated from control arteries. We found that the inhibition of cytokine downstream signaling may mitigate the effect of cytokines on the change in VSMCs phenotype. The results of this study support that regulating or targeting immune cell infiltration and function might be a therapeutic strategy to mitigate the effects of chronic inflammation to attenuate plaque formation, early thrombosis, and stenosis, and thus enhance AVF maturation.

Gut-brain communication in COVID-19: molecular mechanisms, mediators, biomarkers, and therapeutics

INTRODUCTION

Infection with COVID-19 results in acute respiratory symptoms followed by long COVID multi-organ effects presenting with neurological, cardiovascular, musculoskeletal, and gastrointestinal (GI) manifestations. Temporal relationship between gastrointestinal and neurological symptoms is unclear but warranted for exploring better clinical care for COVID-19 patients.

AREAS COVERED

We critically reviewed the temporal relationship between gut-brain axis after SARS-CoV-2 infection and the molecular mechanisms involved in neuroinvasion following GI infection. Mediators are identified that could serve as biomarkers and therapeutic targets in SARS-CoV-2. We discussed the potential therapeutic approaches to mitigate the effects of GI infection with SARS-CoV-2.

EXPERT OPINION

Altered gut microbiota cause increased expression of various mediators, including zonulin causing disruption of tight junction. This stimulates enteric nervous system and signals to CNS precipitating neurological sequalae. Published reports suggest potential role of cytokines, immune cells, B(0)AT1 (SLC6A19), ACE2, TMRSS2, TMPRSS4, IFN-γ, IL-17A, zonulin, and altered gut microbiome in gut-brain axis and associated neurological sequalae. Targeting these mediators and gut microbiome to improve immunity will be of therapeutic significance. In-depth research and well-designed large-scale population-based clinical trials with multidisciplinary and collaborative approaches are warranted. Investigating the temporal relationship between organs involved in long-term sequalae is critical due to evolving variants of SARS-CoV-2.

Stem Cells and Angiogenesis: Implications and Limitations in Enhancing Chronic Diabetic Foot Ulcer Healing

Nonhealing diabetic foot ulcers (DFUs) are a continuing clinical issue despite the improved treatment with wound debridement, off-loading the ulcer, medication, wound dressings, and preventing infection by keeping the ulcer clean. Wound healing is associated with granulation tissue formation and angiogenesis favoring the wound to enter the resolution phase of healing followed by healing. However, chronic inflammation and reduced angiogenesis in a hyperglycemic environment impair the normal healing cascade and result in chronically non-healing diabetic foot ulcers. Promoting angiogenesis is associated with enhanced wound healing and using vascular endothelial growth factors has been proven beneficial to promote neo-angiogenesis. However, still, nonhealing DFUs persist with increased risks of amputation. Regenerative medicine is an evolving branch applicable in wound healing with the use of stem cells to promote angiogenesis. Various studies have reported promising results, but the associated limitations need in-depth research. This article focuses on summarizing and critically reviewing the published literature since 2021 on the use of stem cells to promote angiogenesis and enhance wound healing in chronic non-healing DFUs.

Heterogeneous Population of Immune cells Associated with Early Thrombosis in Arteriovenous Fistula

End-Stage Renal Disease (ESRD) is a growing cause of morbidity and mortality in the practice of modern medicine. Advances in medicine have elongated the average life span and subsequently made chronic diseases prevalent. Hemodialysis is the main treatment that is used to treat ESRD and is a clinical procedure that is being re-imagined with novel approaches to improve patient and clinic practicality and effectiveness. Arteriovenous Fistulas (AVF) are now used in place of catheters due to their higher success and lower co-morbidities. The main drawback of AVF is the time gap that is needed from the surgical creation of AVF to its use. During this time, the AVF is susceptible to thrombosis and occlusion rendering the fistula ineffective for treatment. Immune cells play a major role in vascular pathologies and macrophages, dendritic cells, and T-regulatory cells are the main cells seen during the inflammatory and anti-inflammatory phases. However, the role of immune response and immune cells in AVF maturation is poorly understood. This study aimed to investigate the immune response and immune cell expression in femoral vessels after AVF creation in a miniswine model of AVF using immunohistochemistry and qRT-PCR. The results of this study revealed an increased expression of immune cells in AVF vessels and suggest an association of immune response with AVF creation and maturation.

Diagnostic yield of calcofluor white in the identification of Candida albicans in oral squamous cell carcinoma

Background

Although oral cancer is multifactorial in origin only few had evaluated the diagnostic parameters for candidal infection in oral squamous cell carcinoma (OSCC).

Aims

To compare and assess the accuracy of Calcofluor White (CFW) to that of conventional staining methods to identify the presence of candidal infection in OSCC.

Methods

Archival collections of 43 OSCC were retrieved for this investigation. Standard staining protocol was followed for the index test (CFW) and reference standard (Periodic Acid Schiff). Two examiners were blinded for either one of the staining techniques. Diagnostic test evaluation and Kappa statistic was calculated using MedCalc software.

Results

The study comprised 37 males, six females, and their mean age at the time of presentation was 51 (range 23 to 75 years). The sensitivity and specificity of CFW was 75.8% (CI 57.7 to 88.9%) and 10.0% (CI 0.2 to 44.5%). While the positive predictive and negative predictive values were 63.1% (CI - 50.6-74.0%) and 67.0% (CI - 49.2-81.0%).

Conclusion

Our results show minimal agreement with PAS with a Kappa score of 0.148 (95% CI = 0.39 to 0.09). Overall detection rate was similar for both the index test and reference standard although there was considerable number of intermediate test results. Sensitivity of CFW was comparable to that of earlier studies but specificity was low and the degree of concordance was 60.4%. Although CFW staining can come with high false positive they are a useful test for ruling out candida infection when the test result is negative.

LPS and oxLDL-induced S100A12 and RAGE expression in carotid arteries of atherosclerotic Yucatan microswine

BACKGROUND

S100A12, also known as Calgranulin C, is a ligand for the receptor for advanced glycation end products (RAGE) and plays key roles in cardiovascular and other inflammatory diseases. Interactions between S100A12 and RAGE initiate downstream signaling activating extracellular signal-regulated kinases (ERK1/2), mitogen activated protein kinases (MAPK), and transcription factor NF-κB. This increases the expression of pro-inflammatory cytokines to induce the inflammatory response. S100A12, and RAGE play a critical role in the development and progression of atherosclerosis. There is a well-known relationship between the bacterial endotoxin lipopolysaccharide (LPS) and the lipid antigens oxidized low-density lipoprotein (oxLDL) in driving the immune response in atherosclerosis.

METHODS AND RESULTS

Our study aimed to compare the potential of LPS and oxLDL in regulating the expression of S100A12 and RAGE in atherosclerosis. The expression of these proteins was assessed in the harvested carotid arteries from LPS- and oxLDL-treated atherosclerotic Yucatan microswine. Tissues were collected from five different treatment groups: (i) angioplasty alone, (ii) LPS alone, (iii) oxLDL alone, (iv) angioplasty with LPS, and (v) angioplasty with oxLDL. Immunohistochemical findings revealed that angioplasty with LPS induced higher expression of S100A12 and RAGE compared to other treatment groups. The results were further corroborated by testing their gene expression through qPCR in cultured vascular smooth muscle cells (VSMCs) isolated from control carotid arteries and LPS- and oxLDL-treated arteries.

CONCLUSIONS

The results of this study suggest that LPS induces the expression of S100A12 and RAGE more than oxLDL in atherosclerotic artery and both S100A12 and RAGE could be therapeutic targets.

Innate and Adaptive Immune Cells Associates with Arteriovenous Fistula Maturation and Failure

Creation of arteriovenous fistula (AVF) causes local injury resulting in immune response of the body and infiltration of immune cells. Acute inflammation is favorable to control inflammation and proceed AVF towards maturation while chronic inflammation in AVF lead to AVF maturation failure. Chronic inflammation in AVF is due to chronic infiltration of immune cells and secretion of inflammatory cytokines. A balance between pro-inflammatory and anti-inflammatory response is must for AVF maturation and an overwhelmed proinflammatory infiltrate endue chronic inflammation and AVF failure. Since immune cell infiltration plays a critical role in maturation and failure of AVF, it is important to investigate the role of immune cells as well as their density in early and late phase of AVF maturation. The role of inflammation has been discussed in the literature and this review article focuses on the role of pro- and anti-inflammatory immune cells including macrophages, dendritic cells, T-cells, and T-regulatory cells in AVF maturation and maturation failure.

Counteractive Effects of IL-33 and IL-37 on Inflammation in Osteoarthritis

Osteoarthritis (OA) is a chronic inflammatory disease where pro-inflammatory cytokines, damage-associated molecular patterns (DAMPs), and macrophages play a crucial role. However, the interactive role of these mediators, the exact cause precipitating OA and definitive treatment for OA are not known yet. Moreover, the interactive role of interleukin (IL)-33 and IL-37 with other factors in the pathogenesis of OA has not been discussed elaborately. In this study, we analyzed the expression of IL-33 and IL-37 in human OA knee and hip joint cartilage tissues. The effect of increased DAMPs, IL-33, and IL-37 on IL-6, tumor necrosis factor (TNF)-α, toll-like receptors (TLRs), and matrix metalloproteinases (MMPs) expression was delineated using human normal and osteoarthritic chondrocytes. The effect of anti-inflammatory cytokine IL-37 on various mediators of inflammation in the presence of IL-33, rHMGB-1, and LPS was investigated to delineate the effects of IL-37. Further, the effects of blocking IL-33 downstream signaling and the effects of IL-33 and IL-37 on macrophage polarization were assessed along with examining the macrophage phenotypes in human OA cartilage tissues. The results of this study revealed increased expression of IL-33 in OA cartilage and that IL-33 increases IL-6, TNF-α, TLRs, and MMPs expression and favors phenotypic conversion towards the M1 phenotype, while IL-37 and blocking IL-33 receptor ST2 have opposite effects. Overall, the results suggest that blocking IL-33 and increasing IL-37 act synergistically to attenuate inflammation and might serve as potential therapeutics in OA.

Clinically relevant experimental rodent models of diabetic foot ulcer

Chronic wounds are a substantial clinical problem in diabetes and nearly 6% of diabetics suffer from foot disease including ulceration, infection, and tissue necrosis. Wound healing in diabetes is impaired and delayed and is augmented by diabetic complications. Wound healing involves complex cellular, molecular, and biochemical processes and animal models are the most suitable prototype to investigate and understand the underlying pathological changes in the process of wound healing. Animal models are also useful in evaluating the safety and efficacy of newer therapeutic agents and improving the clinical approaches for human patients with chronic ulcers. The wound healing strategies get more complicated in the presence of diabetes and its associated complication. Despite the advancement in methods of wound healing, the healing of the chronic diabetic foot ulcer (DFU) remains an important clinical problem resulting in costly and prolonged treatment and poses a risk for major amputation. Saying that it is important to elucidate the newer therapeutic targets and strategies via an in-depth understanding of the complicated cascade of the chronic DFU. A major challenge in translating lab findings to clinics is the lack of an optimal preclinical model capable of properly recapitulating human wounds. Both small and large animal models of wound healing involving rodents, rabbits, and pigs have been discussed. Mouse and rats as small animal models and pig as large animal models have been discussed in association with the diabetic wound but there are advantages and limitations for each model. In this review, we critically reviewed the pros and cons of experimental models of diabetic wound healing with a focus on type II diabetes rodent models.

Targets of immunotherapy for hepatocellular carcinoma: An update

Hepatocellular carcinoma, the most common primary liver cancer, in an immunogenic tumor with a poor prognosis because these tumors are diagnosed at late stages. Although, surgical resection, ablation, liver transplant, and locoregional therapies are available for early stages; however, there are yet no effective treatment for advanced and recurrent tumors. Immune checkpoint inhibitor therapy and adoptive cell transfer therapy has gained the popularity with some positive results because these therapies overcome anergy and systemic immune suppression. However, still there is a lack of an effective treatment and thus there is an unmet need of a novel treatment. At present, the focus of the research is on oncolytic viral therapy and combination therapy where therapies including radiotherapy, immune checkpoint therapy, adoptive cell transfer therapy, and vaccines are combined to get an additive or synergistic effect enhancing the immune response of the liver with a cytotoxic effect on tumor cells. This review discusses the recent key development, the basis of drug resistance, immune evasion, immune tolerance, the available therapies based on stage of the tumor, and the ongoing clinical trials on immune checkpoint inhibitor therapy, adoptive cell transfer therapy, oncolytic viral vaccine therapy, and combination therapy.

The role of CXCL8 in chronic nonhealing diabetic foot ulcers and phenotypic changes in fibroblasts: a molecular perspective

INTRODUCTION

A persistent inflammation is perpetuated by infiltrating immune cells and cytokines secreted from these immune cells. Additionally, apoptotic keratinocytes and adipocytes in diabetes causes diabetic foot ulcer (DFU) to arrest in an inflammatory phase without progressing to the resolution phase. This leads to a nonhealing DFU and, despite advanced treatments consisting of wound debridement, off-loading the ulcer of necrotic tissue, wound dressings to keep it moist and control exudate, medication, and preventing infection, DFUs remain a clinical problem. Nonhealing DFUs pose not only an economic burden but also increased morbidity and mortality in the form of psychological stress with and increased chance of amputation, and even death. Thus, investigating the complicated underlying molecular mechanism responsible for nonhealing patterns and designing better therapeutics is warranted. This review article focuses on the role of IL-8-mediated persistent inflammation and phenotypic change of fibroblasts due to this inflammatory cascade. We have discussed various sources of interleukin (IL)-8 secretion and the possible association of IL8-fibroblast plasticity as a cause of nonhealing DFUs.

MATERIAL AND METHODS

A literature search on PubMed, Google Scholar, and PMC was done including the terms diabetic foot ulcer, diabetes, diabetic ulcer, chronic inflammation, interleukin 8, diabetic wound, and nonhealing diabetic foot ulcers. The articles in the English language and published in last 10 years were selected. From the pool of these, the articles describing the relationship between IL-8 and nonhealing diabetic foot ulcer and diabetic ulcer were used sorted out and used for this review article following PRISMA guidelines.

CONCLUSION

Increased infiltration of inflammatory immune cells, secretion of pro-inflammatory cytokines, altered keratinocyte-fibroblast function, and phenotypic changes of fibroblasts in DFUs seem to be critical to the nonhealing of DFUs. Thus, inhibiting IL-8 secretion and downstream signaling seems to be a goal of potential therapeutics.

TLR-4 Inhibition Attenuates Inflammation, Thrombosis, and Stenosis in Arteriovenous Fistula in Yucatan Miniswine

Arteriovenous fistula (AVF) is the preferred vascular access in hemodialysis patients; however, it is afflicted with a high failure rate. Chronic inflammation, excessive neointimal hyperplasia (NIH), vessel stenosis, early thrombosis, and failure of outward remodeling are the major causes of AVF maturation failure. Inflammatory mediator toll-like receptor (TLR)-4 plays a critical role in NIH, arterial thrombosis, and stenosis. We investigated the effect of TLR-4 inhibition on early thrombosis. Yucatan miniswine were used to create AVF involving femoral artery and femoral vein and treated with TLR-4 inhibitor TAK-242 with ethanol as the vehicle. The vessels were assessed after 12 weeks using histomorphometry, immunostaining, ultrasound, angiography, and optical coherence tomography. Inhibition of TLR-4 attenuated inflammation and early thrombosis in 50% of animals, and blood flow was present through AVF in 25% of animals. Thus, targeting TLR-4 to attenuate inflammation and early thrombosis might be a therapeutic approach to keep AVF patent and maintain blood flow through the outflow vein.

Translational and Clinical Significance of DAMPs, PAMPs, and PRRs in Trauma-induced Inflammation

Increased morbidity and mortality after polytrauma due to multiple organ failure (MOF) is a major concern for clinicians. Systemic inflammatory response syndrome (SIRS) and sepsis are the major underlying causes. Damage-associated molecular proteins (DAMPs) released after polytrauma induce an inflammatory immune response to repair the tissue, however, persistent inflammation finally results in immunosuppression and MOF. During immunosuppression, additional exposure of the traumatized tissue to pattern-associated molecular patterns (PAMPs) further adds to the continuum of inflammatory cascade causing sepsis. These two hits worsen the condition of the patient and increase morbidity and mortality. Thus, it is critical to stratify the patient based on trauma severity and inflammatory biomarkers levels and design treatment accordingly for a better clinical outcome. Although some of the molecular mechanisms involved in SIRS and MOF after polytrauma have been reported, there is limited information on the critical factors related to the study of DAMPs and PAMPs, including the timing of sampling (time elapsed after trauma), source of sampling (blood, urine, saliva), proteomics and metabolomics, multiplex plasma assay, comparative interpretation of the results from various sources and diagnostic value, and interpretation on the translational and clinical significance. Additionally, there is limited literature on DAMPs like heat shock proteins, mitochondrial DNA, neutrophil extracellular traps, and their role in SIRS and MOF. Further, it is also important to distinguish between the biomarkers of SIRS and sepsis in a time-bound window to have a better clinical outcome. This critical review focuses on these aspects to provide comprehensive information and thought-provoking discussion to design future investigation and clinical trials.

Molecular Pathways Modulating Sensory Hair Cell Regeneration in Adult Mammalian Cochleae: Progress and Perspectives

Noise-induced, drug-related, and age-related disabling hearing loss is a major public health problem and affect approximately 466 million people worldwide. In non-mammalian vertebrates, the death of sensory hair cells (HCs) induces the proliferation and transdifferentiation of adjacent supporting cells into new HCs; however, this capacity is lost in juvenile and adult mammalian cochleae leading to permanent hearing loss. At present, cochlear implants and hearing devices are the only available treatments and can help patients to a certain extent; however, no biological approach or FDA-approved drug is effective to treat disabling hearing loss and restore hearing. Recently, regeneration of mammalian cochlear HCs by modulating molecular pathways or transcription factors has offered some promising results, although the immaturity of the regenerated HCs remains the biggest concern. Furthermore, most of the research done is in neonates and not in adults. This review focuses on critically summarizing the studies done in adult mammalian cochleae and discusses various strategies to elucidate novel transcription factors for better therapeutics.

TUB and ZNF532 Promote the Atoh1-Mediated Hair Cell Regeneration in Mouse Cochleae

Hair cell (HC) regeneration is a promising therapy for permanent sensorineural hearing loss caused by HC loss in mammals. Atoh1 has been shown to convert supporting cells (SCs) to HCs in neonatal cochleae; its combinations with other factors can improve the efficiency of HC regeneration. To identify additional transcription factors for efficient Atoh1-mediated HC regeneration, here we optimized the electroporation procedure for explant culture of neonatal mouse organs of Corti and tested multiple transcription factors, Six2, Ikzf2, Lbh, Arid3b, Hmg20 a, Tub, Sall1, and Znf532, for their potential to promote Atoh1-mediated conversion of SCs to HCs. These transcription factors are expressed highly in HCs but differentially compared to the converted HCs based on previous studies, and are also potential co-reprograming factors for Atoh1-mediated SC-to-HC conversion by literature review. P0.5 cochlear explants were electroporated with these transcription factors alone or jointly with Atoh1. We found that Sox2+ progenitors concentrated within the lateral greater epithelial ridge (GER) can be electroporated efficiently with minimal HC damage. Atoh1 ectopic expression promoted HC regeneration in Sox2+ lateral GER cells. Transcription factors Tub and Znf532, but not the other six tested, promoted the HC regeneration mediated by Atoh1, consistent with previous studies that Isl1 promotes Atoh1-mediated HC conversionex vivo and in vivo and that both Tub and Znf532 are downstream targets of Isl1. Thus, our studies revealed an optimized electroporation method that can transfect the Sox2+ lateral GER cells efficiently with minimal damage to the endogenous HCs. Our results also demonstrate the importance of the Isl1/Tub/Znf532 pathway in promoting Atoh1-mediated HC regeneration.

Fibrolipomatous Hamartoma of Median Nerve - A Diagnostic Challenge

INTRODUCTION

Fibrolipomatous hamartoma (FLH) is an uncommon slow-growing tumor of benign etiology, which predominantly affects the median nerve.

CASE REPORT

We report the case study of a 17-year-old male patient, who presented with complaints of a gradually increasing localized swelling over the volar aspect of left hand for 1 year. A contrast-enhanced Magnetic resonance (MR) scan of the left hand was performed which demonstrated characteristic findings. The patient was treated surgically and post-excision histopathological examination confirmed the diagnosis.

CONCLUSION

The characteristic MR imaging features of coaxial cable-like appearance on axial section or spaghetti shaped enlarged nerve fascicles and fibrous tissue is confirmatory for a definitive diagnosis of FLH, which alleviates the need for any unnecessary biopsy.

IL-33, IL-37, and Vitamin D Interaction Mediate Immunomodulation of Inflammation in Degenerating Cartilage

Chronic joint inflammation due to increased secretion of pro-inflammatory cytokines, the accumulation of inflammatory immune cells (mainly macrophages), and vitamin D deficiency leads to cartilage degeneration and the development of osteoarthritis (OA). This study investigated the effect of vitamin D status on the expression of mediators of inflammation including interleukin (IL)-33, IL-37, IL-6, tumor necrosis factor (TNF)-α, toll-like receptors (TLRs), damage-associated molecular patterns (DAMPs), and matrix metalloproteinases (MMPs) in degenerating the cartilage of hyperlipidemic microswine. Additionally, in vitro studies with normal human chondrocytes were conducted to investigate the effect of calcitriol on the expression of IL-33, IL-37, IL-6, TNF-α, TLRs, DAMPs, and MMPs. We also studied the effects of calcitriol on macrophage polarization using THP-1 cells. The results of this study revealed that vitamin D deficiency is associated with an increased expression of IL-33, IL-37, IL-6, TNF-α, TLRs, DAMPs, and MMPs, while vitamin D supplementation is associated with a decreased expression of the former. Additionally, vitamin D deficiency is associated with increased M1, while vitamin D-supplemented microswine cartilage showed increased M2 macrophages. It was also revealed that calcitriol favors M2 macrophage polarization. Taken together, the results of this study suggest that modulating expression of IL-33, IL-6, TNF-α, TLRs, DAMPs, and MMPs with vitamin D supplementation may serve as a novel therapeutic to attenuate inflammation and cartilage degeneration in osteoarthritis.

Discerning the promising binding sites of S100/calgranulins and their therapeutic potential in atherosclerosis

INTRODUCTION

Atherosclerosis is a chronic inflammatory disease in which the members of S100 family proteins (calgranulins) bind with their receptors, particularly receptor for advanced glycation end products (RAGE) and toll-like receptor-4 (TLR-4) and play a key role in the pathogenesis and progression of disease. Thus, these proteins could be considered as potential biomarkers and therapeutic targets in the treatment of atherosclerotic inflammation.

AREAS COVERED

This review summarizes the pathology of S100A8, S100A9, and S100A12 in the development of atherosclerosis and reveals key structural features of these proteins which are potentially critical in their pathological effects. This article focuses on the translational significance of antagonizing these proteins by using small molecules in patent literature, clinical and preclinical studies and also discusses future approaches that could be employed to block these proteins in the treatment of atherosclerosis.

EXPERT OPINION

Based on the critical role of S100/calgranulins in the regulation of atherosclerosis, these proteins are potential targets to develop better therapeutic options in the treatment of inflammatory diseases. However, further research is still needed to clarify their exact molecular mechanism by analyzing their detailed structural features that can expedite future research to develop novel therapeutics against these proteins to treat atherosclerotic inflammation.

Impact of resolvin mediators in the immunopathology of diabetes and wound healing

Introduction: Wound healing in diabetes may be delayed by persistent wound infection due to deficient immune and cellular response to tissue injury. Hyperglycemia due to decreased insulin availability and increased insulin resistance affects the immune response of the body. Accumulation of inflammatory immune cells and pro-inflammatory cytokines results in chronic inflammation and an altered resolution and remodeling phase of wound healing.Areas covered: Pro-resolving mediators called 'resolvins' target the resolution phase of wound healing and are becoming an area of increased interest. Resolvins stimulate self-limited innate immune responses and enhance innate microbial killing and clearance. Resolvins resolve inflammation by decreasing neutrophil infiltration and transmigration, increasing the phagocytic activity of macrophages, decreasing adipose tissue macrophages, downregulating platelet activation, suppressing nuclear factor-kappa beta activation, promoting the apoptosis of polymorphonuclear leukocytes, and improving insulin sensitivity. This review discusses the role of resolvins in diabetic wound healing and potential therapeutic strategies. The review is based on a literature search of PubMed and the Web of Science restricted to publications between January 2001 and October 2020.Expert opinion: There is increasing support for the use of resolvins in clinical applications related to diabetes and wound healing. Further research will help clarify this potential.

Novel ligands and modulators of triggering receptor expressed on myeloid cells receptor family: 2015-2020 updates

Introduction: Triggering receptors expressed on myeloid cells (TREMs) are inflammatory amplifiers with defined pathophysiological role in various infectious diseases, acute and chronic aseptic inflammations, and a variety of cancers, depicting TREMs as prominent therapeutic targets.Areas covered: Herein, updates from 2015 to 2020 are discussed to divulge the TREM ligands, as well as their peptide blockers, claimed to modulate their expression. The article also presents different strategies employed during the last five years to block interactions between TREMs and their ligands to treat various disease conditions by modulating their expression and activity.Expert opinion: There has been significant progress in the discovery of novel ligands and modulators of TREMs in the last five years that mainly revolved around the function of TREM molecules. A few peptides showed encouraging results to modulate the expression and activity of TREMs in preclinical studies, and these peptides are currently under clinical investigation. Based on the findings so far in several careful studies, we expect novel therapeutics in the near future which could have the ability to treat various disease conditions associated with TREM expression.

Targets (Metabolic Mediators) of Therapeutic Importance in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC), an extremely aggressive invasive cancer, is the fourth most common cause of cancer-related death in the United States. The higher mortality in PDAC is often attributed to the inability to detect it until it has reached advanced stages. The major challenge in tackling PDAC is due to its elusive pathology, minimal effectiveness, and resistance to existing therapeutics. The aggressiveness of PDAC is due to the capacity of tumor cells to alter their metabolism, utilize the diverse available fuel sources to adapt and grow in a hypoxic and harsh environment. Therapeutic resistance is due to the presence of thick stroma with poor angiogenesis, thus making drug delivery to tumor cells difficult. Investigating the metabolic mediators and enzymes involved in metabolic reprogramming may lead to the identification of novel therapeutic targets. The metabolic mediators of glucose, glutamine, lipids, nucleotides, amino acids and mitochondrial metabolism have emerged as novel therapeutic targets. Additionally, the role of autophagy, macropinocytosis, lysosomal transport, recycling, amino acid transport, lipid transport, and the role of reactive oxygen species has also been discussed. The role of various pro-inflammatory cytokines and immune cells in the pathogenesis of PDAC and the metabolites involved in the signaling pathways as therapeutic targets have been previously discussed. This review focuses on the therapeutic potential of metabolic mediators in PDAC along with stemness due to metabolic alterations and their therapeutic importance.

The immune response after noise damage in the cochlea is characterized by a heterogeneous mix of adaptive and innate immune cells

Cells of the immune system are present in the adult cochlea and respond to damage caused by noise exposure. However, the types of immune cells involved and their locations within the cochlea are unclear. We used flow cytometry and immunostaining to reveal the heterogeneity of the immune cells in the cochlea and validated the presence of immune cell gene expression by analyzing existing single-cell RNA-sequencing (scRNAseq) data. We demonstrate that cell types of both the innate and adaptive immune system are present in the cochlea. In response to noise damage, immune cells increase in number. B, T, NK, and myeloid cells (macrophages and neutrophils) are the predominant immune cells present. Interestingly, immune cells appear to respond to noise damage by infiltrating the organ of Corti. Our studies highlight the need to further understand the role of these immune cells within the cochlea after noise exposure.

Role of Vitamin D in Cardiovascular Diseases

Vitamin D is critical in mineral homeostasis and skeletal health and plays a regulatory role in nonskeletal tissues. Vitamin D deficiency is associated with chronic inflammatory diseases, including diabetes and obesity, both strong risk factors for cardiovascular diseases (CVDs). CVDs, including coronary artery disease, myocardial infarction, hypertrophy, cardiomyopathy, cardiac fibrosis, heart failure, aneurysm, peripheral arterial disease, hypertension, and atherosclerosis, are major causes of morbidity and mortality. The association of these diseases with vitamin D deficiency and improvement with vitamin D supplementation suggest its therapeutic benefit. The authors review the findings on the association of vitamin D deficiency and CVDs.