Use of proteomics to identify biomarkers associated with chronic kidney disease and long-term outcomes in patients with myocardial infarction.

BACKGROUND: Patients with chronic kidney disease (CKD) have poor outcomes following myocardial infarction (MI). We performed an untargeted examination of 175 biomarkers to identify those with the strongest association with CKD and to examine the association of those biomarkers with long-term outcomes. METHODS: A total of 175 different biomarkers from MI patients enrolled in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry were analysed either by a multiple reaction monitoring mass spectrometry assay or by a multiplex assay (proximity extension assay). Random forests statistical models were used to assess the predictor importance of biomarkers, CKD and outcomes. RESULTS: A total of 1098 MI patients with a median estimated glomerular filtration rate of 85 mL min-1 /1.73 m2 were followed for a median of 3.2 years. The random forests analyses, without and with adjustment for differences in demography, comorbidities and severity of disease, identified six biomarkers (adrenomedullin, TNF receptor-1, adipocyte fatty acid-binding protein-4, TNF-related apoptosis-inducing ligand receptor 2, growth differentiation factor-15 and TNF receptor-2) to be strongly associated with CKD. All six biomarkers were also amongst the 15 strongest predictors for death, and four of them were amongst the strongest predictors of subsequent MI and heart failure hospitalization. CONCLUSION: In patients with MI, a proteomic approach could identify six biomarkers that best predicted CKD. These biomarkers were also amongst the most important predictors of long-term outcomes. Thus, these biomarkers indicate underlying mechanisms that may contribute to the poor prognosis seen in patients with MI and CKD.

Non-COVID-19 excess deaths by age and gender in the United States during the first three months of the COVID-19 pandemic.

OBJECTIVES: The first three months of the COVID-19 pandemic has disrupted healthcare systems, creating an environment by which deaths have occurred that are not directly due to COVID-19, but have occurred owing to the healthcare and societal environment resulting from COVID-19. The objective of this research is to quantify such excess deaths, partitioned by age group and gender. STUDY DESIGN: This is a data analysis. METHODS: Excess deaths by age and gender are estimated using provisional death data available from the Centers for disease control and prevention (CDC) over the time period from March 1, 2020 through May 30, 2020. Previous year fatality and population data are used as the benchmark. RESULTS: Several of the eighteen age and gender cohorts experienced statistically significant excess deaths. The results also indicate that COVID-19 has been protective for one of the age and gender cohorts. CONCLUSIONS: There have been more excess deaths in several age group and gender cohorts during the first three months of the pandemic, beyond direct deaths directly attributable to COVID-19. These non-COVID-19 excess deaths are most apparent in the 25- to 44-year age group for women and 15- to 54-year age group for men. Further research is needed to assess the cause of such excess deaths and introduce safeguards to reduce such deaths in the future.

GBA mutations in Parkinson disease: earlier death but similar neuropathological features.

BACKGROUND AND PURPOSE: Mutations in the glucocerebrosidase (GBA) gene are known to be a risk factor for Parkinson's disease (PD). Data on clinicopathological correlation are limited. The purpose of this study was to determine the clinicopathological findings that might distinguish PD cases with and without mutations in the GBA gene. METHODS: Data from the Arizona Study of Aging and Neurodegenerative Disorders were used to identify autopsied PD cases that did or did not have a GBA gene mutation. Clinical and neuropathological data were compared. RESULTS: Twelve PD cases had a GBA mutation and 102 did not. The GBA mutation cases died younger (76 vs. 81 years of age) but there was no difference in disease duration or clinical examination findings. No neuropathological differences were found in total or regional semi-quantitative scores for Lewy-type synucleinopathy, senile plaques, neurofibrillary tangles, white matter rarefaction or cerebral amyloid angiopathy scores. CONCLUSIONS: In longitudinally assessed, autopsied PD cases, those with GBA mutations had a younger age at death but there was no evidence for clinical or neuropathological differences compared to cases without GBA mutations. Due to the small GBA group size, small differences cannot be excluded.

Formation of asteroid pairs by rotational fission.

Pairs of asteroids sharing similar heliocentric orbits, but not bound together, were found recently. Backward integrations of their orbits indicated that they separated gently with low relative velocities, but did not provide additional insight into their formation mechanism. A previously hypothesized rotational fission process may explain their formation-critical predictions are that the mass ratios are less than about 0.2 and, as the mass ratio approaches this upper limit, the spin period of the larger body becomes long. Here we report photometric observations of a sample of asteroid pairs, revealing that the primaries of pairs with mass ratios much less than 0.2 rotate rapidly, near their critical fission frequency. As the mass ratio approaches 0.2, the primary period grows long. This occurs as the total energy of the system approaches zero, requiring the asteroid pair to extract an increasing fraction of energy from the primary's spin in order to escape. We do not find asteroid pairs with mass ratios larger than 0.2. Rotationally fissioned systems beyond this limit have insufficient energy to disrupt. We conclude that asteroid pairs are formed by the rotational fission of a parent asteroid into a proto-binary system, which subsequently disrupts under its own internal system dynamics soon after formation.

Serum proteomic analysis of a pre-symptomatic multiple sclerosis cohort.

BACKGROUND AND PURPOSE: Susceptibility to multiple sclerosis (MS) is determined by environmental and genetic factors, but the cause remains unknown. Changes to the proteome prior to first symptom onset may reflect the underlying pathophysiology of the disease. METHODS: This preliminary study utilized pre-symptomatic and post-symptomatic serum from a sample of 100 incident population-based US military veterans with MS along with 100 matched healthy controls. All samples were obtained from the Department of Defense Serum Repository. Multidimensional protein identification technology tandem mass spectrometry analysis was performed on tryptic peptides of lectin-captured glycosylated serum proteins following albumin/immunoglobulin G depletion. Identified proteins were analyzed with the Ingenuity Pathway Analysis program. RESULTS: The mean intervals between first symptom onset and the collection of pre-symptomatic and post-symptomatic sera were -6.0 and +1.1 years, respectively. Pre-symptomatic proteins from the MS group were differentially regulated compared with both control groups indicating that proteomic changes are detected prior to symptom onset. Pathway analysis showed that proteins involved in the complement and coagulation pathways and lipid transport are significantly altered in the serum of subjects with MS compared with healthy donors. CONCLUSIONS: Compared with healthy controls, differential proteomic changes were noted in the serum of patients with MS that preceded the onset of symptomatic disease. Further work is in progress to confirm or refute these findings.

Oligoclonal bands in multiple sclerosis reactive against two herpesviruses and association with magnetic resonance imaging findings.

BACKGROUND: Two human herpesviruses, human herpesvirus 6 (HHV-6), and Epstein-Barr virus (EBV), have been repeatedly linked to multiple sclerosis (MS). OBJECTIVE: The aim of this study was to investigate HHV-6 and EBV reactive oligoclonal bands (OCBs), and viral DNA in the intrathecal compartment in MS. METHODS: The reactivity of OCBs in cerebrospinal fluid (CSF) for EBV and HHV-6 antigens and stability of virus reactive OCBs over time were studied in a well-characterized MS patient cohort. Associations between virus reactive OCBs and viral DNA in CSF (and any clinical and/or radiological findings) were investigated. RESULTS: Of patients with MS, 38% had OCBs reactive to either one of the viruses studied, compared to none in the patients with other inflammatory neurological diseases (p=0.005). The banding pattern of virus reactive OCBs remained the same over time. Furthermore, MS patients with viral DNA in CSF had more contrast enhancing lesions (CELs). CONCLUSION: The stable presence of herpesvirus reactive OCBs in CSF further strengthens the association of MS with these viruses. The finding that herpesviruses might be linked to the appearance of active lesions warrants investigation of new therapeutic strategies to treat these viruses in MS.

Occurrence of multinucleated hepatocytes in cynomolgus monkeys (Macaca fascicularis) from different geographical regions.

Multinucleated hepatocytes (MNHs) have been occasionally reported in macaques, as well as chimpanzees and gorillas, as an incidental finding. However, information is sparse on variations in incidence in the cynomolgus macaque (Macaca fascicularis). A survey was conducted to assess the occurrence of MNHs in the liver of stock (nonstudy) animals from SNBL SRC (Alice, TX) and SNBL USA (Everett, WA) submitted for diagnostic purposes. A total of 215 cynomolgus monkeys originally from Cambodia (61), China (5), Indonesia (125), and Mauritius (24) were used for this investigation. From each animal, usually 2 liver samples were processed for histopathology with 2 sections in each slide. An MNH was defined as a hepatocyte with 3 or more nuclei. A threshold of 3 MNHs was selected for the Multinucleated Hepatocyte Grading System: 0 = not remarkable (≤3 MNHs counted from 2-4 liver sections), minimal = 4 to 15 MNHs, mild = 16 to 30 MNHs, moderate = 31 to 59 MNHs, and severe ≥60 MNHs. The incidence of MNHs was 60 of 86 (70%) in males and 72 of 129 (56%) in females for a total overall incidence of 132 of 215 animals (61%). Affected hepatocytes were frequently observed close to the capsule and generally had 3 to 8 nuclei per hepatocyte but as many as 15 occurred in a single cell. Awareness of the incidence of MNHs in cynomolgus monkeys is important for potential use as background data in preclinical safety and toxicity evaluation studies.

Seatbelt usage: is there an association with obesity?

Wearing a seatbelt can prevent motor vehicle crash deaths. While primary seatbelt laws are designed to encourage vehicle passengers to wear seatbelts by allowing law enforcement officers to issue tickets when passengers do not wear seatbelts, discomfort may discourage obese individuals from wearing a seatbelt. The objective of this study is to assess the association between state-level obesity and seatbelt usage rates in the US, and to examine the possible role played by seatbelt laws in these associations. The strength of the association between obesity rates, seatbelt usage, and primary seatbelt laws at the state level is investigated using data from 2006 to 2011. Linear regression analysis is employed. This model estimates that increasing the obesity rate by 1% in a state where a primary seatbelt law (by which law enforcement officers can issue a ticket when seatbelts are not worn) is in effect is associated with a 0.06% decrease in seatbelt usage. However the same percentage of increase in the obesity rate in a state where no primary seatbelt law is in effect is associated with a 0.55% decrease in seatbelt usage. The magnitude of the statistical association between state obesity rates and state-level seatbelt usage is related to the existence of a primary seatbelt law, such that obesity has less impact on seatbelt usage in states where primary seatbelt laws are in effect.

Retinal optogenetic therapies: clinical criteria for candidacy.

Severe blinding retinal degenerative diseases have been without treatments that could improve vision until recently. Gene therapy has been in clinical trials for certain inherited retinopathies in which photoreceptors are retained despite severe visual loss. Optogenetics is being discussed for retinal diseases in which there is severe visual loss and nearly complete photoreceptor cell death. As a retinal therapy, optogenetics would be the genetic targeting of light-sensing molecules to residual cells in a degenerate retina. Parallel with scientific advances in optogenetics should be the development of detailed criteria for patient candidacy. Here, molecularly defined retinal degenerations are used to exemplify how some diseases or stages of disease would satisfy the criteria. Measurements are made of the thickness of ganglion cell and the nerve fiber layers of the retina. Whereas the clinical category of retinitis pigmentosa has been most often mentioned for treatment by optogenetics, an argument is made for expanding the target diseases to some early-onset disorders diagnosed as Leber congenital amaurosis.

Increased accumulation of CD16+ monocytes at local sites of inflammation in patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) display a high prevalence of cardiovascular events and acute infections. Potential effector cells are the CD16(+) monocytes, known to be increased in the peripheral circulation in CKD. The aim of this study was to assess the expression of CD16 and CX3 CR1 on peripheral and in vivo extravasated monocytes in patients with CKD (GFR < 20 ml/min × 1.73 m²) using flow cytometry. In vivo extravasated monocytes were collected from a local inflammatory site, induced by a skin blistering technique. Soluble markers were assessed by Luminex. The number of CD16(+) monocytes was significantly higher in patients with CKD compared with healthy subjects, both in the peripheral circulation (P < 0.05) and at the site of induced inflammation (P < 0.001). Patients with CKD displayed significantly higher concentration of soluble CX3 CL1 both in the peripheral circulation (P < 0.01) and in the interstitial fluid (P < 0.001). In addition, patients with CKD had a significantly higher concentration of TNF-α in the peripheral circulation (P < 0.001). On the contrary, at the inflammatory site, concentrations of both TNF-α and IL-10 were significantly lower in patients with CKD compared with healthy controls (P < 0.05 for both). In conclusion, patients with CKD have an increased percentage of CD16(+) monocytes in both circulation and at the inflammatory site, and this finding is in concurrence with simultaneous changes in CX3 CR1. Together with distorted TNF-α and IL-10 levels, this may have potential impact on the altered inflammatory response in CKD.

Night blindness in Sorsby's fundus dystrophy reversed by vitamin A.

Sorsby's fundus dystrophy (SFD) is an autosomal dominant retinal degeneration caused by mutations in the tissue inhibitor of metalloproteinases-3 (TIMP3) gene. Mechanisms of the visual loss in SFD, however, remain unknown. In a SFD family with a novel TIMP3 point mutation, we tested a hypothesis that their night blindness is due to a chronic deprivation of vitamin A at the level of the photoreceptors caused by a thickened membrane barrier between the photoreceptor layer and its blood supply. Vitamin A at 50,000 IU/d was administered orally. Within a week, the night blindness disappeared in patients at early stages of disease. Nutritional night blindness is thus part of the pathophysiology of this genetic disease and vitamin A supplementation can lead to dramatic restoration of photoreceptor function.

Total colourblindness is caused by mutations in the gene encoding the alpha-subunit of the cone photoreceptor cGMP-gated cation channel.

Total colourblindness (OMIM 216900), also referred to as rod monochromacy (RM) or complete achromatopsia, is a rare, autosomal recessive inherited and congenital disorder characterized by photophobia, reduced visual acuity, nystagmus and the complete inability to discriminate between colours. Electroretinographic recordings show that in RM, rod photoreceptor function is normal, whereas cone photoreceptor responses are absent. The locus for RM has been mapped to chromosome 2q11 (ref. 2), however the gene underlying RM has not yet been identified. Recently, a suitable candidate gene, CNGA3, encoding the alpha-subunit of the cone photoreceptor cGMP-gated cation channel, a key component of the phototransduction pathway, has been cloned and assigned to human chromosome 2q11 (refs 3,4). We report the identification of missense mutations in CNGA3 in five families with RM. Homozygous mutations are present in two families, whereas the remaining families show compound heterozygous mutations. In all cases, the segregation pattern of the mutations is consistent with the autosomal recessive inheritance of the disease and all mutations affect amino acids that are highly conserved among cyclic nucleotide gated channels (CNG) in various species. This is the first report of a colour vision disorder caused by defects other than mutations in the cone pigment genes, and implies at least in this instance a common genetic basis for phototransduction in the three different cone photoreceptors of the human retina.

Mutations in MERTK, the human orthologue of the RCS rat retinal dystrophy gene, cause retinitis pigmentosa.

Mutation of a receptor tyrosine kinase gene, Mertk, in the Royal College of Surgeons (RCS) rat results in defective phagocytosis of photoreceptor outer segments by the retinal pigment epithelium (RPE) and retinal degeneration. We screened the human orthologue, MERTK, located at 2q14.1 (ref. 10), in 328 DNA samples from individuals with various retinal dystrophies and found three mutations in three individuals with retinitis pigmentosa (RP). Our findings are the first conclusive evidence implicating the RPE phagocytosis pathway in human retinal disease.

Gene therapy restores vision in a canine model of childhood blindness.

The relationship between the neurosensory photoreceptors and the adjacent retinal pigment epithelium (RPE) controls not only normal retinal function, but also the pathogenesis of hereditary retinal degenerations. The molecular bases for both primary photoreceptor and RPE diseases that cause blindness have been identified. Gene therapy has been used successfully to slow degeneration in rodent models of primary photoreceptor diseases, but efficacy of gene therapy directed at photoreceptors and RPE in a large-animal model of human disease has not been reported. Here we study one of the most clinically severe retinal degenerations, Leber congenital amaurosis (LCA). LCA causes near total blindness in infancy and can result from mutations in RPE65 (LCA, type II; MIM 180069 and 204100). A naturally occurring animal model, the RPE65-/- dog, suffers from early and severe visual impairment similar to that seen in human LCA. We used a recombinant adeno-associated virus (AAV) carrying wild-type RPE65 (AAV-RPE65) to test the efficacy of gene therapy in this model. Our results indicate that visual function was restored in this large animal model of childhood blindness.

TULP1 mutation in two extended Dominican kindreds with autosomal recessive retinitis pigmentosa.

The RP14 autosomal recessive Retinitis pigmentosa (arRP) locus has been mapped to a 2cM region of chromosome 6p21.3. TULP1 (the gene encoding tubby-like protein 1) is a candidate target for the disease mutation because it maps to the RP14 minimum genetic region and because a mutation in the highly homologous mouse tub gene leads to obesity, deafness and early progressive retinal degeneration. Here we report a splice-site mutation (IVS14+1, G-->A) that is homozygous in all affected individuals (N=33) and heterozygous in all obligate carriers (N=50) from two RP14-linked kindreds. The mutation was not observed in 210 unrelated controls. The data indicate that impairment of TULP1 protein function is a rare cause of arRP and that the normal protein plays an essential role in the physiology of the retina.

Identification of the gene that, when mutated, causes the human obesity syndrome BBS4.

Bardet-Biedl syndrome (BBS, MIM 209900) is a heterogeneous autosomal recessive disorder characterized by obesity, pigmentary retinopathy, polydactyly, renal malformations, mental retardation, and hypogenitalism. The disorder is also associated with diabetes mellitus, hypertension, and congenital heart disease. Six distinct BBS loci map to 11q13 (BBS1), 16q21 (BBS2), 3p13-p12 (BBS3), 15q22.3-q23 (BBS4), 2q31 (BBS5), and 20p12 (BBS6). Although BBS is rare in the general population (<1/100,000), there is considerable interest in identifying the genes causing BBS because components of the phenotype, such as obesity and diabetes, are common. We and others have demonstrated that BBS6 is caused by mutations in the gene MKKS (refs. 12,13), mutation of which also causes McKusick-Kaufman syndrome (hydrometrocolpos, post-axial polydactyly, and congenital heart defects). MKKS has sequence homology to the alpha subunit of a prokaryotic chaperonin in the thermosome Thermoplasma acidophilum. We recently identified a novel gene that causes BBS2. The BBS2 protein has no significant similarity to other chaperonins or known proteins. Here we report the positional cloning and identification of mutations in BBS patients in a novel gene designated BBS4.

Mutation of a nuclear receptor gene, NR2E3, causes enhanced S cone syndrome, a disorder of retinal cell fate.

Hereditary human retinal degenerative diseases usually affect the mature photoreceptor topography by reducing the number of cells through apoptosis, resulting in loss of visual function. Only one inherited retinal disease, the enhanced S-cone syndrome (ESCS), manifests a gain in function of photoreceptors. ESCS is an autosomal recessive retinopathy in which patients have an increased sensitivity to blue light; perception of blue light is mediated by what is normally the least populous cone photoreceptor subtype, the S (short wavelength, blue) cones. People with ESCS also suffer visual loss, with night blindness occurring from early in life, varying degrees of L (long, red)- and M (middle, green)-cone vision, and retinal degeneration. The altered ratio of S- to L/M-cone photoreceptor sensitivity in ESCS may be due to abnormal cone cell fate determination during retinal development. In 94% of a cohort of ESCS probands we found mutations in NR2E3 (also known as PNR), which encodes a retinal nuclear receptor recently discovered to be a ligand-dependent transcription factor. Expression of NR2E3 was limited to the outer nuclear layer of the human retina. Our results suggest that NR2E3 has a role in determining photoreceptor phenotype during human retinogenesis.

Mutations in NYX, encoding the leucine-rich proteoglycan nyctalopin, cause X-linked complete congenital stationary night blindness.

During development, visual photoreceptors, bipolar cells and other neurons establish connections within the retina enabling the eye to process visual images over approximately 7 log units of illumination. Within the retina, cells that respond to light increment and light decrement are separated into ON- and OFF-pathways. Hereditary diseases are known to disturb these retinal pathways, causing either progressive degeneration or stationary deficits. Congenital stationary night blindness (CSNB) is a group of stable retinal disorders that are characterized by abnormal night vision. Genetic subtypes of CSNB have been defined and different disease actions have been postulated. The molecular bases have been elucidated in several subtypes, providing a better understanding of the disease mechanisms and developmental retinal neurobiology. Here we have studied 22 families with 'complete' X-linked CSNB (CSNB1; MIM 310500; ref. 4) in which affected males have night blindness, some photopic vision loss and a defect of the ON-pathway. We have found 14 different mutations, including 1 founder mutation in 7 families from the United States, in a novel candidate gene, NYX. NYX, which encodes a glycosylphosphatidyl (GPI)-anchored protein called nyctalopin, is a new and unique member of the small leucine-rich proteoglycan (SLRP) family. The role of other SLRP proteins suggests that mutant nyctalopin disrupts developing retinal interconnections involving the ON-bipolar cells, leading to the visual losses seen in patients with complete CSNB.

In-vivo extravasation induces the expression of interleukin 1 receptor type 1 in human neutrophils.

In order to address neutrophil activation during inflammation we assessed the expression of interleukin 1 receptor type 1 (IL-1R1) following in-vivo extravasation. Extravasated neutrophils were collected from 11 healthy study subjects by a skin chamber technique and compared to neutrophils in peripheral blood. Expression of IL-1R1 was assessed by microarray, quantitative polymerase chain reaction (qPCR), Western blot, flow cytometry, enzyme linked immunosorbent assay (ELISA) and immunoelectron microscopy (iEM). IL-1R1 was induced following extravasation, demonstrated by both gene array and qPCR. Western blot demonstrated an increased expression of IL-1R1 in extravasated leucocytes. This was confirmed further in neutrophils by flow cytometry and iEM that also demonstrated an increased intracellular pool of IL-1R1 that could be mobilized by N-formyl-methionine-leucine-phenylalanine (fMLP). Stimulation of peripheral neutrophils with IL-1 resulted in transcription of NFκB and a number of downstream chemokines and the corresponding chemokines were also induced following in-vivo extravasation. The present results demonstrate that IL-1R1 is induced following extravasation and exists on the neutrophil surface, as well as in a mobile intracellular pool. Furthermore, neutrophils express functional IL-1R1 as demonstrated by the induction of chemokines following IL-1 stimulation. The results indicate a potential role for IL-1 in the activation of neutrophils at inflammatory sites.

IL-8 from local subcutaneous wounds regulates CD11b activation.

The cellular and soluble mediators of a dermal inflammation can be studied by the skin chamber technique. The aim of this study was to address the physiological effect of soluble mediators, released into the skin chamber, with special focus on neutrophil CD11b activation. Mediators released at the inflammatory site were studied by Milliplex and enzyme-linked immunosorbent assay (ELISA) and correlated with transmigration and CD11b activation in vivo and in vitro. Transmigration was studied by the skin chamber technique and by the transwell method, and expression of the CBRM1/5 epitope on activated CD11b was analysed by flow cytometry following in vivo and in vitro incubation with chamber fluid or recombinant interleukin-8 (IL-8). Leucocyte in vivo and in vitro transmigration both correlated with the concentrations of IL-1ß, tumour necrosis factor alpha (TNFα) and IL-8 at P < 0.05 (R > 0.7). Furthermore, CD11b was activated, in terms of exposure of the activation epitope, on neutrophils after 30 min of in vitro incubation with chamber fluid and correlated solely with the concentration of IL-8, P < 0.05 (R = 0.72). In vitro incubation with recombinant IL-8 confirmed a concentration-dependent expression of the activation epitope; however, induction of CBRM1/5 by recombinant IL-8 required a concentration that was significantly higher compared with that in chamber fluid. In addition, the CBRM1/5 epitope was analysed on in vivo extravasated neutrophils that displayed a significantly higher expression compared with circulating neutrophils, P = 0.04. We conclude that IL-8 is the major factor regulating the expression of CD11b activation epitope in neutrophils.