Therapeutic potential and recent progression of BTK inhibitors against rheumatoid arthritis.

Rheumatoid arthritis (RA) is a complex chronic inflammatory illness that affects the entire physiology of human body. It has become one of the top causes of disability worldwide. The development and progression of RA involves a complex interplay between an individual's genetic background and various environmental factors. In order to effectively manage RA, a multidisciplinary approach is required, as this disease is complicated and its pathophysiological mechanism is not fully understood yet. In majority of arthritis patients, the presence of abnormal B cells and autoantibodies, primarily anti-citrullinated peptide antibodies and rheumatoid factor affects the progression of RA. Therefore, drugs targeting B cells have now become a hot topic in the treatment of RA which is quite evident from the recent trends seen in the discovery of various B cell receptors (BCRs) targeting agents. Bruton's tyrosine kinase (BTK) is one of these recent targets which play a role in the upstream phase of BCR signalling. BTK is an important enzyme that regulates the survival, proliferation, activation and differentiation of B-lineage cells by preventing BCR activation, FC-receptor signalling and osteoclast development. Several BTK inhibitors have been found to be effective against RA during the in vitro and in vivo studies conducted using diverse animal models. This review focuses on BTK inhibition mechanism and its possible impact on immune-mediated disease, along with the types of RA currently being investigated, preclinical and clinical studies and future prospective.

Biodistribution of Intravenously Transplanted Mitochondria Conjugated with Graphene Quantum Dots in Diabetic Rats.

Mitochondria transplantation has emerged as a successful therapeutic modality to treat several degenerative diseases. However, the biodistribution of transplanted mitochondria has not been well studied. We investigated the ex-vivo systemic biodistribution and therapeutic efficacy of intravenously transplanted graphene quantum dots (GQDs) conjugated to isolated mitochondria (Mt-GQDs) in diabetic rat tissues. The results revealed that Mt-GQDs facilitate the tracking of transplanted mitochondria without affecting their therapeutic efficacy. It is compelling to note that Mt-GQDs and isolated mitochondria show comparable therapeutic efficacies in decreasing blood glucose levels, oxidative stress, inflammatory gene expressions, and restoration of different mitochondrial functions in pancreatic tissues of diabetic rats. In addition, histological section examination under a fluorescence microscope demonstrated the localization of Mt-GQDs in multiple tissues of diabetic rats. In conclusion, this study indicates that Mt-GQDs provide an effective mitochondrial transplantation tracking modality.

Mitochondrial transfer restores impaired liver functions by AMPK/ mTOR/PI3K-AKT pathways in metabolic syndrome.

AIM: We investigated the effect of mitochondria transfer in high fat diet and streptozotocin (HFD + STZ) induced metabolic syndrome (MeS) in rats. The effect of mitochondria transfer in MeS with co-existing hypertension, hyperlipidaemia, diabetes and fatty liver together, has not been reported. MATERIALS AND METHODS: Heathy mitochondria was transferred intravenously and the effect on several physiological parameters and biochemical parameters were examined in HFD + STZ rats. In addition, RNA-sequencing of healthy liver tissues was performed to elucidate the molecular pathways affected by mitochondria transfer in restoring metabolic health. KEY FINDINGS: We observed reduction in both systolic and diastolic blood pressure levels, reduced blood glucose levels, and a marked reduction in serum lipid profiles. The levels of alanine transaminase (ALT) and aspartate transaminase (AST) also improved along with evident restoration of liver morphology demonstrated by histopathological analysis. Enhanced mitochondrial biogenetics and reduction in oxidative stress and inflammatory markers was also observed. The pathway enrichment analysis revealed reduction in insulin resistance, inflammatory markers, regulation of mitochondrial bioenergetics, calcium ion homeostasis, fatty-acid ß-oxidation, cytokine immune regulators, and enhanced lipid solubilisation. The significant effect of healthy mitochondria transfer in restoration of metabolic functions was observed by the activation of PI3K-AKT, AMPK/mTOR pathways and cytokine immune regulators, suggesting that inflammatory mediators were also significantly affected after mitochondria transfer. SIGNIFICANCE: This study, provides insights on molecular processes triggered by mitochondria transfer in fatty liver regeneration and improvement of overall metabolic health.

GSK-3ß and its Inhibitors in Alzheimer's Disease: A Recent Update.

Alzheimer's disease (AD) is an emerging major health and socioeconomic burden worldwide. It is characterized by neuronal loss, memory loss and cognitive impairment in the aging population. Despite several scientific advancements over the past five decades, the underlying molecular mechanism of the disease progression is yet unknown. Glycogen synthase kinase-3ß (GSK-3ß) has huge implications on the brain function, causing molecular pathologies, neuronal damage and impairment of brain performance in AD. It is one of the key players in signaling pathways for normal brain functioning and a critical molecular link between amyloid-beta (Aß) and tau neurofibrillary tangles (NFTs). GSK-3ß activation is driven by phosphorylation of tau(τ) protein which results in disruption of neuronal synaptic activities and the formation of neuronal plaques. Although the accumulation of Aß plaques and intracellular tangles of hyperphosphorylated tau protein has been well established as neuropathological hallmarks of the disease, the molecular mechanism has not been unraveled. This review focuses on the role of GSK-3ß in the molecular mechanisms participating in the manifestation and progression of AD. The review also suggests that GSK-3ß inhibitors can be used as potential therapeutic targets for amelioration of AD.

Repurposing of digoxin in pain and inflammation: An evidence-based study.

In recent years, the drug repositioning strategy has gained considerable attention in the drug discovery process that involves establishing new therapeutic uses of already known drugs. In line with this, we have identified digoxin a cardiac glycoside, as a potent inhibitor of soluble epoxide hydrolase (sEH) enzyme employing in silico high throughput screening protocols and further confirmed using in vitro cell-free sEH inhibitory assay and in vivo preclinical studies in rodents for its repurposing in hyperalgesia, inflammation, and related disorders. Oral administration of digoxin at dose 0.2 mg/kg significantly reduced (p < .0001) the allodynia in mice induced by using hot plate (3.6 ± 1.9) and tail-flick test (7.58 ± 0.9). In addition, digoxin at a dose of 0.2 mg/kg showed marked reduction (94%, p < .0001) in acetic acid-induced abdominal contraction in rats. Further, digoxin also demonstrated antipyretic activity (37.04 ± 0.2, p < .0001) and showed notable reduction (0.60 ± 0.06) in carrageenan-induced paw edema in rats. Also, the histopathological evaluation revealed that digoxin treatment attenuated the edema, neutrophil infiltration, and alveolar septal thickening in lung tissue. These findings are novel and highlight the newer insights towards repurposing digoxin as a new lead in the treatment of hyperalgesia, inflammation, and related disorders.

Simvastatin ameliorates oxidative stress levels in HepG2 cells and hyperlipidemic rats.

Simvastatin is an established anti-hyperlipidemic drug and few studies have indicated its role in the mitigation of oxidative stress. However, a systematic study considering molecular binding/interaction of simvastatin with anti-oxidant enzymes followed by confirmational in vitro and in vivo studies have never been done. We investigated the molecular binding of simvastatin with multiple anti-oxidant enzymes and assessed their levels after the treatment of simvastatin in vitro and in vivo. This study is the first to show the molecular binding of simvastatin to catalase through molecular docking analysis. Moreover, the anti-oxidative properties of simvastatin have not been studied in Lipopolysaccharide (LPS) induced oxidative stress in HepG2 cells. We found that simvastatin effectively attenuated oxidative stress in LPS induced HepG2 cells and high-fat diet (HFD) fed hyperlipidemic rats by increasing the levels of antioxidant enzymes. The activity of catalase and superoxide dismutase (SOD) both increased significantly in oxidatively stressed HepG2 cells after the treatment with simvastatin (10 â€‹µM, 24 â€‹h). In addition to this, he original cell morphology of oxidatively stressed cells was restored by simvastatin, and an increase in antioxidant enzymes, catalase (0.08 U/cells to 0.12 U/cells), and SOD (0.57 U/cells to 0.74 U/cells) was also noted in HepG2 cells. Furthermore, a significant increase in the antioxidant enzymes such as Catalase, SOD, and reduced glutathione (GSH) was noted after simvastatin treatment in the HFD model. Moreover, we also observed degradation of by-products of lipid peroxidation thiobarbituric acid reactive substances (TBARs), nitric oxide (NO), and protein carbonyl levels. This indicates that simvastatin enhances anti-oxidant enzyme activities and can be repurposed for the treatment of oxidative stress in liver diseases in humans after extensive clinical trials.

A Clinical Perspective of Soluble Epoxide Hydrolase Inhibitors in Metabolic and Related Cardiovascular Diseases.

Epoxide hydrolase (EH) is a crucial enzyme responsible for catabolism, detoxification, and regulation of signaling molecules in various organisms including human beings. In mammals, EHs are classified according to their DNA sequence, sub-cellular location, and activity into eight major classes: soluble EH (sEH), microsomal EH (mEH), leukotriene A4 hydrolase (LTA4H), cholesterol EH (ChEH), hepoxilin EH, paternally expressed gene 1 (peg1/MEST), EH3, and EH4. The sEH, an α/ß-hydrolase fold family enzyme, is an emerging pharmacological target in multiple diseases namely, cardiovascular disease, neurodegenerative disease, chronic pain, fibrosis, diabetes, pulmonary diseases, and immunological disease. It exhibits prominent physiological effects including anti-inflammatory, anti-migratory, and vasodilatory effects. Its efficacy has been documented in various clinical trials and observational studies. This review specifically highlights the development of soluble epoxide hydrolase inhibitors (sEHIs) in the clinical setting for the management of metabolic syndrome and related disorders, such as cardiovascular effects, endothelial dysfunction, arterial disease, hypertension, diabetes, obesity, heart failure, and dyslipidemia. In addition, limitations and future aspects of sEHIs have also been highlighted which will help the investigators to bring the sEHI to the clinics.

Stem cell plasticity and regenerative potential regulation through Ca2+-mediated mitochondrial nuclear crosstalk.

The multi-lineage differentiation potential is one of the prominent mechanisms through which stem cells can repair damaged tissues. The regenerative potential of stem cells is the manifestation of several changes at the structural and molecular levels in stem cells that are regulated through intricate mitochondrial-nuclear interactions maintained by Ca2+ ion signaling. Despite the exhilarating evidences strengthening the versatile and indispensible role of Ca2+ in regulating mitochondrial-nuclear interactions, the extensive details of signaling mechanisms remains largely unexplored. In this review we have discussed the effect of Ca2+ ion mediated mitochondrial-nuclear interactions participating in stem plasticity and its regenerative potential.

Mitochondrial-nuclear coadaptation revealed through mtDNA replacements in Saccharomyces cerevisiae.

BACKGROUND: Mitochondrial function requires numerous genetic interactions between mitochondrial- and nuclear- encoded genes. While selection for optimal mitonuclear interactions should result in coevolution between both genomes, evidence for mitonuclear coadaptation is challenging to document. Genetic models where mitonuclear interactions can be explored are needed. RESULTS: We systematically exchanged mtDNAs between 15 Saccharomyces cerevisiae isolates from a variety of ecological niches to create 225 unique mitochondrial-nuclear genotypes. Analysis of phenotypic profiles confirmed that environmentally-sensitive interactions between mitochondrial and nuclear genotype contributed to growth differences. Exchanges of mtDNAs between strains of the same or different clades were just as likely to demonstrate mitonuclear epistasis although epistatic effect sizes increased with genetic distances. Strains with their original mtDNAs were more fit than strains with synthetic mitonuclear combinations when grown in media that resembled isolation habitats. CONCLUSIONS: This study shows that natural variation in mitonuclear interactions contributes to fitness landscapes. Multiple examples of coadapted mitochondrial-nuclear genotypes suggest that selection for mitonuclear interactions may play a role in helping yeasts adapt to novel environments and promote coevolution.

Correction to: Human tissue-specific MSCs demonstrate differential mitochondria transfer abilities that may determine their regenerative abilities.

The original article [1] contains errors in Fig. 1. The authors noticed a potentially misleading aspect of the original article Fig. 1 where representative flow cytometry data for different panels were from different data sets and thus the gates were not in the same line. This may cause confusion to the readers who attempt to compare panels and, thus the amended Fig. 1 shown ahead represents data from a single data set that is suitable for between panel comparisons.

Human tissue-specific MSCs demonstrate differential mitochondria transfer abilities that may determine their regenerative abilities.

BACKGROUND: Recent studies have demonstrated mesenchymal stem cells (MSCs) as effective mitochondrial donors with therapeutic success in multiple experimental models of human disease. MSCs obtained from different tissue sources such as bone marrow (BM), adipose (AD), dental pulp (DP), and Wharton's jelly (WJ) are routinely used in clinical trials with no known study of their mitochondrial donor capacity. Here, we show for the first time that MSCs derived from different tissue sources have different mitochondrial donor properties and that this is correlated with their intrinsic respiratory states. METHODS: MitoTracker®-labeled MSCs were co-cultured with Cell Trace-labeled U87-MG cells or rat cardiomyocytes. Mitochondrial transfer abilities of MSCs were assessed by using flow cytometry analysis and fluorescence imaging. Mitochondrial reactive oxygen species (mtROS) levels were analyzed by using MitoSOX red-based staining, and mitochondrial respiration parameters were analyzed by using a Seahorse XF Analyzer. RESULTS: AD-MSCs and BM-MSCs displayed higher mitochondrial transfer than DP-MSCs and WJ-MSCs. Counterintuitively, DP-MSCs and WJ-MSCs were more effective in suppressing mtROS levels in stressed recipient cells than AD-MSCs or BM-MSCs. Interestingly, the oxygen consumption rates and intrinsic mitochondrial respiration parameters like ATP levels, basal and maximal respiration, and mitochondrial DNA copy number in donor MSCs showed a highly significant inverse correlation with their mitochondrial donation. CONCLUSIONS: We find that there are intrinsic differences in the mitochondrial respiration, donation capacity, and therapeutic efficacy among MSCs of different tissue origin. MSCs with high mitochondrial respiration capacities are associated with lower mitochondrial transfer but more effective suppression of mtROS in stressed recipient cells. This is most compatible with a model where recipient cells optimally regulate mitochondrial transfer such that they take more mitochondria from MSCs with lower mitochondrial function. Furthermore, it appears to be advantageous to use MSCs such as DP-MSCs or WJ-MSCs with higher mitochondrial respiratory abilities that achieved better therapeutic effect with lower mitochondrial transfer in our study. This opens up a new direction in stem cell therapeutics.

Regenerative abilities of mesenchymal stem cells through mitochondrial transfer.

The past decade has witnessed an upsurge in studies demonstrating mitochondrial transfer as one of the emerging mechanisms through which mesenchymal stem cells (MSCs) can regenerate and repair damaged cells or tissues. It has been found to play a critical role in healing several diseases related to brain injury, cardiac myopathies, muscle sepsis, lung disorders and acute respiratory disorders. Several studies have shown that various mechanisms are involved in mitochondrial transfer that includes tunnel tube formation, micro vesicle formation, gap junctions, cell fusion and others modes of transfer. Few studies have investigated the mechanisms that contribute to mitochondrial transfer, primarily comprising of signaling pathways involved in tunnel tube formation that facilitates tunnel tube formation for movement of mitochondria from one cell to another. Various stress signals such as release of damaged mitochondria, mtDNA and mitochondrial products along with elevated reactive oxygen species levels trigger the transfer of mitochondria from MSCs to recipient cells. However, extensive cell signaling pathways that lead to mitochondrial transfer from healthy cells are still under investigation and the changes that contribute to restoration of mitochondrial bioenergetics in recipient cells remain largely elusive. In this review, we have discussed the phenomenon of mitochondrial transfer from MSCs to neighboring stressed cells, and how this aids in cellular repair and regeneration of different organs such as lung, heart, eye, brain and kidney. The potential scope of mitochondrial transfer in providing novel therapeutic strategies for treatment of various pathophysiological conditions has also been discussed.

Differential reduction of reactive oxygen species by human tissuespecific mesenchymal stem cells from different donors under oxidative stress.

Clinical trials using human Mesenchymal Stem Cells (MSCs) have shown promising results in the treatment of various diseases. Different tissue sources, such as bone marrow, adipose tissue, dental pulp and umbilical cord, are being routinely used in regenerative medicine. MSCs are known to reduce increased oxidative stress levels in pathophysiological conditions. Differences in the ability of MSCs from different donors and tissues to ameliorate oxidative damage have not been reported yet. In this study, for the first time, we investigated the differences in the reactive oxygen species (ROS) reduction abilities of tissue-specific MSCs to mitigate cellular damage in oxidative stress. Hepatic Stellate cells (LX-2) and cardiomyocytes were treated with Antimycin A (AMA) to induce oxidative stress and tissue specific MSCs were co-cultured to study the reduction in ROS levels. We found that both donor's age and source of tissue affected the ability of MSCs to reduce increased ROS levels in damaged cells. In addition, the abilities of same MSCs differed in LX-2 and cardiomyocytes in terms of magnitude of reduction of ROS, suggesting that the type of recipient cells should be kept in consideration when using MSCs in regenerative medicine for treatment purposes.

Can multidetector CT detect the site of gastrointestinal tract injury in trauma? - A retrospective study.

PURPOSE: We aimed to assess the performance of computed tomography (CT) in localizing site of traumatic gastrointestinal tract (GIT) injury and determine the diagnostic value of CT signs in site localization. METHODS: CT scans of 97 patients with surgically proven GIT or mesenteric injuries were retrospectively reviewed by radiologists blinded to surgical findings. Diagnosis of either GIT or mesenteric injuries was made. In patients with GIT injuries, site of injury and presence of CT signs such as focal bowel wall hyperenhancement, hypoenhancement, wall discontinuity, wall thickening, extramural air, intramural air, perivisceral infiltration, and active vascular contrast leak were evaluated. RESULTS: Out of 97 patients, 90 had GIT injuries (70 single site injuries and 20 multiple site injuries) and seven had isolated mesenteric injury. The overall concordance between CT and operative findings for exact site localization was 67.8% (61/90), partial concordance rate was 11.1% (10/90), and discordance rate was 21.1% (19/90). For single site localization, concordance rate was 77.1% (54/70), discordance rate was 21.4% (15/70), and partial concordance rate was 1.4% (1/70). In multiple site injury, concordance rate for all sites of injury was 35% (7/20), partial concordance rate was 45% (9/20), and discordance rate was 20% (4/20). For upper GIT injuries, wall discontinuity was the most accurate sign for localization. For small bowel injury, intramural air and hyperenhancement were the most specific signs for site localization, while for large bowel injury, wall discontinuity and hypoenhancement were the most specific signs. CONCLUSION: CT performs better in diagnosing small bowel injury compared with large bowel injury. CT can well predict the presence of multiple site injury but has limited performance in exact localization of all injury sites.

Mitochondrial-nuclear epistasis contributes to phenotypic variation and coadaptation in natural isolates of Saccharomyces cerevisiae.

Mitochondria are essential multifunctional organelles whose metabolic functions, biogenesis, and maintenance are controlled through genetic interactions between mitochondrial and nuclear genomes. In natural populations, mitochondrial efficiencies may be impacted by epistatic interactions between naturally segregating genome variants. The extent that mitochondrial-nuclear epistasis contributes to the phenotypic variation present in nature is unknown. We have systematically replaced mitochondrial DNAs in a collection of divergent Saccharomyces cerevisiae yeast isolates and quantified the effects on growth rates in a variety of environments. We found that mitochondrial-nuclear interactions significantly affected growth rates and explained a substantial proportion of the phenotypic variances under some environmental conditions. Naturally occurring mitochondrial-nuclear genome combinations were more likely to provide growth advantages, but genetic distance could not predict the effects of epistasis. Interruption of naturally occurring mitochondrial-nuclear genome combinations increased endogenous reactive oxygen species in several strains to levels that were not always proportional to growth rate differences. Our results demonstrate that interactions between mitochondrial and nuclear genomes generate phenotypic diversity in natural populations of yeasts and that coadaptation of intergenomic interactions likely occurs quickly within the specific niches that yeast occupy. This study reveals the importance of considering allelic interactions between mitochondrial and nuclear genomes when investigating evolutionary relationships and mapping the genetic basis underlying complex traits.