Live and Dead Clostridium butyricum GKB7 Diminish Osteoarthritis Pain and Progression in Preclinical Animal Model.

Osteoarthritis (OA) is a degenerative joint disease primarily affecting the elderly. It is characterized by the progressive decline of joint cartilage and alterations in the underlying bone. Several probiotic strains have exhibited immunomodulatory and anti-inflammatory properties. Here, we examined the functions of live and dead Clostridium butyricum GKB7 (GKB7-L and GKB7-D) in a preclinical anterior cruciate ligament transection (ACLT)-enhanced OA procedure. Oral administration of GKB7-L and GKB7-D ameliorated ACLT-induced bone pain as assessed by weight-bearing behavioral testing but did not affect body weight. Micro-computed tomography (CT) results showed that GKB7-L and GKB7-D diminished ACLT-induced bone destruction and loss. GKB7-L and GKB7-D-enriched therapies also reduced ACLT-induced production of the pro-inflammatory cytokines interleukin (IL)-1ß and tumor necrosis factor (TNF)-α, as well as the chondrolytic factor matrix metalloproteinase (MMP)-3, leading to inhibition of aggrecan and collagen type II degradation and thereby blocking cartilage breakdown. We therefore suggest that oral supplementation with GKB7-L or GKB7-D can be beneficial in the prevention and treatment of OA.

Metabolic Reprogramming in Response to Alterations of Mitochondrial DNA and Mitochondrial Dysfunction in Gastric Adenocarcinoma.

We used gastric cancer cell line AGS and clinical samples to investigate the roles of mitochondrial DNA (mtDNA) alterations and mitochondrial respiratory dysfunction in gastric adenocarcinoma (GAC). A total of 131 clinical samples, including 17 normal gastric mucosa (N-GM) from overweight patients who had received sleeve gastrectomy and 57 paired non-cancerous gastric mucosae (NC-GM) and GAC from GAC patients who had undergone partial/subtotal/total gastrectomy, were recruited to examine the copy number and D310 sequences of mtDNA. The gastric cancer cell line AGS was used with knockdown (KD) mitochondrial transcription factor A (TFAM) to achieve mitochondrial dysfunction through a decrease of mtDNA copy number. Parental (PT), null-target (NT), and TFAM-KD-(A/B/C) represented the parental, control, and TFAM knocked-down AGS cells, respectively. These cells were used to compare the parameters reflecting mitochondrial biogenesis, glycolysis, and cell migration activity. The median mtDNA copy numbers of 17 N-GM, 57 NC-GM, and 57 GAC were 0.058, 0.055, and 0.045, respectively. The trend of decrease was significant (p = 0.030). In addition, GAC had a lower mean mtDNA copy number of 0.055 as compared with the paired NC-GM of 0.078 (p < 0.001). The mean mtDNA copy number ratio (mtDNA copy number of GAC/mtDNA copy number of paired NC-GM) was 0.891. A total of 35 (61.4%) GAC samples had an mtDNA copy number ratio ≤0.804 (p = 0.017) and 27 (47.4%) harbored a D310 mutation (p = 0.047), and these patients had shorter survival time and poorer prognosis. After effective knockdown of TFAM, TFAM-KD-B/C cells expressed higher levels of hexokinase II (HK-II) and v-akt murine thymoma viral oncogene homolog 1 gene (AKT)-encoded AKT, but lower levels of phosphorylated pyruvate dehydrogenase (p-PDH) than did the NT/PT AGS cells. Except for a higher level of p-PDH, the expression levels of these proteins remained unchanged in TFAM-KD-A, which had a mild knockdown of TFAM. Compared to those of NT, TFAM-KD-C had not only a lower mtDNA copy number (p = 0.050), but also lower oxygen consumption rates (OCR), including basal respiration (OCRBR), ATP-coupled respiration (OCRATP), reserve capacity (OCRRC), and proton leak (OCRPL)(all with p = 0.050). In contrast, TFAM-KD-C expressed a higher extracellular acidification rate (ECAR)/OCRBR ratio (p = 0.050) and a faster wound healing migration at 6, 12, and 18 h, respectively (all with p = 0.050). Beyond a threshold, the decrease in mtDNA copy number, the mtDNA D310 mutation, and mitochondrial dysfunction were involved in the carcinogenesis and progression of GACs. Activation of PDH might be considered as compensation for the mitochondrial dysfunction in response to glucose metabolic reprogramming or to adjust mitochondrial plasticity in GAC.

Association of Tumor Hydroxyindole O-Methyltransferase and Serum 5-Methoxytryptophan with Long-Term Survival of Hepatocellular Carcinoma.

5-methoxytryptophan (5-MTP) is a recently discovered tryptophan (Trp) metabolite with anti-inflammatory and tumor-suppressing actions. Its synthesis is catalyzed by hydroxyindole O-methyltransferase (HIOMT). HIOMT levels were reported to be decreased in some patients with colorectal, pancreatic and breast cancer. It is unclear whether tissue HIOMT levels is altered in hepatocellular carcinoma (HCC). It is also unclear whether serum 5-MTP concentration is influenced by HCC. In this study, 150 HCC and adjacent normal liver tissues and serum samples were obtained from the HCC biobank established by a prospective multicenter study. Serum samples from 47 healthy subjects were included as a reference. HIOMT mRNA was measured by real time PCR. Serum 5-MTP and selected Trp metabolites were analyzed by quantitative LC-MS. HCC tissue HIOMT mRNA levels adjusted for adjacent normal tissue HIOMT mRNA levels was associated with overall and relapse-free (RF) survival. Combined serum 5-MTP or tissue HIOMT mRNA and serum kynurenine (Kyn) analysis predicted prolonged overall and RF survival following liver resection. A high serum 5-MTP or tissue HIOMT mRNA and low serum Kyn is associated with long-term survival. In conclusion, tumor tissue HIOMT mRNA and serum 5-MTP are potential biomarkers of HCC, especially when analyzed in combination with serum Kyn.

Reduced Expression of Metallothionein-I/II in Renal Proximal Tubules Is Associated with Advanced Chronic Kidney Disease.

Chronic kidney disease (CKD) is a commonly occurring complex renal syndrome that causes overall mortality in many diseases. The clinical manifestations of CKD include renal tubulointerstitial fibrosis and loss of renal function. Metallothionein-I/II (MT-I/II) is potentially expressed in the liver and kidney, and possesses antioxidant and metal detoxification properties. However, whether MT-I/II expression is associated with the prognosis of nephropathy remains unknown. In this study, we investigated the MT-I/II level in human CKD, using immunohistochemistry. MT-I/II is located on the proximal tubules and is notably reduced in patients with CKD. MT-I/II expression was significantly correlated with the functional and histological grades of CKD. In an aristolochic acid (AAI)-induced nephropathy mouse model, MT-I/II was abundantly increased after AAI injection for 7 days, but decreased subsequently compared to that induced in the acute phase when injected with AAI for 28 days. Furthermore, we found that ammonium pyrrolidinedithiocarbamate (PDTC) restored AAI-induced MT-I/II reduction in HK2 cells. The injection of PDTC ameliorated AAI-induced renal tubulointerstitial fibrosis and reduced the concentrations of blood urea nitrogen and creatinine in mouse sera. Taken together, our results indicate that MT-I/II reduction is associated with advanced CKD, and the retention of renal MT-I/II is a potential therapeutic strategy for CKD.

Liver fibrosis regression correlates with downregulation in liver angiogenesis in chronic hepatitis C through viral eradication.

OBJECTIVES: The impact of viral eradication on hepatic angiogenesis is unknown. This study aimed to analyze the correlations of liver angiogenesis with liver fibrosis progression or regression in chronic hepatitis C (CHC) after viral eradication. METHODS: From 2003 to 2020, a cohort of 130 eligible participants underwent paired percutaneous liver biopsies (median = 48 months apart; range = 46-62) at the treatment baseline and after sustained virological response to CHC treatment at the tertiary referral center. The collagen proportionate area (CPA) of liver tissue sections was determined using picrosirius red staining through digital image analysis. CD34 and α-smooth muscle actin (α-SMA) phenotypically quantitated liver angiogenesis and myofibroblasts, respectively, through immunohistochemistry staining, to correlate the total, portal, and extraportal liver angiogenesis with fibrogenesis. RESULTS: Paired histology manifested significant regressions in fibrosis stages, and necroinflammatory grades (both P < 0.001). The median of changes in CPAs (follow-up minus baseline) was -6.12% (interquartile range = -12.35 to -2.05%). The median of CPA changes per year was -1.38%/year (interquartile range = -2.98 to -0.51%/year). The significance of declines in total CD34 [coefficient (95% confidence interval), 5.577 (3.286-7.868); P < 0.001] outweighed α-SMA declines, when explaining (R2 = 0.522; adjusted R2 = 0.502) the CPA declines through multiple regression analysis adjusting for other histological variables. CONCLUSION: Through viral eradication in CHC, the downregulated liver angiogenesis significantly explains the CPA regression.

Repetitively hypoxic preconditioning attenuates ischemia/reperfusion-induced liver dysfunction through upregulation of hypoxia-induced factor-1 alpha-dependent mitochondrial Bcl-xl in rat.

Repetitive hypoxic preconditioning (HP) enforces protective effects to subsequently severe hypoxic/ischemic stress. We hypothesized that HP may provide protection against ischemia/reperfusion (I/R) injury in rat livers via hypoxia-induced factor-1 alpha (HIF-1α)/reactive oxygen species (ROS)-dependent defensive mechanisms. Female Wistar rats were exposed to hypoxia (15 h/day) in a hypobaric hypoxic chamber (5500 m) for HP induction, whereas the others were kept in sea level. These rats were subjected to 45 min of hepatic ischemia by portal vein occlusion followed by 6 h of reperfusion. We evaluated HIF-1α in nuclear extracts, MnSOD, CuZnSOD, catalase, Bad/Bcl-xL/caspase 3/poly-(ADP-ribose)-polymerase (PARP), mitochondrial Bcl-xL, and cytosolic cytochrome C expression with Western blot and nitroblue tetrazolium/3-nitrotyrosine stain. Kupffer cell infiltration and terminal deoxynucleotidyl transferase-mediated nick-end labeling method apoptosis were determined by immunocytochemistry. The ROS value from liver surface and bile was detected by an ultrasensitive chemiluminescence-amplification method. Hepatic function was assessed with plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. HP increased nuclear translocation of HIF-1α and enhanced Bcl-xL, MnSOD, CuZnSOD, and catalase protein expression in a time-dependent manner. The response of HP enhanced hepatic HIF-1α, and Bcl-xL expression was abrogated by a HIF-1α inhibitor YC-1. Hepatic I/R increased ROS levels, myeloperoxidase activity, Kupffer cell infiltration, ALT and AST levels associated with the enhancement of cytosolic Bad translocation to mitochondria, release of cytochrome C to cytosol, and activation of caspase 3/PARP-mediated apoptosis. HP significantly ameliorated hepatic I/R-enhanced oxidative stress, apoptosis, and mitochondrial and hepatic dysfunction. In summary, HP enhances HIF-1α/ROS-dependent cascades to upregulate mitochondrial Bcl-xL protein expression and to confer protection against I/R injury in the livers.

Multiple Progressive Thermopreconditioning Improves Cardiac Ischemia/Reperfusion-induced Left Ventricular Contractile Dysfunction and Structural Abnormality in Rat.

BACKGROUND: Triple progressive thermopreconditioning (3PTP) may induce high Hsp-70 expression to maintain cardiac function. We suggest that 3PTP may reduce myocardial ischemia/reperfusion (I/R) injury during organ transplantation through Bag3/Hsp-70 mediated defense mechanisms. METHODS: Male Wistar rats were divided into sham control group and 72 h after 3PTP in a 42°C water bath (3PTP) group. Rats underwent 60 min of ischemia by occlusion of the left anterior descending coronary artery followed by 240 min reperfusion. Hemodynamic parameters, including the electrocardiogram, microcirculation, heart rate, left ventricular end-diastolic pressure, maximal rate of rise (+dp/dt), and fall (-dp/dt) in the left ventricular pressure for index of contraction and relaxation were determined. Myocardial infarct size was evaluated by the Evans blue-2,3,5-triphenyltetrazolium chloride method. 3PTP-induced protective mechanisms were determined by Western blot and immunohistochemistry. RESULTS: Cardiac I/R depressed cardiac microcirculation, induced S-T segment elevation, and R-R and P-R interval elongation increased infarct size associated with erythrocyte extravasation, leukocytes and macrophage/monocyte infiltration, granulocyte colony-stimulating factor, poly(ADP-ribose) polymerase 1 stain, and transferase-mediated dUTP-biotin nick end labeling positive cells. However, 3PTP evoked significant cardioprotection against I/R injury, characterized by the increased +dp/dt value and the decreased elevated left ventricular end-diastolic pressure, erythrocyte extravasation, leukocyte and macrophage/monocyte infiltration, granulocyte colony-stimulating factor expression, poly(ADP-ribose) polymerase 1 expression, transferase-mediated dUTP-biotin nick end labeling positive cells, and fragmentation and infarct area. In addition, 3PTP increased Hsp-70 and Bag3 expression and decreased Bax/Bcl-2 ratio, but did not affect the Beclin-1 and LC3-II/LC3-I ratio in the heart with I/R injury. CONCLUSIONS: 3PTP therapies may through Bag3 upregulation alleviate I/R injury-induced left ventricular structural deterioration and dysfunction.

Sulforaphane improves voiding function via the preserving mitochondrial function in diabetic rats.

BACKGROUND: Hyperglycemia evoked oxidative stress contributing to diabetes (DM)-induced voiding dysfunction. We explored whether antioxidant sulforaphane,a NF-E2-related nuclear factor erythroid-2 (Nrf-2) activator, may ameliorate DM-induced bladder dysfunction. METHODS: DM was induced by streptozotocin and sulforaphanewas administered before DM induction.Bladder reactive oxygen species (ROS) were determined by an ultrasensitive chemiluminescence analyzer. Mitochondrial function index mitochondrial Bax and cytosolic cytochrome c, antioxidant defense Nrf-2/HO-1, endoplasmic reticulum stress marker ATF-6/CHOP, and caspase 3/PARP were evaluated by Western blot. RESULTS: DM increased Keap1 and reduced Nrf-2 expression, associated with increase of bladder ROS, mitochondrial Bax translocation, cytosolic cytochrome c release, ATF-6/CHOP, caspase-3/PARP in bladders which resulted in voiding dysfunction by increased intercontraction intervals and micturition duration. However, sulforaphanesignificantly increased nuclear Nrf-2/HO-1axis expression, decreased bladder ROS amount, mitochondrial Bax translocation, cytochrome c release, ATF-6/CHOP and caspase 3/PARP/apoptosis, thereby improved the voiding function by the shortened intercontraction intervals and micturition duration. CONCLUSION: We suggest that sulforaphanevia activating Nrf-2/HO-1 signaling preserved mitochondrial function and suppressed DM-induced ROS, endoplasmic reticulum stress, apoptosis and voiding dysfunction.

Restoration of hydroxyindole O-methyltransferase levels in human cancer cells induces a tryptophan-metabolic switch and attenuates cancer progression.

5-Methoxytryptophan (5-MTP) is a tryptophan metabolite with recently discovered anti-inflammatory and tumor-suppressing activities. Its synthesis is catalyzed by a hydroxyindole O-methyltransferase (HIOMT)-like enzyme. However, the exact identity of this HIOMT in human cells remains unclear. Human HIOMT exists in several alternatively spliced isoforms, and we hypothesized that 5-MTP-producing HIOMT is a distinct isoform. Here, we show that human fibroblasts and cancer cells express the HIOMT298 isoform as contrasted with the expression of the HIOMT345 isoform in pineal cells. Sequencing analysis of the cloned isoforms revealed that HIOMT298 is identical to the sequence of a previously reported truncated HIOMT isoform. Of note, HIOMT298 expression was reduced in cancer cells and tissues. Stable transfection of A549 cancer cells with HIOMT298 restored HIOMT expression to normal levels, accompanied by 5-MTP production. Furthermore, HIOMT298 transfection caused a tryptophan-metabolic switch from serotonin to 5-MTP production. To determine the in vivo relevance of this alteration, we compared growth and lung metastasis of HIOMT298-transfected A549 cells with those of vector- or untransfected A549 cells as controls in a murine xenograft model. Of note, the HIOMT298-transfected A549 cells exhibited slower growth and lower metastasis than the controls. Our findings provide insight into the crucial role of HIOMT298 in 5-MTP production in cells and in inhibiting cancer progression and highlight the potential therapeutic value of 5-MTP for managing cancer.

5-methoxytryptophan protects MSCs from stress induced premature senescence by upregulating FoxO3a and mTOR.

5-methoxytryptophan (5-MTP) is a newly discovered tryptophan metabolite which controls stress-induced inflammatory signals. To determine whether 5-MTP protects against stress-induced mesenchymal stem cell (MSC) senescence, we incubated bone marrow-derived MSC (BM-MSC) in high-glucose medium or regular medium for 2 weeks followed by addiction of 5-MTP (10 µM) or vehicle for 48 h. 5-MTP reduced p16 and p21 expression, senescence-associated ß-Gal (SA-ß-Gal) and IL-6 secretion and increased BrdU incorporation. 5-MTP exerted a similar effect on BM-MSC senescence induced by a sublethal concentration of H2O2. 5-MTP enhanced FoxO3a expression and increased superoxide dismutase and catalase activities in HG BM-MSCs. Silencing of FoxO3a with siRNA abrogated 5-MTP-mediated reduction of SA-ß-Gal and IL-6 secretion but not p21 or p16. Since mechanistic target of rapamycin (mTOR) is involved in cellular senescence, we determined whether 5-MTP influences mTOR expression. Our data reveal that mTOR protein level was depressed in HG-MSC which was rescued by 5-MTP. Rapamycin abrogated 5-MTP-mediated suppression of p16, p21, SA-ß-Gal and IL-6 and rise of BrdU incorporation. Our findings suggest that 5-MTP protects MSCs against stress-induced senescence via FoxO3a and mTOR upregulation and has potential to improve cell expansion for cell therapy.

An Efficient Transfection Method for Differentiation and Cell Proliferation of Mouse Embryonic Stem Cells.

Embryonic stem (ES) cells are an important source of stem cells in tissue engineering and regenerative medicine because of their high self-renewal capacities and differentiation potentials. However, the detailed molecular mechanisms controlling the differentiation and renewal programs in ES cells remained unclear. One of the difficulties in understanding these mechanisms substantially results from the low efficacies of gene manipulation by delivering exogenous gene expression or knockdown of endogenous gene expression with small interfering RNA (siRNA) in ES cells. Here we describe an optimized protocol for efficiently transfecting mouse ES cells by Effectene, a liposome-based method. The high transfection efficiency in mouse ES cells is demonstrated in this chapter by (1) achieving a percentage of enhanced green fluorescence protein (EGFP) expression in >98% embryoid bodies after introducing plasmids encoding the protein; (2) decreased SOX-2 and Oct-3/4 expression and subsequent morphological evidences of cell differentiation after introducing siRNA expression for suppressing SOX-2 and Oct-3/4, which are known to be essential for maintenance of stem cell properties in mouse ES cells; and (3) overexpression or attenuated expression of 14-3-3σ to regulate cell proliferation of mouse ES cells.

Paracrine regulation of matrix metalloproteinases contributes to cancer cell invasion by hepatocellular carcinoma-secreted 14-3-3σ.

14-3-3σ overexpression results in enhanced hepatocellular carcinoma (HCC) cell migration and HCC tumor vascular-invasion is significantly associated with 14-3-3σ expression. However, increased expression of 14-3-3σ paradoxically suppresses in vitro cell invasion of HCC. We hypothesize that surrounding tumor-associated stromal cells play a crucial role in 14-3-3σ-regulated HCC cell invasion. In this study, H68 fibroblasts, THP-1 and phorbol-12-myristate-13-acetate (PMA)-treated THP-1 (PMA-THP-1) cells were incubated with conditioned media of control (control-CM) and 14-3-3σ-overepxressing cells (14-3-3σ-CM), followed by co-culture with HCC cells. Invasiveness of HCC cells was examined by a Boyden chamber assay. HCC cells co-cultured with 14-3-3σ-CM treated cells significantly enhanced their invasive ability compared with control-CM treated cells. Moreover, incubation with 14-3-3σ-CM induced differential expression profiles of matrix metalloproteinases (MMPs) in fibroblasts (MMP-1, MMP-2, MMP-9, MMP-12 and MMP-14), THP-1 (MMP-1 and MMP-12) and PMA-THP-1 cells (MMP-2, MMP-12 and MMP-14). In contrast, silencing of 14-3-3σ by siRNA significantly abolished 14-3-3σ-CM induced MMPs. In addition, treatment with recombinant 14-3-3σ (r14-3-3σ) protein exhibits a similar expression profile of MMPs induced by 14-3-3σ-CM in fibroblasts, THP-1 and PMA-THP-1 cells. Finally, knockdown of aminopeptidase N (APN) significantly abrogated r14-3-3σ induced expression of MMPs in HS68 fibroblasts. These results suggest that HCC-secreted 14-3-3σ promotes expression of MMPs in cancerous surrounding cells via an APN dependent mechanism. 14-3-3σ has a paracrine effect in educating stromal cells in tumor-associated microenvironment.

M2 macrophage polarization modulates epithelial-mesenchymal transition in cisplatin-induced tubulointerstitial fibrosis.

Cisplatin-induced nephrotoxicity leaded to apoptosis of tubular epithelial cells (ECs) and tubulointerstitial fibrosis through ROS stress and inflammatory cytokines. Tubulointerstitial fibrosis caused by cisplatin might be via activation of resident fibroblasts and epithelial-mesenchymal transition (EMT) of tubular ECs. Inflammatory niche was crucial for progression of fibroblast activation or EMT. It had been reported that M1/M2 macrophage polarization regulated pro-inflammation or pro-resolving phase in damage repairing. However, the role of macrophage polarization on cisplatin-induced EMT of tubular ECs had not been well elucidated. In this study, we used co-cultured cell model and condition medium to examine the interaction between tubular ECs, fibroblasts and M1/M2 macrophages. Our data showed that cisplatin alone induced incomplete EMT of tubular ECs, whereas fibroblasts co-cultured with cisplatin-treated ECs could lead to fibroblast activation by detection of α-SMA and collagen-1. Moreover, decrease of iNOS and increase of argenase-1 and CD206 expression indicated that macrophages co-cultured with cisplatin-treated ECs would turn to M2 phenotype. Finally, we found that condition medium of M2 macrophages could promote complete EMT of cisplatin-treated ECs. Taken together, cisplatin created an inflammatory niche via tubular ECs to activate fibroblasts and stimulated M2 macrophage polarization. M2 macrophages could turn back to promote EMT of cisplatin-treated ECs. These results revealed the cooperative roles of tubular ECs, fibroblast and M2 macrophages to facilitate the progression of renal fibroblasis.

Dense magnetized plasma associated with a fast radio burst.

Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.

High glucose induces bone marrow-derived mesenchymal stem cell senescence by upregulating autophagy.

Hyperglycemia was reported to cause bone marrow hematopoietic niche dysfunction, and high glucose (HG) in the cultured medium induces MSC senescence. The underlying mechanism is unclear. Here, we investigated the role of HG-induced autophagy in bone-marrow-derived mesenchymal stem cell (BMSC) senescence. HG (25 mM) increased expression of Beclin-1, Atg 5, 7 and 12, generation of LC3-II and autophagosome formation which was correlated with development of cell senescence. Pretreatment of HG-MSC with 3-methyladenine (3-MA) prevented senescence but increased apoptosis. N-acetylcysteine (NAC) was effective in abrogating HG-induced autophagy accompanied by prevention of senescence. Diphenyleneiodonium (DPI), an inhibitor of NADPH oxidase, blocked autophagy and senescence in a manner comparable to NAC. 3-MA, NAC and DPI inhibited HG-induced interleukin-6 production in BMSCs. These results suggest that hyperglycemia induces MSC senescence and local inflammation via a novel oxidant-mediated autophagy which contributes to bone marrow niche dysfunction and hematopoietic impairment.

14-3-3σ induces heat shock protein 70 expression in hepatocellular carcinoma.

BACKGROUND: 14-3-3σ is implicated in promoting tumor development of various malignancies. However, the clinical relevance of 14-3-3σ in hepatocellular carcinoma (HCC) tumor progression and modulation and pathway elucidation remain unclear. METHODS: We investigated 14-3-3σ expression in 109 HCC tissues by immunohistochemistry. Overexpression and knockdown experiments were performed by transfection with cDNA or siRNA. Protein expression and cell migration were determined by Western blot and Boyden chamber assay. RESULTS: In this study, we found that 14-3-3σ is abundantly expressed in HCC tumors. Stable or transient overexpression of 14-3-3σ induces the expression of heat shock factor-1α (HSF-1α) and heat shock protein 70 (HSP70) in HCC cells. Moreover, expression of 14-3-3σ significantly correlates with HSF-1α/HSP70 in HCC tumors and both 14-3-3σ and HSP70 overexpression are associated with micro-vascular thrombi in HCC patients, suggesting that 14-3-3σ/HSP70 expression is potentially involved in cell migration/invasion. Results of an in vitro migration assay indicate that 14-3-3σ promotes cell migration and that 14-3-3σ-induced cell migration is impaired by siRNA knockdown of HSP70. Finally, 14-3-3σ-induced HSF-1α/HSP70 expression is abolished by the knockdown of ß-catenin or activation of GSK-3ß. CONCLUSIONS: Our findings indicate that 14-3-3σ participates in promoting HCC cell migration and tumor development via ß-catenin/HSF-1α/HSP70 pathway regulation. Thus, 14-3-3σ alone or combined with HSP70 are potential prognostic biomarkers for HCC.

5-methoxyindole metabolites of L-tryptophan: control of COX-2 expression, inflammation and tumorigenesis.

Cyclooxygenase-2(COX-2) overexpression promotes inflammation and tumorigenesis. COX-2 expression in response to diverse stimuli is tightly controlled to avoid persistent overexpression. 5-methoxyindole metabolites of L-tryptophan represent a new class of compounds that control COX-2 expression at the transcriptional level. Two of the metabolites, the newly discovered 5-methoxytryptophan (5-MTP, also known as cytoguardin) and N-acetyl 5-methoxytryptamine (melatonin) are the focus of this review. 5-MTP is produced by mesenchymal cells such as fibroblasts via 5-hydroxytryptophan (5-HTP). It inhibits COX-2 transcriptional activation induced by diverse proinflammatory and mitogenic factors. Cancer cells are deficient in cytoguardin production which contributes to COX-2 overexpression. Fibroblast-generated 5-MTP is capable of restoring the control of COX-2 overexpression in cancer cells. 5-MTP blocks cancer cell migration and invasion in vitro and inhibits tumor growth and cancer metastasis in a xenograft model. Melatonin possesses similar COX-2 suppressing and anti-cancer properties albeit at supra-pharmacological concentrations. By contrast, 5-hydroxyindole metabolites of L-tryptophan such as 5-hydroxytryptamine (serotonin), 5-hydroxytryptophol and other serotonin catabolites do not control COX-2 expression. 5-hydroxytryptophan inhibits COX-2 expression through conversion to 5-MTP. The physiological relevance of 5-MTP as an endogenous regulator of inflammation and cancer metastasis remains to be investigated. On the other hand, 5-methoxyindole metabolites of tryptophan are valuable lead compounds for development of new anti-inflammatory drugs and cancer chemoprevention.

Quiescent and proliferative fibroblasts exhibit differential p300 HAT activation through control of 5-methoxytryptophan production.

Quiescent fibroblasts possess unique genetic program and exhibit high metabolic activity distinct from proliferative fibroblasts. In response to inflammatory stimulation, quiescent fibroblasts are more active in expressing cyclooxygenase-2 and other proinflammatory genes than proliferative fibroblasts. The underlying transcriptional mechanism is unclear. Here we show that phorbol 12-myristate 13-acetate (PMA) and cytokines increased p300 histone acetyltransferase activity to a higher magnitude (> 2 fold) in quiescent fibroblasts than in proliferative fibroblasts. Binding of p300 to cyclooxygenase-2 promoter was reduced in proliferative fibroblasts. By ultrahigh-performance liquid chromatography coupled with a quadrupole time of flight mass spectrometer and enzyme-immunoassay, we found that production of 5-methoxytryptophan was 2-3 folds higher in proliferative fibroblasts than that in quiescent fibroblasts. Addition of 5-methoxytryptophan and its metabolic precursor, 5-hydroxytryptophan, to quiescent fibroblasts suppressed PMA-induced p300 histone acetyltransferase activity and cyclooxygenase-2 expression to the level of proliferative fibroblasts. Silencing of tryptophan hydroxylase-1 or hydroxyindole O-methyltransferase in proliferative fibroblasts with siRNA resulted in elevation of PMA-induced p300 histone acetyltransferase activity to the level of that in quiescent fibroblasts, which was rescued by addition of 5-hydroxytryptophan or 5-methoxytryptophan. Our findings indicate that robust inflammatory gene expression in quiescent fibroblasts vs. proliferative fibroblasts is attributed to uncontrolled p300 histone acetyltransferase activation due to deficiency of 5-methoxytryptophan production. 5-methoxytryptophan thus is a potential valuable lead compound for new anti-inflammatory drug development.

Upregulation of focal adhesion kinase by 14-3-3ε via NFκB activation in hepatocellular carcinoma.

Focal adhesion kinase (FAK) is implicated in cancer cell survival, proliferation and migration. Expression of FAK expression is elevated and associated with tumor progression and metastasis in various tumors, including hepatocellular carcinoma (HCC). Increased 14-3-3ε expression is shown to be a potential prognostic factor to predict higher risk of distant metastasis and worse overall survival in HCC. The aim of this study is to investigate whether FAK is associated or regulated by 14-3-3ε to modulate tumor progression in HCC. In this study, 114 primary HCC tumors including 34 matched metastatic tumors were subjected to immunohistochemistry analysis of FAK and 14-3-3ε expression. Overexpression of FAK was significantly associated with increased risk of extrahepatic metastasis (p=0.027) and reduced 5-year overall survival rate (p=0.017). A significant correlation of FAK and 14-3-3ε expression was observed in primary tumor (p < 0.001) and also metastatic tumors. Furthermore, overexpression of 14-3-3 ε induced FAK expression and promoter activity which were determined by Western blotting analysis and luciferase-reporter assay. Moreover, 14-3-3ε enhanced NFκB activation and increased nuclear translocation of NFκB. Results from chromatin immunoprecipitation assay revealed that 14-3-3ε induced NFκB binding on FAK promoter region. These findings suggest that FAK expression is correlated with and upregulated by 14-3-3ε via activation of NFκB. Target to suppress or inactivate FAK alone, or combine with 14-3-3ε is thus considered as the potential therapeutic strategy for preventing HCC tumor progression.