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It is widely accepted that aging is characterized by a gradual decline in the efficiency and accuracy of biological processes, leading to deterioration of physiological functions and development of age-associated diseases. Age-dependent accumulation of genomic instability and development of metabolic syndrome are well-recognized components of the aging phenotype, both of which have been extensively studied. Existing findings strongly support the view that the integrity of the cellular genome and metabolic function can be influenced by light at night (LAN) and associated suppression of circadian melatonin production. While LAN is reported to accelerate aging by promoting age-associated carcinogenesis in several animal models, the specific molecular mechanism(s) of its action are not fully understood. Here, we review literature supporting a connection between LAN-induced central circadian disruption of peripheral circadian rhythms and clock function, LINE-1 retrotransposon-associated genomic instability, metabolic deregulation, and aging. We propose that aging is a progressive decline in the stability, continuity and synchronization of multi-frequency oscillations in biological processes to a temporally disorganized state. By extension, healthy aging is the ability to maintain the most consistent, stable and entrainable rhythmicity and coordination of these oscillations, at the molecular, cellular, and systemic levels.

A quantitative trait locus (QTL) in the nematode C. elegans, lsq4, was recently implicated by mapping longevity genes. QTLs for lifespan and 3 stress-resistance traits coincided within a span of

It has been recognized that cells do not respond equally to ultraviolet (UV) radiation but it is not clear whether this is due to genetic, biochemical or structural differences of the cells. We have a novel cybrid (cytoplasmic hybrids) model that allows us to analyze the contribution of mitochondrial DNA (mtDNA) to cellular response after exposure to sub-lethal dose of UV. mtDNA can be classified into haplogroups as defined by accumulations of specific single nucleotide polymorphisms (SNPs). Recent studies have shown that J haplogroup is high risk for age-related macular degeneration while the H haplogroup is protective. This study investigates gene expression responses in J cybrids versus H cybrids after exposure to sub-lethal doses of UV-radiation.Cybrids were created by fusing platelets isolated from subjects with either H (n = 3) or J (n = 3) haplogroups with mitochondria-free (Rho0) ARPE-19 cells. The H and J cybrids were cultured for 24 hours, treated with 10 mJ of UV-radiation and cultured for an additional 120 hours. Untreated and treated cybrids were analyzed for growth rates and gene expression profiles. The UV-treated and untreated J cybrids had higher growth rates compared to H cybrids. Before treatment, J cybrids showed lower expression levels for CFH, CD55, IL-33, TGF-A, EFEMP-1, RARA, BCL2L13 and BBC3. At 120 hours after UV-treatment, the J cybrids had decreased CFH, RARA and BBC3 levels but increased CD55, IL-33 and EFEMP-1 compared to UV-treated H cybrids.In cells with identical nuclei, the cellular response to sub-lethal UV-radiation is mediated in part by the mtDNA haplogroup. This supports the hypothesis that differences in growth rates and expression levels of complement, inflammation and apoptosis genes may result from population-specific, hereditary SNP variations in mtDNA. Therefore, when analyzing UV-induced damage in tissues, the mtDNA haplogroup background may be important to consider.

Activation of the Simulator of Interferon Genes (STING) system by mitochondrial (mt) DNA can upregulate type 1 interferon genes and enhance immune responses to combat bacterial and viral infections. In cancers, the tumor-derived DNA activates STING leading to upregulation of IFN-beta and induction of antitumor T cells. The entire mtDNA from the cell lines was sequenced using next-generation sequencing (NGS) technology with independent sequencing of both strands in both directions, allowing identification of low-frequency heteroplasmy SNPs. There were 15 heteroplasmy SNPs showing a range from 3.4% to 40.5% occurrence in the K cybrid cell lines. Three H haplogroup cybrids possessed SNP heteroplasmy that ranged from 4.39% to 30.7%. The present study used qRT-PCR to determine if cybrids of H and K haplogroups differentially regulate expression levels of five cancer genes (BRAC1, ALK, PD1, EGFR, and HER2) and seven STING subunits genes (CGAS, TBK1, IRF3, IκBa, NFκB, TRAF2, and TNFRSF19). Some cybrids underwent siRNA knockdown of STING followed by qRT-PCR in order to determine the impact of STING on gene expression. Rho0 (lacking mtDNA) ARPE-19 cells were used to determine if mtDNA is required for the expression of the cancer genes studied. Our results showed that (a) K cybrids have lower expression levels for BRAC1, ALK, PD1, EGFR, IRF3, and TNFRSF19 genes but increased transcription for IκBa and NFκB compared to H cybrids; (b) STING KD decreases expression of EGFR in both H and K cybrids, and (c) PD1 expression is negligible in Rho0 cells. Our findings suggest that the STING DNA sensing pathway may be a previously unrecognized pathway to target modulation of cancer-related genes and the PD1 expression requires the presence of mtDNA.

Mitochondrial dysfunction is associated with the development and progression of age-related macular degeneration (AMD). Recent studies using populations from the United States and Australia have demonstrated that AMD is associated with mitochondrial (mt) DNA haplogroups (as defined by combinations of mtDNA polymorphisms) that represent Northern European Caucasians. The aim of this study was to use the cytoplasmic hybrid (cybrid) model to investigate the molecular and biological functional consequences that occur when comparing the mtDNA H haplogroup (protective for AMD) versus J haplogroup (high risk for AMD).Cybrids were created by introducing mitochondria from individuals with either H or J haplogroups into a human retinal epithelial cell line (ARPE-19) that was devoid of mitochondrial DNA (Rho0). In cybrid lines, all of the cells carry the same nuclear genes but vary in mtDNA content. The J cybrids had significantly lower levels of ATP and reactive oxygen/nitrogen species production, but increased lactate levels and rates of growth. Q-PCR analyses showed J cybrids had decreased expressions for CFH, C3, and EFEMP1 genes, high risk genes for AMD, and higher expression for MYO7A, a gene associated with retinal degeneration in Usher type IB syndrome. The H and J cybrids also have comparatively altered expression of nuclear genes involved in pathways for cell signaling, inflammation, and metabolism.Our findings demonstrate that mtDNA haplogroup variants mediate not only energy production and cell growth, but also cell signaling for major molecular pathways. These data support the hypothesis that mtDNA variants play important roles in numerous cellular functions and disease processes, including AMD.

Enhanced ceramide glycosylation catalyzed by glucosylceramide synthase (GCS) limits therapeutic efficiencies of antineoplastic agents including doxorubicin in drug-resistant cancer cells. Aimed to determine the role of GCS in tumor response to chemotherapy, a new mixed-backbone oligonucleotide (MBO-asGCS) with higher stability and efficiency has been generated to silence human GCS gene. MBO-asGCS was taken up efficiently in both drug-sensitive and drug-resistant cells, but it selectively suppressed GCS overexpression, and sensitized drug-resistant cells. MBO-asGCS increased doxorubicin sensitivity by 83-fold in human NCI/ADR-RES, and 43-fold in murine EMT6/AR1 breast cancer cells, respectively. In tumor-bearing mice, MBO-asGCS treatment dramatically inhibited the growth of multidrug-resistant NCI/ADR-RE tumors, decreasing tumor volume to 37%, as compared with scrambled control. Furthermore, MBO-asGCS sensitized multidrug-resistant tumors to chemotherapy, increasing doxorubicin efficiency greater than 2-fold. The sensitization effects of MBO-asGCS relied on the decreases of gene expression and enzyme activity of GCS, and on the increases of C(18)-ceramide and of caspase-executed apoptosis. MBO-asGCS was accumulation in tumor xenografts was greater in other tissues, excepting liver and kidneys; but MBO-asGCS did not exert significant toxic effects on liver and kidneys. This study, for the first time in vivo, has demonstrated that GCS is a promising therapeutic target for cancer drug resistance, and MBO-asGCS has the potential to be developed as an antineoplastic agent.

Abstract Various risk factors of Alzheimer’s disease (AD) are known, such as advanced age, possession of certain genetic variants, accumulation of toxic amyloid-β (Aβ) peptides, and unhealthy lifestyle. An estimate of heritability of AD ranges from 0.13 to 0.25, indicating that its phenotypic variation is accounted for mostly by non-genetic factors. DNA methylation is regarded as an epigenetic mechanism that interfaces the genome with non-genetic factors. The Tg2576 mouse model has been insightful in AD research. These transgenic mice express a mutant form of human amyloid precursor protein linked to familial AD. At 9–13 months of age, these mice show elevated levels of Aβ peptides and cognitive impairment. The current literature lacks integrative multiomics of the animal model. We applied transcriptomics and DNA methylomics to the same brain samples from ~ 11-month-old transgenic mice. We found that genes involved in extracellular matrix structures and functions are transcriptionally upregulated, and genes involved in extracellular protein secretion and localization are differentially methylated in the transgenic mice. Integrative analysis found enrichment of GO terms related to memory and synaptic functionability. Our results indicate a possibility of transcriptional modulation by DNA methylation underlying AD neuropathology.

Unfortunately, the original version of this article was published with error in the materials and methods section.

The development of chronic inflammation, called inflammaging, contributes to the pathogenesis of age-related diseases. Although it is known that both B and T lymphocyte compartments of the adaptive immune system deteriorate with advancing age, the impact of aging on immune functions of Th17-type CD161-expressing innate immune cells and their role in inflammaging remain incompletely understood. Here, utilizing the nonhuman primate model of rhesus macaques, we report that a dysregulated Th17-type effector function of CD161+ immune cells is associated with leaky gut and inflammatory phenotype of aging. Higher plasma levels of inflammatory cytokines IL-6, TNF-α, IL-1β, GM-CSF, IL-12, and Eotaxin correlated with elevated markers of gut permeability including LPS-binding protein (LBP), intestinal fatty acid binding protein (I-FABP), and sCD14 in aging macaques. Further, older macaques displayed significantly lower frequencies of circulating Th17-type immune cells comprised of CD161+ T cell subsets, NK cells, and innate lymphoid cells. Corresponding with the increased markers of gut permeability, production of the type-17 cytokines IL-17 and IL-22 was impaired in CD161+ T cell subsets and NK cells, along with a skewing towards IFN-γ cytokine production. These findings suggest that reduced frequencies of CD161+ immune cells along with a specific loss in Th17-type effector functions contribute to impaired gut barrier integrity and systemic inflammation in aging macaques. Modulating type-17 immune cell functions via cytokine therapy or dietary interventions towards reducing chronic inflammation in inflammaging individuals may have the potential to prevent or delay age-related chronic diseases and improve immune responses in the elderly population.

Abstract Activation of the Simulator of Interferon Genes (STING) system by mitochondrial (mt) DNA can upregulate type 1 interferon genes and enhance immune responses to combat bacterial and viral infections. In cancers, the tumor‐derived DNA activates STING leading to upregulation of IFN‐beta and induction of antitumor T cells. The entire mtDNA from the cell lines was sequenced using next‐generation sequencing (NGS) technology with independent sequencing of both strands in both directions, allowing identification of low‐frequency heteroplasmy SNPs. There were 15 heteroplasmy SNPs showing a range from 3.4% to 40.5% occurrence in the K cybrid cell lines. Three H haplogroup cybrids possessed SNP heteroplasmy that ranged from 4.39% to 30.7%. The present study used qRT‐PCR to determine if cybrids of H and K haplogroups differentially regulate expression levels of five cancer genes (BRAC1, ALK, PD1, EGFR, and HER2) and seven STING subunits genes (CGAS, TBK1, IRF3, IκBa, NFκB, TRAF2, and TNFRSF19). Some cybrids underwent siRNA knockdown of STING followed by qRT‐PCR in order to determine the impact of STING on gene expression. Rho0 (lacking mtDNA) ARPE‐19 cells were used to determine if mtDNA is required for the expression of the cancer genes studied. Our results showed that (a) K cybrids have lower expression levels for BRAC1, ALK, PD1, EGFR, IRF3, and TNFRSF19 genes but increased transcription for IκBa and NFκB compared to H cybrids; (b) STING KD decreases expression of EGFR in both H and K cybrids, and (c) PD1 expression is negligible in Rho0 cells. Our findings suggest that the STING DNA sensing pathway may be a previously unrecognized pathway to target modulation of cancer‐related genes and the PD1 expression requires the presence of mtDNA.

Results are presented for the measurement of large-scale anisotropies in the arrival directions of ultra–high-energy cosmic rays detected at the Pierre Auger Observatory during 19 yr of operation, prior to AugerPrime, the upgrade of the observatory. The 3D dipole amplitude and direction are reconstructed above 4 EeV in four energy bins. Besides the established dipolar anisotropy in R.A. above 8 EeV, the Fourier amplitude of the 8–16 EeV energy bin is now also above the 5 σ discovery level. No time variation of the dipole moment above 8 EeV is found, setting an upper limit to the rate of change of such variations of 0.3% yr ^−1 at the 95% confidence level. Additionally, the results for the angular power spectrum are shown, demonstrating no other statistically significant multipoles. The results for the equatorial dipole component down to 0.03 EeV are presented, using for the first time a data set obtained with a trigger that has been optimized for lower energies. Finally, model predictions are discussed and compared with observations, based on two source emission scenarios obtained in the combined fit of spectrum and composition above 0.6 EeV.

Background: Cisplatin, a powerful antitumor agent, causes formation of DNA adducts, and activation of apoptotic pathways. Presently, cisplatin resistance develops in up to 70% of patients but the underlying molecular mechanism(s) are unclear and there are no markers to determine which patients will become resistant. Mitochondria play a significant role not only in energy metabolism but also retrograde signaling (mitochondria to nucleus) that modulates inflammation, complement, and apoptosis pathways. Maternally inherited mitochondrial (mt) DNA can be classified into haplogroups representing different ethnic populations that have diverse susceptibilities to diseases and medications. Methods: Transmitochondrial cybrids, where all cell lines possess identical nuclear genomes but either the H (Southern European) or J (Northern European) mtDNA haplogroups, were treated with cisplatin and analyzed for differential responses related to viability, oxidative stress, and expression levels of genes associated with cancer, cisplatin-induced nephrotoxicity and resistance, apoptosis and signaling pathways. Results: The cisplatin-treated-J cybrids showed greater loss of cell viability along with lower levels of reactive oxygen species and mitochondrial membrane potential compared to cisplatin-treated-H cybrids. After cisplatin treatment, J cybrids showed increased gene expression of BAX, CASP3, and CYP51A, but lower levels of SFRP1 compared to untreated-J cybrids. The cisplatin-treated-H cybrids had elevated expression of CDKN1A/P21, which has a role in cisplatin toxicity, compared to untreated-H cybrids. The cisplatin-treated H had higher transcription levels of ABCC1, DHRS2/HEP27, and EFEMP1 compared to cisplatin-treated-J cybrids. Conclusions: Cybrid cell lines that contain identical nuclei but either H mtDNA mitochondria or J mtDNA mitochondria respond differently to cisplatin treatments suggesting involvement of the retrograde signaling (from mitochondria to nucleus) in the drug-induced cell death. Varying toxicities and transcription levels of the H vs. J cybrids after cisplatin treatment support the hypothesis that mtDNA variants play a role in the expression of genes affecting resistance and side effects of cisplatin.

Background The role of Th17 cells in prostate cancer is not fully understood. The transcription factor BATF controls the differentiation of Th17 cells. Mice deficient in Batf do not produce Th17 cells. Methods In this study, we aimed to characterize the role of Batf -dependent Th17 cells in prostate cancer by crossbreeding Batf knockout mice with mice conditionally mutant for Pten. Results We found that Batf knockout mice had changes in the morphology of prostate epithelial cells compared with normal mice, and Batf knockout mice deficient in Pten (called Batf-) had smaller prostate size and developed fewer invasive prostate adenocarcinomas than Pten -deficient mice with Batf expression (called Batf+). The prostate tumors in Batf- mice showed reduced proliferation, increased apoptosis, decreased angiogenesis and inflammatory cell infiltration, and activation of nuclear factor–κB signaling. Moreover, Batf- mice showed significantly reduced interleukin 23 (IL-23)-IL-23R signaling. In the prostate stroma of Batf- mice, IL-23R–positive cells were decreased considerably compared with Batf + mice. Splenocytes and prostate tissues from Batf- mice cultured under Th17 differentiation conditions expressed reduced IL-23/IL-23R than cultured cells from Batf + mice. Anti–IL-23p19 antibody treatment of Pten -deficient mice reduced prostate tumors and angiogenesis compared with control immunoglobulin G–treated mice. In human prostate tumors, BATF messenger RNA level was positively correlated with IL-23A and IL-23R but not RORC. Conclusion Our novel findings underscore the crucial role of IL-23-IL-23R signaling in mediating the function of Batf -dependent Th17 cells, thereby promoting prostate cancer initiation and progression. This finding highlights the BATF–IL-23R axis as a promising target for the development of innovative strategies for prostate cancer prevention and treatment. [ABSTRACT FROM AUTHOR]

Abstract We present a measurement of the cosmic-ray spectrum above 100 PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750 m. An inflection of the spectrum is observed, confirming the presence of the so-called second-knee feature. The spectrum is then combined with that of the 1500 m array to produce a single measurement of the flux, linking this spectral feature with the three additional breaks at the highest energies. The combined spectrum, with an energy scale set calorimetrically via fluorescence telescopes and using a single detector type, results in the most statistically and systematically precise measurement of spectral breaks yet obtained. These measurements are critical for furthering our understanding of the highest energy cosmic rays.

A reliable model of biological age is instrumental in the field of geriatrics and gerontology. This model should account for the heterogeneity and plasticity of aging and also accurately predict aging-related adverse outcomes. Epigenetic age models are based on DNA methylation levels at selected genomic sites and can be significant predictors of mortality and healthy/unhealthy aging. However, the biological function of DNA methylation at selected sites is yet to be determined. Frailty is a syndrome resulting from decreased physiological reserves and resilience. The frailty index is a probability-based extension of the concept of frailty. Defined as the proportion of health deficits, the frailty index quantifies the progression of unhealthy aging. The frailty index is currently the best predictor of mortality. It is associated with various biological factors and provides insight into the biological processes of aging. Investigation of the multi-omics factors associated with the frailty index will provide further insight.

Mitochondrial (mt) DNA haplogroups, defined by specific single nucleotide polymorphism (SNP) patterns, represent populations of diverse geographic origins and have been associated with increased risk or protection of many diseases. The H haplogroup is the most common European haplogroup while the K haplogroup is highly associated with the Ashkenazi Jewish population. Transmitochondrial cybrids (cell lines with identical nuclei, but mtDNA from either H (n=8) or K (n=8) subjects) were analyzed by the Seahorse flux analyzer, quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry (IHC). Cybrids were treated with amyloid-β peptides and cell viabilities were measured. Other cybrids were demethylated with 5-aza-2'-deoxycytidine (5-aza-dC) and expression levels for APOE and NFkB2 were measured. Results show K cybrids have (a) significantly lower mtDNA copy numbers, (b) higher expression levels for MT-DNA encoded genes critical for oxidative phosphorylation, (c) lower Spare Respiratory Capacity, (d) increased expression of inhibitors of the complement pathway and important inflammasome-related genes; and (e) significantly higher levels of APOE transcription that were independent of methylation status. After exposure to amyloid-β1-42 peptides (active form), H haplogroup cybrids demonstrated decreased cell viability compared to those treated with amyloid-β42-1 (inactive form) (p

A search for time-directional coincidences of ultra-high-energy (UHE) photons above 10 EeV with gravitational wave (GW) events from the LIGO/Virgo runs O1 to O3 is conducted with the Pierre Auger Observatory. Due to the distinctive properties of photon interactions and to the background expected from hadronic showers, a subset of the most interesting GW events is selected based on their localization quality and distance. Time periods of 1000 s around and 1 day after the GW events are analyzed. No coincidences are observed. Upper limits on the UHE photon fluence from a GW event are derived that are typically at ∼7 MeV cm ^−2 (time period 1000 s) and ∼35 MeV cm ^−2 (time period 1 day). Due to the proximity of the binary neutron star merger GW170817, the energy of the source transferred into UHE photons above 40 EeV is constrained to be less than 20% of its total GW energy. These are the first limits on UHE photons from GW sources.

A catalog containing details of the highest-energy cosmic rays recorded through the detection of extensive air showers at the Pierre Auger Observatory is presented with the aim of opening the data to detailed examination. Descriptions of the 100 showers created by the highest-energy particles recorded between 2004 January 1 and 2020 December 31 are given for cosmic rays that have energies in the range 78–166 EeV. Details are also given on a further nine very energetic events that have been used in the calibration procedure adopted to determine the energy of each primary. A sky plot of the arrival directions of the most energetic particles is shown. No interpretations of the data are offered.

Prostate cancer (PCa) is associated with advanced age, but how age contributes to prostate carcinogenesis remains unknown. The prostate-specific Pten conditional knockout mouse model closely imitates human PCa initiation and progression. To better understand how age impacts PCa in an experimental model, we have generated a spatially and temporally controlled Pten-null PCa murine model at different ages (aged vs. non-aged) of adult mice. Here, we present a protocol to inject the Cre-expressing adenovirus with luciferin tag, intraductally, into the prostate anterior lobes of Pten-floxed mice; Pten-loss will be triggered post-Cre expression at different ages. In vivo imaging of luciferin signal following viral infection confirmed successful delivery of the virus and Cre activity. Immunohistochemical staining confirmed prostate epithelial-specific expression of Cre recombinase and the loss of Pten and activation of P-Akt, P-S6, and P-4E-BP1. The Cre-expression, Pten ablation, and activated PI3K/AKT/mTOR pathways were limited to the prostate epithelium. All mice developed prostatic epithelial hyperplasia within 4 weeks after Pten ablation and prostatic intraepithelial neoplasia (PIN) within 8 weeks post-Pten ablation. Some PINs had progressed to invasive adenocarcinoma at 8–16 weeks post-Pten ablation. Aged mice exhibited significantly accelerated PI3K/AKT/mTOR signaling and increased PCa onset and progression compared to young mice. The viral infection success rate is ∼80%. This model will be beneficial for investigations of cancer-related to aging.

The geographic origins of populations can be identified by their maternally inherited mitochondrial DNA (mtDNA) haplogroups. This study compared human cybrids (cytoplasmic hybrids), which are cell lines with identical nuclei but mitochondria from different individuals with mtDNA from either the H haplogroup or L haplogroup backgrounds. The most common European haplogroup is H while individuals of maternal African origin are of the L haplogroup. Despite lower mtDNA copy numbers, L cybrids had higher expression levels for nine mtDNA-encoded respiratory complex genes, decreased ATP (adenosine triphosphate) turnover rates and lower levels of reactive oxygen species production, parameters which are consistent with more efficient oxidative phosphorylation. Surprisingly, GeneChip arrays showed that the L and H cybrids had major differences in expression of genes of the canonical complement system (5 genes), dermatan/chondroitin sulfate biosynthesis (5 genes) and CCR3 (chemokine, CC motif, receptor 3) signaling (9 genes). Quantitative nuclear gene expression studies confirmed that L cybrids had (a) lower expression levels of complement pathway and innate immunity genes and (b) increased levels of inflammation-related signaling genes, which are critical in human diseases. Our data support the hypothesis that mtDNA haplogroups representing populations from different geographic origins may play a role in differential susceptibilities to diseases.

BackgroundIt has been recognized that cells do not respond equally to ultraviolet (UV) radiation but it is not clear whether this is due to genetic, biochemical or structural differences of the cells. We have a novel cybrid (cytoplasmic hybrids) model that allows us to analyze the contribution of mitochondrial DNA (mtDNA) to cellular response after exposure to sub-lethal dose of UV. mtDNA can be classified into haplogroups as defined by accumulations of specific single nucleotide polymorphisms (SNPs). Recent studies have shown that J haplogroup is high risk for age-related macular degeneration while the H haplogroup is protective. This study investigates gene expression responses in J cybrids versus H cybrids after exposure to sub-lethal doses of UV-radiation.Methodology/principal findingsCybrids were created by fusing platelets isolated from subjects with either H (n = 3) or J (n = 3) haplogroups with mitochondria-free (Rho0) ARPE-19 cells. The H and J cybrids were cultured for 24 hours, treated with 10 mJ of UV-radiation and cultured for an additional 120 hours. Untreated and treated cybrids were analyzed for growth rates and gene expression profiles. The UV-treated and untreated J cybrids had higher growth rates compared to H cybrids. Before treatment, J cybrids showed lower expression levels for CFH, CD55, IL-33, TGF-A, EFEMP-1, RARA, BCL2L13 and BBC3. At 120 hours after UV-treatment, the J cybrids had decreased CFH, RARA and BBC3 levels but increased CD55, IL-33 and EFEMP-1 compared to UV-treated H cybrids.Conclusion/significanceIn cells with identical nuclei, the cellular response to sub-lethal UV-radiation is mediated in part by the mtDNA haplogroup. This supports the hypothesis that differences in growth rates and expression levels of complement, inflammation and apoptosis genes may result from population-specific, hereditary SNP variations in mtDNA. Therefore, when analyzing UV-induced damage in tissues, the mtDNA haplogroup background may be important to consider.

HIV-associated inflammation has been implicated in the premature aging and increased risk of age-associated comorbidities in cART-treated individuals. However, the immune mechanisms underlying the chronic inflammatory state of cART-suppressed HIV infection remain unclear. Here, we investigated the role of γδT cells, a group of innate IL-17 producing T lymphocytes, in the development of systemic inflammation and leaky gut phenotype during cART-suppressed SIV infection of macaques. Plasma levels of inflammatory mediators, intestinal epithelial barrier disruption (IEBD) and microbial translocation (MT) biomarkers, and Th1/Th17-type cytokine functions were longitudinally assessed in blood and gut mucosa of SIV-infected, cART-suppressed macaques. Among the various gut mucosal IL-17/IL-22-producing T lymphocyte subsets including Th17, γδT, CD161+ CD8+ T, and MAIT cells, a specific decline in the Vδ2 subset of γδT cells and impaired IL-17/IL-22 production in γδT cells significantly correlated with the subsequent increase in plasma IEBD/MT markers (IFABP, LPS-binding protein, and sCD14) and pro-inflammatory cytokines (IL-6, IL-1β, IP10, etc.) despite continued viral suppression during long-term cART. Further, the plasma inflammatory cytokine signature during long-term cART was distinct from acute SIV infection and resembled the inflammatory cytokine profile of uninfected aging (inflammaging) macaques. Overall, our data suggest that during cART-suppressed chronic SIV infection, dysregulation of IL-17/IL-22 cytokine effector functions and decline of Vδ2 γδT cell subsets may contribute to gut epithelial barrier disruption and development of a distinct plasma inflammatory signature characteristic of inflammaging. Our results advance the current understanding of the impact of chronic HIV/SIV infection on γδT cell functions and demonstrate that in the setting of long-term cART, the loss of epithelial barrier-protective functions of Vδ2 T cells and ensuing IEBD/MT occurs before the hallmark expansion of Vδ1 subsets and skewed Vδ2/Vδ1 ratio. Thus, our work suggests that novel therapeutic approaches toward restoring IL-17/IL-22 cytokine functions of intestinal Vδ2 T cells may be beneficial in preserving gut epithelial barrier function and reducing chronic inflammation in HIV-infected individuals.

Abstract Background Drug resistance is the outcome of multiple-gene interactions in cancer cells under stress of anticancer agents. MDR1 overexpression is most commonly detected in drug-resistant cancers and accompanied with other gene alterations including enhanced glucosylceramide synthase (GCS). MDR1 encodes for P-glycoprotein that extrudes anticancer drugs. Polymorphisms of MDR1 disrupt the effects of P-glycoprotein antagonists and limit the success of drug resistance reversal in clinical trials. GCS converts ceramide to glucosylceramide, reducing the impact of ceramide-induced apoptosis and increasing glycosphingolipid (GSL) synthesis. Understanding the molecular mechanisms underlying MDR1 overexpression and how it interacts with GCS may find effective approaches to reverse drug resistance. Results MDR1 and GCS were coincidently overexpressed in drug-resistant breast, ovary, cervical and colon cancer cells; silencing GCS using a novel mixed-backbone oligonucleotide (MBO-asGCS) sensitized these four drug-resistant cell lines to doxorubicin. This sensitization was correlated with the decreased MDR1 expression and the increased doxorubicin accumulation. Doxorubicin treatment induced GCS and MDR1 expression in tumors, but MBO-asGCS treatment eliminated "in-vivo" growth of drug-resistant tumor (NCI/ADR-RES). MBO-asGCS suppressed the expression of MDR1 with GCS and sensitized NCI/ADR-RES tumor to doxorubicin. The expression of P-glycoprotein and the function of its drug efflux of tumors were decreased by 4 and 8 times after MBO-asGCS treatment, even though this treatment did not have a significant effect on P-glycoprotein in normal small intestine. GCS transient transfection induced MDR1 overexpression and increased P-glycoprotein efflux in dose-dependent fashion in OVCAR-8 cancer cells. GSL profiling, silencing of globotriaosylceramide synthase and assessment of signaling pathway indicated that GCS transfection significantly increased globo series GSLs (globotriaosylceramide Gb3, globotetraosylceramide Gb4) on GSL-enriched microdomain (GEM), activated cSrc kinase, decreased β-catenin phosphorylation, and increased nuclear β-catenin. These consequently increased MDR1 promoter activation and its expression. Conversely, MBO-asGCS treatments decreased globo series GSLs (Gb3, Gb4), cSrc kinase and nuclear β-catenin, and suppressed MDR-1 expression in dose-dependent pattern. Conclusion This study demonstrates, for the first time, that GCS upregulates MDR1 expression modulating drug resistance of cancer. GSLs, in particular globo series GSLs mediate gene expression of MDR1 through cSrc and β-catenin signaling pathway.

Geographic atrophy is a blinding form of age-related macular degeneration characterized by retinal pigmented epithelium (RPE) death; the RPE also exhibits DICER1 deficiency, resultant accumulation of endogenous Alu-retroelement RNA, and NLRP3-inflammasome activation. How the inflammasome is activated in this untreatable disease is largely unknown. Here we demonstrate that RPE degeneration in human-cell-culture and mouse models is driven by a noncanonical-inflammasome pathway that activates caspase-4 (caspase-11 in mice) and caspase-1, and requires cyclic GMP-AMP synthase (cGAS)-dependent interferon-[beta] production and gasdermin D-dependent interleukin-18 secretion. Decreased DICER1 levels or Alu-RNA accumulation triggers cytosolic escape of mitochondrial DNA, which engages cGAS. Moreover, caspase-4, gasdermin D, interferon-[beta], and cGAS levels were elevated in the RPE in human eyes with geographic atrophy. Collectively, these data highlight an unexpected role of cGAS in responding to mobile-element transcripts, reveal cGAS-driven interferon signaling as a conduit for mitochondrial-damage-induced inflammasome activation, expand the immune-sensing repertoire of cGAS and caspase-4 to noninfectious human disease, and identify new potential targets for treatment of a major cause of blindness., Author(s): Nagaraj Kerur (corresponding author) [1, 2, 3]; Shinichi Fukuda [1, 2, 4]; Daipayan Banerjee [1, 2, 3]; Younghee Kim [1, 2, 3]; Dongxu Fu [1, 2]; Ivana Apicella [1, [...]

Gut dysbiosis is a common feature associated with the chronic inflammation of HIV infection. Toward understanding the interplay of chronic treated HIV infection, dysbiosis, and systemic inflammation, we investigated longitudinal fecal microbiome changes and plasma inflammatory markers in the nonhuman primate model. Following simian immunodeficiency virus (SIV) infection in rhesus macaques, significant changes were observed in several members of the phylum Firmicutes along with an increase in Bacteroidetes. Viral suppression with antiretroviral therapy (ART) resulted in an early but partial recovery of compositional changes and butyrate producing genes in the gut microbiome. Over the course of chronic SIV infection and long-term ART, however, the specific loss of Faecalibacterium prausnitzii and Treponema succinifaciens significantly correlated with an increase in plasma inflammatory cytokines including IL-6, G-CSF, I-TAC, and MIG. Further, the loss of T. succinifaciens correlated with an increase in circulating biomarkers of gut epithelial barrier damage (IFABP) and microbial translocation (LBP and sCD14). As F. prausnitzii and T. succinifaciens are major short-chain fatty acid producing bacteria, their sustained loss during chronic SV-ART may contribute to gut inflammation and metabolic alterations despite effective long-term control of viremia. A better understanding of the correlations between the anti-inflammatory bacterial community and healthy gut barrier functions in the setting of long-term ART may have a major impact on the clinical management of inflammatory comorbidities in HIV-infected individuals.

Mitochondrial (mt) DNA haplogroups, defined by specific single nucleotide polymorphism (SNP) patterns, represent populations of diverse geographic origins and have been associated with increased risk or protection of many diseases. The H haplogroup is the most common European haplogroup while the K haplogroup is highly associated with the Ashkenazi Jewish population. Transmitochondrial cybrids (cell lines with identical nuclei, but mtDNA from either H (n = 8) or K (n = 8) subjects) were analyzed by the Seahorse flux analyzer, quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry (IHC). Cybrids were treated with amyloid-β peptides and cell viabilities were measured. Other cybrids were demethylated with 5-aza-2′-deoxycytidine (5-aza-dC) and expression levels for APOE and NFkB2 were measured. Results show K cybrids have (a) significantly lower mtDNA copy numbers, (b) higher expression levels for MT-DNA encoded genes critical for oxidative phosphorylation, (c) lower Spare Respiratory Capacity, (d) increased expression of inhibitors of the complement pathway and important inflammasome-related genes; and (e) significantly higher levels of APOE transcription that were independent of methylation status. After exposure to amyloid-β1–42 peptides (active form), H haplogroup cybrids demonstrated decreased cell viability compared to those treated with amyloid-β42–1 (inactive form) (p