An Inner Mitochondrial Membrane Microprotein from the SLC35A4 Upstream ORF Regulates Cellular Metabolism.

Upstream open reading frames (uORFs) are cis-acting elements that can dynamically regulate the translation of downstream ORFs by suppressing downstream translation under basal conditions and, in some cases, increasing downstream translation under stress conditions. Computational and empirical methods have identified uORFs in the 5'-UTRs of approximately half of all mouse and human transcripts, making uORFs one of the largest regulatory elements known. Because the prevailing dogma was that eukaryotic mRNAs produce a single functional protein, the peptides and small proteins, or microproteins, encoded by uORFs were rarely studied. We hypothesized that a uORF in the SLC35A4 mRNA is producing a functional microprotein (SLC35A4-MP) because of its conserved amino acid sequence. Through a series of biochemical and cellular experiments, we find that the 103-amino acid SLC35A4-MP is a single-pass transmembrane inner mitochondrial membrane (IMM) microprotein. The IMM contains the protein machinery crucial for cellular respiration and ATP generation, and loss of function studies with SLC35A4-MP significantly diminish maximal cellular respiration, indicating a vital role for this microprotein in cellular metabolism. The findings add SLC35A4-MP to the growing list of functional microproteins and, more generally, indicate that uORFs that encode conserved microproteins are an untapped reservoir of functional microproteins.

A class of anti-inflammatory lipids decrease with aging in the central nervous system.

Lipids contribute to the structure, development, and function of healthy brains. Dysregulated lipid metabolism is linked to aging and diseased brains. However, our understanding of lipid metabolism in aging brains remains limited. Here we examined the brain lipidome of mice across their lifespan using untargeted lipidomics. Co-expression network analysis highlighted a progressive decrease in 3-sulfogalactosyl diacylglycerols (SGDGs) and SGDG pathway members, including the potential degradation products lyso-SGDGs. SGDGs show an age-related decline specifically in the central nervous system and are associated with myelination. We also found that an SGDG dramatically suppresses LPS-induced gene expression and release of pro-inflammatory cytokines from macrophages and microglia by acting on the NF-κB pathway. The detection of SGDGs in human and macaque brains establishes their evolutionary conservation. This work enhances interest in SGDGs regarding their roles in aging and inflammatory diseases and highlights the complexity of the brain lipidome and potential biological functions in aging.

Panoramic imaged carotid atheromas are associated with increased neutrophil count: both validated, independent predictors of near-term myocardial infarction.

OBJECTIVES: Panoramic images (PXs) demonstrating calcified carotid artery atheromas (CCAAs) are associated with heightened risk of near-term myocardial infarction (MI). Elevated neutrophil counts (NC) within normal range 2,500-6,000 per mm3 are likewise associated with future MI signaling the role neutrophils play in the chronic inflammation process underlying coronary artery atherogenesis. We determined if CCAAs on PXs are associated with increased NC. METHODS: Investigators implemented a retrospective study of PXs and accompanying medical records of white males ≥ 65 years treated by a VA dental service. Two groups (N = 60 each) were constituted, one with atheromas (CCAA+) and one without (CCAA-). Predictor variable was CCAA + and outcome variable was NC. Bootstrapping analysis determined the difference in mean NCs between two groups, significance set at ≤0.05. RESULTS: The study group of (CCAA+) (mean age 75.9; range 69-91 years) demonstrated a mean NC of 4,843 per mm3 and control group (CCAA-) (mean age 75.3; range; 66-94) a mean NC of 4,108 per mm3. The difference between the groups was significant (p = 0.0008) (95% CI of difference of mean: -432, 431; observed effect size 736). CONCLUSIONS: CCAAs on PXs of elderly white males are associated with elevated NC; amplifying need for medical consultation prior to invasive dental procedures.

Elevated White Blood Cell Count Resultant Atherogenesis is Associated With Panoramic-Imaged Carotid Plaque.

PURPOSE: Atherosclerotic plaques develop as a result of a low-grade, chronic, systemic inflammatory response to the injury of endothelial cells arising from lipid deposition within the intima. Increased white blood cell count (WBCC) is both a validated "biologic marker" of the extent of this inflammatory process and a key participant in the development of subsequent atherosclerotic ischemic heart disease manifesting as myocardial infarction. We sought to determine if calcified carotid artery plaque (CCAP) on a panoramic image (PI), also a validated risk indicator of future myocardial infarction, is associated with increased WBCC. PATIENTS AND METHODS: We retrospectively evaluated the PI and medical records of White male military veterans aged 55 years and older treated by a VA dental service. Established were 2 cohorts of patients, 50 having plaques (CCAP+) and 50 without plaques (CCAP-). Predictor variable was CCAP+; outcome variable was WBCC. Bootstrapping analysis determined the differences in mean WBCCs between groups. Statistical significance set at ≤ 0.05. RESULTS: The study group, (mean age 74; range 59 to 91 years) demonstrated a mean WBCC of 8,062 per mm3. The control group, (mean age 72 range; 57 to 94) evidenced a mean WBCC of 7,058 per mm3. Bootstrapping analysis of WBCC values demonstrated a significant (P = .012) difference (95% confidence interval of difference of mean, -806, 742; observed effect size, 1004) between groups. CONCLUSIONS: The presence of CCAP demonstrated on PIs of older Caucasian men is associated with elevated WBCC. Concomitant presence of CCAP on PI and increased WBCC (≥7,800 per mm3) amplifies need for medical consultation before intravenous anesthesia and maxillofacial surgical procedures.

Red Cell Distribution Width, Unlike Neutrophil Lymphocyte Ratio Is Unable to Accurately Gauge Enhanced Systemic Inflammation Associated With Panoramic Imaged Carotid Plaque.

INTRODUCTION: We have previously shown that panoramic X-rays (PXs) demonstrating calcified carotid artery atheromas (CCAA) are associated with increased systemic inflammation demonstrating increased neutrophil lymphocyte ratios (NLRs), a validated risk indicator of fatal myocardial infarctions arising from coronary artery atherosclerosis. Using this same cohort of patients (with minor adjustments because of missing data), we sought to determine if a like association existed between PXs evidencing CCAA and elevated red blood cell distribution width (RDW) given conflicting data as its reliability relative to NLR as a biologic marker of system inflammation. We hypothesized that CCAAs on PXs would simultaneously be associated with both increased NLR and RDW. MATERIALS AND METHODS: Investigators implemented a cross-sectional study design. Study sample consisted of patient medical records and PXs of white men ≥ 55 years. Two groups (N = 50 each) were constituted, one with atheromas (CCAA+) and without atheromas (CCAA-). The predictor variable was CCAA+ and outcome variables were NLR and RDW. Bootstrapping analysis was employed to analyze the differences in mean NLRs and RDWs between groups since the data was not normally distributed. Statistical significance determined to be ≤ 0.05 for all tests. The Medical Center's Institutional Review Board approved the research protocol. RESULTS: A study group of 50 CCAA+ men (mean age 71; range 58-89 years) demonstrated a mean NLR of 2.98 ± 1.38 and an RDW of 13.21 ± 0.85. A control group of 50 CCAA- males (mean age 70 range; 55-91 years) evidenced a mean NLR of 2.38 ± 0.77 and an RDW of 13.16 ± 0.77. Bootstrapping comparison of NLR values evidenced significant (P = 0.008) difference (95% confidence interval of difference of mean: - 0.4272, 0.4384; observed effect size: 0.579) between groups; however, there was no significant difference in RDW values between the groups. Furthermore, logistic regression modeling demonstrated that for a one unit increase in NLR the odds of being CCAA+ (vs. CCAA-) increases by a factor of 1.659. CONCLUSION: The existence of CCAA seen on PXs of elderly white men is associated with significantly (P = 0.008) elevated NLR values but is not associated with increases in RDW.

Regulation of the ER stress response by a mitochondrial microprotein.

Cellular homeostasis relies on having dedicated and coordinated responses to a variety of stresses. The accumulation of unfolded proteins in the endoplasmic reticulum (ER) is a common stress that triggers a conserved pathway called the unfolded protein response (UPR) that mitigates damage, and dysregulation of UPR underlies several debilitating diseases. Here, we discover that a previously uncharacterized 54-amino acid microprotein PIGBOS regulates UPR. PIGBOS localizes to the mitochondrial outer membrane where it interacts with the ER protein CLCC1 at ER-mitochondria contact sites. Functional studies reveal that the loss of PIGBOS leads to heightened UPR and increased cell death. The characterization of PIGBOS reveals an undiscovered role for a mitochondrial protein, in this case a microprotein, in the regulation of UPR originating in the ER. This study demonstrates microproteins to be an unappreciated class of genes that are critical for inter-organelle communication, homeostasis, and cell survival.

Stereochemistry of Linoleic Acid Esters of Hydroxy Linoleic Acids.

The syntheses of linoleic acid esters of hydroxy linoleic acids (LAHLAs) present in oat oil and human serum have been achieved, providing access to material for testing and the determination of the stereochemistry of the natural compounds. While 9- and 13-LAHLAs were found to be a mixture of enantiomers 15-LAHLA is generated in a single optical form in oat oil. The stereochemistry of 15-LAHLA in oat oil was found to be opposite to that reported for digalactosyldiacylglycerol that possesses an embedded 15-LAHLA.

Substrate-Selective Enzyme Inhibitors.

Enzymes with multiple substrates pose a unique challenge for drug development because of an increased potential for on-target side effects. Maianti and colleagues (Nat. Chem. Biol., 2019) identify novel exo-site inhibitors with abilities to alter the substrate-selectivity of insulin-degrading enzymes (IDE). Their work illuminates new therapeutic avenues for discovering small-molecule enzyme inhibitors and redefines our current understanding of drugging enzymes with multiple substrates.

Severe Sleep Apnea Associated With Increased Systemic Inflammation and Decreased Serum Bilirubin.

PURPOSE: Obstructive sleep apnea hypopnea syndrome (OSAHS) among older men has been associated with increased systemic inflammation, as evidenced by an increased neutrophil/lymphocyte ratio (NLR) and provocation of coronary artery atherosclerosis, potentially resulting in myocardial infarction (MI). The total serum bilirubin levels (TSBLs; formed primarily from senescent red blood cells via the catabolic pathway in the reticuloendothelial system) at the higher end of the normal reference range are anti-inflammatory. However, at the lower end of the physiologic range, they have been associated with increased adverse vascular events. We compared the relationship between NLR and TSBL among subjects with "severe" OSAHS. MATERIALS AND METHODS: We used a retrospective, cross-sectional study design. The electronic medical records of older male subjects (age range, 55 to 74 years) with "severe" OSAHS treated by the dental service (January 1, 2017 to December 31, 2017) were examined. The predictor variable was the NLR, and the outcome variable was the TSBL; both were analyzed using continuous scales. Spearman's rank order correlation analysis explicated the relationship between the NLR and TBSL. Traditional proatherogenic risk factors (ie, age, body mass index, hypertension, hyperlipidemia, diabetes) were evaluated for independence using descriptive and logistic regression analysis. Significance was set at P = .05 for all tests. RESULTS: A total sample size of 47 subjects (mean age, 63.74 ± 4.12 years) was enrolled in the present study. The Spearman rank order correlation analysis determined that the NLR is significantly (P = .038) and inversely related to the TSBL (rs = -0.304). CONCLUSIONS: Older men with "severe" OSAHS demonstrated an inverse relationship between NLR and TSBL. This combination of a heightened severity marker of systemic inflammation (ie, elevated NLR) and an indicator of amplified atherosclerotic activity (ie, diminished TSBL) will identify patients potentially at increased risk of future MI and the need for cardiovascular evaluation.

Linoleic acid esters of hydroxy linoleic acids are anti-inflammatory lipids found in plants and mammals.

Fatty acid esters of hydroxy fatty acids (FAHFAs) are a recently discovered class of biologically active lipids. Here we identify the linoleic acid ester of 13-hydroxy linoleic acid (13-LAHLA) as an anti-inflammatory lipid. An oat oil fraction and FAHFA-enriched extract from this fraction showed anti-inflammatory activity in a lipopolysaccharide-induced cytokine secretion assay. Structural studies identified three LAHLA isomers (15-, 13-, and 9-LAHLA) as being the most abundant FAHFAs in the oat oil fraction. Of these LAHLAs, 13-LAHLA is the most abundant LAHLA isomer in human serum after ingestion of liposomes made of fractionated oat oil, and it is also the most abundant endogenous LAHLA in mouse and human adipose tissue. As a result, we chemically synthesized 13-LAHLA for biological assays. 13-LAHLA suppresses lipopolysaccharide-stimulated secretion of cytokines and expression of pro-inflammatory genes. These studies identify LAHLAs as an evolutionarily conserved lipid with anti-inflammatory activity in mammalian cells.

Synthesis of chemically edited derivatives of the endogenous regulator of inflammation 9-PAHSA.

Fatty acid esters of hydroxy fatty acids (FAHFAs) are a growing class of natural products found in organisms ranging from plants to humans. The roles these endogenous derivatives of fatty acids play in biology and their novel pathways for controlling inflammation have increased our understanding of basic human physiology. FAHFAs incorporate diverse fatty acids into their structures, however, given their recent discovery non-natural derivatives have not been a focus and as a result structure-activity relationships remain unknown. The importance of the long chain hydrocarbons extending from the ester linkage as they relate to anti-inflammatory activity is unknown. Herein the systematic removal of carbons from either the hydroxy fatty acid or fatty acid regions of the most studied FAHFA, palmitic acid ester of 9-hydroxystearic acid (9-PAHSA), was achieved and these synthetic, abridged analogs were tested for their ability to attenuate IL-6 production. Reduction of the carbon chain lengths of the 9-hydroxystearic acid portion or palmitic acid hydrocarbon chain resulted in lower molecular weight analogs that maintained anti-inflammatory activity or in one case enhanced activity.

Severe Obstructive Sleep Apnea With Imaged Carotid Plaque Is Significantly Associated With Systemic Inflammation.

PURPOSE: Persons with obstructive sleep apnea (OSA) are at heightened risk of myocardial infarction (MI) and stroke caused by adiposity and intermittent hypoxia, which provoke proinflammatory cytokines to induce systemic and vascular inflammation, resulting in endothelial dysfunction and development of atherosclerotic plaque. This study compared levels of systemic inflammation, as indexed by the neutrophil-to-lymphocyte ratio (NLR), between groups of patients with severe OSA with and without carotid artery calcified plaque (CACP+ and CACP-, respectively) on their panoramic image (PI). MATERIALS AND METHODS: This study had a retrospective cross-sectional study design. Medical records and PIs of men with severe OSA treated by the dental service (January 1, 2017 to December 31, 2017) were reviewed. The predictor variable was the presence or absence of CACP on PIs and the outcome variable was NLR. The t test was used to analyze differences in mean NLRs between groups. Atherogenic risk factors (age, body mass index, hypertension, and diabetes) were assessed for independence by descriptive and logistic regression analyses. Significance set at .05 for all tests. RESULTS: The study group (n = 39) of patients with CACP+ (mean age, 63 ± 7.4 yr) showed a mean NLR of 3.09 ± 1.42. The control group (n = 46) of patients with CACP- (mean age, 62 ± 6.8 yr) showed a mean NLR of 2.10 ± 0.58. The difference between groups was significant (P < .001). Logistic regression for NLR and CACP failed to show meaningful correlations with covariates. CONCLUSION: Older men with severe OSA and carotid atheromas on PIs show substantially greater systemic inflammation measured by NLRs. The combination of severe OSA, atheroma formation, and markedly increased NLR suggests a higher risk of MI and stroke and greater need for cardiovascular and cerebrovascular evaluation.

Relationship between symptomatic lower limb peripheral artery disease and calcified carotid artery plaque detected on panoramic images of neurologically asymptomatic males.

OBJECTIVE: Males with peripheral arterial disease (PAD) are at high risk of ischaemic stroke given that atherogenic risk factors for both diseases are similar. We hypothesized that neurologically asymptomatic males diagnosed with PAD would demonstrate calcified carotid artery plaques (CCAP) on panoramic images (PI) significantly more often than similarly aged males not having PAD. METHODS: Investigators implemented a retrospective cross-sectional study. Subjects were male patients over age 50 diagnosed with PAD by ankle-brachial systolic pressure index results of ≤ 0.9. Controls negative for PAD had an ankle-brachial systolic pressure index > 0.9. Predictor variable was a diagnosis of PAD and outcome variable was presence of CCAP. Prevalence of CCAP amongst the PAD+ patients was compared to prevalence of CCAP among PAD- patients. Descriptive and bivariate statistics were computed and p-value was set at 0.05. RESULTS: Final sample size consisted of 234 males (mean age 72.68 ± 9.09); 116 subjects and 118 controls. Among the PAD+ cohort, CCAP+ prevalence rate (57.76%) was significantly (p = 0.001) greater than the CCAP+ rate (36.44%) of the PAD- (control). There was no significant difference in atherogenic "risk factors" in the PAD+ cohort between CCAP+ and CCAP- subjects. CONCLUSION: We demonstrated that CCAP, a "risk factor" for future stroke and "risk indicator" of future myocardial infarction is seen significantly more often detected on the PIs of older male patients with PAD than among those without. Dentists treating patients with PAD must be uniquely vigilant for the presence of CCAPs on their patients' PI.

Severity of Obstructive Sleep Apnea Is Positively Associated With the Presence of Carotid Artery Atheromas.

PURPOSE: Hypoxemia and hypertension caused by obstructive sleep apnea (OSA) often result in atherosclerosis of the carotid and coronary vessels and heightened risk of stroke and myocardial infarction (MI). Therefore, this study investigated whether severity of OSA, based on the apnea-hypopnea index (AHI), is associated with the presence of calcified carotid artery (atherosclerotic) plaque (CCAP) seen on panoramic images (PIs). MATERIALS AND METHODS: Using a cross-sectional study design, the electronic medical records and PIs of all male patients referred from the sleep medicine service to the dental service from 2010 through 2016 were reviewed. The predictor variable was the patients' OSA intensity level as defined by the American Academy of Sleep Medicine based on the AHI score. The outcome variable was the presence of CCAP on the PI. Other variables of interest, that is, demographic and atherogenic risk factors (age, body mass index, diabetes, hypertension, and hyperlipidemia), were included in a multivariate analysis to assess the association of OSA with CCAP. RESULTS: The study sample consisted of 108 men (mean age, 54.7 ± 13.5 yr). Approximately one third (n = 33; 30.6%) presented with CCAP and this group was significantly older with greater odds of co-diagnosis of diabetes (P < .05). Patients with more "severe" OSA showed significantly greater odds of having CCAP on their PIs compared with those with "milder" OSA (odds ratio = 1.035; 95% confidence interval, 1.008-1.062; P = .010) when adjusted for confounders. CONCLUSION: There is a significant association between severity of OSA and the presence of CCAP visible on PI. These atherosclerotic plaques are "risk factors" for stroke and "risk indicators" for future MI; therefore, clinicians providing corrective airway surgery for these patients and noting concomitant CCAP on PI should refer these patients for a thorough cerebrovascular and cardiovascular workup.

Positive Association Between Neutrophil-Lymphocyte Ratio and Presence of Panoramically Imaged Carotid Atheromas Among Men.

PURPOSE: Heightened levels of systemic inflammation documented by increased neutrophil-to-lymphocyte ratios (NLRs) characterize a robust atherosclerosis processes evidenced by carotid and coronary artery plaques at ultrasound and angiography with associated strokes and myocardial infarctions (MIs). Therefore, this study investigated whether calcified carotid artery plaques (CCAPs) on panoramic images (PIs), known to herald future stroke and MI, are associated with increased NLRs. MATERIALS AND METHODS: Using a cross-sectional study design, electronic medical records and PIs of non-Hispanic white men at least 55 years old who were treated by the dental service (January 1, 2017 to December 31, 2017) were retrieved. Two groups of patients (n = 50 per group) with plaque (CCAP+) and without plaque (CCAP-) were constituted. The predictor variable was CCAP+ and the outcome variable was the NLR. A t test analyzed the differences in mean NLRs between groups. Other variables of interest, that is, atherogenic risk factors (hypertension, hyperlipidemia, and diabetes mellitus), were included in a logistic regression analysis to assess their influence on the association of CCAP with the NLR. Significance was set at .05 for all tests. RESULTS: The study group of 50 men with CCAP+ (mean age, 71.7 ± 7.47 yr) evidenced a mean NLR of 3.07 ± 1.43. The control group of 50 men with CCAP- (mean age, 69.8 ± 9.29 yr) evidenced a mean NLR of 2.13 ± 0.68. A t test analysis comparison showed a significant (P = .00007) difference (95% confidence interval, 0.49-1.39). Logistic regression failed to show any relevant relation of the NLR with the covariate and other variables of interest. CONCLUSION: There is a strong association between CCAP+ in older non-Hispanic white men and extent of systemic inflammation as evidenced by increased NLRs. These plaques are "risk factors or indicators" for future stroke and MI. Therefore, maxillofacial surgeons providing care for patients with CCAP+ should consider referring them for a comprehensive cerebrovascular and cardiovascular workup.

Prevalence of Panoramically Imaged Carotid Atheromas in Alcoholic Patients With Chronic Pancreatitis and Comorbid Diabetes.

PURPOSE: Men with alcohol-related chronic pancreatitis (ARCP) resulting in type 3c diabetes mellitus (DM) are at a uniquely elevated risk of adverse ischemic events given the role of inflammation in both the underlying disease processes and atherosclerosis. We hypothesized that their panoramic images would show a prevalence of calcified carotid artery atheromas (calcified carotid artery plaques [CCAPs]) significantly more often than a general population of similarly aged men. PATIENTS AND METHODS: We implemented a retrospective observational study. The sample was composed of male patients older than 30 years having panoramic images. The predictor variable was a diagnosis of ARCP-DM, and the outcome variable was the prevalence rate of CCAPs. The prevalence of CCAPs among the patients with ARCP-DM was then compared with that of a historical general population composed of similarly aged men. Descriptive and bivariate statistics were computed, and the P value was set at .05. RESULTS: Of the 32 men (mean age, 61.7 ± 11.2 years) with ARCP-DM, 8 (25%) (mean age, 63.3 ± 4.80 years) had atheromas (CCAPs). There was a statistically significant (P < .05) association between a diagnosis of ARCP-DM and the presence of an atheroma on the panoramic image in comparison with the 3% rate manifested by the historical general-population cohort. The presence or absence of classic atherogenic risk factors within the ARCP-DM cohort failed to distinguish between individuals with and individuals without atheroma formation on their panoramic images. CONCLUSIONS: The results of this study suggest that CCAP, a risk indicator for future adverse cardiovascular events, is frequently seen on the panoramic images of male patients with ARCP-DM. Dentists treating male patients with the disorder must be uniquely vigilant for the presence of these lesions.

Prevalence of primary open-angle glaucoma among patients with obstructive sleep apnea.

OBJECTIVE: Our objective was to determine primary open-angle glaucoma (POAG) prevalence among obstructive sleep apnea (OSA) patients because the perioperative environment risks further damaging the optic nerve. STUDY DESIGN: We analyzed a "convenience sample" referred by Sleep Medicine for oral appliances because of continuous positive airway pressure intolerance. We determined the aggregate prevalence of the 3 POAG subtypes-"classic" open-angle glaucoma (COAG), normal-tension glaucoma (NTG), and open-angle glaucoma suspect (OAGS)-among the index population and compared it with that of same hospital's general population. Similarly determined were associations between OSA severity levels (apnea-hypopnea index [AHI]) and POAG subtypes. RESULTS: Among the study sample of 225 patients with OSA (96.4% male; mean age 58.5 ± 12.3 years), 47 (20.9%) had POAG, with a subtype distribution of COAG: 12 (25.5%), NTG: 8 (17.0%), and OAGS: 27 (57.4%). The POAG prevalence rate among medical center's general population was 2.5%, which was significantly less (P < .00001) than among those with comorbid OSA. Severity of the breathing disorder (AHI) failed to identify a significant correlation to any POAG subtype (P > .05). CONCLUSION: The significant prevalence of POAG among OSA sufferers suggests need for preoperative consultations from an ophthalmologist to determine eye health and possibly an anesthesiologist to avoid potential vision loss.