| 1. |
- Li, Hao, et al.
(author)
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Regeneration in the Auditory Organ in Cuban and African Dwarf Crocodiles (Crocodylus rhombifer and Osteolaemus tetraspis) Can We Learn From the Crocodile How to Restore Our Hearing?
- 2022
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In: Frontiers in Cell and Developmental Biology. - : Frontiers Media S.A.. - 2296-634X. ; 10
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Journal article (peer-reviewed)abstract
- Background: In several non-mammalian species, auditory receptors undergo cell renewal after damage. This has raised hope of finding new options to treat human sensorineural deafness. Uncertainty remains as to the triggering mechanisms and whether hair cells are regenerated even under normal conditions. In the present investigation, we explored the auditory organ in the crocodile to validate possible ongoing natural hair cell regeneration. Materials and Methods: Two male Cuban crocodiles (Crocodylus rhombifer) and an adult male African Dwarf crocodile (Osteolaemus tetraspis) were analyzed using transmission electron microscopy and immunohistochemistry using confocal microscopy. The crocodile ears were fixed in formaldehyde and glutaraldehyde and underwent micro-computed tomography (micro-CT) and 3D reconstruction. The temporal bones were drilled out and decalcified. Results: The crocodile papilla basilaris contained tall (inner) and short (outer) hair cells surrounded by a mosaic of tightly connected supporting cells coupled with gap junctions. Afferent neurons with and without ribbon synapses innervated both hair cell types. Supporting cells occasionally showed signs of trans-differentiation into hair cells. They expressed the MAFA and SOX2 transcription factors. Supporting cells contained organelles that may transfer genetic information between cells, including the efferent nerve fibers during the regeneration process. The tectorial membrane showed signs of being replenished and its architecture being sculpted by extracellular exosome-like proteolysis. Discussion: Crocodilians seem to produce new hair cells during their life span from a range of supporting cells. Imposing efferent nerve fibers may play a role in regeneration and re-innervation of the auditory receptors, possibly triggered by apoptotic signals from wasted hair cells. Intercellular signaling may be accomplished by elaborate gap junction and organelle systems, including neural emperipolesis. Crocodilians seem to restore and sculpt their tectorial membranes throughout their lives.
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| 2. |
- Liu, Wei, et al.
(author)
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A combined genome-wide association and molecular study of age-related hearing loss in H. sapiens
- 2021
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In: BMC Medicine. - : BioMed Central (BMC). - 1741-7015. ; 19:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Sensorineural hearing loss is one of the most common sensory deficiencies. However, the molecular contribution to age-related hearing loss is not fully elucidated.METHODS: We performed genome-wide association studies (GWAS) for hearing loss-related traits in the UK Biobank (N = 362,396) and selected a high confidence set of ten hearing-associated gene products for staining in human cochlear samples: EYA4, LMX1A, PTK2/FAK, UBE3B, MMP2, SYNJ2, GRM5, TRIOBP, LMO-7, and NOX4.RESULTS: All proteins were found to be expressed in human cochlear structures. Our findings illustrate cochlear structures that mediate mechano-electric transduction of auditory stimuli, neuronal conductance, and neuronal plasticity to be involved in age-related hearing loss.CONCLUSIONS: Our results suggest common genetic variation to influence structural resilience to damage as well as cochlear recovery after trauma, which protect against accumulated damage to cochlear structures and the development of hearing loss over time.
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| 3. |
- Ahsan, Muhammad, et al.
(author)
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The relative contribution of DNA methylation and genetic variants on protein biomarkers for human diseases.
- 2017
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In: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 13:9
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Journal article (peer-reviewed)abstract
- Associations between epigenetic alterations and disease status have been identified for many diseases. However, there is no strong evidence that epigenetic alterations are directly causal for disease pathogenesis. In this study, we combined SNP and DNA methylation data with measurements of protein biomarkers for cancer, inflammation or cardiovascular disease, to investigate the relative contribution of genetic and epigenetic variation on biomarker levels. A total of 121 protein biomarkers were measured and analyzed in relation to DNA methylation at 470,000 genomic positions and to over 10 million SNPs. We performed epigenome-wide association study (EWAS) and genome-wide association study (GWAS) analyses, and integrated biomarker, DNA methylation and SNP data using between 698 and 1033 samples depending on data availability for the different analyses. We identified 124 and 45 loci (Bonferroni adjusted P < 0.05) with effect sizes up to 0.22 standard units' change per 1% change in DNA methylation levels and up to four standard units' change per copy of the effective allele in the EWAS and GWAS respectively. Most GWAS loci were cis-regulatory whereas most EWAS loci were located in trans. Eleven EWAS loci were associated with multiple biomarkers, including one in NLRC5 associated with CXCL11, CXCL9, IL-12, and IL-18 levels. All EWAS signals that overlapped with a GWAS locus were driven by underlying genetic variants and three EWAS signals were confounded by smoking. While some cis-regulatory SNPs for biomarkers appeared to have an effect also on DNA methylation levels, cis-regulatory SNPs for DNA methylation were not observed to affect biomarker levels. We present associations between protein biomarker and DNA methylation levels at numerous loci in the genome. The associations are likely to reflect the underlying pattern of genetic variants, specific environmental exposures, or represent secondary effects to the pathogenesis of disease.
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| 4. |
- Al-Sabri, Mohamed H., et al.
(author)
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Statins Induce Locomotion and Muscular Phenotypes in Drosophila melanogaster That Are Reminiscent of Human Myopathy : Evidence for the Role of the Chloride Channel Inhibition in the Muscular Phenotypes
- 2022
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In: Cells. - : MDPI. - 2073-4409. ; 11:22
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Journal article (peer-reviewed)abstract
- The underlying mechanisms for statin-induced myopathy (SIM) are still equivocal. In this study, we employ Drosophila melanogaster to dissect possible underlying mechanisms for SIM. We observe that chronic fluvastatin treatment causes reduced general locomotion activity and climbing ability. In addition, transmission microscopy of dissected skeletal muscles of fluvastatin-treated flies reveals strong myofibrillar damage, including increased sarcomere lengths and Z-line streaming, which are reminiscent of myopathy, along with fragmented mitochondria of larger sizes, most of which are round-like shapes. Furthermore, chronic fluvastatin treatment is associated with impaired lipid metabolism and insulin signalling. Mechanistically, knockdown of the statin-target Hmgcr in the skeletal muscles recapitulates fluvastatin-induced mitochondrial phenotypes and lowered general locomotion activity; however, it was not sufficient to alter sarcomere length or elicit myofibrillar damage compared to controls or fluvastatin treatment. Moreover, we found that fluvastatin treatment was associated with reduced expression of the skeletal muscle chloride channel, C1C-a (Drosophila homolog of CLCN1), while selective knockdown of skeletal muscle C1C-a also recapitulated fluvastatin-induced myofibril damage and increased sarcomere lengths. Surprisingly, exercising fluvastatin-treated flies restored C1C-a expression and normalized sarcomere lengths, suggesting that fluvastatin-induced myofibrillar phenotypes could be linked to lowered C1C-a expression. Taken together, these results may indicate the potential role of C1C-a inhibition in statinassociated muscular phenotypes. This study underlines the importance of Drosophila melanogaster as a powerful model system for elucidating the locomotion and muscular phenotypes, promoting a better understanding of the molecular mechanisms underlying SIM.
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| 5. |
- Al-Sabri, Mohamed H., et al.
(author)
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The regulatory role of AP-2 beta in monoaminergic neurotransmitter systems : insights on its signalling pathway, linked disorders and theragnostic potential
- 2022
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In: Cell & Bioscience. - : BioMed Central (BMC). - 2045-3701. ; 12:1
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Research review (peer-reviewed)abstract
- Monoaminergic neurotransmitter systems play a central role in neuronal function and behaviour. Dysregulation of these systems gives rise to neuropsychiatric and neurodegenerative disorders with high prevalence and societal burden, collectively termed monoamine neurotransmitter disorders (MNDs). Despite extensive research, the transcriptional regulation of monoaminergic neurotransmitter systems is not fully explored. Interestingly, certain drugs that act on these systems have been shown to modulate central levels of the transcription factor AP-2 beta (AP-2 beta, gene: TFAP2B). AP-2 beta regulates multiple key genes within these systems and thereby its levels correlate with monoamine neurotransmitters measures; yet, its signalling pathways are not well understood. Moreover, although dysregulation of TFAP2B has been associated with MNDs, the underlying mechanisms for these associations remain elusive. In this context, this review addresses AP-2 beta, considering its basic structural aspects, regulation and signalling pathways in the controlling of monoaminergic neurotransmitter systems, and possible mechanisms underpinning associated MNDS. It also underscores the significance of AP-2 beta as a potential diagnostic biomarker and its potential and limitations as a therapeutic target for specific MNDs as well as possible pharmaceutical interventions for targeting it. In essence, this review emphasizes the role of AP-2 beta as a key regulator of the monoaminergic neurotransmitter systems and its importance for understanding the pathogenesis and improving the management of MNDs.
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| 6. |
- Alsiö, Johan, et al.
(author)
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Exposure to a high-fat high-sugar diet causes strong up-regulation of proopiomelanocortin and differentially affects dopamine D1 and D2 receptor gene expression in the brainstem of rats
- 2014
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In: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 559, s. 18-23
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Journal article (peer-reviewed)abstract
- A strong link between obesity and dopamine (DA) has been established by studies associating body weight status to variants of genes related to DA signalling. Human and animal studies investigating this relationship have so far focused mainly on the role of DA within the mesolimbic pathway. The aim of this study was to investigate potential DA receptor dysregulation in the brainstem, where these receptors play a potential role in meal termination, during high-fat high-sugar diet (HFHS) exposure. Expression of other key genes, including proopiomelanocortin (POMC), was also analyzed. We randomized rats into three groups; ad libitum access to HFHS (n=24), restricted HFHS access (n=10), or controls (chow-fed, n=10). After 5 weeks, brainstem gene expression was investigated by qRT-PCR. We observed an increase in POMC expression in ad libitum HFHS-fed rats compared to chow-fed controls (p<0.05). Further, expression of DA D2 receptor mRNA was down-regulated in the brainstem of the HFHS ad libitum-fed rats (p<0.05), whereas expression of the DA D1 receptor was upregulated (p<0.05) in these animals compared to chow-fed rats. In control experiments, we observed no effect relative to chow-fed controls on DA-receptor or POMC gene expression in the hypothalamus of HFHS diet-exposed rats, or in the brainstem of acutely food deprived rats. The present findings suggest brainstem POMC to be responsive to palatable foods, and that DA dysregulation after access to energy-dense diets occurs not only in striatal regions, but also in the brainstem, which could be relevant for overeating and for the development and maintenance of obesity.
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| 7. |
- Attwood, Misty M., et al.
(author)
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Orphan Drugs and Their Impact on Pharmaceutical Development
- 2018
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In: TIPS - Trends in Pharmacological Sciences. - : Elsevier BV. - 0165-6147 .- 1873-3735. ; 39:6, s. 525-535
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Research review (peer-reviewed)abstract
- High levels of productivity, with an increasing number of approvals for new molecular entities (NMEs) by the FDA during the past decade, have coincided with the emergence of innovative drugs for treatments of rare diseases that have utilized the FDA orphan drug program. Since 2000, NMEs with orphan designation encompass a significant portion of approved drugs and constitute about 80% of the approved drugs that have established novel human genome-encoded products in recent years. Biological approvals are also expanding, with 40% of the approved biological agents having orphan designation. This trend illustrates a pivot within the pharmaceutical industry: from research programs that focus on canonical blockbuster indications and targets, towards the establishment of new treatments for rare and difficult to treat diseases.
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| 8. |
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| 9. |
- Attwood, Misty M., et al.
(author)
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Soluble ligands as drug targets
- 2020
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In: Nature reviews. Drug discovery. - : NATURE RESEARCH. - 1474-1776 .- 1474-1784. ; 19:10, s. 695-710
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Research review (peer-reviewed)abstract
- Historically, the main classes of drug targets have been receptors, enzymes, ion channels and transporters. However, owing largely to the rise of antibody-based therapies in the past two decades, soluble protein ligands such as inflammatory cytokines have become an increasingly important class of drug targets. In this Review, we analyse drugs targeting ligands that have reached clinical development at some point since 1992. We identify 291 drugs that target 99 unique ligands, and we discuss trends in the characteristics of the ligands, drugs and indications for which they have been tested. In the last 5 years, the number of ligand-targeting drugs approved by the FDA has doubled to 34, while the number of clinically validated ligand targets has doubled to 22. Cytokines and growth factors are the predominant types of targeted ligands (70%), and inflammation and autoimmune disorders, cancer and ophthalmological diseases are the top therapeutic areas for both approved agents and agents in clinical studies, reflecting the central role of cytokine and/or growth factor pathways in such diseases. With the rise of antibody-based therapies in the past two decades, soluble protein ligands such as inflammatory cytokines have become an increasingly important class of drug targets. This Review analyses drugs targeting ligands that have reached clinical development in the past three decades and discusses strategic issues such as the pros and cons of different ligand-targeting therapeutic modalities.
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| 10. |
- Boström, Adrian Desai E., et al.
(author)
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Accelerated epigenetic aging in women with emotionally unstable personality disorder and a history of suicide attempts
- 2023
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In: Translational Psychiatry. - : Nature Publishing Group. - 2158-3188. ; 13:1
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Journal article (peer-reviewed)abstract
- Emotional unstable personality disorder (EUPD; previously borderline personality disorder, BPD) is associated with excess natural-cause mortality, comorbid medical conditions, poor health habits and stress related epigenomic alterations. Previous studies demonstrated that GrimAge – a state-of-the-art epigenetic age (EA) estimator – strongly predicts mortality risk and physiological dysregulation. Herein, we utilize the GrimAge algorithm to investigate whether women with EUPD and a history of recent suicide attempts exhibit EA acceleration (EAA) in comparison to healthy controls. Genome-wide methylation patterns were measured using the Illumina Infinum Methylation Epic BeadChip in whole blood from 97 EUPD patients and 32 healthy controls. The control group was significantly older (p < 0.0001) and reported lesser exposure to violent behavior in both youth and adulthood (p < 0.0001). Groups were otherwise comparable regarding gender, BMI, or tobacco usage (p > 0.05). EA estimator DNAmGrimAge exceeded chronological age by 8.8 and 2.3 years in the EUPD and control group, respectively. Similarly, EAA marker AgeAccelGrim was substantially higher in EUPD subjects when compared to controls, in both univariate and multivariate analyzes (p < 0.00001). Tobacco usage conferred substantial within-group effects on the EA-chronological age difference, i.e., 10.74 years (SD = 4.19) compared to 6.00 years (SD = 3.10) in the non-user EUPD group (p < 0.00001). Notably, past alcohol and substance abuse, use of psychotropic medications, global assessment of functioning, self-reported exposure to violent behavior in youth and adulthood, later completed suicide (N = 8) and age at first suicide attempt did not predict EAA in the EUPD group (p > 0.05). These results underscore the importance of addressing medical health conditions along with low-cost preventative interventions aimed at improving somatic health outcomes in EUPD, such as efforts to support cessation of tobacco use. The independency of GrimAge to other EA algorithms in this group of severely impaired EUPD patients, suggest it may have unique characteristics to evaluate risk of adverse health outcomes in context of psychiatric disorders.
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