Kanhaiya Singh

• PhD
• Professor (Associate) at University of Pittsburgh

Sir, The Toll-like receptor 4 (TLR4) plays an important role in immunity, tissue repair, and regeneration.1 TLR4 is also an important regulator of wound inflammation and plays an important role in restoring damaged tissue integrity during normal wound healing.2 Any imbalance in TLR4 mediated signaling may abrogate the proper wound healing cascade....

Toll like Receptor 4 (TLR4), is known for its key role in initiation of innate immunity and regulation of adaptive immune responses. TLR4 is also an important regulator of wound inflammation, stimulator of growth factors like vascular endothelial growth factor (VEGF) and plays an important role in restoring damaged tissue integrity during normal...

The variants of transcription factor 7-like 2 (TCF7L2) gene have been shown to be associated with type 2 diabetes mellitus (T2DM) and its several secondary complications. Here, we aimed to examine the possible role of one of the common variant of this gene, rs7903146 (C/T), with impairment of wound healing in cases with T2DM. A total of 750 individ...

Impaired neovascularization is the hallmark of type 2 diabetes, which results in various macro- and microvascular complications and the development of foot ulcerations later in life. Matrix metalloproteinases (MMPs) are the key enzymes which influence matrix remodeling. Here, we aim to investigate that whether single nucleotide polymorphism (SNP -1...

The Toll-Like receptor 4 (TLR4) plays an important role in immunity, tissue repair, and regeneration. The objective of the present work was to evaluate the association of TLR4 single nucleotide polymorphisms (SNPs) rs4986790, rs4986791, rs11536858 (merged into rs10759931), rs1927911, and rs1927914 with increased diabetic foot ulcer (DFU) risk in pa...

Diabetic wounds are complicated by underlying peripheral vasculopathy. Reliance on vascular endothelial growth factor (VEGF) therapy to improve perfusion makes logical sense, yet clinical study outcomes on rescuing diabetic wound vascularization have yielded disappointing results. Our previous work has identified that low endothelial phospholipase...

Tissue nanotransfection (TNT) topically delivers Etv2, Foxc2, and Fli1 (EFF) plasmids increasing vasculogenic fibroblasts (VF) and promoting vascularization in ischemic murine skin. Human dermal fibroblasts respond to EFF nanoelectroporation with elevated expression of endothelial genes in vitro, which is linked to increased ten-eleven translocase...

Genomic plasticity helps adapt to extreme environmental conditions. We tested the hypothesis that exposure to space environment (ESE) impacts the epigenome inducing genomic plasticity. Murine skin samples from the Rodent Research Reference Mission-1 were procured from the International Space Station (ISS) National Laboratory. Targeted RNA sequencin...

A single-center, prospective, observational pilot study was performed to evaluate wound healing endpoint and recurrence by measuring transepidermal water loss (TEWL) post-closure at the site of wound repair. Patients with clinically-defined chronic wounds (such as pressure ulcers, diabetic ulcers, and trauma wounds) who visited the Plastic Surgery...

In the era of renewed space exploration, comprehending the effects of the space environment on human health, particularly for deep space missions, is crucial. While extensive research exists on the impacts of spaceflight, there is a gap regarding female reproductive risks. We hypothesize that space stressors could have enduring effects on female he...

Chronic wounds pose a significant challenge to healthcare. Stemming from impaired wound healing, the consequences can be severe, ranging from amputation to mortality. This comprehensive review explores the multifaceted impact of chronic wounds in medicine and the roles that diet and nutritional pathologies play in the wound-healing process. It has...

Our recent work reported on the identification of the vasculogenic fibroblast (VF) that is capable of generating new blood vessels during tissue repair (Pal et al. Nat Com, 2023). While VF are physiologic and injury-inducible, inducible VF generation is blunted under conditions of diabetes. We report that such barrier may be overcome by the inducti...

Significant knowledge gaps exist regarding the responses of cells, tissues, and organs to organismal death. Examining the survival mechanisms influenced by metabolism and environment, this research has the potential to transform regenerative medicine, redefine legal death, and provide insights into life's physiological limits, paralleling inquiries...

Macrophages assume diverse phenotypes and functions in response to cues from the microenvironment. Earlier we reported an anti-inflammatory effect of Collagenase Santyl® Ointment (CSO) and the active constituent of CSO (CS-API) on wound macrophages in resolving wound inflammation indicating roles beyond debridement in wound healing. Building upon o...

Human death is a complex, time-governed phenomenon that leads to the irreversible cessation of all bodily functions. Recent molecular and genetic studies have revealed remarkable experimental evidence of genetically programmed cellular death characterized by several physiological processes; however, the basic physiological function that occurs duri...

Background and Objective: Chronic wounds affect almost 2.5% of the United States population. Along with substantial healthcare costs, other factors like reduced employment opportunities and social isolation further complicate the patient’s quality of life. Socioeconomic status (SES) has been shown to influence gene expression that can increase susc...

The study investigates a mechanistic link if bacterial biofilm mediated host-pathogen interaction leads to immunological complications associated with breast implant illness (BII). Over 10 million women worldwide have breast implants. In recent years, women have described a constellation of immunological symptoms believed to be related to their bre...

Chronic wounds like diabetic foot ulcers (DFU) can result in significant medical issues like limb amputation, infection, sepsis, and even death. In those with DFU, 65% recur within 5 years after wound closure. Infection is a common complication of DFU. Biofilm infection of wound may result in a state where the wound appears closed (visually, standa...

Unlabelled: Hydrolyzed collagen-based matrices are widely used as wound care dressings. Information on the mechanism of action of such dressings is scanty. Objective: The objective of this study was to test the effect of a specific hydrolyzed collagen powder (HCP) which is extensively used for wound care management in the United States. Approac...

Fetal skin achieves scarless wound repair. Dermal fibroblasts play a central role in extracellular matrix deposition and scarring outcomes. Both fetal and gingival wound repair share minimal scarring outcomes. We tested the hypothesis that compared to adult skin fibroblasts, human fetal skin fibroblast diversity is unique and partly overlaps with g...

Injury-induced transient downregulation of endothelial miR-200b is required to jump-start wound angiogenesis, but the underlying mechanisms remain unclear. Single cell RNA sequencing was performed on ~15000 human endothelial cells under high (mimic treated) miR-200b conditions. Unsupervised clustering using CellRanger identified five cell clusters,...

Our recent work reported on the identification of the vasculogenic fibroblast (VF) that is capable of generating new blood vessels during tissue repair (Pal et al. Nat Com, 2023). While these cells are physiologic and injury-inducible, the generation of VF is blunted under conditions of diabetes. Such barrier may be overcome by the inhibition of fi...

Our previous work (PMID: 35192691) has identified that genetically silenced phospholipase Cγ2 (PLCγ2) hinders VEGF therapy of the diabetic ischemic limb. Hyperglycemia caused hypermethylation of endothelial specific gene promoter. Given that epigenetic changes are reversible, this work tests the significance of gene-targeted therapeutic DNA demethy...

Human death marks the end of organismal life under conditions such that the components of the human body continue to be alive. Such postmortem cellular survival depends on the nature (Hardy scale of slow-fast death) of human death. Slow and expected death typically results from terminal illnesses and includes a prolonged terminal phase of life. As...

Repair of epithelial defect is complicated by infection and related metabolites. Pyocyanin is one such metabolite which is secreted during Pseudomonas aeruginosa infection. Keratinocyte migration is required for the closure of skin epithelial defects. The current work sought to understand pyocyanin-keratinocyte interaction and its significance in t...

Background/Objective: 8.2 million US patients are affected with chronic wounds, with costs ranging from $28.1-$96.8 billion. Increasing healthcare costs, population age, and chronic condition incidences pose immense threats to the healthcare system and patients struck with the burden of chronic wounds. A sociogenomic approach to investigating mecha...

Introduction Patients with sepsis exhibit significant, persistent immunologic dysfunction. Evidence supports the hypothesis that epigenetic regulation of key cytokines plays an important role in this dysfunction. In sepsis, circulating microvesicles (MVs) containing elevated levels of DNA methyltransferase (DNMT) mRNA cause gene methylation and sil...

Tissue injury to skin diminishes miR-200b in dermal fibroblasts. Fibroblasts are widely reported to directly reprogram into endothelial-like cells and we hypothesized that miR-200b inhibition may cause such changes. We transfected human dermal fibroblasts with anti-miR-200b oligonucleotide, then using single cell RNA sequencing, identified emergenc...

Background/Objective: Chronic wound (CW) represents a major burden on the individual patients who are typically challenged with many underlying health related complications. Stress is now recognized as a universal premorbid factor associated with many risk factors of various chronic diseases. This study utilized socio-demographic data of CW patient...

Wound healing is a well-organized dynamic process involving coordinated consecutive phases: homeostasis, inflammation, proliferation and resolution. Fibroblasts play major roles in skin wound healing such as in wound contraction and release of growth factors which are of importance in angiogenesis and tissue remodeling. Abnormal fibroblast phenotyp...

α-Tocotrienol (TCT) form of natural vitamin E is more potent than better known α-tocopherol against stroke. Angiographic studies of canine stroke revealed beneficial cerebrovascular effects of TCT. This work sought to understand the molecular basis of such effect. In mice, TCT supplementation improved perfusion at the stroke-affected site by induci...

Type 2 diabetes mellitus (T2DM) causes peripheral vascular disease because of which several blood-borne factors, including vital nutrients fail to reach the affected tissue. Tissue epigenome is sensitive to chronic hyperglycemia and is known to cause pathogenesis of micro- and macrovascular complications. These vascular complications of T2DM may pe...

Extracellular vesicles (EV) are nanovesicles released by all eukaryotic cells. This work reports the first nanoscale fluorescent visualization of tumor-originating vesicles bearing an angiogenic miR-126 cargo. In a validated experimental model of lethal murine vascular neoplasm, tumor-originating EV delivered its miR-126 cargo to tumor-associated m...

PurposePreterm infants are more susceptible to necrotizing enterocolitis (NEC) than term Queryinfants. This may be due to a relative paucity of Lgr5+ or Bmi1+-expressing intestinal stem cells (ISCs) which are responsible for promoting intestinal recovery after injury. We hypothesized that the cellular markers of Lgr5+ and Bmi1+, which represent the...

Cardiac dysfunction/damage following trauma, shock, sepsis, and ischemia impacts clinical outcomes. Acute inflammation and oxidative stress triggered by these injuries impair mitochondria, which are critical to maintaining cardiac function. Despite sex dimorphisms in consequences of these injuries, it is unclear whether mitochondrial bioenergetic r...

Lysosomal acid lipase (LAL) is a key enzyme in the metabolic pathway of neutral lipids. In the blood of LAL deficient (lal-/-) mice, increased CD11c+ cells were accompanied by up-regulated PD-L1 expression. Single cell RNA sequencing of lal-/- CD11c+ cells identified two distinctive clusters with a major metabolic shift towards glucose utilization...

An extreme chronic wound tissue microenvironment causes epigenetic gene silencing. Unbiased whole-genome methylome was studied in the wound-edge (WE) tissue of chronic wound patients. A total of 4689 differentially methylated regions (DMRs) were identified in chronic WE compared to unwounded (UW) human skin. Hypermethylation was more frequently obs...

Introduction: Survivors of sepsis exhibit persistent immunosuppression. Epigenetic events may be responsible for some of these immunosuppressive changes. During sepsis circulating exosomes contain large quantities of DNA methyltransferase (DNMT) mRNAs. We hypothesized that exosomes directly transfer DNMT mRNAs to recipient monocytes with resultant...

Therapeutic VEGF replenishment has met with limited success for the management of critical limb threatening ischemia (CLTI). To improve outcomes of VEGF therapy we applied single-cell RNA sequencing technology to study the endothelial cells of the human diabetic skin. Single-cell suspensions were generated from the human skin followed by cDNA prepa...

Each cell in the body contains an intricate regulation for the expression of its relevant DNA. While every cell in a multicellular organism contains identical DNA, each tissue-specific cell expresses a different set of active genes. This organizational property exists in a paradigm that is largely controlled by forces external to the DNA sequence v...

Coronavirus with intact infectivity attached to PPE surfaces pose significant threat to the spread of COVID-19. We tested the hypothesis that an electroceutical fabric, generating weak potential difference of 0.5 V, disrupts the infectivity of coronavirus upon contact by destabilizing the electrokinetic properties of the virion. Porcine respiratory...

Background Heart transplantation, a life-saving approach for patients with end-stage heart disease, is limited by shortage of donor organs. While prolonged storage provides more organs, it increases the extent of ischemia. Therefore, we seek to understand molecular mechanisms underlying pathophysiological changes of donor hearts during prolonged st...

Objective: This work addressing complexities in wound infection, seeks to test the reliance of bacterial pathogen Pseudomonas aeruginosa (PA) on host skin lipids to form biofilm with pathological consequences. Background: PA biofilm causes wound chronicity. Both CDC as well as NIH recognizes biofilm infection as a threat leading to wound chronic...

Purpose: Breast Implant Illness (BII) is patient-described constellation of symptoms that are believed to be related to their breast implant. The symptoms described include fibromyalgia, chronic fatigue and a host of other symptoms that are often associated with autoimmune illnesses. In this work, we report that bacterial biofilm associated with br...

Background: Coronavirus Disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), is currently a pandemic. Although pulmonary health has been the primary focus of studies during the early days of COVID-19, development of a comprehensive understanding of this emergent disease requires knowledge of all possible...

Over 10 million women worldwide have breast implants for breast cancer/prophylactic reconstruction or cosmetic augmentation. In recent years, a number of patients have described a constellation of symptoms that are believed to be related to their breast implants. This constellation of symptoms has been named Breast Implant Illness (BII). The sympto...

Urolithin A (UA) is a natural compound that is known to improve muscle function. In this work we sought to evaluate the effect of UA on muscle angiogenesis and identify the underlying molecular mechanisms. C57BL/6 mice were administered with UA (10 mg/body weight) for 12–16 weeks. ATP levels and NAD⁺ levels were measured using in vivo ³¹P NMR and H...

Introduction: Cardiac dysfunction adversely impacts patient outcomes following surgically induced myocardial ischemia/reperfusion (I/R). Maintaining mitochondrial activity is crucial to reducing myocardial I/R. Inflammation and oxidative stress triggered by I/R impair mitochondria. Our group has shown sex differences in myocardial functional recove...

Objective: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently a pandemic. Although pulmonary health has been the primary focus of studies during the early days of COVID-19, development of a comprehensive understanding of this emergent disease requires knowledge of all possible d...

Bidirectional cell-cell communication involving exosome-borne cargo such as miRNA, has emerged as a critical mechanism for wound healing. Unlike other shedding vesicles, exosomes selectively package miRNA by SUMOylation of heterogeneous nuclear ribonucleoproteinA2B1 (hnRNPA2B1). In this work, we elucidate the significance of exosome in keratinocyte...

Aims: Hemangioendothelioma (HE) may be benign or malignant. EOMA cells are validated to study mechanisms in HE. This work demonstrates that EOMA cells heavily rely on mitochondria to thrive. Thus, a combination therapy including weak X-ray therapy (XRT, 0.5Gy) and a standardized natural berry extract (NBE) that is known to be effective in managing...

Injury induced transient downregulation of endothelial miR-200b is required to jump-start wound angiogenesis but the underlying mechanisms remain unclear. To interrogate the transcriptional changes, single-cell RNA sequencing was performed on ∼15000 human endothelial cells following treatment with miR-200b inhibitor or its mimic. The 3’ scRNA-seq a...

Human lungs single cell RNA sequencing data from healthy donors (elderly and young; GEO accession number GSE122960) were analyzed to isolate and specifically study gene expression in alveolar type II cells. Co-localization of ACE2 and TMPRSS2 enables SARS-CoV 2 to enter the cells. Expression of these genes in the alveolar type II cells of elderly a...

Background: Sperm chromosome aneuploidy and the extent of sperm DNA fragmentation (SDF) are contributing factors to male infertility. Their extent can be measured using platforms such as sperm chromatin dispersion (SCD) and sperm fluorescence in situ hybridization (sFISH). Additional studies, however, are needed to understand the clinical applicabi...

Pseudomonas aeruginosa biofilms represent a major threat to health care. Rugose small colony variants (RSCV) of P. aeruginosa, isolated from chronic infections, display hyperbiofilm phenotype. RSCV biofilms are highly resistant to antibiotics and host defenses. This work shows that RSCV biofilm aggregates consist of two distinct bacterial subpopula...

Wounds that have not progressed through the normal process of healing and are open for more than a month are classified as chronic wounds. Patients suffering from diabetes and obesity are at a high risk of developing chronic wounds. Epigenetic events can be summarized as the changes in gene transcription that are not due to changes in the DNA seque...

Preserving mitochondrial activity is crucial in rescuing cardiac function following acute myocardial ischemia/reperfusion (I/R). The sex difference in myocardial functional recovery has been observed after I/R. Given the key role of mitochondrial connexin43 (Cx43) in cardiac protection initiated by ischemic preconditioning, we aimed to determine th...

Extracellular vesicles (EVs) are mRNA-containing cell fragments shed into circulation during pathophysiological events. DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B) regulate gene expression by modifying DNA methylation and altering transcription. Sepsis is a systemic insult resulting in vascular dysfunction, which can lead to shock and death....

Background: Patients with sepsis exhibit significant long-term immunosuppressive sequelae. Monocyte dysfunction is a hallmark of this damage. Circulating exosomes are an important mediator of the systemic signaling events that occur during the septic response; thus, we sought to characterize the contribution of circulating exosomes to the inflammat...

Epithelial to mesenchymal transition (EMT) and wound vascularization are two critical interrelated processes that enable cutaneous wound healing. Zinc finger E-box binding homeobox 1 (ZEB1), primarily studied in the context of tumor biology, is a potent EMT activator. ZEB1 is also known to contribute to endothelial cell survival as well as stimulat...

Objective: Shilajit is a pale-brown to blackish-brown organic mineral substance available from Himalayan rocks. We demonstrated that in type I obese humans, shilajit supplementation significantly upregulated extracellular matrix (ECM)–related genes in the skeletal muscle. Such an effect was highly synergistic with exercise. The present study (clini...

Compelling evidence suggest that germs cells are predominantly sensitive to DNA damaging agents in comparison to other cells. High fidelity DNA repair in testicular cells thus becomes indispensable to preserve the genomic integrity for passing on to the progeny. Compromised DNA repair machinery in the testicular cells may result in impaired spermat...

Aim Genetic and epigenetic mechanisms have been implicated in the pathogenesis of type 1 diabetes (T1D), and histone acetylation is an epigenetic modification pattern that activates gene transcription. However, the genome‐wide histone H3 acetylation in newly onset T1D patients has been less described. Accordingly, we aimed to unveil the genome‐wide...

Inflammation, following injury, induces cellular plasticity as an inherent component of physiological tissue repair. The dominant fate of wound macrophages is unclear and debated. Here we show that two-thirds of all granulation tissue fibroblasts, otherwise known to be of mesenchymal origin, are derived from myeloid cells which are likely to be wou...

Hyperglycemia (HG) induces genome-wide cytosine demethylation. Our previous work recognized miR-200b as a critical angiomiR, which must be transiently downregulated to initiate wound angiogenesis. Under HG, miR-200b downregulation is not responsive to injury. Here, we demonstrate that HG may drive vasculopathy by epigenetic modification of a miR pr...

Shilajit (mumie, moomiyo, mummiyo, mumijo, salajeet) is a resinous phyto-mineral exudate found in sedimentary rocks that has been used for many years for a wide variety of illnesses and health benefits. In recent years, a growing number of studies have been published involving humans, animal, and in vitro systems in support of its uses and health-r...

Although cellular therapies represent a promising strategy for a number of conditions, current approaches face major translational hurdles, including limited cell sources and the need for cumbersome pre-processing steps (for example, isolation, induced pluripotency). In vivo cell reprogramming has the potential to enable more-effective cell-based t...

Objective: Retinal angiogenesis is a hallmark of diabetic retinopathy. Matrix Metalloproteinases (MMPs) are involved in degradation of extracellular matrix (ECM). Functional SNP-1562C>T in the promoter of the MMP-9 gene results increase in transcriptional activity. The present work was designed to evaluate the contribution of functional SNP-1562C>...

In 2011, our laboratory first reported that angiostatic miR-200b helps in maintaining resting cutaneous vascular homeostasis. Transient down-regulation of miR-200b is required to jump-start wound angiogenesis. Epithelial to mesenchymal transition (EMT) is an indispensable process involved in wound healing. Wounds with increased levels of endothelia...

Although cellular therapies represent a promising strategy for a number of conditions, current approaches face major trans-lational hurdles, including limited cell sources and the need for cumbersome pre-processing steps (for example, isolation, induced pluripotency) 1-6. In vivo cell reprogramming has the potential to enable more-effective cell-ba...

Background: Type 2 diabetes mellitus (T2DM) is characterized by persistent hyperglycemia which causes a chain of abrupt biochemical and physiological changes. Immune dys-regulation is the hallmark of T2DM that could contribute to prolonged inflammation causing transformation of wounds into non-healing chronic ulcers. Toll like receptor -9 (TLR9) i...

Metal complexes of type [Cu(L1H)2(bpy)] (1), [Zn(L1H)2(bpy)] (2), [Cu(L2H)2(bpy)] (3)and[Cu(L2H)2(Phen)] (4)(L1H2 = 3-[N0 -(1-acetyl-2-oxo-propylidene)-hydrazino]-benzoic acid, L2H2 = 4-[N0 - (1-acetyl-2-ox o-propylidene)-hydrazino]-benzoic acid, bpy = 2,20 -bipyridine, Phen = 1,10 phenanthroline) are synthe- sized and characterized using spectrosc...

Octahedral complexes of type [Co(L)2]�2NO3 1, [Co(L)2]�3NO3 2 and [Zn(L)2]�2NO3 3 (L = 40-phenyl- 2,20:60,200 terpyridine) are synthesized and characterized using elemental analysis, NMR, IR, UV–Vis and fluorescence spectra and further supported by their X- ray diffraction studies. The binding properties of the complexes with DNA are carried out usi...

Heat shock proteins (HSPs) are inducible stress proteins expressed in cells exposed to stress. HSPs promote wound healing by recruitment of dermal fibroblasts to the site of injury and bring about protein homeostasis. Diabetic wounds are hard to heal and inadequate HSPs may be important contributors in the etiology of diabetic foot ulcers (DFU). To...

The inflammatory phase of wound healing cascade is an important determinant of the fate of the wound. Acute inflammation is necessary to initiate proper wound healing, while chronic inflammation abrogates wound healing. Different endosomal members of toll-like receptor (TLR) family initiate inflammatory signalling via a range of different inflammat...

There is a close association of chronic tissue damage, inflammation and cancer. A chronic injury may contribute to sustained healing response leading to fibrosis, organ failure and carcinogenesis. Wounds created due to mechanical or patho-physiological insults, generally follow a sophisticated series of mutually coherent steps leading to the re-est...

Aim: Persistent hyperglycemic microenvironment in type 2 diabetes mellitus (T2DM) leads to the development of secondary complications like wound healing impairment. Proper co-ordination of innate immune system plays an integral role in wound healing. Toll like receptors (TLRs) are prominent contributors for the induction of the innate immune and i...

Persistent hyperglycemia in patients with Type 2 diabetes mellitus is driving force for developing secondary complications like neuropathy, retinopathy, nephropathy, cardiomyopathy and wound healing impairment in them. Other genetic risk factor includes variants of transcription factor 7-like 2 (TCF7L2) gene, which have been shown to be associated...

Purpose Persistent inflammation and impaired neovascularization in type 2 diabetes mellitus (T2DM) patients may lead to development of macro- and microvascular complications. Diabetic retinopathy (DR) is one of the secondary microvascular complications of T2DM. Improper activation of the innate immune system may be an important contributor in the p...

Coordinated extracellular matrix deposition is a prerequisite for proper wound healing which is mainly orchestrated by matrix metalloproteinases (MMPs). Diabetic wounds generally show compromised wound healing cascade and abnormal MMP9 concentration is one of the cause. Our group have recently shown that the polymorphism -1562 C>T in the promoter r...