Regulation of nuclear transcription by mitochondrial RNA in endothelial cells.

Chromatin-associated RNAs (caRNAs) form a relatively poorly recognized layer of the epigenome. The caRNAs reported to date are transcribed from the nuclear genome. Here, leveraging a recently developed assay for detection of caRNAs and their genomic association, we report that mitochondrial RNAs (mtRNAs) are attached to the nuclear genome and constitute a subset of caRNA, thus termed mt-caRNA. In four human cell types analyzed, mt-caRNAs preferentially attach to promoter regions. In human endothelial cells (ECs), the level of mt-caRNA-promoter attachment changes in response to environmental stress that mimics diabetes. Suppression of a non-coding mt-caRNA in ECs attenuates stress-induced nascent RNA transcription from the nuclear genome, including that of critical genes regulating cell adhesion, and abolishes stress-induced monocyte adhesion, a hallmark of dysfunctional ECs. Finally, we report increased nuclear localization of multiple mtRNAs in the ECs of human diabetic donors, suggesting many mtRNA translocate to the nucleus in a cell stress and disease-dependent manner. These data nominate mt-caRNAs as messenger molecules responsible for mitochondrial-nuclear communication and connect the immediate product of mitochondrial transcription with the transcriptional regulation of the nuclear genome.

Dual roles of myocardial mitochondrial AKT on diabetic cardiomyopathy and whole body metabolism.

BACKGROUND: The PI3K/AKT pathway transduces the majority of the metabolic actions of insulin. In addition to cytosolic targets, insulin-stimulated phospho-AKT also translocates to mitochondria in the myocardium. Mouse models of diabetes exhibit impaired mitochondrial AKT signaling but the implications of this on cardiac structure and function is unknown. We hypothesized that loss of mitochondrial AKT signaling is a critical step in cardiomyopathy and reduces cardiac oxidative phosphorylation. METHODS: To focus our investigation on the pathophysiological consequences of this mitochondrial signaling pathway, we generated transgenic mouse models of cardiac-specific, mitochondria-targeting, dominant negative AKT1 (CAMDAKT) and constitutively active AKT1 expression (CAMCAKT). Myocardial structure and function were examined using echocardiography, histology, and biochemical assays. We further investigated the underlying effects of mitochondrial AKT1 on mitochondrial structure and function, its interaction with ATP synthase, and explored in vivo metabolism beyond the heart. RESULTS: Upon induction of dominant negative mitochondrial AKT1, CAMDAKT mice developed cardiac fibrosis accompanied by left ventricular hypertrophy and dysfunction. Cardiac mitochondrial oxidative phosphorylation efficiency and ATP content were reduced, mitochondrial cristae structure was lost, and ATP synthase structure was compromised. Conversely, CAMCAKT mice were protected against development of diabetic cardiomyopathy when challenged with a high calorie diet. Activation of mitochondrial AKT1 protected cardiac function and increased fatty acid uptake in myocardium. In addition, total energy expenditure was increased in CAMCAKT mice, accompanied by reduced adiposity and reduced development of fatty liver. CONCLUSION: CAMDAKT mice modeled the effects of impaired mitochondrial signaling which occurs in the diabetic myocardium. Disruption of this pathway is a key step in the development of cardiomyopathy. Activation of mitochondrial AKT1 in CAMCAKT had a protective role against diabetic cardiomyopathy as well as improved metabolism beyond the heart.

The circadian clock CRY1 regulates pluripotent stem cell identity and somatic cell reprogramming.

Distinct metabolic conditions rewire circadian-clock-controlled signaling pathways leading to the de novo construction of signal transduction networks. However, it remains unclear whether metabolic hallmarks unique to pluripotent stem cells (PSCs) are connected to clock functions. Reprogramming somatic cells to a pluripotent state, here we highlighted non-canonical functions of the circadian repressor CRY1 specific to PSCs. Metabolic reprogramming, including AMPK inactivation and SREBP1 activation, was coupled with the accumulation of CRY1 in PSCs. Functional assays verified that CRY1 is required for the maintenance of self-renewal capacity, colony organization, and metabolic signatures. Genome-wide occupancy of CRY1 identified CRY1-regulatory genes enriched in development and differentiation in PSCs, albeit not somatic cells. Last, cells lacking CRY1 exhibit differential gene expression profiles during induced PSC (iPSC) reprogramming, resulting in impaired iPSC reprogramming efficiency. Collectively, these results suggest the functional implication of CRY1 in pluripotent reprogramming and ontogenesis, thereby dictating PSC identity.

GRHL3 activates FSCN1 to relax cell-cell adhesions between migrating keratinocytes during wound reepithelialization.

The migrating keratinocyte wound front is required for skin wound closure. Despite significant advances in wound healing research, we do not fully understand the molecular mechanisms that orchestrate collective keratinocyte migration. Here, we show that, in the wound front, the epidermal transcription factor Grainyhead like-3 (GRHL3) mediates decreased expression of the adherens junction protein E-cadherin; this results in relaxed adhesions between suprabasal keratinocytes, thus promoting collective cell migration and wound closure. Wound fronts from mice lacking GRHL3 in epithelial cells (Grhl3-cKO) have lower expression of Fascin-1 (FSCN1), a known negative regulator of E-cadherin. Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) on wounded keratinocytes shows decreased wound-induced chromatin accessibility near the Fscn1 gene in Grhl3-cKO mice, a region enriched for GRHL3 motifs. These data reveal a wound-induced GRHL3/FSCN1/E-cadherin pathway that regulates keratinocyte-keratinocyte adhesion during wound-front migration; this pathway is activated in acute human wounds and is altered in diabetic wounds in mice, suggesting translational relevance.

Total Syntheses of (+)-Peniciketals A-B and (-)-Diocollettines A Exploiting a Photoisomerization/Cyclization Union Protocol.

A late-stage photoisomerization/cyclization union tactic, in conjunction with Type I Anion Relay Chemistry (ARC), permits enantioselective total syntheses and then biological evaluation of (+)-peniciketals A and B. The photochemical protocol was further showcased by an efficient three-step construction of the architecturally complex polycyclic skeleton found in (-)-diocollettines A. The mechanism and diastereoselectivity of the photochemical protocol have also been explored by both experiment and density functional theory calculations.

Anterograde regulation of mitochondrial genes and FGF21 signaling by hepatic LSD1.

Mitochondrial biogenesis and function are controlled by anterograde regulatory pathways involving more than 1000 nuclear-encoded proteins. Transcriptional networks controlling the nuclear-encoded mitochondrial genes remain to be fully elucidated. Here, we show that histone demethylase LSD1 KO from adult mouse liver (LSD1-LKO) reduces the expression of one-third of all nuclear-encoded mitochondrial genes and decreases mitochondrial biogenesis and function. LSD1-modulated histone methylation epigenetically regulates nuclear-encoded mitochondrial genes. Furthermore, LSD1 regulates gene expression and protein methylation of nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1), which controls the final step of NAD+ synthesis and limits NAD+ availability in the nucleus. Lsd1 KO reduces NAD+-dependent SIRT1 and SIRT7 deacetylase activity, leading to hyperacetylation and hypofunctioning of GABPß and PGC-1α, the major transcriptional factor/cofactor for nuclear-encoded mitochondrial genes. Despite the reduced mitochondrial function in the liver, LSD1-LKO mice are protected from diet-induced hepatic steatosis and glucose intolerance, partially due to induction of hepatokine FGF21. Thus, LSD1 orchestrates a core regulatory network involving epigenetic modifications and NAD+ synthesis to control mitochondrial function and hepatokine production.

Enantioselective Total Synthesis of (+)-Peniciketals A and B: Two Architecturally Complex Spiroketals.

The enantioselective total syntheses of (+)-peniciketals A and B, two members of a family of architecturally complex spiroketals, have been achieved. Key synthetic transformations comprise Type I Anion Relay Chemistry (ARC) to construct the benzannulated [6,6]-spiroketal skeleton, a Negishi cross-coupling/olefin cross-metathesis reaction sequence to generate the trans-enone structure, and a late-stage large fragment union exploiting our recently developed photoisomerization/cyclization tactic.

Tubular mitochondrial AKT1 is activated during ischemia reperfusion injury and has a critical role in predisposition to chronic kidney disease.

Kidney tubular dysfunction contributes to acute kidney injury and to the transition to chronic kidney disease. Although tubular mitochondria have been implicated in the pathophysiology of kidney failure, the mechanisms are not yet clear. Here, we demonstrated that ischemia-reperfusion injury induced acute translocation and activation of mitochondrial protein kinase B (also known as AKT1) in the kidney tubules. We hypothesized that mitochondrial AKT1 signaling protects against the development of acute kidney injury and subsequent chronic kidney disease. To test this prediction, we generated two novel kidney tubule-specific transgenic mouse strains with inducible expression of mitochondria-targeted dominant negative AKT1 or constitutively active AKT1, using a Cre-Lox strategy. Inhibition of mitochondrial AKT1 in mitochondria-targeted dominant negative AKT1 mice aggravated azotemia, tubular injuries, kidney fibrosis, glomerulosclerosis, and negatively impacted survival after ischemia-reperfusion injury. Conversely, enhancing tubular mitochondrial AKT1 signaling in mitochondria-targeted constitutively active AKT1 mice attenuated kidney injuries, protected kidney function, and significantly improved survival after ischemia-reperfusion injury (76.9% vs. 20.8%, respectively). Uncoupled mitochondrial respiration and increased oxidative stress was found in the kidney tubules when mitochondria AKT1 was inhibited, supporting the role of mitochondrial dysfunction in the pathophysiology of kidney failure. Thus, our studies suggest tubular mitochondrial AKT1 signaling could be a novel target to develop new strategies for better prevention and treatment of kidney injury.

Emotional eating: A treatment-worthy construct, or artifact of relations between mood and eating behaviors in younger and older women with obesity.

Emotional eating (EE) is considered important for controlling weight, especially in women; however, it might be affected by age. Within a recently proposed model assessing theoretical paths from physical activity to changes in psychological variables and then eating behavior and weight, it was unclear if EE was a construct requiring specific treatment attention or if attending to effects of physical activity-induced mood changes on eating was sufficient. Women with obesity of >35 years-of-age (n = 100) and ≤35 years (n = 44) participated in a behavioral weight loss treatment and were assessed on psychological factors and physical activity and eating behaviors over 6 months. At baseline, the younger group demonstrated significantly higher scores on physical activity and depression, and significantly lower scores on fruit/vegetable intake. Improvements in Tension (i.e., anxiety), Overall Negative Mood, and dimensions of EE from baseline-Month 3 were significantly greater in the younger group. Similar significant improvements in physical activity and the intake of sweets and fruits/vegetables over 6 months were observed in both groups. Incorporating aggregated data, change in physical activity was significantly related to mood improvements. With the exception of EE related to Anger/Frustration, changes in dimensions of EE and Overall EE significantly mediated the prediction of sweets and fruit/vegetable intake by corresponding dimensions of mood and Overall Mood. Age group significantly moderated embedded relationships between changes in Overall EE and EE-Anxiety and change in fruit/vegetable intake, with the older age group having stronger relations. Findings suggest that EE is a construct requiring distinct attention within behavioral obesity treatments.

[Study on nasal absorption of Cistanche deserticola phenylethanol glycosides nanoemulsion in vivo].

To investigate the transnasal absorption characteristics of Cistanche deserticola phenylethanol glycosides nanoemulsion and its influencing factors. With the use of the classic in vivo nasal circulation perfusion model in rats, the absorption rate constant was used as the index to compare the nasal absorption characteristics of C. deserticola phenylethanol glycosides nanoemulsion and its aqueous solution in different concentrations, and to explore the effects of pH value of the preparation and absorption accelerator Azone on the nasal absorption of C. deserticola phenylethanol glycosides nanoemulsion. The results showed that, as compared with the aqueous solution group, the absorption rate constant was significantly higher in C. deserticola phenylethanol glycosides nanoemulsion with the same concentration(P<0.05), and C. deserticola phenylethanol glycosides nanoemulsion was more easily absorbed by the nasal cavity of rats; with the increase of the concentration of C. deserticola phenylethanol glycosides, the transnasal absorption amount of nanoemulsion was also increased in a dose-dependent manner. When the pH value of nanoemulsion was 6.0 and the ratio of Azone was 2%, the absorption rate constant was highest and the effect of promoting infiltration was the best.

Mitigation of the effects of emotional eating on sweets consumption by treatment-associated self-regulatory skills usage in emerging adult and middle-age women with obesity.

An urge to eat in response to negative emotions or mood (emotional eating) is associated with an overconsumption of unhealthy foods such as sweets. Propensities for emotional eating is most prevalent in women, but its effects might differ by age. Within behavioral obesity treatments, it is unclear whether learned self-regulatory skills mitigate the effects of emotional eating susceptibilities on sweets intake, or if expected exercise-induced mood improvements affect the emotional eating-sweets intake relationship. Emerging adult (18-25 years-of-age; n = 43) and middle-age (45-65 years-of-age; n = 79) women with obesity participating in the same cognitive-behavioral treatment that emphasized exercise prior to eating-behavior changes were assessed on levels of propensities for emotional eating, self-regulatory skills usage, mood, and intake of sweets. There were overall significant improvements in self-regulation for eating, overall mood, and daily intake of sweets; with a significantly greater reduction in sweets in the emerging adult women. Self-regulation for eating at Month 3 significantly mediated the prediction of sweets intake at Month 6 by overall emotional eating and emotional eating related to depression. When dimensions of mood (i.e., total negative mood, depression, anxiety, anger) at Month 3 were entered into the models as possible moderators of relationships between a corresponding dimension of emotional eating and sweets intake, anxiety was found to be a significant moderator. Because sweets intake was affected by age, it should be considered in behavioral obesity interventions. Findings suggested advantages of fostering self-regulatory skills and reductions in anxiety, possibly through supported exercise, to mitigate unhealthy eating behaviors associated with propensities for emotional eating.

Participation of Female Emerging Adults in a Theory- and Evidence-Based Behavioral Weight Loss Program.

Emerging adults are less likely to participate in and more likely to drop out of behavioral weight loss programs. Thirty-five female emerging adults who dropped out of a behavioral weight loss program, Weight Loss For Life, completed an online survey. Main reasons for dropout relate to insufficient behavioral skills and unique characteristics of emerging adults, especially when in college (e.g., citing working and getting good grades to be more important than losing weight). Most desired >50% of program online, having virtual groups, and using small groups to model desirable behaviors. Around $140 and $180 seemed sufficient to them to encourage participation in all scheduled treatment sessions and reaching overall weight loss goal, respectively. Future behavioral weight loss programs for emerging adults may consider helping develop time management and task management, decision-making that focuses on longer term outcomes, and immediate tangible rewards similar to what college students typically receive after they complete each class assignment.

Clinical Implications of the Association of Race With Body Satisfaction and Perceived Control Over Eating in Women Initiating a Behavioral Obesity Treatment.

OBJECTIVE: An improved understanding of the implications of race on body satisfaction might optimize the weight loss process and quality of life in women with obesity. METHODS: Women with obesity (mean [standard deviation] age, 33.0 [13.8] years) of black (n = 32) and white (n = 38) racial groups volunteered for a cognitive-behavioral weight management program. RESULTS: Body satisfaction scores at baseline and month 3 were significantly higher in the black group; however, the significant within-group improvements in that variable and on weight, physical activity, fruit and vegetable consumption, sweets intake, perceived ability to control eating, and emotional eating did not significantly differ by racial group. Neither weight nor age significantly added to the strength of the association between race and body satisfaction. Perceived ability to control eating mediated the associations between race and body satisfaction as well as change in weight and change in body satisfaction. In post hoc analyses, inverse associations between body satisfaction and emotional eating were detected regardless of race. CONCLUSION: The findings of this study increased understanding of body satisfaction in women with obesity and have implications for addressing psychosocial factors within weight loss treatments across racial and at-risk groups.

Mitochondrial Akt Signaling Modulated Reprogramming of Somatic Cells.

The signaling mechanisms controlling somatic cell reprogramming are not fully understood. In this study, we report a novel role for mitochondrial Akt1 signaling that enhanced somatic cell reprogramming efficiency. The role of mitochondrial Akt1 in somatic cell reprogramming was investigated by transducing fibroblasts with the four reprogramming factors (Oct4, Sox2, Klf4, c-Myc) in conjunction with Mito-Akt1, Mito-dnAkt1, or control virus. Mito-Akt1 enhanced reprogramming efficiency whereas Mito-dnAkt1 inhibited reprogramming. The resulting iPSCs formed embryoid bodies in vitro and teratomas in vivo. Moreover, Oct4 and Nanog promoter methylation was reduced in the iPSCs generated in the presence of Mito-Akt1. Akt1 was activated and translocated into mitochondria after growth factor stimulation in embryonic stem cells (ESCs). To study the effect of mitochondrial Akt in ESCs, a mitochondria-targeting constitutively active Akt1 (Mito-Akt1) was expressed in ESCs. Gene expression profiling showed upregulation of genes that promote stem cell proliferation and survival and down-regulation of genes that promote differentiation. Analysis of cellular respiration indicated similar metabolic profile in the resulting iPSCs and ESCs, suggesting comparable bioenergetics. These findings showed that activation of mitochondrial Akt1 signaling was required during somatic cell reprogramming.

A Hemizygous Deletion Within the PGK1 Gene in Males with PGK1 Deficiency.

Phosphoglycerate kinase-1 (PGK1) deficiency is a rare X-linked disorder caused by pathogenic variants in the PGK1 gene. Complete loss-of-function variants have not been reported in this gene, indicating that residual enzyme function is critical for viability in males. Therefore, copy number variants (CNVs) that include single exon or multiple exon deletions or duplications are generally not expected in individuals with PGK1 deficiency. Here we describe a 64-year-old male presenting with a family history (three additional affected males) and a personal history of childhood-onset metabolic myopathy that involves episodes of muscle pain, stiffness after activity, exercise intolerance, and myoglobinuria after exertion. Biochemical analysis on a muscle biopsy indicated significantly reduced activity (15% compared to normal) for phosphoglycerate kinase (PGK1), a glycolytic enzyme encoded by PGK1. A diagnosis of PGK1 deficiency was established by molecular analysis which detected an approximately 886 kb deletion involving the polyadenylation site in the 3'UTR of the PGK1 gene. RNA analysis showed significantly reduced PGK1 transcript levels (30% compared to normal). This is the first deletion reported in the PGK1 gene and is the first pathogenic variant involving the 3'UTR polyadenylation site of this gene. Our report emphasizes the role of 3'UTR variants in human disorders and underscores the need for exploring noncoding regions of disease-associated genes when seeking a molecular diagnosis.

Factors Related to Weight Gain/Loss among Emerging Adults with Obesity.

OBJECTIVES: We examined the reasons for weight gain and barriers to weight loss among emerging adults with obesity. METHODS: Eighty-one female undergraduate students with obesity completed 4-open ended questions in 2015-2016. Qualitative responses were analyzed using NVivo 11 Pro software. RESULTS: Most participants experienced weight gain prior to attending college. The most commonly reported reasons for weight gain include a lack of ability to control one's behaviors or overcome barriers (ie, poor eating habits, lack of physical activity, lack of time, easy access to food), emotional/mental health issues, physical health, and influence of significant others. Nearly half reported having a weight loss goal. Most reported having used one or more weight loss methods. Few reached short-term weight loss but quickly regained the lost weight. Major reported barriers reflect a lack of self-regulation skills, negative mood and stress, and lack of self-efficacy for healthy eating or physical activity. CONCLUSIONS: Results suggest that the perceived ability to control one's behaviors and overcome barriers, self-efficacy, and mood are important in weight-related behaviors, weight, and weight loss success among emerging adults, especially those enrolled in college.

Tracking Functional Tumor Cell Subpopulations of Malignant Glioma by Phasor Fluorescence Lifetime Imaging Microscopy of NADH.

Intra-tumoral heterogeneity is associated with therapeutic resistance of cancer and there exists a need to non-invasively identify functional tumor subpopulations responsible for tumor recurrence. Reduced nicotinamide adenine dinucleotide (NADH) is a metabolic coenzyme essential in cellular respiration. Fluorescence lifetime imaging microscopy (FLIM) of NADH has been demonstrated to be a powerful label-free indicator for inferring metabolic states of living cells. Using FLIM, we identified a significant shift towards longer NADH fluorescence lifetimes, suggesting an increase in the fraction of protein-bound NADH, in the invasive stem-like tumor-initiating cell (STIC) subpopulation relative to the tumor mass-forming cell (TMC) subpopulation of malignant gliomas. By applying our previously studied model to transition glioma from a majority of STIC to a majority of TMC in serum-adherent culture conditions following serial passages, we compared changes in NADH states, cellular respirations (oxidative phosphorylation and glycolysis), EGFR expression, and cell-growth speed over passages. We identified a significant positive correlation between free-NADH fraction and cell growth, which was related to an increase of TMC fraction. In comparison, the increase of EGFR and cellular respirations preceded all these changes. In conclusion, FLIM of NADH provides a non-invasive method to monitor the dynamics of tumor heterogeneity before and after treatment.

Structural Basis of Microtubule Stabilization by Discodermolide.

Microtubule-stabilizing agents (MSAs) are widely used in chemotherapy. Using X-ray crystallography we elucidated the detailed binding modes of two potent MSAs, (+)-discodermolide (DDM) and the DDM-paclitaxel hybrid KS-1-199-32, in the taxane pocket of ß-tubulin. The two compounds bind in a very similar hairpin conformation, as previously observed in solution. However, they stabilize the M-loop of ß-tubulin differently: KS-1-199-32 induces an M-loop helical conformation that is not observed for DDM. In the context of the microtubule structure, both MSAs connect the ß-tubulin helices H6 and H7 and loop S9-S10 with the M-loop. This is similar to the structural effects elicited by epothilone A, but distinct from paclitaxel. Together, our data reveal differential binding mechanisms of DDM and KS-1-199-32 on tubulin.