UV-induced skin's green autofluorescence is a biomarker for both non-invasive evaluations of the dosages of UV exposures of the skin and non-invasive prediction of UV-induced skin damage.

It is crucial to discover biomarkers for non-invasive evaluations of the dosages of UV exposures to a person during post-UV exposure period, and for non-invasive prediction of UV-induced skin damage. Our current study has obtained findings: UVB exposures produced dose-dependent increases in skin's green autofluorescence (AF) intensity of mice, which were significantly associated with the UVB dosages. The UVC-induced green AF increases were dose dependent, which were highly associated with the UVC dosages. Moreover, both previous reports and our current study have collectively shown significant association between UVB/UVC dosages and UVB/UVC-induced skin damage. Collectively, our study has indicated that the UVB/UVC-induced skin's AF are first biomarkers for both non-invasive evaluations of the dosages of UV exposures to a person during post-UV exposure period and non-invasive and label-free prediction of UVB/UVC-induced skin damage.

NAD+ administration decreases microvascular damage following cardiac ischemia/reperfusion by restoring autophagic flux.

Microvascular damage is a key pathological change in myocardial ischemia/reperfusion (I/R) injury. Using a rat model of myocardial I/R, our current study has provided the first evidence that nicotinamide adenine dinucleotide (NAD+) administration can significantly attenuate myocardial I/R-induced microvascular damage, including reduced regional blood perfusion, decreased microvessel density and integrity, and coronary microvascular endothelial cells (CMECs) injury. In studies with primary cultured CMECs under hypoxia/reoxygenation (HR) and a rat model of I/R, our results suggested that the protective effect of NAD+ on CMECs exposed to HR or I/R is at least partially mediated by the NAD+-induced restoration of autophagic flux, especially lysosomal autophagy: NAD+ treatment markedly induced transcription factor EB (TFEB) activation and attenuated lysosomal dysfunction in the I/R or HR-exposed cells. Collectively, our study has provided the first in vivo and in vitro evidence that NAD+ significantly rescued the impaired autophagic flux and cell apoptosis that was induced by I/R in rat CMECs, which is mediated in part through the action of TFEB-mediated lysosomal autophagy.

SIRT2 inhibition exacerbates neuroinflammation and blood-brain barrier disruption in experimental traumatic brain injury by enhancing NF-κB p65 acetylation and activation.

Sirtuin 2 (SIRT2) is a member of the sirtuin family of NAD(+) -dependent protein deacetylases. In recent years, SIRT2 inhibition has emerged as a promising treatment for neurodegenerative diseases. However, to date, there is no evidence of a specific role for SIRT2 in traumatic brain injury (TBI). We investigated the effects of SIRT2 inhibition on experimental TBI using the controlled cortical impact (CCI) injury model. Adult male mice underwent CCI or sham surgery. A selective brain-permeable SIRT2 inhibitor, AK-7, was administrated 30 min before injury. The volume of the brain edema lesion and the water content of the brain were significantly increased in mice treated with AK-7 (20 mg/kg), compared with the vehicle group, following TBI (p < 0.05 at 1 day and p < 0.05 at 3 days, respectively). Concomitantly, AK-7 administration greatly worsened neurobehavioral deficits on days 3 and 7 after CCI. Furthermore, blood-brain barrier disruption and matrix metalloproteinases (MMP)-9 activity increased following SIRT2 inhibition. AK-7 treatment increased TBI-induced microglial activation both in vivo and in vitro, accompanied by a large increase in the expression and release of inflammatory cytokines. Mechanistically, SIRT2 inhibition increased both K310 acetylation and nuclear translocation of NF-κB p65, leading to enhanced NF-κB activation and up-regulation of its target genes, including aquaporin 4 (AQP4), MMP-9, and pro-inflammatory cytokines. Together, these data demonstrate that SIRT2 inhibition exacerbates TBI by increasing NF-κB p65 acetylation and activation. Our findings provide additional evidence of an anti-inflammatory effect of SIRT2. SIRT2 is a member of the sirtuin family of NAD+-dependent protein deacetylases. Our study suggests that the SIRT2 inhibitor AK-7 exacerbates traumatic brain injury (TBI) via a potential mechanism involving increased acetylation and nuclear translocation of NF-κB p65, resulting in up-regulation of NF-κB target genes, including aquaporin 4 (AQP4), matrix metalloproteinase 9 (MMP-9), and pro-inflammatory cytokines. Our findings provide additional evidence of an anti-inflammatory effect of SIRT2.

SIRT2 Plays Significant Roles in Lipopolysaccharides-Induced Neuroinflammation and Brain Injury in Mice.

Several recent studies have suggested seemingly contrasting roles of SIRT2 in inflammation: Our previous cell culture study has indicated that SIRT2 siRNA-produced decrease in SIRT2 levels can lead to significant inhibition of lipopolysaccharides (LPS)-induced activation of BV2 microglia, suggesting that SIRT2 is required for LPS-induced microglial activation. In contrast, some studies have suggested that SIRT2 deficiency can lead to increased inflammation. In our current study, we used a mouse model of neuroinflammation to determine the roles of SIRT2 in LPS-induced inflammation. We found that administration of SIRT2 inhibitor AGK2 can significantly decrease LPS-induced increases in CD11b signals and the mRNA of TNF-α and IL-6. We further found that AGK2 can block LPS-induced nuclear translocation of NFκB. In addition, our study has shown that AGK2 can decrease not only LPS-induced increase in TUNEL signals-a marker of apoptosis-like damage, but also LPS-induced increases in the levels of active Caspase-3 and Bax. Collectively, our current in vivo study, together with our previous cell culture study, has suggested that SIRT2 is required for LPS-induced neuroinflammation and brain injury.

NAD+ treatment can prevent rotenone-induced increases in DNA damage, Bax levels and nuclear translocation of apoptosis-inducing factor in differentiated PC12 cells.

Nicotinamide adenine dinucleotide (NAD(+)) plays critical roles in energy metabolism, mitochondrial functions, calcium homeostasis and immunological functions. Our previous studies have found that NAD(+) administration can profoundly decrease ischemic brain injury and traumatic brain injury. Our recent study has also provided first direct evidence indicating that NAD(+) treatment can decrease cellular apoptosis, while the mechanisms underlying this protective effect remain unclear. In our current study, we determined the effects of NAD(+) treatment on several major factors in apoptosis and necrosis, including levels of Bax and nuclear translocation of apoptosis-inducing factor (AIF), as well as levels of DNA double-strand breaks (DSBs) and intracellular ATP in rotenone-treated differentiated PC12 cells. We found that NAD(+) treatment can markedly attenuate the rotenone-induced increases in the levels of Bax and nuclear translocation of AIF in the cells. We further found that NAD(+) treatment can significantly attenuate the rotenone-induced increase in the levels of DSBs and decrease in the intracellular ATP levels. Collectively, our study has suggested mechanisms underlying the preventive effects of NAD(+) on apoptosis, which has highlighted the therapeutic potential of NAD(+) for decreasing apoptotic changes in multiple major diseases.

Malate-Aspartate Shuttle Inhibitor Aminooxyacetate Acid Induces Apoptosis and Impairs Energy Metabolism of Both Resting Microglia and LPS-Activated Microglia.

NADH shuttles mediate the transfer of the reducing equivalents of cytosolic NADH into mitochondria. Cumulating evidence has suggested that malate-aspartate shuttle (MAS), one of the two types of NADH shuttles, plays significant roles in such biological processes as glutamate synthesis in neurons. However, there has been no information regarding the roles of NADH shuttle in the survival and energy metabolism of microglia. In current study, using microglial BV2 cells as a cellular model, we determined the roles of MAS in the survival and energy metabolism of microglia by using aminooxyacetate acid (AOAA)-a widely used MAS inhibitor. Our study has suggested that AOAA can effectively inhibit the MAS activity of the cells. We also found that AOAA can induce both early- and late-stage apoptosis of resting microglia and lipopolysaccharides (LPS)-activated microglia. AOAA also induced mitochondrial depolarization, increases in the cytosolic Ca(2+) concentrations, and decreases in the intracellular ATP levels. Moreover, our study has excluded the possibility that the major nonspecific effect of AOAA-inhibition of GABA transaminase-is involved in theses effects of AOAA. Collectively, our study has provided first information suggesting significant roles of MAS in the survival and energy metabolism in both resting microglia and LPS-activated microglia.

Basal CD38/cyclic ADP-ribose-dependent signaling mediates ATP release and survival of microglia by modulating connexin 43 hemichannels.

It is necessary to investigate the mechanisms underlying ATP release from neural cells, because extracellular ATP plays multiple important biological roles in the brain. CD38 is an ectoenzyme that consumes NAD(+) to produce cyclic ADP-ribose (cADPR), a potent agonist of ryanodine receptors. Our previous study showed that CD38 reductions led to microglial apoptosis. In this study, we used both murine microglial BV2 cells and primary microglial cultures as cellular models to test our hypothesis that basal CD38/cyclic ADP-ribose (CD38/cADPR)-dependent signaling plays a key role in ATP release, which mediates basal survival of microglia. We found that inhibition of CD38/cADPR-dependent signaling by CD38 silencing or 8-Bromo-cADPR, a ryanodine receptor antagonist, produced significant ATP release from BV2 microglia. Cx43 small interfering RNA and Cx43 hemichannel blocker 18-α-glycyrrhetinic acid completely prevented the CD38 silencing or 8-Bromo-cADPR-induced ATP release. Prevention of the ATP release could also be due to P2X7 receptor antagonists. Our study has further suggested a key role of ATP release in the microglial apoptosis induced by decreased CD38/cADPR-dependent signaling. In addition, by using primary microglial cultures, we found that 8-Bromo-cADPR also induced significant ATP release, which could be attenuated by 18-α-glycyrrhetinic acid. 8-Bromo-cADPR was also found to induce death of primary microglial cultures. In conclusion, our results have suggested novel roles of basal activation of CD38/cADPR-dependent signaling in mediating microglial functions and survival: It mediates ATP release from microglia by modulating Cx43 hemichannels, which can significantly affect microglial survival.

Green autofluorescence of the skin and fingernails is a novel biomarker for evaluating the risk for developing acute ischemic stroke.

The only existing approach for assessing the risk of developing acute ischemic stroke (AIS) necessitates that individuals possess a strong understanding of their health status. Our research gathered compelling evidence in favor of our hypothesis, suggesting that the likelihood of developing AIS can be assessed by analyzing the green autofluorescence (AF) of the skin and fingernails. Utilizing machine learning-based analyses of AF images, we found that the area under the curve (AUC) for distinguishing subjects with three risk factors from those with zero, one, or two risk factors was 0.79, 0.76, and 0.75, respectively. Our research has revealed that green AF serves as an innovative biomarker for assessing the risk of developing AIS. Our method is objective, non-invasive, efficient, and economic, which shows great promise to boost a technology for screening natural populations for risk of developing AIS.

Phenomic Studies on Diseases: Potential and Challenges.

The rapid development of such research field as multi-omics and artificial intelligence (AI) has made it possible to acquire and analyze the multi-dimensional big data of human phenomes. Increasing evidence has indicated that phenomics can provide a revolutionary strategy and approach for discovering new risk factors, diagnostic biomarkers and precision therapies of diseases, which holds profound advantages over conventional approaches for realizing precision medicine: first, the big data of patients' phenomes can provide remarkably richer information than that of the genomes; second, phenomic studies on diseases may expose the correlations among cross-scale and multi-dimensional phenomic parameters as well as the mechanisms underlying the correlations; and third, phenomics-based studies are big data-driven studies, which can significantly enhance the possibility and efficiency for generating novel discoveries. However, phenomic studies on human diseases are still in early developmental stage, which are facing multiple major challenges and tasks: first, there is significant deficiency in analytical and modeling approaches for analyzing the multi-dimensional data of human phenomes; second, it is crucial to establish universal standards for acquirement and management of phenomic data of patients; third, new methods and devices for acquirement of phenomic data of patients under clinical settings should be developed; fourth, it is of significance to establish the regulatory and ethical guidelines for phenomic studies on diseases; and fifth, it is important to develop effective international cooperation. It is expected that phenomic studies on diseases would profoundly and comprehensively enhance our capacity in prevention, diagnosis and treatment of diseases.

Methylene blue reduces the serum levels of interleukin-6 and inhibits STAT3 activation in the brain and the skin of lipopolysaccharide-administered mice.

It is valuable to search for novel and economical agents for inhibiting STAT3 activation and blocking increases in IL-6 levels, due to the important roles of STAT3 and IL-6 in inflammation. Since Methylene Blue (MB) has shown therapeutical potential for multiple diseases, it has become increasingly important to investigate the mechanisms underlying the effects of MB on inflammation. Using a mouse model of lipopolysaccharide (LPS)-induced inflammation, we investigated the mechanisms underlying the effects of MB on inflammation, obtaining the following findings: First, MB administration attenuated the LPS-induced increases in the serum levels of IL-6; second, MB administration attenuated LPS-induced STAT3 activation of the brain; and third, MB administration attenuated LPS-induced STAT3 activation of the skin. Collectively, our study has suggested that MB administration can decrease the levels of IL-6 and STAT3 activation - two important factors in inflammation. Since MB is a clinically used and relatively economical drug, our findings have suggested therapeutic potential of MB for multiple inflammation-associated diseases due to its effects on STAT3 activation and IL-6 levels.

NAD+ administration profoundly decreases UVC-induced skin damage by attenuating oxidative stress, inflammation, DNA damage and apoptosis.

Ultraviolet (UV) radiation is a major cause of multiple major skin diseases including skin cancer. It is crucial to discover new agents that can produce profound protective effects on UV-produced skin damage. Using a mouse model, in this study we determined the effects of NAD+ on UVC-induced skin damage and investigated the mechanisms underlying the effects, obtaining the following discoveries: First, UVC-induced skin's green autofluorescence (AF) was highly correlated with the extent of UVC-indued skin's damage; second, NAD+ administration profoundly decreased UVC-induced skin damage; third, NAD+ administration significantly attenuated UVC-induced decreases in the levels of mitochondrial superoxide dismutase and catalase; fourth, NAD+ administration significantly attenuated UVC-induced increase in the level of cyclooxygenase (COX) 2 - a marker of inflammation; fifth, NAD+ administration profoundly attenuated UVC-induced increase in double-strand DNA (dsDNA) damage; and sixth, NAD+ administration profoundly attenuated UVC-induced decreases in the ratios of Bcl-2/Bax - an index of apoptosis. Collectively, our study has found that NAD+ administration can profoundly decrease UVC-induced skin damage by attenuating oxidative stress, inflammation, DNA damage, and apoptosis, suggesting great potential of NAD+ as a protective agent for UVC-induced skin damage. Moreover, our study has further indicated that the skin's green AF is a biomarker for predicting UVC-induced skin damage.

SIRT2 activity is required for the survival of C6 glioma cells.

SIRT2 is a tubulin deacetylase, which can play either detrimental or beneficial roles in cell survival under different conditions. While it has been suggested that reduced SIRT2 expression in human gliomas may contribute to development of gliomas, there has been no study that directly determines the effects of decreased SIRT2 activity on the survival of glioma cells. In this study we applied both pharmacological and molecular approaches to determine the roles of SIRT2 in the survival of glioma cells. Our studies, by conducting such assays as flow cytometry-based Annexin V assay and caspase-3 immunostaining, have indicated that decreased SIRT2 activity leads to apoptosis of C6 glioma cells by caspase-3-dependent pathway. Our experiments have further shown that reduced SIRT2 activity produces necrosis of C6 glioma cells. Moreover, our study applying SIRT2 siRNA has also shown that decreased SIRT2 leads to both necrosis and apoptotic changes of C6 glioma cells. Collectively, our study has provided novel evidence indicating that SIRT2 activity plays a key role in maintaining the survival of glioma cells, and that reduced SIRT2 activity can induce both necrosis and caspase-3-dependent apoptosis of C6 glioma cells. These results have also suggested that inhibition of SIRT2 might become a novel therapeutic strategy for gliomas.

CD38 is a key enzyme for the survival of mouse microglial BV2 cells.

CD38 is a multifunctional enzyme that can not only generate cyclic adenosine diphosphate-ribose (cADPR) - a key Ca(2+) -mobilizing second messenger - by consuming NAD(+), but also hydrolyze extracellular NAD(+). There have been only a small number of studies on the functions of CD38 in the CNS. Brain inflammation plays critical roles in ischemic brain injury and multiple other neurological diseases, in which microglia activation is a key event. In this study we determined the roles of CD38 in the basal survival of mouse BV2 microglia cells by applying CD38 siRNA. Our study found that silencing of CD38 led to significantly decreased survival of the cells. We also found that decreased CD38 levels can lead to apoptosis of the microglial cells, as assessed by flow cytometry-based Annexin V/7-AAD assay, caspase-3 immunostaining and Hoechst staining assays. Our study has further indicated that the CD38 silencing-induced apoptosis is mainly caspase 3-dependent. Collectively, our study has provided the first evidence suggesting that CD38 plays a critical role in the basal survival of microglia, and decreased CD38 can lead to caspase 3-dependent apoptosis of the cells. These results suggest that CD38 may become a therapeutic target for modulating microglial survival in neurological diseases.

[An ultra-low power, wearable, long-term ECG monitoring system with mass storage].

In this paper, we described an ultra-low power, wearable ECG system capable of long term monitoring and mass storage. This system is based on micro-chip PIC18F27J13 with consideration of its high level of integration and low power consumption. The communication with the micro-SD card is achieved through SPI bus. Through the USB, it can be connected to the computer for replay and disease diagnosis. Given its low power cost, lithium cells are used to support continuous ECG acquiring and storage for up to 15 days. Meanwhile, the wearable electrodes avoid the pains and possible risks in implanting. Besides, the mini size of the system makes long wearing possible for patients and meets the needs of long-term dynamic monitoring and mass storage requirements.

Skin's green autofluorescence at dorsal centremetacarpus may become a novel biomarker for diagnosis of lung cancer.

It is critical to discover novel biomarkers of lung cancer for establishing economical technology for diagnosis of lung cancer. Our study has suggested that the autofluorescence (AF) of the skin may become a novel biomarker of this type: First, development of lung cancer led to a significant increase in the skin's green AF in a mouse model of lung cancer; second, lung cancer patients had significantly higher skin's green AF at certain positions compared with healthy volunteers and pulmonary infection patients; and third, using the skin's green AF intensity at dorsal centremetacarpus as the variable, the areas under curve (AUC) for differentiating lung cancer patients and pulmonary infection patients and for differentiating lung cancer patients and healthy volunteers was 0.871 and 0.813, respectively. Collectively, our study has indicated that the skin's green AF at dorsal centremetacarpus may become a novel biomarker for establishing a ground-breaking diagnostic strategy for lung cancer.

Decreased green autofluorescence of lung parenchyma is a biomarker for lung cancer tissues.

It is highly valuable to discover novel biomarkers for differentiating noninvasively the cancerous tissues from the nonneoplastic tissues of lung cancer. In current study, we determined the green autofluorescence (AF) of the pulmonary parenchyma of lung cancer patients, indicating that decreased green AF of pulmonary parenchyma may be the biomarker of this type: First, the green AF intensity of the cancerous tissues was significantly lower than that of the nonneoplastic tissues of the lung cancer patients; second, the green AF intensity of the nonneoplastic tissues of the lung squamous cell carcinoma was significantly lower than that of the lung adenocarcinoma; and third, "decreased green AF intensity" could be used for differentiating the nonneoplastic tissues and the cancerous tissues. Collectively, our study has suggested that decreased green AF of lung parenchyma is a biomarker for differentiating the cancerous tissues from the nonneoplastic tissues of lung cancer.

A Comprehensive Study of De Novo Mutations on the Protein-Protein Interaction Interfaces Provides New Insights into Developmental Delay.

Mutations, especially those at the protein-protein interaction (PPI) interface, have been associated with various diseases. Meanwhile, though de novo mutations (DNMs) have been proven important in neuropsychiatric disorders, such as developmental delay (DD), the relationship between PPI interface DNMs and DD has not been well studied. Here we curated developmental delay DNM datasets from the PsyMuKB database and showed that DD patients showed a higher rate and deleteriousness in DNM missense on the PPI interface than sibling control. Next, we identified 302 DD-related PsychiPPIs, defined as PPIs harboring a statistically significant number of DNM missenses at their interface, and 42 DD candidate genes from PsychiPPI. We observed that PsychiPPIs preferentially affected the human protein interactome network hub proteins. When analyzing DD candidate genes using gene ontology and gene spatio-expression, we found that PsychiPPI genes carrying PPI interface mutations, such as FGFR3 and ALOX5, were enriched in development-related pathways and the development of the neocortex, and cerebellar cortex, suggesting their potential involvement in the etiology of DD. Our results demonstrated that DD patients carried an excess burden of PPI-truncating DNM, which could be used to efficiently search for disease-related genes and mutations in large-scale sequencing studies. In conclusion, our comprehensive study indicated the significant role of PPI interface DNMs in developmental delay pathogenicity.

Green autofluorescence of the index fingernails is a novel biomarker for noninvasive determinations on the status of tobacco smoking.

It is critical to discover novel biomarkers for tobacco smoking. Our study has indicated the green autofluorescence (AF) of Index Fingernails as a novel biomarker for rapid and noninvasive determinations on the status of tobacco smoking: The green AF intensity of the Index Fingernails of the smokers was remarkably higher than that of the nonsmokers in the natural populations. When the AF intensity of the Fingernails was used as the variable, the area under curve (AUC) for differentiating the smokers from the nonsmokers was 0.91. Similar results were obtained by analyzing the green AF of the Index Fingernails of the healthy populations and the patients of acute ischemic stroke. Collectively, our study has indicated the green AF of the Index Fingernails as a novel biomarker for tobacco smoking, based on which the first method for noninvasive, rapid and economical determinations on the status of tobacco smoking may be established.

NAD+ depletion is necessary and sufficient for poly(ADP-ribose) polymerase-1-mediated neuronal death.

Poly(ADP-ribose)-1 (PARP-1) is a key mediator of cell death in excitotoxicity, ischemia, and oxidative stress. PARP-1 activation leads to cytosolic NAD(+) depletion and mitochondrial release of apoptosis-inducing factor (AIF), but the causal relationships between these two events have been difficult to resolve. Here, we examined this issue by using extracellular NAD(+) to restore neuronal NAD(+) levels after PARP-1 activation. Exogenous NAD(+) was found to enter neurons through P2X(7)-gated channels. Restoration of cytosolic NAD(+) by this means prevented the glycolytic inhibition, mitochondrial failure, AIF translocation, and neuron death that otherwise results from extensive PARP-1 activation. Bypassing the glycolytic inhibition with the metabolic substrates pyruvate, acetoacetate, or hydroxybutyrate also prevented mitochondrial failure and neuron death. Conversely, depletion of cytosolic NAD(+) with NAD(+) glycohydrolase produced a block in glycolysis inhibition, mitochondrial depolarization, AIF translocation, and neuron death, independent of PARP-1 activation. These results establish NAD(+) depletion as a causal event in PARP-1-mediated cell death and place NAD(+) depletion and glycolytic failure upstream of mitochondrial AIF release.

NAD+ treatment induces delayed autophagy in Neuro2a cells partially by increasing oxidative stress.

NAD(+) plays important roles in various biological processes. In this study, we reported that treatment of NAD(+) induces delayed autophagy in Neuro2a cells. Moreover, the effects of NAD(+) on the autophagy in the cells appear to be, at least partially, mediated by oxidative stress. However, nicotinamide, a degradation product of NAD(+), does not affect the autophagy. Our experiments have further indicated that the NAD(+)-induced autophagy contributes to the NAD(+)-induced decrease in the survival of these cells. In summary, our study has provided the first evidence that NAD(+) treatment induces autophagy in cancer cells such as Neuro2a cells, which contributes to the NAD(+)-induced decrease in cancer cell survival.