The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 system has been widely used for nuclear DNA editing to generate mutations or correct specific disease alleles. Despite its ...flexible application, it has not been determined if CRISPR/Cas9, originally identified as a bacterial defense system against virus, can be targeted to mitochondria for mtDNA editing. Here, we show that regular FLAG-Cas9 can localize to mitochondria to edit mitochondrial DNA with sgRNAs targeting specific loci of the mitochondrial genome. Expression of FLAG-Cas9 together with gRNA targeting Cox1 and Cox3 leads to cleavage of the specific mtDNA loci. In addition, we observed disruption of mitochondrial protein homeostasis following mtDNA truncation or cleavage by CRISPR/Cas9. To overcome nonspecific distribution of FLAG-Cas9, we also created a mitochondria-targeted Cas9 (mitoCas9). This new version of Cas9 localizes only to mitochondria; together with expression of gRNA targeting mtDNA, there is specific cleavage of mtDNA. MitoCas9-induced reduction of mtDNA and its transcription leads to mitochondrial membrane potential disruption and cell growth inhibition. This mitoCas9 could be applied to edit mtDNA together with gRNA expression vectors without affecting genomic DNA. In this brief study, we demonstrate that mtDNA editing is possible using CRISPR/Cas9. Moreover, our development of mitoCas9 with specific localization to the mitochondria should facilitate its application for mitochondrial genome editing.
Metabolic syndrome (MetS) arises from complex interactions between host genetic and environmental factors. Although it is now widely accepted that the gut microbiota plays a crucial role in host ...metabolism, current knowledge on the effect of host genetics on specific gut microbes related to MetS status remains limited. Here, we investigated the links among host genetic factors, gut microbiota and MetS in humans.
We characterised the gut microbial community composition of 655 monozygotic (n=306) and dizygotic (n=74) twins and their families (n=275), of which approximately 18% (121 individuals) had MetS. We evaluated the association of MetS status with the gut microbiota and estimated the heritability of each taxon. For the MetS-related and heritable taxa, we further investigated their associations with the apolipoprotein A-V gene (
) single nucleotide polymorphism (SNP) rs651821, which is known to be associated with triglyceride levels and MetS.
Individuals with MetS had a lower gut microbiota diversity than healthy individuals. The abundances of several taxa were associated with MetS status;
,
and
were enriched in the MetS group, whereas
,
and
were enriched in the healthy group. Among the taxa associated with MetS status, the phylum Actinobacteria, to which
belongs, had the highest heritability (45.7%). Even after adjustment for MetS status, reduced abundances of Actinobacteria and
were significantly linked to the minor allele at the
SNP rs651821.
Our results suggest that an altered microbiota composition mediated by a specific host genotype can contribute to the development of MetS.
Abstract
ZNF746 was identified as parkin‐interacting substrate (PARIS). Investigating its pathophysiological properties, we find that PARIS undergoes liquid–liquid phase separation (LLPS) and ...amorphous solid formation. The N‐terminal low complexity domain 1 (LCD1) of PARIS is required for LLPS, whereas the C‐terminal prion‐like domain (PrLD) drives the transition from liquid to solid phase. In addition, we observe that poly(ADP‐ribose) (PAR) strongly binds to the C‐terminus of PARIS near the PrLD, accelerating its LLPS and solidification.
N
‐Methyl‐
N′
‐nitro‐
N
‐nitrosoguanidine (MNNG)‐induced PAR formation leads to PARIS oligomerization in human iPSC‐derived dopaminergic neurons that is prevented by the PARP inhibitor, ABT‐888. Furthermore, SDS‐resistant PARIS species are observed in the substantia nigra (SN) of aged mice overexpressing wild‐type PARIS, but not with a PAR binding‐deficient PARIS mutant. PARIS solidification is also found in the SN of mice injected with preformed fibrils of α‐synuclein (α‐syn PFF) and adult mice with a conditional knockout (KO) of parkin, but not if α‐syn PFF is injected into mice deficient for PARP1. Herein, we demonstrate that PARIS undergoes LLPS and PAR‐mediated solidification in models of Parkinson's disease.
Synopsis
image
ZNF746 (PARIS) forms liquid condensates that transition to amorphous aggregates in a PAR‐dependent manner. PARIS accumulation is observed during aging and in animal models of Parkinson's disease.
PARIS undergoes dynamic liquid–liquid phase separation (LLPS) and liquid–solid transition via PARIS self‐assembly.
Low complexity domain 1 (LCD1) and prion‐like domain (PrLD) of PARIS are required for liquid and solid assembly, respectively.
Poly(ADP‐ribose) (PAR) binds to the C‐terminus of PARIS near the PrLD and accelerates amorphous aggregation of PARIS.
PAR‐mediated PARIS solidification is observed in animal models for sporadic PD.
A rapid solvent evaporation method based on the triple point of a processing solvent is presented to prepare carbon nanotube (CNT) foam with a porous structure for thermoelectric (TE) power ...generators. The rapid solvent evaporation process allows the preparation of CNT foam with various sizes and shapes. The obtained highly porous CNT foam with porosity exceeding 90% exhibits a low thermal conductivity of 0.17 W m−1 K−1 with increased phonon scattering, which is 100 times lower than that of a CNT film with a densely packed network. The aforementioned structural and thermal properties of the CNT foam are advantageous to develop a sufficient temperature gradient between the hot and cold parts to enhance TE output characteristics. To improve the electrical conductivity and Seebeck coefficient further, p‐ and n‐molecular dopants are easily introduced into the CNT foam, and the optimized condition is investigated based on the TE properties. Finally, optimized p‐ and n‐doped CNT foams are used to fabricate a vertical and flexible TE power generator with a combination of series and parallel mixed circuits. The maximum output power and output power per weight of the TE generator reach 1.5 µW and 82 µW g−1, respectively, at a temperature difference of 13.9 K.
As a flexible thermoelectric (TE) material, freely shapable and 3D porous carbon nanotube (CNT) foam is prepared via a rapid solvent evaporation method. The porous and vertical CNT structure exhibits low thermal conductivity owing to the increased phonon scattering effect. The flexible TE power generator exhibits a maximum output power of 1.5 µW at a temperature difference of 13.9 K.
Background
The objective of this study was to investigate the effects of reduction, cessation, and resumption of smoking on cancer development.
Methods
The authors identified 893,582 participants who ...currently smoked, had undergone a health screening in 2009, and had a follow‐up screening in 2011. Among them, 682,996 participated in a third screening in 2013. Participants were categorized as quitters, reducers I (≥50% reduction), reducers II (<50% reduction), sustainers (referent), or increasers (≥20% increase). Outcome data were obtained through December 31, 2018.
Results
Reducers I exhibited a decreased risk of all cancers (adjusted hazard ratio aHR, 0.96; 95% confidence interval CI, 0.93‐0.99), smoking‐related cancers (aHR, 0.95; 95% CI, 0.92‐0.99), and lung cancer (aHR, 0.83; 95% CI, 0.77‐0.88). Quitters had the lowest risk of all cancers (aHR, 0.94; 95% CI, 0.92‐0.96), smoking‐related cancers (aHR, 0.91; 95% CI, 0.89‐0.93), and lung cancer (aHR, 0.79; 95% CI, 0.76‐0.83). In further analysis with 3 consecutive screenings, additional smoking reduction (from reducers II to reducers I) lowered the risk of lung cancer (aHR, 0.74; 95% CI, 0.58‐0.94) in comparison with sustainers. Quitting among reducers I further decreased the risk of all cancers (aHR, 0.90; 95% CI, 0.80‐1.00), smoking‐related cancers (aHR, 0.81; 95% CI, 0.81‐0.92), and lung cancer (aHR, 0.66; 95% CI, 0.52‐0.84) in comparison with sustainers. Smoking resumption after quitting, even at a lower level, increased the risk of smoking‐related cancers (aHR, 1.19; 95% CI, 1.06‐1.33) and lung cancer (aHR, 1.48; 95% CI, 1.21‐1.80) in comparison with sustained quitting.
Conclusions
Smoking cessation and, to a lesser extent, smoking reduction decreased the risks of cancer. Smoking resumption increased cancer risks in comparison with sustained quitting.
Lay Summary
Worldwide, tobacco use is the single leading preventable risk factor for cancer and cancer death.
This study examined the effects of reduction, cessation, and resumption of smoking on cancer development by measuring smoking behavior repetitively.
Although smoking reduction has a substantial cancer prevention benefit for those who cannot quit, cessation should be encouraged whenever possible. Quitters should be monitored to ensure that they do not resume smoking.
Although smoking reduction has substantial cancer prevention benefits for those who cannot quit, cessation should be encouraged whenever possible. Quitters should be monitored to ensure that they do not resume smoking.
Obesity and type 2 diabetes (T2D) are linked both with host genetics and with environmental factors, including dysbioses of the gut microbiota. However, it is unclear whether these microbial changes ...precede disease onset. Twin cohorts present a unique genetically-controlled opportunity to study the relationships between lifestyle factors and the microbiome. In particular, we hypothesized that family-independent changes in microbial composition and metabolic function during the sub-clinical state of T2D could be either causal or early biomarkers of progression.
We collected fecal samples and clinical metadata from 20 monozygotic Korean twins at up to two time points, resulting in 36 stool shotgun metagenomes. While the participants were neither obese nor diabetic, they spanned the entire range of healthy to near-clinical values and thus enabled the study of microbial associations during sub-clinical disease while accounting for genetic background.
We found changes both in composition and in function of the sub-clinical gut microbiome, including a decrease in Akkermansia muciniphila suggesting a role prior to the onset of disease, and functional changes reflecting a response to oxidative stress comparable to that previously observed in chronic T2D and inflammatory bowel diseases. Finally, our unique study design allowed us to examine the strain similarity between twins, and we found that twins demonstrate strain-level differences in composition despite species-level similarities.
These changes in the microbiome might be used for the early diagnosis of an inflamed gut and T2D prior to clinical onset of the disease and will help to advance toward microbial interventions.
For thermoelectric (TE) applications, the surface of exfoliated black phosphorus (BP) can be successfully functionalized with Au nanoparticles (NPs), leading to significantly enhanced TE performance ...for a controlled Au NP content. A facile and selective decoration of metal species on the defect sites of BP is achieved by the spontaneous formation of Au NPs on the surface of BP through a redox reaction of Au precursors. Such a heterostructure provided by the Au decoration of BP enhances electrical conductivity (from 0.001 to 63.3 S cm−1) through tuning of the charge carrier concentration and retains the initial Seebeck coefficient of BP. Consequently, the TE power factor of the Au‐decorated BP increases significantly to 68.5 µV m−1 K−2, which is 2740 times that of the pristine BP. More significantly, in contrast to the severe degradation of the pristine BP in the air, surface‐functionalized BP exhibits excellent stability upon exposure to air for a long period, which is beneficial for practical TE applications. Given these interesting and unique properties of Au‐decorated BP, a vertical TE generator with a high power output of 79.3 nW (ΔT = 2 °C) is prepared by using the Au‐decorated BP as a p‐type TE material.
The electronic and thermoelectric (TE) properties of the exfoliated black phosphorus (BP) are delicately tuned by decoration of gold nanoparticles on the surface of BP through a facile solution process. Moreover, the air stability of BP is dramatically improved by the occupation of its energetic defects by gold nanoparticles. A vertical TE generator using gold‐decorated BP exhibits excellent power output.
Fertility preservation is an emerging discipline, which is of substantial clinical value in the care of young patients with cancer. Chemotherapy and radiation may induce ovarian damage in prepubertal ...girls and young women. Although many studies have explored the mechanisms implicated in ovarian toxicity during cancer treatment, its molecular pathophysiology is not fully understood. Chemotherapy may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions. Oxidative stress and the radiosensitivity of oocytes are the main causes of gonadal damage after radiation treatment. Fertility preservation options can be differentiated by patient age, desire for conception, treatment regimen, socioeconomic status, and treatment duration. This review will help highlight the importance of multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.
The progressive neurodegeneration in Parkinson's disease (PD) is accompanied by neuroinflammation and endothelial vascular impairment. Although the vitamin D receptor (VDR) is expressed in both ...dopamine neurons and brain endothelial cells, its role in the regulation of endothelial biology has not been explored in the context of PD. In a 6-hydroxydopamine (6-OHDA)-induced PD mouse model, we observed reduced transcription of the VDR and its downstream target genes,
and
. The 6-OHDA-induced transcriptional repression of these genes were recovered after the VDR ligand-1α,25-dihydroxyvitamin D
(1,25(OH)
D
) treatment. Similarly, reduced vascular protein expression of P-glycoprotein (P-gp), encoded by
, after 6-OHDA administration was reversed by 1,25(OH)
D
. Moreover, marked reduction of endothelial P-gp expression with concomitant α-synuclein aggregation was found in a combinatorial
/αSyn preformed fibril (PFF) injection mouse model and postmortem PD brains. Supporting the direct effect of α-synuclein aggregation on endothelial biology, PFF treatment of human umbilical vein endothelial cells (HUVECs) was sufficient to induce α-synuclein aggregation and repress transcription of the VDR. PFF-induced P-gp downregulation and impaired functional activity in HUVECs completely recovered after 1,25(OH)
D
treatment. Taken together, our results suggest that a dysfunctional VDR-P-gp pathway could be a potential target for the maintenance of vascular homeostasis in PD pathological conditions.
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