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Brain Communications 2023American football players and other individuals exposed to repetitive head impacts can exhibit a constellation of later-life cognitive and neuropsychiatric symptoms....
American football players and other individuals exposed to repetitive head impacts can exhibit a constellation of later-life cognitive and neuropsychiatric symptoms. While tau-based diseases such as chronic traumatic encephalopathy can underpin certain symptoms, contributions from non-tau pathologies from repetitive head impacts are increasingly recognized. We examined cross-sectional associations between myelin integrity using immunoassays for myelin-associated glycoprotein and proteolipid protein 1 with risk factors and clinical outcomes in brain donors exposed to repetitive head impacts from American football. Immunoassays for myelin-associated glycoprotein and proteolipid protein 1 were conducted on dorsolateral frontal white matter tissue samples of 205 male brain donors. Proxies of exposure to repetitive head impacts included years of exposure and age of first exposure to American football play. Informants completed the Functional Activities Questionnaire, Behavior Rating Inventory of Executive Function-Adult Version (Behavioral Regulation Index), and Barratt Impulsiveness Scale-11. Associations between myelin-associated glycoprotein and proteolipid protein 1 with exposure proxies and clinical scales were tested. Of the 205 male brain donors who played amateur and professional football, the mean age was 67.17 (SD = 16.78), and 75.9% ( = 126) were reported by informants to be functionally impaired prior to death. Myelin-associated glycoprotein and proteolipid protein 1 correlated with the ischaemic injury scale score, a global indicator of cerebrovascular disease ( = -0.23 and -0.20, respectively, s < 0.01). Chronic traumatic encephalopathy was the most common neurodegenerative disease ( = 151, 73.7%). Myelin-associated glycoprotein and proteolipid protein 1 were not associated with chronic traumatic encephalopathy status, but lower proteolipid protein 1 was associated with more severe chronic traumatic encephalopathy ( = 0.03). Myelin-associated glycoprotein and proteolipid protein 1 were not associated with other neurodegenerative disease pathologies. More years of football play was associated with lower proteolipid protein 1 [beta = -2.45, 95% confidence interval (CI) [-4.52, -0.38]] and compared with those who played <11 years of football ( = 78), those who played 11 or more years ( = 128) had lower myelin-associated glycoprotein (mean difference = 46.00, 95% CI [5.32, 86.69]) and proteolipid protein 1 (mean difference = 24.72, 95% CI [2.40, 47.05]). Younger age of first exposure corresponded to lower proteolipid protein 1 (beta = 4.35, 95% CI [0.25, 8.45]). Among brain donors who were aged 50 or older ( = 144), lower proteolipid protein 1 (beta = -0.02, 95% CI [-0.047, -0.001]) and myelin-associated glycoprotein (beta = -0.01, 95% CI [-0.03, -0.002]) were associated with higher Functional Activities Questionnaire scores. Lower myelin-associated glycoprotein correlated with higher Barratt Impulsiveness Scale-11 scores (beta = -0.02, 95% CI [-0.04, -0.0003]). Results suggest that decreased myelin may represent a late effect of repetitive head impacts that contributes to the manifestation of cognitive symptoms and impulsivity. Clinical-pathological correlation studies with prospective objective clinical assessments are needed to confirm our findings.
PubMed: 36895961
DOI: 10.1093/braincomms/fcad019 -
Journal of Translational Medicine Mar 2023Cancer/testis antigens (CTAs) participate in the regulation of malignant biological behaviors in breast cancer. However, the function and mechanism of KK-LC-1, a member...
BACKGROUND
Cancer/testis antigens (CTAs) participate in the regulation of malignant biological behaviors in breast cancer. However, the function and mechanism of KK-LC-1, a member of the CTA family, in breast cancer are still unclear.
METHODS
Bioinformatic tools, immunohistochemistry, and western blotting were utilized to detect the expression of KK-LC-1 in breast cancer and to explore the prognostic effect of KK-LC-1 expression in breast cancer patients. Cell function assays, animal assays, and next-generation sequencing were utilized to explore the function and mechanism of KK-LC-1 in the malignant biological behaviors of triple-negative breast cancer. Small molecular compounds targeting KK-LC-1 were also screened and drug susceptibility testing was performed.
RESULTS
KK-LC-1 was significantly highly expressed in triple-negative breast cancer tissues than in normal breast tissues. KK-LC-1 high expression was related to poor survival outcomes in patients with breast cancer. In vitro studies suggested that KK-LC-1 silencing can inhibit triple-negative breast cancer cell proliferation, invasion, migration, and scratch healing ability, increase cell apoptosis ratio, and arrest the cell cycle in the G0-G1 phase. In vivo studies have suggested that KK-LC-1 silencing decreases tumor weight and volume in nude mice. Results showed that KK-CL-1 can regulate the malignant biological behaviors of triple-negative breast cancer via the MAL2/MUC1-C/PI3K/AKT/mTOR pathway. The small-molecule compound Z839878730 had excellent KK-LC-1 targeting ability and cancer cell killing ability. The EC value was 9.7 μM for MDA-MB-231 cells and 13.67 µM for MDA-MB-468 cells. Besides, Z839878730 has little tumor-killing effect on human normal mammary epithelial cells MCF10A and can inhibit the malignant biological behaviors of triple-negative breast cancer cells by MAL2/MUC1-C/PI3K/AKT/mTOR pathway.
CONCLUSIONS
Our findings suggest that KK-LC-1 may serve as a novel therapeutic target for triple-negative breast cancer. Z839878730, which targets KK-LC-1, presents a new path for breast cancer clinical treatment.
Topics: Male; Animals; Mice; Humans; Triple Negative Breast Neoplasms; Proto-Oncogene Proteins c-akt; Mice, Nude; Phosphatidylinositol 3-Kinases; Microbial Sensitivity Tests; Mycobacterium tuberculosis; TOR Serine-Threonine Kinases; Antigens, Neoplasm; Cell Proliferation; Cell Line, Tumor; Cell Movement; Apoptosis; Myelin and Lymphocyte-Associated Proteolipid Proteins
PubMed: 36895039
DOI: 10.1186/s12967-023-04030-9 -
Global Pediatric Health 2023Pelizaeus-Merzbacher disease, a rare X-linked recessive disease occurring predominantly in males, is a disorder of proteolipid protein expression in myelin formation in...
Pelizaeus-Merzbacher disease, a rare X-linked recessive disease occurring predominantly in males, is a disorder of proteolipid protein expression in myelin formation in the central nervous system. The disease is clinically manifested by neurodevelopmental delay, ataxia, hypotonia, and pendular eye movement. It is best confirmed by genetic study. A 4-year female child presented with ataxia, neuroregression, decreased scholastic performance, slurred speech, loss of bladder and bowel control, and hypotonia. MRI brain showed generalized hypomyelination and atrophy of the cerebrum and cerebellum. This case highlights that Pelizaeus-Merzbacher disease can be considered even in a female child who presented with neurodevelopmental delay and neuro regression, ataxia, and decreased scholastic performance and further confirmed by MRI showing diffuse demyelination along with cerebral and cerebellar atrophy.
PubMed: 36873559
DOI: 10.1177/2333794X231157979 -
Science Advances Mar 2023Autoimmune central nervous system (CNS) demyelinating diseases are a major public health burden and poorly controlled by current immunosuppressants. More precise...
Autoimmune central nervous system (CNS) demyelinating diseases are a major public health burden and poorly controlled by current immunosuppressants. More precise immunotherapies with higher efficacy and fewer side effects are sought. We investigated the effectiveness and mechanism of an injectable myelin-based antigenic polyprotein MMPt (myelin oligodendrocyte glycoprotein, myelin basic protein and proteolipid protein, truncated). We find that it suppresses mouse experimental autoimmune encephalomyelitis without major side effects. MMPt induces rapid apoptosis of the encephalitogenic T cells and suppresses inflammation in the affected CNS. Intravital microscopy shows that MMPt is taken up by perivascular F4/80 cells but not conventional antigen-presenting dendritic cells, B cells, or microglia. MMPt-stimulated F4/80 cells induce reactive T cell immobilization and apoptosis in situ, resulting in reduced infiltration of inflammatory cells and chemokine production. Our study reveals alternative mechanisms that explain how cognate antigen suppresses CNS inflammation and may be applicable for effectively and safely treating demyelinating diseases.
Topics: Animals; Mice; Inflammation; Encephalitis; Encephalomyelitis, Autoimmune, Experimental; Apoptosis; B-Lymphocytes; Drug-Related Side Effects and Adverse Reactions
PubMed: 36857453
DOI: 10.1126/sciadv.abo2810 -
Pharmaceutics Feb 2023Because of their high biocompatibility, biological barrier negotiation, and functionalization properties, biological nanoparticles have been actively investigated for...
Because of their high biocompatibility, biological barrier negotiation, and functionalization properties, biological nanoparticles have been actively investigated for many medical applications. Biological nanoparticles, including natural extracellular vesicles (EVs) and synthetic extracellular vesicle-mimetic nanovesicles (EMNVs), represent novel drug delivery vehicles that can accommodate different payloads. In this study, we investigated the physical, biological, and delivery properties of EVs and EMNVs and analyzed their ability to deliver the chemotherapeutic drug doxorubicin. EMNVs and EVs exhibit similar properties, but EMNVs are more effectively internalized, while EVs show higher intracellular doxorubicin release activity. In addition, these nanotherapeutics were investigated in combination with the FDA-approved drug hydroxychloroquine (HCQ). We demonstrate that HCQ-induced lysosome destabilization and could significantly increase nanoparticle internalization, doxorubicin release, and cytotoxicity. Altogether, these data demonstrate that, from the delivery standpoint in vitro, the internalization of EMNVs and EVs and their payload release were slightly different and both nanotherapeutics had comparable cytotoxic performance. However, the synthesis of EMNVs was significantly faster and cost-effective. In addition, we highlight the benefits of combining biological nanoparticles with the lysosome-destabilizing agent HCQ that increased both the internalization and the cytotoxic properties of the particles.
PubMed: 36839856
DOI: 10.3390/pharmaceutics15020534 -
Frontiers in Cellular Neuroscience 2022Oligodendrocytes (OLs) are the myelin-forming cells of the central nervous system (CNS). Although OLs can be differentiated from human-induced pluripotent stem cells...
INTRODUCTION
Oligodendrocytes (OLs) are the myelin-forming cells of the central nervous system (CNS). Although OLs can be differentiated from human-induced pluripotent stem cells (hiPSCs), the modeling of axon myelination in human cells remains challenging. Brain microphysiological systems (bMPS, e.g. organoids) are complex three-dimensional (3D) cultures that offer an ideal system to study this process as OLs differentiate in a more -like environment; surrounded by neurons and astrocytes, which support the myelination of axons.
METHODS
Here, we take advantage of CRISPR/Cas9 technology to generate a hiPSC line in which proteolipid protein 1 (PLP1), an OLs marker, is tagged with super-fold GFP (sfGFP). While generating the PLP1-sfGFP reporter, we used reverse transfection and obtained higher Knock-In (KI) efficiency compared to forward transfection (61-72 vs. 46%).
RESULTS
After validation of the KI and quality control of the PLP1-sfGFP line, selected clones were differentiated into bMPS, and the fidelity, specificity, and function of the tagged PLP protein were verified in this model. We tracked different stages of oligodendrogenesis in the verified lines based on PLP1-sfGFP cells' morphology, and the presence of PLP1-sfGFP surrounding axons during bMPS' differentiation. Finally, we challenged the bMPS with cuprizone and quantified changes in both the percentage of PLP1-sfGFP expressing cells and the intensity of GFP expression.
DISCUSSION
This work demonstrates an efficient method for generating hiPSC KI lines and the description of a new 3D model to study OL differentiation, migration, and maturation both during neurodevelopment as well as in response to environmental chemicals or disease-associated stressors.
PubMed: 36744062
DOI: 10.3389/fncel.2022.1094291 -
Brain Pathology (Zurich, Switzerland) Nov 2023Magnetic resonance imaging (MRI) of focal or diffuse myelin damage or remyelination may provide important insights into disease progression and potential treatment...
Quantitative magnetic resonance imaging reflects different levels of histologically determined myelin densities in multiple sclerosis, including remyelination in inactive multiple sclerosis lesions.
Magnetic resonance imaging (MRI) of focal or diffuse myelin damage or remyelination may provide important insights into disease progression and potential treatment efficacy in multiple sclerosis (MS). We performed post-mortem MRI and histopathological myelin measurements in seven progressive MS cases to evaluate the ability of three myelin-sensitive MRI scans to distinguish different stages of MS pathology, particularly chronic demyelinated and remyelinated lesions. At 3 Tesla, we acquired two different myelin water imaging (MWI) scans and magnetisation transfer ratio (MTR) data. Histopathology included histochemical stainings for myelin phospholipids (LFB) and iron as well as immunohistochemistry for myelin proteolipid protein (PLP), CD68 (phagocytosing microglia/macrophages) and BCAS1 (remyelinating oligodendrocytes). Mixed-effects modelling determined which histopathological metric best predicted MWF and MTR in normal-appearing and diffusely abnormal white matter, active/inactive, inactive, remyelinated and ischemic lesions. Both MWI measures correlated well with each other and histology across regions, reflecting the different stages of MS pathology. MTR data showed a considerable influence of components other than myelin and a strong dependency on tissue storage duration. Both MRI and histology revealed increased myelin densities in inactive compared with active/inactive lesions. Chronic inactive lesions harboured single scattered myelin fibres indicative of low-level remyelination. Mixed-effects modelling showed that smaller differences between white matter areas were linked to PLP densities and only to a small extent confounded by iron. MWI reflects differences in myelin lipids and proteins across various levels of myelin densities encountered in MS, including low-level remyelination in chronic inactive lesions.
Topics: Humans; Myelin Sheath; Multiple Sclerosis; Remyelination; Magnetic Resonance Imaging; Iron; Brain; Neoplasm Proteins
PubMed: 36720269
DOI: 10.1111/bpa.13150 -
Frontiers in Cellular Neuroscience 2022Much of what is known about the mechanisms that control the developmental expression of the myelin proteolipid protein gene () has been attained through use of...
transgenic mice reveal that splice variants containing "human-specific" exons are relatively minor in comparison to the archetypal transcript and that an upstream regulatory element bolsters expression during early postnatal brain development.
Much of what is known about the mechanisms that control the developmental expression of the myelin proteolipid protein gene () has been attained through use of transgenic animal models. In this study, we analyzed expression of related transgenes which utilize genomic DNA from either human or mouse to drive expression of a reporter. Human () sequence span either the proximal 6.2 or 2.7 kb of 5'-flanking DNA to an internal site in Exon 2, while those from mouse comprise the proximal 2.3 kb of 5'-flanking DNA to an analogous site in Exon 2. Transgenes with sequence were named, in part, to the amount of upstream sequence they have [6.2hPLP(+)Z/FL and 2.7hPLP(+)Z]. The transgene containing mouse sequence is referred to here as mPLP(+)Z, to denote the species origin of DNA. Mice which harbor the 6.2hPLP(+)Z/FL transgene were used as a model system to investigate the developmental expression of splice variants that incorporate supplementary exons from what is classically defined as intron 1. While expression of the splice variants were detected in brain through RT-PCR analysis, they are present at much lower levels relative to the archetypal (classic) transcript. Additionally, we show that mice which harbor the 6.2hPLP(+)Z/FL transgene demonstrate wide-ranging expression throughout brain at P2, whereas expression of mPLP(+)Z is quite limited at this age. Therefore, we generated new transgenic mouse lines with the 2.7hPLP(+)Z transgene, which contains sequence orthologous to just that in mPLP(+)Z. Of the seven lines analyzed, six showed higher levels of 2.7hPLP(+)Z expression in brain at P21 compared to P2; the other line expressed the transgene, only weakly, at either age. This trend, coupled with the robust expression observed for 6.2hPLP(+)Z/FL at P2, suggests that the distal 3.5 kb of 5'-flanking DNA specific to 6.2hPLP(+)Z/FL contains regulatory element(s) important for promoting early postnatal expression in brain.
PubMed: 36713780
DOI: 10.3389/fncel.2022.1087145 -
Saudi Pharmaceutical Journal : SPJ :... Jan 2023The complicated multiple sclerosis (MS) can exhibit subacute sight deterioration and can lead to total deprivation of vision. In the current work, we explored the...
The complicated multiple sclerosis (MS) can exhibit subacute sight deterioration and can lead to total deprivation of vision. In the current work, we explored the therapeutic outcome of Cathepsin B inhibitor (CA-074) against retinopathy and optic neuritis (ON) caused by experimental autoimmune encephalomyelitis (EAE) induced by proteolipid protein peptide (PLP) in female SJL/J mice. A daily dose of 10 mg/kg CA-074 was administered to the EAE mice intraperitoneally for 14 days from day 14 post-immunization until day 28. The Western blot and immunofluorescence analyses show inflammation in the optic nerve through the elevation of iNOS and NFkB markers in EAE mice. Optic neuritis was reported which is a consequence of demyelination and axon injury, estimated with the reduction in myelin basic protein (MBP). The glial fibrillary acidic protein (GFAP) expression level was found to be elevated in the retina of EAE mice which confirmed the retinopathy. The administration of CA-074 ameliorated optic neuritis and retinopathy by reducing inflammation. The treatment with CA-074 also reduced the demyelination and axonal injuries in the EAE mice. The findings of this study have shown the protective effect of CA-074 in the case of retinopathy and ON inflicted by EAE in SJL/J mice.
PubMed: 36685301
DOI: 10.1016/j.jsps.2022.11.013 -
Brain Sciences Dec 2022The X chromosome gene encodes myelin proteolipid protein (PLP), the most prevalent protein in the myelin sheath surrounding the central nervous system. X-linked...
The X chromosome gene encodes myelin proteolipid protein (PLP), the most prevalent protein in the myelin sheath surrounding the central nervous system. X-linked dysmyelinating disorders such as Pelizaeus-Merzbacher disease (PMD) or spastic paraplegia type 2 (SPG2) are typically caused by point mutations in . Nevertheless, numerous case reports have shown individuals with missense point mutations which also presented clinical symptoms and indications that were consistent with the diagnostic criteria of multiple sclerosis (MS), a disabling disease of the brain and spinal cord with no current cure. Computational structural biology methods were used to assess the impact of these mutations on the stability and flexibility of PLP structure in order to determine the role of mutations in MS pathogenicity. The analysis showed that most of the variants can alter the functionality of the protein structure such as R137W variants which results in loss of helix and H140Y which alters the ordered protein interface. In silico genomic methods were also performed to predict the significance of these mutations associated with impairments in protein functionality and could suggest a better definition for therapeutic strategies and clinical application in MS patients.
PubMed: 36672024
DOI: 10.3390/brainsci13010042