Adipose mesenchymal stem cell-derived extracellular vesicles reduce glutamate-induced excitotoxicity in the retina.

Adipose mesenchymal stem cells (ADSCs) have protective effects against glutamate-induced excitotoxicity, but ADSCs are limited in use for treatment of optic nerve injury. Studies have shown that the extracellular vesicles (EVs) secreted by ADSCs (ADSC-EVs) not only have the function of ADSCs, but also have unique advantages including non-immunogenicity, low probability of abnormal growth, and easy access to target cells. In the present study, we showed that intravitreal injection of ADSC-EVs substantially reduced glutamate-induced damage to retinal morphology and electroretinography. In addition, R28 cell pretreatment with ADSC-EVs before injury inhibited glutamate-induced overload of intracellular calcium, downregulation of α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptor (AMPAR) subunit GluA2, and phosphorylation of GluA2 and protein kinase C alpha in vitro. A protein kinase C alpha agonist, 12-O-tetradecanoylphorbol 13-acetate, inhibited the neuroprotective effects of ADSC-EVs on glutamate-induced R28 cells. These findings suggest that ADSC-EVs ameliorate glutamate-induced excitotoxicity in the retina through inhibiting protein kinase C alpha activation.

Hepatocellular Carcinoma Cell-Derived Exosomal miR-21-5p Induces Macrophage M2 Polarization by Targeting RhoB.

M2-like polarized tumor-associated macrophages (TAMs) are the major component of infiltrating immune cells in hepatocellular carcinoma (HCC), which have been proved to exhibit significant immunosuppressive and pro-tumoral effects. However, the underlying mechanism of the tumor microenvironment (TME) educating TAMs to express M2-like phenotypes is still not fully understood. Here, we report that HCC-derived exosomes are involved in intercellular communications and exhibit a greater capacity to mediate TAMs' phenotypic differentiation. In our study, HCC cell-derived exosomes were collected and used to treat THP-1 cells in vitro. Quantitative polymerase chain reaction (qPCR) results showed that the exosomes significantly promoted THP-1 macrophages to differentiate into M2-like macrophages, which have a high production of transforming growth factor-ß (TGF-ß) and interleukin (IL)-10. The analysis of bioinformatics indicated that exosomal miR-21-5p is closely related to TAM differentiation and is associated with unfavorable prognosis in HCC. Overexpressing miR-21-5p in human monocyte-derived leukemia (THP-1) cells induced down-regulation of IL-1ß levels; however, it enhanced production of IL-10 and promoted the malignant growth of HCC cells in vitro. A reporter assay confirmed that miR-21-5p directly targeted Ras homolog family member B (RhoB) 3'-untranslatedregion (UTR) in THP-1 cells. Downregulated RhoB levels in THP-1 cells would weaken mitogen-activated protein kinase (MAPK) axis signaling pathways. Taken together, tumor-derived miR-21-5p promote the malignant advance of HCC, which mediated intercellular crosstalk between tumor cells and macrophages. Targeting M2-like TAMs and intercepting their associated signaling pathways would provide potentially specific and novel therapeutic approaches for HCC treatment.

Autophagy in glaucoma pathogenesis: Therapeutic potential and future perspectives.

Glaucoma is a common blinding eye disease characterized by progressive loss of retinal ganglion cells (RGCs) and their axons, progressive loss of visual field, and optic nerve atrophy. Autophagy plays a pivotal role in the pathophysiology of glaucoma and is closely related to its pathogenesis. Targeting autophagy and blocking the apoptosis of RGCs provides emerging guidance for the treatment of glaucoma. Here, we provide a systematic review of the mechanisms and targets of interventions related to autophagy in glaucoma and discuss the outlook of emerging ideas, techniques, and multidisciplinary combinations to provide a new basis for further research and the prevention of glaucomatous visual impairment.

HIV-Proteins-Associated CNS Neurotoxicity, Their Mediators, and Alternative Treatments.

Human immunodeficiency virus (HIV)-infected people's livelihoods are gradually being prolonged with the use of combined antiretroviral therapy (ART). Conversely, despite viral suppression by ART, the symptoms of HIV-associated neurocognitive disorder (HAND) endure. HAND persists because ART cannot really permanently confiscate the virus from the body. HAND encompasses a variety of conditions based on clinical presentation and severity level, comprising asymptomatic neurocognitive impairment, moderate neurocognitive disorder, and HIV-associated dementia. During the early stages of HIV infection, inflammation compromises the blood-brain barrier, allowing toxic virus, infected monocytes, macrophages, T-lymphocytes, and cellular products from the bloodstream to enter the brain and eventually the entire central nervous system. Since there are no resident T-lymphocytes in the brain, the virus will live for decades in macrophages and astrocytes, establishing a reservoir of infection. The HIV proteins then inflame neurons both directly and indirectly. The purpose of this review is to provide a synopsis of the effects of these proteins on the central nervous system and conceptualize avenues to be considered in mitigating HAND. We used bioinformatics repositories extensively to simulate the transcription factors that bind to the promoter of the HIV-1 protein and possibly could be used as a target to circumvent HIV-associated neurocognitive disorders. In the same vein, a protein-protein interaction complex was also deduced from a Search Tool for the Retrieval of Interacting Genes. In conclusion, this provides an alternative strategy that could be used to avert HAND.

Extracellular vesicles derived from mesenchymal stem cells: A platform that can be engineered.

Mesenchymal stem cells play an important role in tissue damage and repair. This role is mainly due to a paracrine mechanism, and extracellular vesicles (EVs) are an important part of the paracrine function. EVs play a vital role in many aspects of cell homeostasis, physiology, and pathology, and EVs can be used as clinical biomarkers, vaccines, or drug delivery vehicles. A large number of studies have shown that EVs derived from mesenchymal stem cells (MSC-EVs) play an important role in the treatment of various diseases. However, the problems of low production, low retention rate, and poor targeting of MSC-EVs are obstacles to current clinical applications. The engineering transformation of MSC-EVs can make up for those shortcomings, thereby improving treatment efficiency. This review summarizes the latest research progress of MSC-EV direct and indirect engineering transformation from the aspects of improving MSC-EV retention rate, yield, targeting, and MSC-EV visualization research, and proposes some feasible MSC-EV engineering methods of transformation.

Identification of DNAH6 mutations in infertile men with multiple morphological abnormalities of the sperm flagella.

Male infertility due to spermatogenesis defects affects millions of men worldwide. However, the genetic etiology of the vast majority remains unclear. Here we describe three men with primary infertility due to multiple morphological abnormalities of the sperm flagella (MMAF) from two unrelated Han Chinese families. We performed whole-exome sequencing (WES) and Sanger sequencing on the proband of family 1, and found that he carried novel compound heterozygous missense mutations in dynein axonemal heavy chain 6 (DNAH6) that resulted in the substitution of a conserved amino acid residue and co-segregated with the MMAF phenotype in this family. Papanicolaou staining and transmission electron microscopy analysis revealed morphological and ultrastructural abnormalities in the sperm flagella in carriers of these genetic variants. Immunostaining experiments showed that DNAH6 was localized in the sperm tail. This is the first report identifying novel recessive mutations in DNAH6 as a cause of MMAF. These findings expand the spectrum of known MMAF mutations and phenotypes and provide information that can be useful for genetic and reproductive counseling of MMAF patients.

Loss-of-function mutations in TDRD7 lead to a rare novel syndrome combining congenital cataract and nonobstructive azoospermia in humans.

PURPOSE: Comorbid familial nonobstructive azoospermia (NOA) and congenital cataract (CC) have not been reported previously, and no single human gene has been associated with both diseases in humans. Our purpose was to uncover novel human mutations and genes causing familial NOA and CC. METHODS: We performed whole-exome sequencing for two brothers with both NOA and CC from a consanguineous family. Mutation screening of TDRD7 was performed in another similar consanguineous family and 176 patients with azoospermia or CC alone and 520 healthy controls. Histological analysis was performed for the biopsied testicle sample in one patient, and knockout mice were constructed to verify the phenotype of the mutation in TDRD7. RESULTS: Two novel loss-of-function mutations (c.324_325insA (T110Nfs*30) and c.688_689insA (p.Y230X), respectively) of TDRD7 were found in the affected patients from the two unrelated consanguineous families. Histological analysis demonstrated a lack of mature sperm in the male patient's seminiferous tubules. The mutations were not detected in patients with CC or NOA alone. Mice with Tdrd7 gene disrupted at a similar position precisely replicated the human syndrome. CONCLUSION: We identified TDRD7 causing CC as a new pathogenic gene for male azoospermia in human, with an autosomal recessive mode of inheritance.

Maternal interchromosomal insertional translocation leading to 1q43-q44 deletion and duplication in two siblings.

BACKGROUND: 1q43-q44 deletion syndrome is a well-defined chromosomal disorder which is characterized by moderate to severe mental retardation, and variable but characteristic facial features determined by the size of the segment and the number of genes involved. However, patients with 1q43-q44 duplication with a clinical phenotype comparable to that of 1q43-q44 deletion are rarely reported. Moreover, pure 1q43-q44 deletions and duplications derived from balanced insertional translocation within the same family with precisely identified breakpoints have not been reported. CASE PRESENTATION: The proband is a 6-year-old girl with profound developmental delay, mental retardation, microcephaly, epilepsy, agenesis of the corpus callosum and hearing impairment. Her younger brother is a 3-month-old boy with macrocephaly and mild developmental delay in gross motor functions. G-banding analysis of the subjects at the 400-band level did not reveal any subtle structural changes in their karyotypes. However, single-nucleotide polymorphism (SNP) array analysis showed a deletion and a duplication of approximately 6.0 Mb at 1q43-q44 in the proband and her younger brother, respectively. The Levicare analysis pipeline of whole-genome sequencing (WGS) further demonstrated that a segment of 1q43-q44 was inserted at 14q23.1 in the unaffected mother, which indicated that the mother was a carrier of a 46,XX,ins(14;1)(q23.1;q43q44) insertional translocation. Moreover, Sanger sequencing was used to assist the mapping of the breakpoints and the final validation of those breakpoints. The breakpoint on chromosome 1 disrupted the EFCAB2 gene in the first intron, and the breakpoint on chromosome 14 disrupted the PRKCH gene within the 12th intron. In addition, fluorescence in situ hybridization (FISH) further confirmed that the unaffected older sister of the proband carried the same karyotype as the mother. CONCLUSION: Here, we describe a rare family exhibiting pure 1q43-q44 deletion and duplication in two siblings caused by a maternal balanced insertional translocation. Our study demonstrates that WGS with a carefully designed analysis pipeline is a powerful tool for identifying cryptic genomic balanced translocations and mapping the breakpoints at the nucleotide level and could be an effective method for explaining the relationship between karyotype and phenotype.

Rare partial octosomy and hexasomy of 15q11-q13 associated with intellectual impairment and development delay: report of two cases and review of literature.

BACKGROUND: Small supernumerary marker chromosomes (sSMCs) are common structurally abnormal chromosomes that occur in 0.288% of cases of mental retardation. Isodicentric 15 (idic(15)) is common in sSMCs and usually leads to a rare chromosome disorder with distinctive clinical phenotypes, including early central hypotonia, developmental delay, epilepsy, and autistic behavior. It was previously shown that the partial tetrasomy 15q and partial hexasomy 15q syndromes are usually caused by one and two extra idic(15), respectively. Karyotypes containing a mosaic partial octosomy 15q resulting from three extra idic(15) have rarely been reported. CASE PRESENTATION: Two patients with profound intellectual impairment, development delay and hyperpigmentation were recruited for this study. The phenotype was relatively more severe in patient 1 than in patient 2. Conventional cytogenetic analysis of peripheral blood obtained from patients 1 and 2 revealed rare mosaic karyotypes containing sSMCs, i.e., mos 49,XX,+mar × 3[83]/48,XX,+mar × 2[7]/46,XX[10] and mos 48,XX,+mar × 2[72]/47,XX,+mar[28], respectively. The results of analyses of copy number variation (CNV) and fluorescence in situ hybridization (FISH) analyses, showed that the sSMCs were found to be idic(15) involving the Prader-Willi/Angelman Syndrome Critical Region (PWACR) genes and the P gene, with duplication sizes of 6.3 Mb and 9.7 Mb, respectively. DNA fingerprinting analysis of patient 1 showed a maternal origin for the idic(15). Both patients had mosaic idic(15) karyotypes: patient 1 had cells with a 15q partial octosomy (83%), and patient 2 had cells with a 15q partial hexasomy (72%). CONCLUSIONS: We detected two rare mosaic idic(15) karyotypes that were associated with congenital abnormalities, including a rare mosaic octosomy of 15q11-q13. Our cases further validate the notion that the phenotypic severity is correlated with the level of mosaicism and the dosage effect of related genes in the proximal 15q.

DMC1 mutation that causes human non-obstructive azoospermia and premature ovarian insufficiency identified by whole-exome sequencing.

BACKGROUND: The genetic causes of the majority of male and female infertility caused by human non-obstructive azoospermia (NOA) and premature ovarian insufficiency (POI) with meiotic arrest are unknown. OBJECTIVE: To identify the genetic cause of NOA and POI in two affected members from a consanguineous Chinese family. METHODS: We performed whole-exome sequencing of DNA from both affected patients. The identified candidate causative gene was further verified by Sanger sequencing for pedigree analysis in this family. In silico analysis was performed to functionally characterise the mutation, and histological analysis was performed using the biopsied testicle sample from the male patient with NOA. RESULTS: We identified a novel homozygous missense mutation (NM_007068.3: c.106G>A, p.Asp36Asn) in DMC1, which cosegregated with NOA and POI phenotypes in this family. The identified missense mutation resulted in the substitution of a conserved aspartic residue with asparaginate in the modified H3TH motif of DMC1. This substitution results in protein misfolding. Histological analysis demonstrated a lack of spermatozoa in the male patient's seminiferous tubules. Immunohistochemistry using a testis biopsy sample from the male patient showed that spermatogenesis was blocked at the zygotene stage during meiotic prophase I. CONCLUSIONS: To the best of our knowledge, this is the first report identifying DMC1 as the causative gene for human NOA and POI. Furthermore, our pedigree analysis shows an autosomal recessive mode of inheritance for NOA and POI caused by DMC1 in this family.