26
|
Kwon J, Suessmilch M, McColl A, Cavanagh J, Morris BJ. Distinct trans-placental effects of maternal immune activation by TLR3 and TLR7 agonists: implications for schizophrenia risk. Sci Rep 2021; 11:23841. [PMID: 34903784 PMCID: PMC8668921 DOI: 10.1038/s41598-021-03216-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/29/2021] [Indexed: 02/07/2023] Open
Abstract
Exposure to infection in utero predisposes towards psychiatric diseases such as autism, depression and schizophrenia in later life. The mechanisms involved are typically studied by administering mimetics of double-stranded (ds) virus or bacterial infection to pregnant rats or mice. The effect of single-stranded (ss) virus mimetics has been largely ignored, despite evidence linking prenatal ss virus exposure with psychiatric disease. Understanding the effects of gestational ss virus exposure has become even more important with recent events. In this study, in pregnant mice, we compare directly the effects, on the maternal blood, placenta and the embryonic brain, of maternal administration of ds-virus mimetic poly I:C (to activate Toll-like receptor 3, TLR3) and ss-virus mimetic resiquimod (to activate TLR7/8). We find that, 4 h after the administration, both poly I:C and resiquimod elevated the levels of IL-6, TNFα, and chemokines including CCL2 and CCL5, in maternal plasma. Both agents also increased placental mRNA levels of IL-6 and IL-10, but only resiquimod increased placental TNFα mRNA. In foetal brain, poly I:C produced no detectable immune-response-related increases, whereas pronounced increases in cytokine (e.g. Il-6, Tnfα) and chemokine (e.g. Ccl2, Ccl5) expression were observed with maternal resiquimod administration. The data show substantial differences between the effect of maternal exposure to a TLR7/8 activator as compared to a TLR3 activator. There are significant implications for future modelling of diseases where maternal ss virus exposure contributes to environmental disease risk in offspring.
Collapse
|
27
|
Morris BJ, Wodak AD. Causes and consequences of the decline in circumcision in Australia. ANZ J Surg 2021; 91:2546-2547. [PMID: 34766683 DOI: 10.1111/ans.17157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/27/2021] [Accepted: 08/08/2021] [Indexed: 11/28/2022]
|
28
|
Thomson DM, Mitchell EJ, Openshaw RL, Pratt JA, Morris BJ. Mice lacking melatonin MT2 receptors exhibit attentional deficits, anxiety and enhanced social interaction. J Psychopharmacol 2021; 35:1265-1276. [PMID: 34304635 PMCID: PMC8521347 DOI: 10.1177/02698811211032439] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Aside from regulating circadian rhythms, melatonin also affects cognitive processes, such as alertness, and modulates the brain circuitry underlying psychiatric diseases, such as depression, schizophrenia and bipolar disorder, via mechanisms that are not fully clear. In particular, while melatonin MT1 receptors are thought primarily to mediate the circadian effects of the hormone, the contribution of the MT2 receptor to melatonin actions remains enigmatic. AIMS To characterise the contribution of MT2 receptors to melatonin's effects on cognition and anxiety/sociability. METHODS Mice with a genetic deletion of the MT2 receptor, encoded by the Mtnr1b gene, were compared with wild-type littermates for performance in a translational touchscreen version of the continuous performance task (CPT) to assess attentional processes and then monitored over 3 days in an ethological home-cage surveillance system. RESULTS Mtnr1b knockout (KO) mice were able to perform at relatively normal levels in the CPT. However, they showed consistent evidence of more liberal/risky responding strategies relative to control mice, with increases in hit rates and false alarm rates, which were maintained even when the cognitive demands of the task were increased. Assessment in the home-cage monitoring system revealed that female Mtnr1b KO mice have increased anxiety levels, whereas male Mtnr1b KO mice show increased sociability. CONCLUSIONS The results confirm that the MT2 receptor plays a role in cognition and also modulates anxiety and social interactions. These data provide new insights into the functions of endogenous melatonin and will inform future drug development strategies focussed on the MT2 receptor.
Collapse
|
29
|
Morris BJ. Abstract P176: Genes That Increase Human Lifespan By Protecting Against Risk Of Death From Cardiometabolic Diseases. Hypertension 2021. [DOI: 10.1161/hyp.78.suppl_1.p176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Further to our
FOXO3
findings last year, we asked whether other longevity gene variants work by mitigating mortality risk from aging-related diseases. In a longitudinal study, 3,584 American men of Japanese ancestry from the Kuakini Honolulu Heart Program were followed from baseline (Exam 4, 1991-93) until Dec 31, 2019 (1% of men) or death (99%). At baseline, 2,512 subjects had either diabetes (n=1,010), hypertension (n=1,919) or coronary heart disease (CHD; n=738), and 1,072 lacked any cardiometabolic diseases (CMD). DNA samples for genotyping were obtained at baseline. Genotype frequencies of SNPs in
MAP3K5
,
PIK3R1
,
GHR, CTGF
,
EGFR
,
FLT1
,
SIRT5
and
SIRT7
were compared between subjects with and without ageing-related diseases
.
In subjects with CMD,
MAP3K5
rs2076260
longevity-associated genotypes
CC
and
CC
+
TT
were associated with longer lifespan (covariate-adjusted hazard ratio [HR] 1.23 [95% CI: 1.12-1.35,
p=
2.5x10
-5
] in a major allele homozygote model, and 1.22 [95% CI: 1.11-1.33,
p=
1.10x10
-5
] in a heterozygote disadvantage model) compared with
CT
. For diabetes, hypertension and CHD, HR
p
-values were 0.019, 0.00048, 0.093, and 0.0024, 0.00040, 0.0014, in each respective genetic model. For
PIK3R1
, subjects with cardiovascular disease (CVD) having the longevity-associated genotypes
TT
/
CC
of SNP
rs7709243
had survival curves similar to those of subjects without a CVD (HR 1.26 [95% CI, 1.14-1.39;
p
=0.0000043]). In contrast, survival curves of subjects with the
CT
genotype were significantly lower compared with survival curves of subjects without a CVD (
p
=0.0000012 compared with
TT
/
CC
, and
p
=0.0000028 compared with
CT
). For
GHR
SNP
rs4130113
, in a heterozygote disadvantage model
GG
vs longevity-associated
AG
genotype was associated with reduced mortality risk from hypertension (HR 1.23 [95% CI, 0.94-1.41;
p
=0.0041]). Men without CVD showed no association of longevity-associated genotype with lifespan. For each gene, men without the disease outlived men with disease (
p
< 10
-6
), but genotype had no effect on lifespan. In conclusion, for
MAP3K5
,
PIK3R1
and
GHR
, but not other longevity genes, longevity genotype increases lifespan only in individuals who have CMD, CVD or hypertension, likely by protection against disease-related cellular stress.
Collapse
|
30
|
Morris BJ, Matthews JG, Pabalan N, Moreton S, Krieger JN. Male circumcision and prostate cancer: a meta-analysis revisited. THE CANADIAN JOURNAL OF UROLOGY 2021; 28:10768-10776. [PMID: 34378513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
UNLABELLED INTRODUCTION The relationship between circumcision and prostate cancer has been controversial. A recently published meta-analysis contradicted previous meta-analyses of male circumcision and prostate cancer risk. Our aim was to conduct a de novo meta-analysis and critically evaluate this recent paper published by Van Howe. MATERIALS AND METHODS We retrieved data from each of the 12 source studies Van Howe used, then performed a random effects meta-analysis of those data. We critically examined the data and other information in Van Howe's study. RESULTS Using the same values as Van Howe, we confirmed his finding of a positive association of circumcision with prostate cancer (random effects summary OR = 1.14; 95% CI 0.99, 1.31). However, our independent meta-analysis found a negative association of circumcision with prostate cancer (random effects summary OR= 0.87; 95% CI 0.76, 1.00; p = 0.05). The reason for this critical discrepancy was Van Howe's erroneous transposition of values for circumcised and uncircumcised men in his Table columns, leading to inversion of the result. We further critically evaluated a geographical analysis and cost analysis of circumcision and prostate cancer, as well as claims denying a role for sexually transmitted infections in prostate cancer etiology, finding these too to be misleading. CONCLUSIONS Van Howe's 2020 meta-analysis was based on erroneous data transposition leading to an inverted outcome. The journal concerned recently corrected his Table. Van Howe's claim of a positive association of circumcision with country-level-age standardized prostate cancer prevalence and his cost analysis were found to be questionable. Our meta-analysis showed that circumcision is associated with lower prostate cancer risk.
Collapse
|
31
|
Kwon J, Arsenis C, Suessmilch M, McColl A, Cavanagh J, Morris BJ. Differential Effects of Toll-Like Receptor Activation and Differential Mediation by MAP Kinases of Immune Responses in Microglial Cells. Cell Mol Neurobiol 2021; 42:2655-2671. [PMID: 34297254 PMCID: PMC9560989 DOI: 10.1007/s10571-021-01127-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/10/2021] [Indexed: 10/26/2022]
Abstract
Microglial activation is believed to play a role in many psychiatric and neurodegenerative diseases. Based largely on evidence from other cell types, it is widely thought that MAP kinase (ERK, JNK and p38) signalling pathways contribute strongly to microglial activation following immune stimuli acting on toll-like receptor (TLR) 3 or TLR4. We report here that exposure of SimA9 mouse microglial cell line to immune mimetics stimulating TLR4 (lipopolysaccharide-LPS) or TLR7/8 (resiquimod/R848), results in marked MAP kinase activation, followed by induction of nitric oxide synthase, and various cytokines/chemokines. However, in contrast to TLR4 or TLR7/8 stimulation, very few effects of TLR3 stimulation by poly-inosine/cytidine (polyI:C) were detected. Induction of chemokines/cytokines at the mRNA level by LPS and resiquimod were, in general, only marginally affected by MAP kinase inhibition, and expression of TNF, Ccl2 and Ccl5 mRNAs, along with nitrite production, were enhanced by p38 inhibition in a stimulus-specific manner. Selective JNK inhibition enhanced Ccl2 and Ccl5 release. Many distinct responses to stimulation of TLR4 and TLR7 were observed, with JNK mediating TNF protein induction by the latter but not the former, and suppressing Ccl5 release by the former but not the latter. These data reveal complex modulation by MAP kinases of microglial responses to immune challenge, including a dampening of some responses. They demonstrate that abnormal levels of JNK or p38 signalling in microglial cells will perturb their profile of cytokine and chemokine release, potentially contributing to abnormal inflammatory patterns in CNS disease states.
Collapse
|
32
|
Donlon TA, Chen R, Masaki KH, Willcox BJ, Morris BJ. Association with Longevity of Phosphatidylinositol 3-Kinase Regulatory Subunit 1 Gene Variants Stems from Protection against Mortality Risk in Men with Cardiovascular Disease. Gerontology 2021; 68:162-170. [PMID: 34077942 DOI: 10.1159/000515390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/20/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Genetic variation in the phosphatidylinositol 3-kinase reregulatory subunit 1 gene (PIK3R1) is associated with longevity. OBJECTIVE The aim of the study was to determine whether cardiovascular disease (CVD) affects this association. METHODS We performed a longitudinal study of longevity-associated PIK3R1 single-nucleotide polymorphism rs7709243 genotype by CVD status in 3,584 elderly American men of Japanese ancestry. RESULTS At baseline (1991-1993), 2,254 subjects had CVD and 1,314 did not. The follow-up until Dec 31, 2019 found that overall, men with a CVD had higher mortality than men without a CVD (p = 1.7 × 10-5). However, survival curves of CVD subjects differed according to PIK3R1 genotype. Those with longevity-associated PIK3R1 TT/CC had survival curves similar to those of subjects without a CVD (p = 0.11 for TT/CC, and p = 0.054 for TC), whereas survival curves for CVD subjects with the CT genotype were significantly attenuated compared with survival curves of subjects without a CVD (p = 0.0000012 compared with TT/CC, and p = 0.0000028 compared with TC). Men without CVD showed no association of longevity-associated genotype with life span (p = 0.58). Compared to subjects without any CVD, hazard ratios for mortality risk were 1.26 (95% CI, 1.14-1.39; p = 0.0000043) for CT subject with CVD and 1.07 (95% CI 0.99-1.17; p = 0.097) for CC/TT subjects with CVD. There was no genotypic effect on life span for 1,007 subjects with diabetes and 486 with cancer. CONCLUSION Our study provides novel insights into the basis for PIK3R1 as a longevity gene. We suggest that the PIK3R1 longevity genotype attenuates mortality risk in at-risk individuals by protection against cellular stress caused by CVD.
Collapse
|
33
|
Donlon TA, Chen R, Masaki KH, Willcox DC, Allsopp RC, Willcox BJ, Morris BJ. Association of growth hormone receptor gene variant with longevity in men is due to amelioration of increased mortality risk from hypertension. Aging (Albany NY) 2021; 13:14745-14767. [PMID: 34074802 PMCID: PMC8221335 DOI: 10.18632/aging.203133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/20/2021] [Indexed: 12/17/2022]
Abstract
The single nucleotide polymorphism (SNP) rs4130113 of the growth hormone receptor gene (GHR) is associated with longevity. Here we explored whether longevity-associated genotypes protect against mortality in all individuals, or only in individuals with aging-related diseases. Rs4130113 genotypes were tested for association with mortality in 3,557 elderly American men of Japanese ancestry. At baseline (1991–1993), 1,000 had diabetes, 730 had coronary heart disease (CHD), 1,901 had hypertension, 485 had cancer, and 919 lacked these diseases. The men were followed from baseline until Dec 31, 2019 or death (mean 10.8 ± 6.5 SD years, range 0.01–28.8 years; 99.0% deceased by that date). In a heterozygote disadvantage model, longevity-associated genotypes were associated with significantly lower mortality risk in individuals having hypertension (covariate-adjusted hazard ratio [HR] 0.83 [95% CI: 0.76–0.93, p = 4.3 x10–4]. But in individuals with diabetes, CHD, and cancer there was no genotypic difference in lifespan. As expected, normotensive men outlived men with hypertension (p = 0.036). There was no effect, however, of genotypic difference on lifespan in normotensive men (p = 0.11). We found that SNP rs4130113 potentially influenced the binding of transcription factors E2A, MYF, NRSF, TAL1, and TCF12 so as to alter GHR expression. We propose that in individuals with hypertension, longevity-associated genetic variation in GHR enhances cell resilience mechanisms to help protect against cellular stress caused by hypertension. As a result, hypertension-affected men who possess the longevity-associated genetic variant of GHR live as long as normotensive men.
Collapse
|
34
|
Bristow GC, Thomson DM, Openshaw RL, Mitchell EJ, Pratt JA, Dawson N, Morris BJ. 16p11 Duplication Disrupts Hippocampal-Orbitofrontal-Amygdala Connectivity, Revealing a Neural Circuit Endophenotype for Schizophrenia. Cell Rep 2021; 31:107536. [PMID: 32320645 DOI: 10.1016/j.celrep.2020.107536] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 02/18/2020] [Accepted: 03/28/2020] [Indexed: 02/07/2023] Open
Abstract
Chromosome 16p11.2 duplications dramatically increase risk for schizophrenia, but the mechanisms remain largely unknown. Here, we show that mice with an equivalent genetic mutation (16p11.2 duplication mice) exhibit impaired hippocampal-orbitofrontal and hippocampal-amygdala functional connectivity. Expression of schizophrenia-relevant GABAergic cell markers (parvalbumin and calbindin) is selectively decreased in orbitofrontal cortex, while somatostatin expression is decreased in lateral amygdala. When 16p11.2 duplication mice are tested in cognitive tasks dependent on hippocampal-orbitofrontal connectivity, performance is impaired in an 8-arm maze "N-back" working memory task and in a touchscreen continuous performance task. Consistent with hippocampal-amygdala dysconnectivity, deficits in ethologically relevant social behaviors are also observed. Overall, the cellular/molecular, brain network, and behavioral alterations markedly mirror those observed in schizophrenia patients. Moreover, the data suggest that 16p11.2 duplications selectively impact hippocampal-amygdaloid-orbitofrontal circuitry, supporting emerging ideas that dysfunction in this network is a core element of schizophrenia and defining a neural circuit endophenotype for the disease.
Collapse
|
35
|
Morris BJ, Chen R, Donlon TA, Masaki KH, Willcox DC, Allsopp RC, Willcox BJ. Lifespan extension conferred by mitogen-activated protein kinase kinase kinase 5 ( MAP3K5) longevity-associated gene variation is confined to at-risk men with a cardiometabolic disease. Aging (Albany NY) 2021; 13:7953-7974. [PMID: 33739303 PMCID: PMC8034933 DOI: 10.18632/aging.202844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/05/2021] [Indexed: 12/16/2022]
Abstract
Genetic variants of the kinase signaling gene MAP3K5 are associated with longevity. Here we explore whether the longevity-association involves protection against mortality in all individuals, or only in individuals with aging-related diseases. We tested the strongest longevity associated single nucleotide polymorphism (SNP), rs2076260, for association with mortality in 3,516 elderly American men of Japanese ancestry. At baseline (1991-1993), 2,461 had either diabetes (n=990), coronary heart disease (CHD; n=724), or hypertension (n=1,877), and 1,055 lacked any of these cardiometabolic diseases (CMDs). The men were followed from baseline until Dec 31, 2019. Longevity-associated genotype CC in a major allele homozygote model, and CC+TT in a heterozygote disadvantage model were associated with longer lifespan in individuals having a CMD (covariate-adjusted hazard ratio [HR] 1.23 [95% CI: 1.12-1.35, p=2.5x10-5] in major allele homozygote model, and 1.22 [95% CI: 1.11-1.33, p=1.10x10-5] in heterozygote disadvantage model). For diabetes, hypertension and CHD, HR p-values were 0.019, 0.00048, 0.093, and 0.0024, 0.00040, 0.0014, in each respective genetic model. As expected, men without a CMD outlived men with a CMD (p=1.9x10-6). There was, however, no difference in lifespan by genotype in men without a CMD (p=0.21 and 0.86, respectively, in each genetic model). In conclusion, we propose that in individuals with a cardiometabolic disease, longevity-associated genetic variation in MAP3K5 enhances resilience mechanisms in cells and tissues to help protect against cardiometabolic stress caused by CMDs. As a result, men with CMD having longevity genotype live as long as all men without a CMD.
Collapse
|
36
|
Chow MR, Ayiotis AI, Schoo DP, Gimmon Y, Lane KE, Morris BJ, Rahman MA, Valentin NS, Boutros PJ, Bowditch SP, Ward BK, Sun DQ, Treviño Guajardo C, Schubert MC, Carey JP, Della Santina CC. Posture, Gait, Quality of Life, and Hearing with a Vestibular Implant. N Engl J Med 2021; 384:521-532. [PMID: 33567192 PMCID: PMC8477665 DOI: 10.1056/nejmoa2020457] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Bilateral vestibular hypofunction is associated with chronic disequilibrium, postural instability, and unsteady gait owing to failure of vestibular reflexes that stabilize the eyes, head, and body. A vestibular implant may be effective in alleviating symptoms. METHODS Persons who had had ototoxic (7 participants) or idiopathic (1 participant) bilateral vestibular hypofunction for 2 to 23 years underwent unilateral implantation of a prosthesis that electrically stimulates the three semicircular canal branches of the vestibular nerve. Clinical outcomes included the score on the Bruininks-Oseretsky Test of Motor Proficiency balance subtest (range, 0 to 36, with higher scores indicating better balance), time to failure on the modified Romberg test (range, 0 to 30 seconds), score on the Dynamic Gait Index (range, 0 to 24, with higher scores indicating better gait performance), time needed to complete the Timed Up and Go test, gait speed, pure-tone auditory detection thresholds, speech discrimination scores, and quality of life. We compared participants' results at baseline (before implantation) with those at 6 months (8 participants) and at 1 year (6 participants) with the device set in its usual treatment mode (varying stimulus pulse rate and amplitude to represent rotational head motion) and in a placebo mode (holding pulse rate and amplitude constant). RESULTS The median scores at baseline and at 6 months on the Bruininks-Oseretsky test were 17.5 and 21.0, respectively (median within-participant difference, 5.5 points; 95% confidence interval [CI], 0 to 10.0); the median times on the modified Romberg test were 3.6 seconds and 8.3 seconds (difference, 5.1; 95% CI, 1.5 to 27.6); the median scores on the Dynamic Gait Index were 12.5 and 22.5 (difference, 10.5 points; 95% CI, 1.5 to 12.0); the median times on the Timed Up and Go test were 11.0 seconds and 8.7 seconds (difference, 2.3; 95% CI, -1.7 to 5.0); and the median speeds on the gait-speed test were 1.03 m per second and 1.10 m per second (difference, 0.13; 95% CI, -0.25 to 0.30). Placebo-mode testing confirmed that improvements were due to treatment-mode stimulation. Among the 6 participants who were also assessed at 1 year, the median within-participant changes from baseline to 1 year were generally consistent with results at 6 months. Implantation caused ipsilateral hearing loss, with the air-conducted pure-tone average detection threshold at 6 months increasing by 3 to 16 dB in 5 participants and by 74 to 104 dB in 3 participants. Changes in participant-reported disability and quality of life paralleled changes in posture and gait. CONCLUSIONS Six months and 1 year after unilateral implantation of a vestibular prosthesis for bilateral vestibular hypofunction, measures of posture, gait, and quality of life were generally in the direction of improvement from baseline, but hearing was reduced in the ear with the implant in all but 1 participant. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT02725463.).
Collapse
|
37
|
Chen R, Morris BJ, Donlon TA, Masaki KH, Willcox DC, Davy PMC, Allsopp RC, Willcox BJ. FOXO3 longevity genotype mitigates the increased mortality risk in men with a cardiometabolic disease. Aging (Albany NY) 2020; 12:23509-23524. [PMID: 33260156 PMCID: PMC7762472 DOI: 10.18632/aging.202175] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/22/2020] [Indexed: 12/31/2022]
Abstract
FOXO3 is a prominent longevity gene. To date, no-one has examined whether longevity-associated FOXO3 genetic variants protect against mortality in all individuals, or only in those with aging-related diseases. We therefore tested longevity-associated FOXO3 single nucleotide polymorphisms in a haplotype block for association with mortality in 3,584 elderly American men of Japanese ancestry, 2,512 with and 1,072 without a cardiometabolic disease (CMD). At baseline (1991–1993), 1,010 CMD subjects had diabetes, 1,919 had hypertension, and 738 had coronary heart disease (CHD). Follow-up until Dec 31, 2019 found that in CMD-affected individuals, longevity-associated alleles of FOXO3 were associated with significantly longer lifespan: haplotype hazard ratio 0.81 (95% CI 0.72-0.91; diabetes 0.77, hypertension 0.82, CHD 0.83). Overall, men with a CMD had higher mortality than men without a CMD (P=6x10-7). However, those men with a CMD who had the FOXO3 longevity genotype had similar survival as men without a CMD. In men without a CMD there was no association of longevity-associated alleles of FOXO3 with lifespan. Our study provides novel insights into the basis for the long-established role of FOXO3 as a longevity gene. We suggest that the FOXO3 longevity genotype increases lifespan only in at-risk individuals by protection against cardiometabolic stress.
Collapse
|
38
|
Morris BJ, Krieger JN. The Contrasting Evidence Concerning the Effect of Male Circumcision on Sexual Function, Sensation, and Pleasure: A Systematic Review. Sex Med 2020; 8:577-598. [PMID: 33008776 PMCID: PMC7691872 DOI: 10.1016/j.esxm.2020.08.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 08/25/2020] [Accepted: 08/31/2020] [Indexed: 12/24/2022] Open
Abstract
INTRODUCTION Active debate concerns whether male circumcision (MC) affects sexual function, penile sensation, or sexual pleasure. AIM To perform a systematic review examining the effect of MC on these parameters. METHODS PRISMA-compliant searches of PubMed, EMBASE, the Cochrane Library, and Google Scholar were performed, with "circumcision" used together with appropriate search terms. Articles meeting the inclusion criteria were rated for quality by the Scottish Intercollegiate Guidelines Network system. MAIN OUTCOME MEASURE Evidence rated by quality. RESULTS Searches identified 46 publications containing original data, as well as 4 systematic reviews (2 with meta-analyses), plus 29 critiques of various studies and 15 author replies, which together comprised a total of 94 publications. There was overall consistency in conclusions arising from high- and moderate-quality survey data in randomized clinical trials, systematic reviews and meta-analyses, physiological studies, large longitudinal studies, and cohort studies in diverse populations. Those studies found MC has no or minimal adverse effect on sexual function, sensation, or pleasure, with some finding improvements. A consensus from physiological and histological studies was that the glans and underside of the shaft, not the foreskin, are involved in neurological pathways mediating erogenous sensation. In contrast to the higher quality evidence, data supporting adverse effects of MC on function, sensation, or pleasure were found to be of low quality, as explained in critiques of those studies. CONCLUSION The consensus of the highest quality literature is that MC has minimal or no adverse effect, and in some studies, it has benefits on sexual functions, sensation, satisfaction, and pleasure for males circumcised neonatally or in adulthood. Morris BJ, Krieger JN. The Contrasting Evidence Concerning the Effect of Male Circumcision on Sexual Function, Sensation, and Pleasure: A Systematic Review. Sex Med 2020;8:577-598.
Collapse
|
39
|
Thomson DM, Openshaw RL, Mitchell EJ, Kouskou M, Millan MJ, Mannoury la Cour C, Morris BJ, Pratt JA. Impaired working memory, cognitive flexibility and reward processing in mice genetically lacking Gpr88: Evidence for a key role for Gpr88 in multiple cortico-striatal-thalamic circuits. GENES BRAIN AND BEHAVIOR 2020; 20:e12710. [PMID: 33078498 DOI: 10.1111/gbb.12710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/08/2020] [Accepted: 10/19/2020] [Indexed: 12/22/2022]
Abstract
The GPR88 orphan G protein-coupled receptor is expressed throughout the striatum, being preferentially localised in medium spiny neurons. It is also present in lower densities in frontal cortex and thalamus. Rare mutations in humans suggest a role in cognition and motor function, while common variants are associated with psychosis. Here we evaluate the influence of genetic deletion of GPR88 upon performance in translational tasks interrogating motivation, reward evaluation and cognitive function. In an automated radial arm maze 'N-back' working memory task, Gpr88 KO mice showed impaired correct responding, suggesting a role for GPR88 receptors in working memory circuitry. Associative learning performance was similar to wild-type controls in a touchscreen task but performance was impaired at the reversal learning stage, suggesting cognitive inflexibility. Gpr88 KO mice showed higher breakpoints, reduced latencies and lengthened session time in a progressive ratio task consistent with enhanced motivation. Simultaneously, locomotor hyperactivity was apparent in this task, supporting previous findings of actions of GPR88 in a cortico-striatal-thalamic motor loop. Evidence for a role of GPR88 in reward processing was demonstrated in a touchscreen-based equivalent of the Iowa gambling task. Although both Gpr88 KO and wild-type mice showed a preference for an optimum contingency choice, Gpr88 KO mice selected more risky choices at the expense of more advantageous lower risk options. Together these novel data suggest that striatal GPR88 receptors influence activity in a range of procedures integrated by prefrontal, orbitofrontal and anterior cingulate cortico-striatal-thalamic loops leading to altered cognitive, motivational and reward evaluation processes.
Collapse
|
40
|
Willis A, Pratt JA, Morris BJ. BDNF and JNK Signaling Modulate Cortical Interneuron and Perineuronal Net Development: Implications for Schizophrenia-Linked 16p11.2 Duplication Syndrome. Schizophr Bull 2020; 47:812-826. [PMID: 33067994 PMCID: PMC8084442 DOI: 10.1093/schbul/sbaa139] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Schizophrenia (SZ) is a neurodevelopmental disorder caused by the interaction of genetic and environmental risk factors. One of the strongest genetic risk variants is duplication (DUP) of chr.16p11.2. SZ is characterized by cortical gamma-amino-butyric acid (GABA)ergic interneuron dysfunction and disruption to surrounding extracellular matrix structures, perineuronal nets (PNNs). Developmental maturation of GABAergic interneurons, and also the resulting closure of the critical period of cortical plasticity, is regulated by brain-derived neurotrophic factor (BDNF), although the mechanisms involved are unknown. Here, we show that BDNF promotes GABAergic interneuron and PNN maturation through JNK signaling. In mice reproducing the 16p11.2 DUP, where the JNK upstream activator Taok2 is overexpressed, we find that JNK is overactive and there are developmental abnormalities in PNNs, which persist into adulthood. Prefrontal cortex parvalbumin (PVB) expression is reduced, while PNN intensity is increased. Additionally, we report a unique role for TAOK2 signaling in the regulation of PVB interneurons. Our work implicates TAOK2-JNK signaling in cortical interneuron and PNN development, and in the responses to BDNF. It also demonstrates that over-activation of this pathway in conditions associated with SZ risk causes long-lasting disruption in cortical interneurons.
Collapse
|
41
|
Morris BJ. Voluntary Medical Male Circumcision Proves Robust for Mitigating Heterosexual Human Immunodeficiency Virus Infection. Clin Infect Dis 2020; 73:e1954-e1956. [DOI: 10.1093/cid/ciaa1542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Indexed: 01/19/2023] Open
|
42
|
Morris BJ. Abstract P113: Genotypic Effect Of
Foxo3
On Lifespan Is Confined To Men With A Cardiometabolic Disorder (hypertension Or Coronary Heart Disease Or Diabetes). Hypertension 2020. [DOI: 10.1161/hyp.76.suppl_1.p113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
FOXO3
is a prominent human longevity gene. To date, no-one has examined whether longevity-associated genetic variants of
FOXO3
protect against mortality in all individuals, or whether they protect against mortality only in individuals with aging-related diseases. Here, we examined this issue for the first time. We tested 9 representative longevity associated single nucleotide polymorphisms (SNPs) located within a haplotype block of
FOXO3
for association with mortality in 3,584 elderly American men of Japanese ancestry. At baseline (1991-1993), 2,512 had either diabetes (n=1,010), coronary heart disease (CHD; n=738), or hypertension (n=1,919), and 1,072 lacked any of these cardiometabolic disorders (CMDs). The men were followed from baseline until Dec 31, 2019. The longevity-associated (minor) alleles of all 9 SNPs were strongly associated with longer lifespan in individuals who had a CMD (covariate-adjusted hazard ratios [HRs] for each SNP: 0.82-0.95 [
P
=0.00008 to 0.020]; covariate adjusted haplotype analysis HR=0.81,
P
=0.0003). For just diabetes, just hypertension, and just CHD, haplotype HRs were 0.77, 0.82 and 0.83 (
P
=0.007, 0.0003 and 0.10), respectively. Reduced mortality was strongest for carriers of the minor (
G
) allele of SNP
rs2802292
(covariate adjusted HR=0.82, 95% CI 0.75-0.90;
P=
0.00008), as were survival curve differences (covariate adjusted Cox proportional hazard model difference,
P
=0.0002). As expected, men without a CMD outlived men with a CMD (Kaplan-Meier Log-rank chi-squared=24.8,
P
=0.0001). There was, however, no genotypic difference in lifespan of men who did not have a CMD (haplotype HR 1.02,
P
= 0.74). We propose that in individuals with a cardiometabolic disorder, longevity-associated genetic variants of
FOXO3
enhance resilience mechanisms in cells and tissues to help protect against cardiometabolic stress caused by CMDs, thereby allowing CMD-affected men to live longer than men without the protective variants.
Collapse
|
43
|
Mitchell EJ, Thomson DM, Openshaw RL, Bristow GC, Dawson N, Pratt JA, Morris BJ. Drug-responsive autism phenotypes in the 16p11.2 deletion mouse model: a central role for gene-environment interactions. Sci Rep 2020; 10:12303. [PMID: 32704009 PMCID: PMC7378168 DOI: 10.1038/s41598-020-69130-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/07/2020] [Indexed: 01/02/2023] Open
Abstract
There are no current treatments for autism, despite its high prevalence. Deletions of chromosome 16p11.2 dramatically increase risk for autism, suggesting that mice with an equivalent genetic rearrangement may offer a valuable model for the testing of novel classes of therapeutic drug. 16p11.2 deletion (16p11.2 DEL) mice and wild-type controls were assessed using an ethological approach, with 24 h monitoring of activity and social interaction of groups of mice in a home-cage environment. The ability of the excitation/inhibition modulator N-acetyl cysteine (NAC) and the 5-HT1B/1D/1F receptor agonist eletriptan to normalise the behavioural deficits observed was tested. 16p11.2 DEL mice exhibited largely normal behaviours, but, following the stress of an injection, showed hyperlocomotion, reduced sociability, and a strong anxiolytic phenotype. The hyperactivity and reduced sociability, but not the suppressed anxiety, were effectively attenuated by both NAC and eletriptan. The data suggest that 16p11.2 DEL mice show an autism-relevant phenotype that becomes overt after an acute stressor, emphasising the importance of gene-environmental interactions in phenotypic analysis. Further, they add to an emerging view that NAC, or 5-HT1B/1D/1F receptor agonist treatment, may be a promising strategy for further investigation as a future treatment.
Collapse
|
44
|
Buse HY, Morris BJ, Gomez-Alvarez V, Szabo JG, Hall JS. Legionella Diversity and Spatiotemporal Variation in The Occurrence of Opportunistic Pathogens within a Large Building Water System. Pathogens 2020; 9:E567. [PMID: 32668779 PMCID: PMC7400177 DOI: 10.3390/pathogens9070567] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 01/22/2023] Open
Abstract
Understanding Legionella survival mechanisms within building water systems (BWSs) is challenging due to varying engineering, operational, and water quality characteristics unique to each system. This study aimed to evaluate Legionella, mycobacteria, and free-living amoebae occurrence within a BWS over 18-28 months at six locations differing in plumbing material and potable water age, quality, and usage. A total of 114 bulk water and 57 biofilm samples were analyzed. Legionella culturability fluctuated seasonally with most culture-positive samples being collected during the winter compared to the spring, summer, and fall months. Positive and negative correlations between Legionella and L. pneumophila occurrence and other physiochemical and microbial water quality parameters varied between location and sample types. Whole genome sequencing of 19 presumptive Legionella isolates, from four locations across three time points, identified nine isolates as L. pneumophila serogroup (sg) 1 sequence-type (ST) 1; three as L. pneumophila sg5 ST1950 and ST2037; six as L. feeleii; and one as Ochrobactrum. Results showed the presence of a diverse Legionella population with consistent and sporadic occurrence at four and two locations, respectively. Viewed collectively with similar studies, this information will enable a better understanding of the engineering, operational, and water quality parameters supporting Legionella growth within BWSs.
Collapse
|
45
|
Almarzooq S, Kwon J, Willis A, Craig J, Morris BJ. Novel alternatively-spliced exons of the VRK2 gene in mouse brain and microglial cells. Mol Biol Rep 2020; 47:5127-5136. [PMID: 32583282 PMCID: PMC7417415 DOI: 10.1007/s11033-020-05584-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/04/2020] [Accepted: 06/11/2020] [Indexed: 12/12/2022]
Abstract
Common sequence variations in the VRK2 gene contribute to genetic risk for various psychiatric diseases including schizophrenia and major depressive disorder. Despite the clear importance of studying the regulation and function of VRK2 for understanding the causes of these diseases, the organisation and expression of the gene remain poorly characterised. Using reverse-transcriptase-PCR, we have amplifed exons of Vrk2 mRNA from regions of mouse brain, and from different cell classes comprising neurones, astrocytes and microglial cells. We find that Vrk2 mRNA is expressed in all cell types, and that the splicing of the mouse Vrk2 gene is much more complex than previously appreciated. In addition to the predicted alternative splicing (absence/presence) of the penultimate 3 prime exon, we also detected a variety of 5 prime structures, including two novel exons spanning the first characterised exon (exon 1), which we term exons 1a and 1b. While expressed in neurones and astrocytes, exon 1b was not expressed in microglial cells. Expression of transcripts containing exon 1a in microglia was increased by immune stimulation. An additional truncated transcript lacking 7 central exons was also identified. As with the human gene, the results confirm complex patterns of alternative splicing which are likely to be relevant for understanding the physiological and pathological function of the gene in the CNS.
Collapse
|
46
|
Corona K, Ronga M, Morris BJ, Tamini J, Zappalà G, Cherubino M, Cerciello S. Comparable clinical and functional outcomes after anterior cruciate ligament reconstruction over and under 40 years of age. Knee Surg Sports Traumatol Arthrosc 2020; 28:1932-1945. [PMID: 31463553 DOI: 10.1007/s00167-019-05680-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 08/19/2019] [Indexed: 02/05/2023]
Abstract
PURPOSE The aim of the present meta-analysis was to update the literature on the outcomes and complications of ACL reconstruction in patients aged 40 years and older. It has been hypothesized that patients older than 40 years of age may have comparable clinical outcomes to those of younger patients. METHODS A systematic review of articles from 1996 to 2018 was completed using Pubmed, Medline, Cochrane Reviews, and Google Scholar databases using the keyword terms "anterior cruciate ligament reconstruction" and "middle-aged OR elderly OR over 40 OR age factors." Functional and clinical outcomes (International Knee Documentation Committee, Lysholm and Tegner score and KT-1000 arthrometer), complication and graft failure rate were evaluated. RESULTS Eleven articles met inclusion criteria. In total, 306 middle-aged patients and 566 younger patients were included in this study. The mean age of patients > 40 was 49 ± 7 (range 40-75) years with a mean follow-up of 25 ± 9 months (range 12-68). The mean age of younger patients was 26 ± 2.7 (range 15-39) years with a mean post-operative follow-up of 26.7 ± 11.5 months (range 3-64). The results were slightly higher (but no significantly different) towards the younger group in terms of objective IKDC (P = n.s.), Lysholm (P = n.s.) and Tegner (P = n.s.) scores and knee laxity assessment (P = n.s.). Complication rate (P = n.s.) and graft failure (P = n.s.) were low even in this cohort. CONCLUSIONS The present meta-analysis shows that patients older than 40 years achieve comparable clinical outcomes to those of younger patients following primary ACL reconstruction. This evidence may push the surgeons toward a more aggressive approach in this specific cohort of patients. LEVEL OF EVIDENCE III.
Collapse
|
47
|
Buse HY, Morris BJ, Rice EW. Early detection of viable Francisella tularensis in environmental matrices by culture-based PCR. BMC Microbiol 2020; 20:66. [PMID: 32213160 PMCID: PMC7093956 DOI: 10.1186/s12866-020-01748-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 03/06/2020] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Francisella tularensis is a fastidious, Gram-negative coccobacillus and is the causative agent of tularemia. To assess viability yet overcome lengthy incubation periods, a culture-based PCR method was used to detect early growth of the lowest possible number of F. tularensis cells. This method utilized a previously developed enhanced F. tularensis growth medium and is based on the change in PCR cycle threshold at the start and end of each incubation. RESULTS To test method robustness, a virulent Type A1 (Schu4) and B (IN99) strain and the avirulent Live Vaccine Strain (LVS) were incubated with inactivated target cells, humic acid, drinking and well water, and test dust at targeted starting concentrations of 1, 10, and 100 CFU mL- 1 (low, mid, and high, respectively). After 48 h, LVS growth was detected at all targeted concentrations in the presence of 106 inactivated LVS cells; while Schu4 and IN99 growth was detected in the presence of 104 Schu4 or IN99 inactivated cells at the mid and high targets. Early detection of F. tularensis growth was strain and concentration dependent in the presence of fast-growing well water and test dust organisms. In contrast, growth was detected at each targeted concentration by 24 h in humic acid and drinking water for all strains. CONCLUSIONS Results indicated that the culture-based PCR assay is quick, sensitive, and specific while still utilizing growth as a measure of pathogen viability. This method can circumvent lengthy incubations required for Francisella identification, especially when swift answers are needed during epidemiological investigations, remediation efforts, and decontamination verification.
Collapse
|
48
|
Morris BJ, Matthews JG, Krieger JN. Prevalence of Phimosis in Males of All Ages: Systematic Review. Urology 2020; 135:124-132. [DOI: 10.1016/j.urology.2019.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 08/14/2019] [Accepted: 10/15/2019] [Indexed: 12/31/2022]
|
49
|
Openshaw RL, Thomson DM, Thompson R, Penninger JM, Pratt JA, Morris BJ, Dawson N. Map2k7 Haploinsufficiency Induces Brain Imaging Endophenotypes and Behavioral Phenotypes Relevant to Schizophrenia. Schizophr Bull 2020; 46:211-223. [PMID: 31219577 PMCID: PMC6942167 DOI: 10.1093/schbul/sbz044] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
c-Jun N-terminal kinase (JNK) signaling contributes to functional plasticity in the brain and cognition. Accumulating evidence implicates a role for MAP kinase kinase 7 (MAP2K7), a JNK activator encoded by the Map2k7 gene, and other JNK pathway components in schizophrenia (ScZ). Mice haploinsufficient for Map2k7 (Map2k7+/- mice) display ScZ-relevant cognitive deficits, although the mechanisms are unclear. Here we show that Map2k7+/- mice display translationally relevant alterations in brain function, including hippocampal and mesolimbic system hypermetabolism with a contrasting prefrontal cortex (PFC) hypometabolism, reminiscent of patients with ScZ. In addition Map2k7+/- mice show alterations in functional brain network connectivity paralleling those reported in early ScZ, including PFC and hippocampal hyperconnectivity and compromised mesolimbic system functional connectivity. We also show that although the cerebral metabolic response to ketamine is preserved, the response to dextroamphetamine (d-amphetamine) is significantly attenuated in Map2k7+/- mice, supporting monoamine neurotransmitter system dysfunction but not glutamate/NMDA receptor (NMDA-R) dysfunction as a consequence of Map2k7 haploinsufficiency. These effects are mirrored behaviorally with an attenuated impact of d-amphetamine on sensorimotor gating and locomotion, whereas similar deficits produced by ketamine are preserved, in Map2k7+/- mice. In addition, Map2k7+/- mice show a basal hyperactivity and sensorimotor gating deficit. Overall, these data suggest that Map2k7 modifies brain and monoamine neurotransmitter system function in a manner relevant to the positive and cognitive symptoms of ScZ.
Collapse
|
50
|
Boutros PJ, Schoo DP, Rahman M, Valentin NS, Chow MR, Ayiotis AI, Morris BJ, Hofner A, Rascon AM, Marx A, Deas R, Fridman GY, Davidovics NS, Ward BK, Treviño C, Bowditch SP, Roberts DC, Lane KE, Gimmon Y, Schubert MC, Carey JP, Jaeger A, Della Santina CC. Continuous vestibular implant stimulation partially restores eye-stabilizing reflexes. JCI Insight 2019; 4:128397. [PMID: 31723056 DOI: 10.1172/jci.insight.128397] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 10/04/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUNDBilateral loss of vestibular (inner ear inertial) sensation causes chronically blurred vision during head movement, postural instability, and increased fall risk. Individuals who fail to compensate despite rehabilitation therapy have no adequate treatment options. Analogous to hearing restoration via cochlear implants, prosthetic electrical stimulation of vestibular nerve branches to encode head motion has garnered interest as a potential treatment, but prior studies in humans have not included continuous long-term stimulation or 3D binocular vestibulo-ocular reflex (VOR) oculography, without which one cannot determine whether an implant selectively stimulates the implanted ear's 3 semicircular canals.METHODSWe report binocular 3D VOR responses of 4 human subjects with ototoxic bilateral vestibular loss unilaterally implanted with a Labyrinth Devices Multichannel Vestibular Implant System vestibular implant, which provides continuous, long-term, motion-modulated prosthetic stimulation via electrodes in 3 semicircular canals.RESULTSInitiation of prosthetic stimulation evoked nystagmus that decayed within 30 minutes. Stimulation targeting 1 canal produced 3D VOR responses approximately aligned with that canal's anatomic axis. Targeting multiple canals yielded responses aligned with a vector sum of individual responses. Over 350-812 days of continuous 24 h/d use, modulated electrical stimulation produced stable VOR responses that grew with stimulus intensity and aligned approximately with any specified 3D head rotation axis.CONCLUSIONThese results demonstrate that a vestibular implant can selectively, continuously, and chronically provide artificial sensory input to all 3 implanted semicircular canals in individuals disabled by bilateral vestibular loss, driving reflexive VOR eye movements that approximately align in 3D with the head motion axis encoded by the implant.TRIAL REGISTRATIONClinicalTrials.gov: NCT02725463.FUNDINGNIH/National Institute on Deafness and Other Communication Disorders: R01DC013536 and 2T32DC000023; Labyrinth Devices, LLC; and Med-El GmbH.
Collapse
|