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Summary: Antiepileptic drugs including lamotrigine (LTG) and carbamazepine (CBZ) are among the most common causes of cutaneous adverse reactions (cADRs). Human leukocyte antigen (HLA)-B*1502 has been strongly associated with CBZ-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). To investigate this relationship, we performed high-resolution HLA genotyping on LTG-tolerant controls, healthy volunteers, and patients affected by LTG-induced cADRs, ranging from maculopapular exanthema (MPE) to SJS/TEN. Patients with LTG-induced cADRs (n =25, including three with SJS/TEN and 22 with MPE), 21 LTG-tolerant controls, and 71 healthy volunteers were enrolled. The differences in the starting dosage of LTG among the SJS/TEN, MPE, and LTG-tolerant control groups were not statistically significant. HLA-B*1502 frequency was 33.3% (1/3; LTG-induced SJS/TEN group), 9.1% (2/22; LTG-induced MPE group), 4.8% (1/21; LTG-tolerant group), and 8.5% (6/71; healthy volunteers). There was no significant difference in the frequency of subjects with the HLA-B*1502 allele between the SJS/TEN group and LTG-tolerant group (p =0.239, OR=10.0, 95% CI 0.44–228.7), and healthy volunteers (p =0.26, OR=5.42, 95% CI 0.43–68.8), MPE and LTG-tolerant groups (p =1.0, OR=1.08, 95% CI 0.20–5.8), and healthy volunteers (p =1.0, OR=2.0, 95% CI 0.17–23.9). None of the HLA alleles detected were associated with LTG-induced cADRs. In conclusion, HLA-B*1502 and other HLA alleles are not directly associated with LTG-induced MPE. The possibility that HLA-B*1502 is associated with an increased risk of LTG-induced SJS/TEN could not be excluded. [ABSTRACT FROM AUTHOR]

The molecular and cellular mechanism of microgravity-induced osteoporosis is unclear. Our previous study showed that it may be due to the decreased mechanosensitivity of osteocytes. Some research indicated that endoplasmic reticulum stress (ERS) could affect the mechanical response of cells. This study investigated the role of ERS in the altered mechanosensitivity of osteocytes under simulated microgravity (SMG). MLO-Y4 cells (osteocyte-like cell line) were cultured under SMG for 48 h and then applied 15 dyn/cm2 fluid shear stress (FSS) in the flow chamber for 1 h. In addition, melatonin (MT, 200 nmol/L), an ERS antagonist, was added to inhibit ERS. The morphology of endoplasmic reticulum was examined by immunofluorescence, ERS marker (GRP78) by Western blot and qPCR, unfolded protein pathway (UPR) related factors (IRE1, XBP1s, PERK, ATF4, ATF6) and apoptosis-related factor (CHOP) by qPCR and the mechanical sensitive factors (NO, PGE2 and ATP) by ELISA were determined. The results showed that under SMG, the endoplasmic reticulum enlarged as the endoplasmic reticulum/nucleus area ratio increased significantly and the morphology was irregular; the expression of GRP78 and UPR related factors increased significantly; NO, PGE2 and ATP induced by FSS decreased. Furthermore, MT could counter above SMG-induced effect. ERS may play an important role in the mechanosensitivity alteration in osteocytes under microgravity. • Simulated microgravity results in endoplasmic reticulum stress (ERS) and decreased mechanosensitivity of osteocytes. • Melatonin improves ERS and mechanosensitivity of osteocytes after simulated microgravity rotation. • The ERS is one of the reasons for the decreased mechanosensitivity of osteocytes under simulated microgravity. [ABSTRACT FROM AUTHOR]

Vibration at high frequency has been demonstrated to be anabolic for bone and embedded osteocytes. The response of osteocytes to vibration is frequency-dependent, but the mechanism remains unclear. Our previous computational study using an osteocyte finite element model has predicted a resonance effect involving in the frequency-dependent response of osteocytes to vibration. However, the cellular spontaneous vibratory motion of osteocytes has not been confirmed. In the present study, the cellular vibratory motions (CVM) of osteocytes were recorded by a custom-built digital holographic microscopy and quantitatively analyzed. The roles of ATP and spectrin network in the CVM of osteocytes were studied. Results showed the MLO-Y4 osteocytes displayed dynamic vibratory motions with an amplitude of ~80 nm, which is relied both on the ATP content and spectrin network. Spectrum analysis showed several frequency peaks in CVM of MLO-Y4 osteocytes at 30 Hz, 39 Hz, 83 Hz and 89 Hz. These peak frequencies are close to the commonly used effective frequencies in animal training and in-vitro cell experiments, and show a correlation with the computational predictions of the osteocyte finite element model. These results implicate that osteocytes are dynamic and the cellular dynamic motion is involved in the cellular mechanotransduction of vibration. • Spontaneous vibratory motions of osteocytes were recorded by a custom-built digital holographic microscope and analyzed. • The MLO-Y4 osteocytes displayed dynamic vibratory motions. • Increased ATP content and disruption of spectrin network both enhanced cellular vibratory motions of osteocytes. • The cellular vibratory motions may be a potential evaluation index for the mechano-sensitivity for cells. [ABSTRACT FROM AUTHOR]

Bone loss occurs in astronauts during long-term space flight, and hardly recover to the normal level after back to the earth. This is because the mechanism of microgravity-induced osteoporosis is still unclear. Advanced glycation end products (AGEs) are formed between reducing sugars and long-lived proteins and are verified to be the pathogenic mechanism for diabetic and aging osteoporosis. These non-enzymatic glycation products are considered to have adverse effects on bone metabolism and bone quality which consist of bone microstructure and bone organic matrix. However, whether AGEs accumulation happened under microgravity is not clear yet. AGEs accumulation can be induced by hyperglycemia in diabetic patients and senior people. Hyperglycemia was also found to occur in astronauts during spaceflight or under simulated microgravity, however, whether it also can cause bone matrix AGEs accumulation remains unrevealed, and whether AGEs involve in the disuse osteoporosis is as well not clear yet. Therefore, in this study, we explored the AGEs changes and genesis, together with its potential relationship with disuse osteoporosis under simulated microgravity by using a rat tail-suspended model. Sixteen 8-week-old female Sprague-Dawley rats were randomly distributed into control (CON) and tail-suspension (TS) groups. After 21-days of an experiment, fluorescent total AGEs and pentosidine in bone matrix were separately detected by fluorescence microscope and High Performance Liquid Chromatography (HPLC); soluble AGEs and glucose-related biomarkers in serum were detected by ELISA; bone microstructure was evaluated by Micro-CT, and mRNA expression of bone metabolism biomarkers (OCN, ALP, RANKL/OPG) in bone was determined by QPCR. Results showed that after tail-suspension AGEs fluorescent intensity and PEN content increased in trabecular bone while no significant changes in cortical bone; serum glucose increased and was positively correlated with bone matrix AGEs; trabecular bone microstructure was deteriorated, ALP and OCN mRNA expression decreased while RANKL/OPG mRNA expression increased, and all of them showed correlations with bone matrix AGEs. The results suggested under simulated microgravity, bone matrix AGEs accumulation may be attributed to the elevated serum glucose, and preferred to occur in trabecular bone first. AGEs accumulation in bone matrix accompanied negative effects on trabecular bone microstructure and bone metabolism activities under simulated microgravity, suggesting AGEs accumulation may be a culprit in disused bone loss. • Advanced glycation end products (AGEs) accumulation in tail-suspended rats was correlated with the elevated serum glucose. • Bone matrix AGEs preferentially accumulated in trabecular bone in tail-suspended rats. • AGEs accumulation in bone accompanied negative effects on trabecular bone microstructure and bone metabolism activities. [ABSTRACT FROM AUTHOR]

Bone loss induced by microgravity was site-specific, which occurred in cortical bone later than in trabecular bone under microgravity. The mechanism of it still remains unclear. Periosteal stem cells (PSCs) are involved in periosteal bone formation and contributed to the development of cortical bone. However, whether the behavior of PSCs involved in preventing cortical bone loss under microgravity was unknown. In this study, the alterations of PSCs under simulated microgravity were investigated by in vivo and in vitro experiments respectively. Firstly, 8-weeks-old rats were tail-suspended for 21 days to simulate microgravity. The bone mineral density (BMD) and cortical bone morphometry of the tibia were examined by μCT, and the number of PSCs as well as bone formation-related factors (RUNX2, SP7, COL1A1) on the periosteal surface of tibia were examined by immunofluorescence. Secondly, the PSCs isolated from 7-days-old rats were cultured in 2D clinostat to simulate microgravity for 5 days. The expressions of osteogenesis-related (RUNX2, SP7, COL1A1, ALP, OCN, BMP2, OPN) and adipogenesis-related factors (PPARG, CEBPA) were determined by qRT-PCR. The in vivo results showed that unlike BMD in trabecular bone that decreased significantly, BMD in cortical bone did not change in the tibia of tail-suspended rats. What's more, there was no significant change in the cortical cross-sectional area. Meanwhile, the number of PSCs and osteoblasts, and the expression levels of RUNX2, SP7 and COL1A1 on the periosteal surface were all increased. As for the in vitro experiment, the expressions of osteogenesis-related factors (RUNX2, SP7, COL1A1, OCN, OPN, BMP2) in PSCs were increased, while the adipogenesis-related factors (PPARG, CEBPA) were decreased significantly. These results suggested that simulated microgravity could enhance the osteogenic potential of PSCs, which may contribute to maintain the cortical bone relatively stable. • The number of periosteal stem cells increases under simulated microgravity. • Periosteal stem cells' osteogenic potential is enhanced under simulated microgravity. • Periosteal stem cells promote cortical bone's stability under simulated microgravity. [ABSTRACT FROM AUTHOR]

Osteocytes sense the mechanical loading and weightlessness, and orchestrate bone remodeling by directing both osteoblast and osteoclast functions. Previous studies mostly focused on the impact of mechanical loading or microgravity on the osteocyte changes in themselves. However as the mechanosensors, it is more meaningful to make clear whether and how the mechanosensitivity of osteocytes affected by weightlessness, since the alteration of mechanosensitivity may further affect the mechanotransduction process in osteocytes, and finally altered the bone remodeling process. Whereas until now, this aspect had long been overlooked and was still not clear yet. To investigate how osteocytes respond to shear stress under weightlessness, a novel custom-made device was designed to simulate microgravity and load fluid flow on cells in vitro at the same time. The osteocyte-like cell line MLO-Y4 was loaded by this novel device at 15 dyn/cm 2 shear stress with 15 rpm rotating speed. There were two loading durations for different determinations: 30 min of loading for the detection of nitric oxide and Prostaglandin E2, and 6 h of loading for the detection of three bone formation biomarkers (alkaline phosphatase, osteocalcin and procollagen type I N propeptide). In order to preliminarily explore the mechanism of this altered response to mechanical loading with different gravity in osteocytes, an observation of cytoskeleton and the determination of the elements in the Wnt/β-catenin signaling pathway were also performed after 6 h of loading. The results showed that (1) the mechanical response of both NO and PGE2 were increased higher during 15–30 min of shear stress under simulated microgravity than that under normal gravity; (2) the mechanical response of ALP activity was decreased, while that of OC and PINP content were increased by simulated microgravity. Moreover, the ALP activity and the OC content were related to the activity of Wnt signaling pathway, which plays a key role in regulating the bone formation; (3) the exploration for the mechanism of altered mechanical bio-response in osteocytes showed that F-actin filaments enhanced by shear stress under simulated microgravity were not so robust as that showed under normal gravity, and some short dendritic processes at cell periphery were only observed within the simulated microgravity groups; (4) further, the simulated microgravity significantly inhibited the mechanosensitivity of the Wnt/β-catenin signaling pathway on protein level in the osteocytes. These results suggested that the mechanosensitivity of osteocytes was altered by simulated microgravity, and this may be an adverse effect on the osteoblastic bone formation whereas be good for osteoclastogenesis. The findings in this study may provide an important clue for searching an efficient approach to prevent osteocytes from changing the orchestration for bone remodeling under microgravity, and further this prevention may finally make the physical exercises capable against bone loss under microgravity. [ABSTRACT FROM AUTHOR]

Highlights: [•] The HLA-A*2402 allele may be a protective marker for the cross-allergic reactions among aromatic AEDs. [•] HLA-B*1502 is not a major responsible allele for the cross-reactivity of cADRs to aromatic AEDs. [•] These patients with AEDs-induced SJS/TEN rarely exhibited another attack of SJS/TEN when converting to other AEDs. [Copyright &y& Elsevier]

Highlights: [•] To date, little is known about the genetic mechanisms of carbamazepine (CBZ) and lamotrigine (LTG)-induced mild rash. [•] A larger group of patients from Han Chinese were included in this study. [•] The HLA-A*0201 or HLA-DRB1*1405 carriers may have a higher risk for CBZ-induced MPE than the non-carriers. [•] The existence of the two alleles, HLA-DRB1*0301 and HLA-B*5801, may decrease the potential risk for CBZ-induced MPE. [•] HLA-A*3001 and HLA-B*1302 may be two risk alleles for LTG-induced MPE, but HLA-A*3303 may be a protective allele. [Copyright &y& Elsevier]

Abstract: Osteocytes, as most abundant cells and major mechanical sensor in bone, play an important role in the mechanism of microgravity-induced bone loss. The response of osteocytes to fluid flow stress under simulated microgravity was investigated in this study. MLO-Y4, an osteocyte-like cell line, was cultured under simulated microgravity condition for 5 days. Then cells were sheared at 15dyn/cm2 in flow chamber. After 15min shear, nitric oxide (NO) was examined by Griess Reagent and prostaglandin E2 (PGE2) by ELISA. After 6h shear, alkaline phosphatase (ALP) was examined by PNPP, osteocalcin (OC) and procollagen type I N propeptide (PINP) by ELISA. Cells were divided into four groups: CON (1G with no shear), CON-S (1G with shear), SM (simulated microgravity with no shear) and SM-S (simulated microgravity with shear). The results showed that (1) NO, ALP activity, OC and PINP increased significantly while PGE2 showed no change in SM compared with CON. (2) NO, PGE2, ALP activity and PINP increased significantly while OC decreased significantly in CON-S compared with CON. (3) NO in SM-S had no significant difference compared to SM, PGE2 and OC increased while ALP activity and PINP decreased significantly in SM-S compared with SM. (4) The increasing amplitude of PGE2 and OC, the decreasing amplitude of ALP activity in SM-S to SM was lower than that in CON-S to CON. In addition, some changes of F-actin cytoskeleton were observed by confocal microscopy. All results indicated that the response induced by fluid shear in osteocytes could be inhibited by simulated microgravity, namely the mechanosensibility of osteocytes decreased under simulated microgravity. This may partly contribute to the mechanism of microgravity-induced osteoporosis and will be helpful to find out effective description. [Copyright &y& Elsevier]

Glutathione (GSH) as one most abundant thiol, acts as important roles in regulating cellular redox activities, and various diseases are closely related with its abnormal levels. Thus, monitoring intracellular GSH levels is essential for understanding cellular metabolism of many related diseases. In this work, we firstly reported a new fluorescence turn-on sensor, which was capable of selectively, sensitively and rapid sensing GSH over other thiols, especially cysteine and homocysteine in solutions and living cells. A meso -aryltellurium boron dipyrromethene (BODIPY) was firstly designed and synthesized, which showed silenced emission due to an efficient photoinduced electron transfer (PET) process from electron-rich Te to BODIPY, and then upon exposure to GSH, the meso -Te-C bond could be rapidly cleaved by the thiol group of GSH, thus resulting in an obvious fluorescence "turn-on" phenomenon through inhibition of the PET effect. This probe exhibited excellent selectivity and sensitivity towards GSH with a short response time of 2 min, showing a remarkable fluorescence enhancement observed at 541 nm with a large fluorescence quantum yield increase from nearly 0 to 0.73 upon excitation at 500 nm in PBS/CH 3 CN (9/1, v/v). The detection limit towards GSH was further calculated to be 1.7 nM by the linear fluorescence change at 541 nm in the GSH-concentration ranging from 0 to 4 μM. Furthermore, its sensing mechanism was validated by using mass spectrometry, confirming the rapid cleavage of the Te–C bond by GSH. Finally, cell imaging experiments demonstrated that this probe could successfully detect GSH in living cells, highlighting its potential for rapid and sensitive detection of intracellular GSH level changes. Therefore, a new meso -aryltellurium-BODIPY fluorescence turn-on sensor was firstly developed, which could selectively, sensitively and fast detect cellular GSH over other thiols based on the rapid cleavage of the meso Te–C bond. Herein, we report for the first time a novel meso -aryltellurium-BODIPY-based fluorescent probe for selective, sensitive and fast detection of GSH over other thiols with an absolutely fluorescent "turn-on" phenomenon through the substitution reaction in solutions and living cells. [Display omitted] • A meso -aryltellurium boron dipyrromethene (BODIPY) was rationally designed and synthesized. • This probe could selectively, sensitively and fast detect GSH over other thiols with an absolute fluorescence turn-on effect. • It sensing mechanism was based on the rapid cleavage of the meso Te–C bond by GSH. • Cell imaging experiments confirmed its potential for sensitive and rapid detection of intracellular GSH level changes. [ABSTRACT FROM AUTHOR]

This study was undertaken to determine if visfatin is involved in the inflammation or apoptosis introduced by LPS in rats. Forty 8-week old Wistar rats were divided into four groups (n = 10 in each group) and injected with saline, visfatin, LPS and visfatin+LPS co-stimulated via caudal vein. The duodenum, jejunum and ileum were harvested from all the rats. Compared to the saline treated group, visfatin significantly increased the number of TUNEL-positive apoptotic cells and the expression of caspase-3 protein in intestinal mucosa. Similarly, ELISA and western blot analysis also showed the up-regulation of pro-caspase-3 and cleaved caspase-3 expression in the visfatin group compared to the control group. In contrast to LPS, visfatin down-regulated the expression of cleaved-caspase-3 in the visfatin+LPS co-stimulated group, resulting in a significant decrease in apoptosis in intestinal mucosal cells. We observed more pro-caspase-3 positive cells in the visfatin+LPS co-stimulated group. The results indicate that, in the presence of LPS, visfatin plays an important role in the regulation of cell apoptosis and inflammation. [ABSTRACT FROM AUTHOR]