Multi-omics approach for identifying CNV-associated lncRNA signatures with prognostic value in prostate cancer.

Background: Prostate cancer, the second most prevalent malignancy among men, poses a significant threat to affected patients' well-being due to its poor prognosis. Novel biomarkers are required to enhance clinical outcomes and tailor personalized treatments. Herein, we describe our research to explore the prognostic value of long non-coding RNAs (lncRNAs) deregulated by copy number variations (CNVs) in prostate cancer. Methods: The study employed an integrative multi-omics data analysis of the prostate cancer transcriptomic, CNV and methylation datasets to identify prognosis-related subtypes. Subtype-specific expression profiles of protein-coding genes (PCGs) and lncRNAs were determined. We analysed CNV patterns of lncRNAs across the genome to identify subtype-specific lncRNAs with CNV changes. LncRNAs exhibiting significant amplification or deletion and a positive correlation were designated CNV-deregulated lncRNAs. A prognostic risk score model was subsequently developed using these CNV-driven lncRNAs. Results: Six molecular subtypes of prostate cancer were identified, demonstrating significant differences in prognosis (P = 0.034). The CNV profiles of subtype-specific lncRNAs were examined, revealing their correlation with CNV amplification or deletion. Six lncRNAs (CCAT2, LINC01593, LINC00276, GACAT2, LINC00457, LINC01343) were selected based on significant CNV amplifications or deletions using a rigorous univariate Cox proportional risk regression model. A robust risk score model was developed, stratifying patients into high-risk and low-risk categories. Notably, our prognostic model based on these six lncRNAs exhibited exceptional predictive capabilities for recurrence-free survival (RFS) in prostate cancer patients (P = 0.024). Conclusions: Our study successfully identified a prognostic risk score model comprising six CNV-driven lncRNAs that could potentially be prognostic biomarkers for prostate cancer. These lncRNA signatures are closely associated with RFS, providing promising prospects for improved patient prognostication and personalized therapeutic strategies for novel prostate cancer treatment.

Journey of CAR T­cells: Emphasising the concepts and advancements in breast cancer (Review).

Cancer is the primary and one of the most prominent causes of the rising global mortality rate, accounting for nearly 10 million deaths annually. Specific methods have been devised to cure cancerous tumours. Effective therapeutic approaches must be developed, both at the cellular and genetic level. Immunotherapy offers promising results by providing sustained remission to patients with refractory malignancies. Genetically modified T­lymphocytic cells have emerged as a novel therapeutic approach for the treatment of solid tumours, haematological malignancies, and relapsed/refractory B­lymphocyte malignancies as a result of recent clinical trial findings; the treatment is referred to as chimeric antigen receptor T­cell therapy (CAR T­cell therapy). Leukapheresis is used to remove T­lymphocytes from the leukocytes, and CARs are created through genetic engineering. Without the aid of a major histocompatibility complex, these genetically modified receptors lyse malignant tissues by interacting directly with the carcinogen. Additionally, the outcomes of preclinical and clinical studies reveal that CAR T­cell therapy has proven to be a potential therapeutic contender against metastatic breast cancer (BCa), triple­negative, and HER 2+ve BCa. Nevertheless, unique toxicities, including (cytokine release syndrome, on/off­target tumour recognition, neurotoxicities, anaphylaxis, antigen escape in BCa, and the immunosuppressive tumour microenvironment in solid tumours, negatively impact the mechanism of action of these receptors. In this review, the potential of CAR T­cell immunotherapy and its method of destroying tumour cells is explored using data from preclinical and clinical trials, as well as providing an update on the approaches used to reduce toxicities, which may improve or broaden the effectiveness of the therapies used in BCa.

Deciphering novel common gene signatures for rheumatoid arthritis and systemic lupus erythematosus by integrative analysis of transcriptomic profiles.

Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE) are the two highly prevalent debilitating and sometimes life-threatening systemic inflammatory autoimmune diseases. The etiology and pathogenesis of RA and SLE are interconnected in several ways, with limited knowledge about the underlying molecular mechanisms. With the motivation to better understand shared biological mechanisms and determine novel therapeutic targets, we explored common molecular disease signatures by performing a meta-analysis of publicly available microarray gene expression datasets of RA and SLE. We performed an integrated, multi-cohort analysis of 1088 transcriptomic profiles from 14 independent studies to identify common gene signatures. We identified sixty-two genes common among RA and SLE, out of which fifty-nine genes (21 upregulated and 38 downregulated) had similar expression profiles in the diseases. However, antagonistic expression profiles were observed for ACVR2A, FAM135A, and MAPRE1 genes. Thirty genes common between RA and SLE were proposed as robust gene signatures, with persistent expression in all the studies and cell types. These gene signatures were found to be involved in innate as well as adaptive immune responses, bone development and growth. In conclusion, our analysis of multicohort and multiple microarray datasets would provide the basis for understanding the common mechanisms of pathogenesis and exploring these gene signatures for their diagnostic and therapeutic potential.

Exosome-based approaches in the management of Alzheimer's disease.

Alzheimer's disease (AD) has been the most extensively studied neurological disorders that affects millions of individuals globally and is associated with misfolding of proteins in the brain. Amyloid-ß and tau are predominantly involved in the pathogenesis of AD. Therapeutic interventions and nanotechnological advancements are useful only in managing the AD symptoms and the cure for this disease remains elusive. Exosomes, originating from most cell and tissue types are regarded as a double-edged sword, considering their roles in the progression and treatment of AD. Exosomes can be manipulated as drug delivery vehicles for a wide range of therapeutic cargos-both small molecules and macromolecules. Herein, we review the roles of exosomes in the pathology, diagnosis, and treatment of AD and highlight their application as a drug carrier to the brain for AD treatment.

Exercise-Linked Skeletal Irisin Ameliorates Diabetes-Associated Osteoporosis by Inhibiting the Oxidative Damage-Dependent miR-150-FNDC5/Pyroptosis Axis.

Recent evidence suggests that physical exercise (EX) promotes skeletal development. However, the impact of EX on the progression of bone loss and deterioration of mechanical strength in mice with type 2 diabetic mellitus (T2DM) remains unexplored. In the current study, we investigated the effect of EX on bone mass and mechanical quality using a diabetic mouse model. The T2DM mouse model was established with a high-fat diet with two streptozotocin injections (50 mg/kg/body wt) in C57BL/6 female mice. The diabetic mice underwent treadmill exercises (5 days/week at 7-11 m/min for 60 min/day) for 8 weeks. The data showed that diabetes upregulated miR-150 expression through oxidative stress and suppressed FNDC5/Irisin by binding to its 3'-untranslated region. The decreased level of irisin further triggers the pyroptosis response in diabetic bone tissue. EX or N-acetyl cysteine or anti-miRNA-150 transfection in T2DM mice restored FNDC5/Irisin expression and bone formation. Furthermore, EX or recombinant irisin administration prevented T2DM-Induced hyperglycemia and improved glucose intolerance in diabetic mice. Furthermore, osteoblastic knockdown of Nlrp3 silencing (si-Nlrp3) or pyroptosis inhibitor (Ac-YVADCMK [AYC]) treatment restores bone mineralization in diabetic mice. Micro-computed tomography scans and mechanical testing revealed that trabecular bone microarchitecture and bone mechanical properties were improved after EX in diabetic mice. Irisin, either induced by skeleton or daily EX or directly administered, prevents bone loss by mitigating inflammasome-associated pyroptosis signaling in diabetic mice. This study demonstrates that EX-induced skeletal irisin ameliorates diabetes-associated glucose intolerance and bone loss and possibly provides a mechanism of its effects on metabolic osteoporosis.

Diabetic Covid-19 severity: Impaired glucose tolerance and pathologic bone loss.

Diabetes mellitus (DM), hypertension, and cardiovascular diseases (CVDs) are the leading chronic comorbidities that enhance the severity and mortality of COVID-19 cases. However, SARS-CoV-2 mediated deregulation of diabetes pathophysiology and comorbidity that links the skeletal bone loss remain unclear. We used both streptozocin-induced type 2 diabetes (T2DM) mouse and hACE2 transgenic mouse to enable SARS-CoV-2-receptor binding domain (RBD) mediated abnormal glucose metabolism and bone loss phenotype in mice. The data demonstrate that SARS-CoV-2-RBD treatment in pre-existing diabetes conditions in hACE2 (T2DM + RBD) mice results in the aggravated osteoblast inflammation and downregulation of Glucose transporter 4 (Glut4) expression via upregulation of miR-294-3p expression. The data also found increased fasting blood glucose and reduced insulin sensitivity in the T2DM + RBD condition compared to the T2DM condition. Femoral trabecular bone mass loss and bone mechanical quality were further reduced in T2DM + RBD mice. Mechanistically, silencing of miR-294 function improved Glut4 expression, glucose metabolism, and bone formation in T2DM + RBD + anti-miR-294 mice. These data uncover the previously undefined role of SARS-CoV-2-RBD treatment mediated complex pathological symptoms of diabetic COVID-19 mice with abnormal bone metabolism via a miRNA-294/Glut4 axis. Therefore, this work would provide a better understanding of the interplay between diabetes and SARS-CoV-2 infection.

Natural selection plays a significant role in governing the codon usage bias in the novel SARS-CoV-2 variants of concern (VOC).

The ongoing prevailing COVID-19 pandemic caused by SARS-CoV-2 is becoming one of the major global health concerns worldwide. The SARS-CoV-2 genome encodes spike (S) glycoprotein that plays a very crucial role in viral entry into the host cell via binding of its receptor binding domain (RBD) to the host angiotensin converting enzyme 2 (ACE2) receptor. The continuously evolving SARS-CoV-2 genome results in more severe and transmissible variants characterized by the emergence of novel mutations called 'variants of concern' (VOC). The currently designated alpha, beta, gamma, delta and omicron VOC are the focus of this study due to their high transmissibility, increased virulence, and concerns for decreased effectiveness of the available vaccines. In VOC, the spike (S) gene and other non-structural protein mutations may affect the efficacies of the approved COVID-19 vaccines. To understand the diversity of SARS-CoV-2, several studies have been performed on a limited number of sequences. However, only a few studies have focused on codon usage bias (CUBs) pattern analysis of all the VOC strains. Therefore, to evaluate the evolutionary divergence of all VOC S-genes, we performed CUBs analysis on 300,354 sequences to understand the evolutionary relationship with its adaptation in different hosts, i.e., humans, bats, and pangolins. Base composition and RSCU analysis revealed the presence of 20 preferred AU-ended and 10 under-preferred GC-ended codons. In addition, CpG was found to be depleted, which may be attributable to the adaptive response by viruses to escape from the host defense process. Moreover, the ENC values revealed a higher bias in codon usage in the VOC S-gene. Further, the neutrality plot analysis demonstrated that S-genes analyzed in this study are under 83.93% influence of natural selection, suggesting its pivotal role in shaping the CUBs. The CUBs pattern of S-genes was found to be very similar among all the VOC strains. Interestingly, we observed that VOC strains followed a trend of antagonistic codon usage with respect to the human host. The identified CUBs divergence would help to understand the virus evolution and its host adaptation, thus help design novel vaccine strategies against the emerging VOC strains. To the best of our knowledge, this is the first report for identifying the evolution of CUBs pattern in all the currently identified VOC.

Mechanisms of autophagy and mitophagy in skeletal development, diseases and therapeutics.

Autophagy is a highly evolutionarily conserved process in the eukaryotic cellular system by which dysfunctional organelles are selectively degraded through a series of processes of lysosomal activity and then returned to the cytoplasm for reuse. All cells require this process to maintain cellular homeostasis and promote cell survival during stress responses such as deprivation and hypoxia. Osteoblasts and osteoclasts are two cellular phenotypes in the bone that mediate bone homeostasis. However, an imbalance between osteoblastic bone formation and osteoclastic bone resorption contributes to the onset of bone diseases. Recent studies suggest that autophagy, mitophagy, and selective mitochondrial autophagy may play an essential role in regulating osteoblast differentiation and osteoclast maturation. Autophagic activity dysregulation alters the equilibrium between osteoblastic bone creation and osteoclastic bone resorption, allowing bone disorders like osteoporosis to develop more easily. The current review emphasizes the role of autophagy and mitophagy and their related molecular mechanisms in bone metabolic disorders. In the current review, we emphasize the role of autophagy and mitophagy as well as their related molecular mechanism in bone metabolic disorders. Furthermore, we will discuss autophagy as a target for the treatment of metabolic bone disease and future application in therapeutic translational research.

Garlic exosome-like nanoparticles reverse high-fat diet induced obesity via the gut/brain axis.

Background: Obesity is becoming a global epidemic and reversing the pathological processes underlying obesity and metabolic co-morbidities is challenging. Obesity induced chronic inflammation including brain inflammation is a hallmark of obesity via the gut-brain axis. The objective of this study was to develop garlic exosome-like nanoparticles (GaELNs) that inhibit systemic as well as brain inflammatory activity and reverse a HFD induced obesity in mice. Methods: GELNs were isolated and administrated orally into HFD fed mice. GaELNs were fluorescent labeled for monitoring their in vivo trafficking route after oral administration and quantified the number particles in several tissues. The brain inflammation was determined by measuring inflammatory cytokines by ELISA and real-time PCR. Mitochondrial membrane permeability of microglial cells was determined using JC-10 fluorescence dye. The in vivo apoptotic cell death was quantified by TUNEL assay. The brain metabolites were identified and quantified by LC-MS analysis. Memory function of the mice was determined by several memory functional analysis. The effect of GaELNs on glucose and insulin response of the mice was determined by glucose and insulin tolerance tests. c-Myc localization and interaction with BASP1 and calmodulin was determined by confocal microscopy. Results: Our results show that GaELNs is preferentially taken up microglial cells and inhibits the brain inflammation in HFD mice. GaELN phosphatidic acid (PA) (36:4) is required for the uptake of GaELNs via interaction with microglial BASP1. Formation of the GaELNs/BASP1 complex is required for inhibition of c-Myc mediated expression of STING. GaELN PA binds to BASP1, leading to inhibition of c-Myc expression and activity through competitively binding to CaM with c-Myc transcription factor. Inhibition of STING activity leads to reducing the expression of an array of inflammatory cytokines including IFN-γ and TNF-α. IFN-γ induces the expression of IDO1, which in turn the metabolites generated as IDO1 dependent manner activate the AHR pathway that contributes to developing obesity. The metabolites derived from the GaELNs treated microglial cells promote neuronal differentiation and inhibit mitochondrial mediated neuronal cell death. GaELNs treated HFD mice showed improved memory function and increased glucose tolerance and insulin sensitivity in these mice. Conclusion: Collectively, these results demonstrate how nanoparticles from a healthy diet can inhibit unhealthy high-fat diet induced brain inflammation and reveal a link between brain microglia/diet to brain inflammatory disease outcomes via diet-derived exosome-like nanoparticles.

Exosomal lncRNA-H19 promotes osteogenesis and angiogenesis through mediating Angpt1/Tie2-NO signaling in CBS-heterozygous mice.

Rationale: Emerging evidence indicates that the growth of blood vessels and osteogenesis is tightly coordinated during bone development. However, the molecular regulators of intercellular communication in the bone microenvironment are not well studied. Therefore, we aim to investigate whether BMMSC-Exo promotes osteogenesis and angiogenesis via transporting lnc-H19 in the CBS- heterozygous mouse model. Methods: Using RT2 lncRNA PCR array screening, we identify a bone-specific, long noncoding RNA-H19 (lncRNA-H19/lnc-H19) in exosomes derived from bone marrow mesenchymal stem cells (BMMSC-Exo) during osteogenesis. Using bioinformatics analysis, we further discovered the seed sequence of miR-106a that could bind to lnc-H19. A luciferase reporter assay was performed to demonstrate the direct binding of miR-106a to the target gene angiopoietin 1 (Angpt1). We employed an immunocompromised Nude mouse model, to evaluate the effects of BMMSC-Exo on angiogenesis in vivo. Using a micro-CT scan, we monitored microstructural changes of bone in the experimental mice. Results: BMMSC-Exo possessed exosomal characteristics including exosome size, and typical markers including CD63, CD9, and TSD101. In vitro, BMMSC-Exo significantly promoted endothelial angiogenesis and osteogenesis. Mechanistic studies have shown that exosomal lnc-H19 acts as "sponges" to absorb miR-106 and regulate the expression of angiogenic factor, Angpt1 that activates lnc-H19/Tie2-NO signaling in mesenchymal and endothelial cells. Both of these effects on osteogenesis and angiogenesis are inhibited by antagonizing Tie2 signaling. Treatment of BMMSC-Exo also restored the bone formation and mechanical quality in vivo. Conclusion: These findings provide a novel insight into how the extracellular role of exosomal lnc-H19 affects osteogenesis and angiogenesis through competing endogenous RNA networks.

Probiotics Stimulate Bone Formation in Obese Mice via Histone Methylations.

Rationale: Manipulation of the gut microbiome can prevent pathologic bone loss. However, the effects of probiotics on mitochondrial epigenetic remodeling and skeletal homeostasis in the high-fat diet (HFD)-linked obesity remains to be explored. Here, we examined the impact of probiotics supplementation on mitochondrial biogenesis and bone homeostasis through the histone methylation mechanism in HFD fed obese mice. Methods: 16S rRNA gene sequencing was performed to study the microbiota composition in the gut and microbial dysbiosis in obese mouse model. High resolution (microPET/CT) imaging was performed to demonstrate the obese associated colonic inflammation. Obese-associated upregulation of target miRNA in osteoblast was investigated using a microRNA qPCR array. Osteoblastic mitochondrial mass was evaluated using confocal imaging. Overexpression of mitochondrial transcription factor (Tfam) was used to investigate the glycolysis and mitochondrial bioenergetic metabolism using Tfam-transgenic (Tg) mice fed on HFD. The bone formation and mechanical strength was evaluated by microCT analysis and three-point bending analysis. Results: High-resolution imaging (µ-CT) and mechanical testing revealed that probiotics induced a significant increase of trabecular bone volume and bone mechanical strength respectively in obese mice. Probiotics or Indole-3-propionic acid (IPA) treatment directly to obese mice, prevents gut inflammation, and improved osteoblast mineralization. Mechanistically, probiotics treatment increases mitochondrial transcription factor A (Tfam) expression in osteoblasts by promoting Kdm6b/Jmjd3 histone demethylase, which inhibits H3K27me3 epigenetic methylation at the Tfam promoter. Furthermore, Tfam-transgenic (Tg) mice, fed with HFD, did not experience obesity-linked reduction of glucose uptake, mitochondrial biogenesis and mineralization in osteoblasts. Conclusions: These results suggest that the probiotics mediated changes in the gut microbiome and its derived metabolite, IPA are potentially be a novel agent for regulating bone anabolism via the gut-bone axis.

Hydrogen sulfide prevents ethanol-induced ZO-1 CpG promoter hypermethylation-dependent vascular permeability via miR-218/DNMT3a axis.

Ethanol (ET) causes cerebrovascular dysfunction by altering homocysteine (Hcy) metabolism and by causing oxidative stress. However, there are no strategies to prevent ET-induced epigenetic deregulation of tight junction protein (hyper-methylation) and endothelial cell permeability to date. Hydrogen sulfide (H2 S) has an antioxidative, antiapoptotic, and anti-inflammatory effect. Here, we investigated the protective role of H2 S in ET-induced endothelial permeability through epigenetic changes in mouse brain endothelial cells (bEnd3). The bEnd3 cells were exposed to 50 mM ET treatment in the presence or absence of 50 µM NaHS (H2 S donor). The result demonstrates that ET-induced cellular toxicity increased intracellular Hcy levels, which further intensified mitochondrial dysfunction and energy defects. Using miScript microRNA (miRNA) polymerase chain reaction array-based screening, we identified a particular miRNA, miR-218, as a novel target of ET-induced DNA methyltransferase-3a (DNMT3a) activation. miR-218 influences CpG island methylation of the zonula occludens 1 (ZO-1) promoter in the endothelial cells. We discovered that ET suppressed miR-218 levels and induced endothelial permeability via DNMT3a-mediated ZO-1 hyper-methylation. Treatment with mito-TEMPO (mitochondria-targeted antioxidant), 5'-azacitidine (DNMT inhibitor), or miR-218 overexpression was shown to protect endothelial cells against ET-induced permeability. Also, bEnd3 cells pretreated with NaHS attenuated ET-induced vascular permeability and prevented CpG island methylation at the promoter. In conclusion, our data provide evidence that H2 S treatment protects vascular integrity from ET-induced stress by mitigating CpG (ZO-1 promoter) DNA hyper-methylation. This finding uncovers a new mechanistic understanding of NaHS/H2 S, that may have therapeutic potential in preventing or diminishing ET-induced brain vascular permeability and dysfunction induced by alcoholism.

Rebuilding Microbiome for Mitigating Traumatic Brain Injury: Importance of Restructuring the Gut-Microbiome-Brain Axis.

Traumatic brain injury (TBI) is a damage to the brain from an external force that results in temporary or permanent impairment in brain functions. Unfortunately, not many treatment options are available to TBI patients. Therefore, knowledge of the complex interplay between gut microbiome (GM) and brain health may shed novel insights as it is a rapidly expanding field of research around the world. Recent studies show that GM plays important roles in shaping neurogenerative processes such as blood-brain-barrier (BBB), myelination, neurogenesis, and microglial maturation. In addition, GM is also known to modulate many aspects of neurological behavior and cognition; however, not much is known about the role of GM in brain injuries. Since GM has been shown to improve cellular and molecular functions via mitigating TBI-induced pathologies such as BBB permeability, neuroinflammation, astroglia activation, and mitochondrial dysfunction, herein we discuss how a dysbiotic gut environment, which in fact, contributes to central nervous system (CNS) disorders during brain injury and how to potentially ward off these harmful effects. We further opine that a better understanding of GM-brain (GMB) axis could help assist in designing better treatment and management strategies in future for the patients who are faced with limited options.

Allyl sulfide promotes osteoblast differentiation and bone density via reducing mitochondrial DNA release mediated Kdm6b/H3K27me3 epigenetic mechanism.

Age-associated bone loss or osteoporosis is a common clinical manifestation during aging (AG). The mechanism underlying age-associated osteoblast dysfunction induced by oxidative damage in the mitochondria and loss of bone density remains elusive. Here, we demonstrated the effect of allyl sulfide (AS), a natural organosulfur compound, on mitochondrial (mt) function in bone marrow-derived mesenchymal stem cells (BMMSCs) and bone density in AG mice. The data demonstrate that AS treatment in AG mice promotes BMMSCs differentiation and mineralization via inhibition of mitochondrial oxidative damage. The data also indicate that AG related mito-damage was associated with reduced mitochondrial biogenesis and oxidative phosphorylation, and release of a greater concentration of mtDNA. Furthermore, the data showed that mtDNA caused histone H3K27 demethylase inhibition, KDM6B, and subsequent inflammation by unbalancing mitochondrial redox homeostasis. KDM6B overexpression in AG BMMSCs or AS administration in AG mice restores osteogenesis and bone density in vitro and in vivo. Mechanistically, AS or the mitochondrial-specific antioxidant Mito-TEMPO increased KDM6B expression and upregulated the expression of Runx2 in BMMSCs, probably via epigenetic inhibition of H3K27me3 methylation at the promoter. These data uncover the previously undefined role of AS mediated prevention of mtDNA release, promoting osteogenesis and bone density via an epigenetic mechanism. Therefore, AS could be a potential drug target for the treatment of aging-associated osteoporosis.

Gut microbiota and the periodontal disease: role of hyperhomocysteinemia.

Periodontal disease is one of the most common conditions resulting from poor oral hygiene and is characterized by a destructive process in the periodontium that essentially includes gingiva, alveolar mucosa, cementum, periodontal ligament, and alveolar bone. Notably, the destructive event in the alveolar bone has been linked to homocysteine (Hcy) metabolism; however, it has not been fully investigated. Therefore; the implication of Hcy towards initiation, progression, and maintenance of the periodontal disease remains incompletely understood. Higher levels of Hcy (also known as hyperhomocysteinemia (HHcy)) exerts deleterious effects on gum health and teeth in distinct ways. Firstly, increased production of proinflammatory cytokines such as TNF-α, IL-1ß, IL-6, and IL-8 leads to an inflammatory cascade of events that affect methionine (Met) and Hcy metabolism (i.e., 1-carbon metabolism) leading to HHcy. Secondly, metabolic dysregulation during chronic medical conditions increases systemic inflammation leading to a decrease in vitamins, more specifically B6, B12, and folic acid, that play important roles as cofactors in Hcy metabolism. Also, given the folate level in the HHcy state that is important during dysbiosis, these two conditions appear to be intimately related, and in this context, HHcy-induced dysbiosis may be one of the potential causes of periodontal disease. This paper sums up the link between periodontitis and HHcy, with a special emphasis on the "oral-gut microbiome axis" and the potential probiotic intervention towards warding off some of the serious periodontal disease conditions.

Effects of fibrinogen synthesis inhibition on vascular cognitive impairment during traumatic brain injury in mice.

Traumatic brain injury (TBI) is associated with increased blood content of fibrinogen (Fg), called hyperfibrinogenemia (HFg), which results in enhanced cerebrovascular permeability and leads to short-term memory (STM) reduction. Previously, we showed that extravasated Fg was deposited in the vasculo-astrocyte interface and was co-localized with cellular prion protein (PrPC) during mild-to-moderate TBI in mice. These effects were accompanied by neurodegeneration and STM reduction. However, there was no evidence presented that the described effects were the direct result of the HFg during TBI. We now present data indicating that inhibition of Fg synthesis can ameliorate TBI-induced cerebrovascular permeability and STM reduction. Cortical contusion injury (CCI) was induced in C57BL/6J mice. Then mice were treated with either Fg antisense oligonucleotide (Fg-ASO) or with control-ASO for two weeks. Cerebrovascular permeability to fluorescently labeled bovine serum albumin was assessed in cortical venules following evaluation of STM with memory assessement tests. Separately, brain samples were collected in order to define the expression of PrPC via Western blotting while deposition and co-localization of Fg and PrPC, as well as gene expression of inflammatory marker activating transcription factor 3 (ATF3), were characterized with real-time PCR. Results showed that inhibition of Fg synthesis with Fg-ASO reduced overexpression of AFT3, ameliorated enhanced cerebrovascular permeability, decreased expression of PrPC and Fg deposition, decreased formation of Fg-PrPC complexes in brain, and improved STM. These data provide direct evidence that a CCI-induced inflammation-mediated HFg could be a triggering mechanism involved in vascular cognitive impairment seen previously in our studies during mild-to-moderate TBI.

The role of gut microbiota in bone homeostasis.

The gut microbiota (GM) is referred to as the second gene pool of the human body and a commensal, symbiotic, and pathogenic microorganism living in our intestines. The knowledge of the complex interaction between intestinal microbiota and health outcomes is a novel and rapidly expanding the field. Earlier studies have reported that the microbial communities affect the cellular responses and shape many aspects of physiology and pathophysiology within the body, including muscle and bone metabolism (formation and resorption). GM influences the skeletal homeostasis via affecting the host metabolism, immune function, hormone secretion, and the gut-brain axis. The premise of this review is to discuss the role of GM on bone homeostasis and skeletal muscle mass function. This review also opens up new perspectives for pathophysiological studies by establishing the presence of a 'microbiota-skeletal' axis and raising the possibility of innovative new treatments for skeletal development.

Role of hydrogen sulfide in the musculoskeletal system.

Hydrogen sulfide (H2S) has been known as a gasotransmitter, and it contributes to various physiological and pathological processes. Multiple enzymes such as cystathionine-ß-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-Mercaptopyruvate sulfurtransferase (MST) produce endogenous H2S, and these are differentially expressed in the various tissue systems including the skeletal system. However, abnormal H2S production is associated with deregulation of the signaling cascade and imbalanced tissue homeostasis. Several studies have previously provided evidence showing the essential regulatory action of H2S in skeletal homeostasis. In this review, we have emphasized the novel function of H2S in both bone and skeletal muscle anabolism, in particular. Additionally, we also reviewed the molecular and epigenetic basis of H2S signaling in bone development and skeletal muscle function.

Hydrogen sulfide attenuates homocysteine-induced osteoblast dysfunction by inhibiting mitochondrial toxicity.

Homocysteine (Hcy) is detrimental to bone health in a mouse model of diet-induced hyperhomocysteinemia (HHcy). However, little is known about Hcy-mediated osteoblast dysfunction via mitochondrial oxidative damage. Hydrogen sulfide (H2 S) has potent antioxidant, anti-inflammatory, and antiapoptotic effects. In this study, we hypothesized that the H2 S mediated recovery of osteoblast dysfunction by maintaining mitochondrial biogenesis in Hcy-treated osteoblast cultures in vitro. MC3T3-E1 osteoblastic cells were exposed to Hcy treatment in the presence or absence of an H2 S donor (NaHS). Cell viability, osteogenic differentiation, reactive oxygen species (ROS) production were determined. Mitochondrial DNA copy number, adenosine triphosphate (ATP) production, and oxygen consumption were also measured. Our results demonstrated that administration of Hcy increases the intracellular Hcy level and decreases intracellular H2 S level and expression of the cystathionine ß-synthase/Cystathionine γ-lyase system, thereby inhibiting osteogenic differentiation. Pretreatment with NaHS attenuated Hcy-induced mitochondrial toxicity (production of total ROS and mito-ROS, ratio of mitochondrial fission (DRP-1)/fusion (Mfn-2)) and restored ATP production and mitochondrial DNA copy numbers as well as oxygen consumption in the osteoblast as compared with the control, indicating its protective effects against Hcy-induced mitochondrial toxicity. In addition, NaHS also decreased the release of cytochrome c from the mitochondria to the cytosol, which induces cell apoptosis. Finally, flow cytometry confirmed that NaHS can rescue cells from apoptosis induced by Hcy. Our studies strongly suggest that NaHS has beneficial effects on mitochondrial toxicity, and could be developed as a potential therapeutic agent against HHcy-induced mitochondrial dysfunction in cultured osteoblasts in vitro.

Hyperhomocysteinemia induced endothelial progenitor cells dysfunction through hyper-methylation of CBS promoter.

Bone marrow (BM)-derived endothelial progenitor cells (EPCs) are the key players in angiogenesis and vascular function. Cystathionine-ß-synthase (CBS), an H2S-generating enzyme in methionine metabolism, regulates the function of these EPCs. This study aims to examine whether CBS hyper-methylation contributes to the bone marrow endothelial progenitor cell (BM-EPCs) function and subsequent bone blood flow in mice fed with a high methionine diet (HMD). Bone marrow (BM) cells were collected from HMD and control mice, differentiated into BM-EPCs, and were characterized by acLDL-DiI labeling. CBS mRNA expression was analyzed by real-time PCR, and the global methylation status and methylation of the CBS promoter were detected by nuclear 5-mC assay and methylation-specific PCR (qMSP) respectively. The result reveals that CBS promoter in BM-EPCs from HMD mice was hyper-methylated and the methylation level was, indeed, negatively correlated with CBS mRNA and angiogenic function of BM-EPCs. In addition, global methylation (5-mC) and DNA methyltransferase-1 (DNMT1) expression were increased in HMD condition. In vitro study also shows that HMD induced hyperhomocysteinemia (HHcy) impaired both adhesion and angiogenesis properties of BM-EPCs, accompanied by higher methylation level of CBS promoter that compared to control. Furthermore, bone blood flow was found to be decreased in HMD mice as compared to wild-type mice. To dissect the epigenetic mechanism, we also administrated DNMT inhibitor, 5-azacytidine (5-Aza) to HMD mice. The administration of 5-Aza in HMD mice restored the CBS expression, EPC mediated angiogenesis and blood flow by reducing abnormal DNA hyper-methylation. In conclusion, HHcy dismantles BM-EPCs function and bone blood flow through the hyper-methylation of the CBS promoter in HMD fed mice.