Obesity and elevated circulating cholesterol are risk factors for breast cancer recurrence, while the use of statins, cholesterol biosynthesis inhibitors widely used for treating ...hypercholesterolemia, is associated with improved disease-free survival. Here, we show that cholesterol mediates the metastatic effects of a high-fat diet via its oxysterol metabolite, 27-hydroxycholesterol. Ablation or inhibition of CYP27A1, the enzyme responsible for the rate-limiting step in 27-hydroxycholesterol biosynthesis, significantly reduces metastasis in relevant animal models of cancer. The robust effects of 27-hydroxycholesterol on metastasis requires myeloid immune cell function, and it was found that this oxysterol increases the number of polymorphonuclear-neutrophils and γδ-T cells at distal metastatic sites. The pro-metastatic actions of 27-hydroxycholesterol requires both polymorphonuclear-neutrophils and γδ-T cells, and 27-hydroxycholesterol treatment results in a decreased number of cytotoxic CD8
T lymphocytes. Therefore, through its actions on γδ-T cells and polymorphonuclear-neutrophils, 27-hydroxycholesterol functions as a biochemical mediator of the metastatic effects of hypercholesterolemia.High cholesterol is a risk factor for breast cancer recurrence. Here the authors show that cholesterol promotes breast cancer metastasis via its metabolite 27-hydroxycholesterol (27HC) that acts on immune myeloid cells residing at the distal metastatic sites, thus promoting an immune suppressive environment.
While ovarian tissue cryopreservation (OTC) is an important fertility preservation option, it has its limitations. Improving OTC and ovarian tissue transplantation (OTT) must include extending the ...function of reimplanted tissue by reducing the extensive activation of primordial follicles (PMFs) and eliminating the risk of reimplanting malignant cells. To develop a more effective OTT, we must understand the effects of the ovarian microenvironment on folliculogenesis. Here, we describe a method for producing decellularized extracellular matrix (dECM) hydrogels that reflect the protein composition of the ovary. These ovarian dECM hydrogels were engineered to assess the effects of ECM on in vitro follicle growth, and we developed a novel method for selectively removing proteins of interest from dECM hydrogels. Finally, we validated the depletion of these proteins and successfully cultured murine follicles encapsulated in the compartment-specific ovarian dECM hydrogels and these same hydrogels depleted of EMILIN1. These are the first, optically clear, tailored tissue-specific hydrogels that support follicle survival and growth comparable to the “gold standard” alginate hydrogels. Furthermore, depleted hydrogels can serve as a novel tool for many tissue types to evaluate the impact of specific ECM proteins on cellular and molecular behavior.
Abstract
Cholesterol has been implicated in the clinical progression of breast cancer, a disease that continues to be the most commonly diagnosed cancer in women. Previous work has identified the ...cholesterol metabolite 27-hydroxycholesterol (27HC) as a major mediator of the effects of cholesterol on breast tumor growth and progression. 27HC can act as an estrogen receptor (ER) modulator to promote the growth of ERα+ tumors, and as a liver X receptor (LXR) ligand in myeloid immune cells to establish an immune-suppressive program. In fact, the metastatic properties of 27HC require the presence of myeloid cells with neutrophils (polymorphonuclear neutrophils; PMNs) being essential for the increase in lung metastasis in murine models. In an effort to further elucidate the mechanisms by which 27HC alters breast cancer progression, we made the striking finding that 27HC promoted the secretion of extracellular vesicles (EVs), a diverse assortment of membrane bound particles that includes exosomes. The resulting EVs had a size distribution that was skewed slightly larger than EVs generated by treating cells with vehicle. The increase in EV secretion and size was consistent across 3 different subtypes: primary murine PMNs, RAW264.7 monocytic cells, and 4T1 murine mammary cancer cells. Label-free analysis of 27HC-EVs indicated that they had a different metabolite composition to those from vehicle-treated cells. Importantly, 27HC-EVs from primary PMNs promoted tumor growth and metastasis in 2 different syngeneic models, demonstrating the potential role of 27HC-induced EVs in the progression of breast cancer. EVs from PMNs were taken up by cancer cells, macrophages, and PMNs, but not T cells. Since EVs did not alter proliferation of cancer cells, it is likely that their protumor effects are mediated through interactions with myeloid cells. Interestingly, RNA-seq analysis of tumors from 27HC-EV-treated mice do not display significantly altered transcriptomes, suggesting that the effects of 27HC-EVs occur early on in tumor establishment and growth. Future work will be required to elucidate the mechanisms by which 27HC increases EV secretion, and how these EVs promote breast cancer progression. Collectively, however, our data indicate that EV secretion and content can be regulated by a cholesterol metabolite, which may have detrimental effects in terms of disease progression, important findings given the prevalence of both breast cancer and hypercholesterolemia.
The last 20 years have seen substantial improvements in fertility and hormone preservation and restoration technologies for a growing number of cancer survivors. However, further advancements are ...required to fill the gaps for those who cannot use current technologies or to improve the efficacy and longevity of current fertility and hormone restoration technologies. Ovarian tissue cryopreservation (OTC) followed by ovarian tissue transplantation (OTT) offers those unable to undergo ovarian stimulation for egg retrieval and cryopreservation an option that restores both fertility and hormone function. However, those with metastatic disease in their ovaries are unable to transplant this tissue. Therefore, new technologies to produce good-quality eggs and restore long-term cyclic ovarian function are being investigated and developed to expand options for a variety of patients. This mini-review describes current and near future technologies including in vitro maturation, in vitro follicle growth and maturation, bioprosthetic ovaries, and stem cell applications in fertility restoration research by their proximity to clinical application.
Abstract
Disclosure: H.B. McDowell: None. N. Henning: None. M.M. Laronda: None.
Chemotherapy treatments can be gonadotoxic and lead to loss of fertility and hormone function. Currently, the only ...pre-treatment strategy available to preserve fertility for prepubescent individuals is ovarian tissue cryopreservation (OTC) and the only option to restore fertility or hormone function is through ovarian tissue transplantation (OTT). Although in most cases OTT restores endocrine function, the tissue functions for an average of 2-5 years. To extend tissue function, the development of a bioengineered ovary that supports long-term follicle growth and endocrine function is critical. Tissue longevity depends on the number of primordial follicles (PMF) and their activation rate. While most PMFs survive the cryopreservation process, 80% are lost shortly after OTT. In bovine ovaries, the cortex, housing PMFs, is 8.5 times more rigid than deep medulla and is comprised of differential matrisome proteins. As mono-ovulatory animals, their ovaries closely mimic humans, making them a suitable model. Here, we developed decellularized extracellular matrix (dECM) hydrogels from bovine cortical tissue (c-dECM) and medullary tissue (m-dECM). Using atomic force microscopy, we determined that c-dECM and m-dECM did not display significantly different rigidities (537Pa, 468Pa). We found that the concentration of COL1, COL4, DCN, and VTN in the dECM hydrogels recapitulated what is seen in native bovine ovarian compartments. Therefore, we hypothesized that differences observed in downstream applications of these gels are due to differences in biochemical cues - or protein composition and relative abundance - in the ovarian ECM. The chemical and structural properties of ECM proteins play an integral role in cellular behavior. Therefore, we performed second harmonic generation scanning microscopy and determined that c-dECM hydrogels have significantly different fiber architecture when compared to m-dECM hydrogels. m-dECM hydrogels had significantly wider and longer fibers than c-dECM (6.22,6.419 and 38.22, 38.84 pixel/ppm microns) and displayed a lower fiber angle alignment (91.01°,87.95°). We assessed whether compartmental c-dECM and m-dECM hydrogels could drive differential expression patterns of downstream candidate genes. We then depleted our gels of proteins of interest using magnetic-activated protein filtration (MAPF). We found that our depleted gels modulate expression of genes associated with regulating follicle growth. Our work employed a novel method for examining the contribution of matrisome proteins in folliculogenesis. We anticipate our work to be influential in studying matrisome-dependent biochemical cues within other organ systems. IMPACT: Determining how the matrisome of the ovary can influence follicle activation will contribute critical data on how we can extend tissue function in OTT.
Presentation: Friday, June 16, 2023
We examined how climate variability affects the mobilization of material from six watersheds. We analyzed one to seven years of high‐frequency sensor data from a temperate ecosystem and a tropical ...rainforest. We applied a windowed analysis to correlate concentration‐discharge (C‐Q) behavior with climate anomalies, providing insight into how hydrological and biogeochemical processes change in response to climate variability. Positive precipitation anomalies homogenized the C‐Q responses for dissolved organic matter, nitrate, specific conductance and turbidity, indicating that hydrological processes dominate the C‐Q signal and watersheds act as “conveyor belts” of material. In contrast, drier and warmer conditions led to C‐Q behavior associated with variation in solute concentration, suggesting that biogeochemical processes are a primary control on solute export and their response to flow. Results indicate that climate variability can move watersheds along a continuum from transporter‐to‐transformer of biologically active solutes and responses can potentially vary by biome.
Plain Language Summary
Watersheds transport and transform material as water moves through the landscape to downstream waterbodies. We evaluated how variability in precipitation and temperature affect the movement of solutes and sediment from watersheds to river networks in temperate forests and tropical rainforests by examining the relationships between concentration and flow across six watersheds. We found that during wetter than typical conditions, hydrology dominates the relationship between concentration and discharge and watersheds act as a conveyor belt of material to the stream network. During drier and warmer than typical conditions, we observed high variability in concentration of solutes relative to discharge suggesting that watershed and in‐stream biogeochemical processes are the primary control on solute export. Under these conditions, the stream and watershed acts as a transformer of material. These results indicate that variability in climate can move watersheds and river networks along a continuum from transporter‐to‐transformer of biologically active solutes.
Key Points
Watersheds transition along a transporter‐transformer continuum across a range of precipitation anomalies in tropical and temperate biomes
Synergistic effects of dry conditions and warming temperatures may affect the export of biologically reactive solutes in temperate systems
Higher nitrate flux occurred during negative precipitation anomalies than during the largest positive precipitation anomalies
Dissolved organic carbon (DOC) and nitrogen (DON) are important energy and nutrient sources for aquatic ecosystems. In many northern temperate, freshwater systems DOC has increased in the past ...50 years. Less is known about how changes in DOC may vary across latitudes, and whether changes in DON track those of DOC. Here, we present long‐term DOC and DON data from 74 streams distributed across seven sites in biomes ranging from the tropics to northern boreal forests with varying histories of atmospheric acid deposition. For each stream, we examined the temporal trends of DOC and DON concentrations and DOC:DON molar ratios. While some sites displayed consistent positive or negative trends in stream DOC and DON concentrations, changes in direction or magnitude were inconsistent at regional or local scales. DON trends did not always track those of DOC, though DOC:DON ratios increased over time for ~30% of streams. Our results indicate that the dissolved organic matter (DOM) pool is experiencing fundamental changes due to the recovery from atmospheric acid deposition. Changes in DOC:DON stoichiometry point to a shifting energy‐nutrient balance in many aquatic ecosystems. Sustained changes in the character of DOM can have major implications for stream metabolism, biogeochemical processes, food webs, and drinking water quality (including disinfection by‐products). Understanding regional and global variation in DOC and DON concentrations is important for developing realistic models and watershed management protocols to effectively target mitigation efforts aimed at bringing DOM flux and nutrient enrichment under control.
The recovery of streams to atmospheric acid deposition has led to the changes in dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) concentrations that have altered the stoichiometric ratios (DOC:DON) of the dissolved organic matter (DOM) pool. Certain sites have shown increasing DOC:DON trends (enrichment of the C‐rich fraction of the DOM pool), declining DOC:DON trends (enrichment of the N‐rich fraction of the DOM pool), and/or no clear trends in DOC:DON ratios. The responses vary geographically suggesting that the controls of DOM trends are at the regional to local scale.
A comprehensive cross‐biome assessment of major nitrogen (N) species that includes dissolved organic N (DON) is central to understanding interactions between inorganic nutrients and organic matter in ...running waters. Here, we synthesize stream water N chemistry across biomes and find that the composition of the dissolved N pool shifts from highly heterogeneous to primarily comprised of inorganic N, in tandem with dissolved organic matter (DOM) becoming more N‐rich, in response to nutrient enrichment from human disturbances. We identify two critical thresholds of total dissolved N (TDN) concentrations where the proportions of organic and inorganic N shift. With low TDN concentrations (0–1.3 mg/L N), the dominant form of N is highly variable, and DON ranges from 0% to 100% of TDN. At TDN concentrations above 2.8 mg/L, inorganic N dominates the N pool and DON rarely exceeds 25% of TDN. This transition to inorganic N dominance coincides with a shift in the stoichiometry of the DOM pool, where DOM becomes progressively enriched in N and DON concentrations are less tightly associated with concentrations of dissolved organic carbon (DOC). This shift in DOM stoichiometry (defined as DOC:DON ratios) suggests that fundamental changes in the biogeochemical cycles of C and N in freshwater ecosystems are occurring across the globe as human activity alters inorganic N and DOM sources and availability. Alterations to DOM stoichiometry are likely to have important implications for both the fate of DOM and its role as a source of N as it is transported downstream to the coastal ocean.
Plain Language Summary
Ammonium and nitrate in freshwaters have received considerable attention due to their clear ecological and health effects. A comprehensive assessment of N in freshwaters that includes DON is lacking. Including DON in studies of surface water chemistry is important because it can cause eutrophication and certain forms can be rapidly removed by microbial communities. Here, we document how elevated levels of TDN impact the concentrations and relative proportions of all three forms of dissolved N and the stoichiometry of DOM. Our results suggest that human activities fundamentally alter the composition of the dissolved nitrogen pool and the stoichiometry of DOM. Results also highlight feedbacks between the C and N cycles in freshwater ecosystems that are poorly studied.
Key Points
We synthesize a global data set of stream chemistry to examine how the composition of dissolved N and DOC:DON ratios respond to N enrichment
Under low total dissolved N concentrations, the dominate form of N is highly variable but switches to primarily inorganic forms at high TDN
With N enrichment, DOM becomes more N‐rich (lower DOC:DON ratios) while concentrations of DON are less associated with concentrations of DOC
Background
Although music therapy (MT) is considered an effective intervention for young people with mental health needs, its efficacy in clinical settings is unclear. We therefore examined the ...efficacy of MT in clinical practice.
Methods
Two hundred and fifty‐one child (8–16 years, with social, emotional, behavioural and developmental difficulties) and parent dyads from six Child and Adolescent Mental Health Service community care facilities in Northern Ireland were randomised to 12 weekly sessions of MT plus usual care n = 123; 76 in final analyses or usual care alone n = 128; 105 in final analyses. Follow‐up occurred at 13 weeks and 26 weeks postrandomisation. Primary outcome was improvement in communication (Social Skills Improvement System Rating Scales) (SSIS) at 13 weeks. Secondary outcomes included social functioning, self‐esteem, depression and family functioning.
Results
There was no significant difference for the child SSIS at week 13 (adjusted difference in mean 2.4; 95% CI −1.2 to 6.1; p = .19) or for the guardian SSIS (0.5; 95% CI −2.9 to 3.8; p = .78). However, for participants aged 13 and over in the intervention group, the child SSIS communication was significantly improved (6.1, 95% CI 1.6 to 10.5; p = .007) but not the guardian SSIS (1.1; 95% CI −2.9 to 5.2; p = .59). Overall, self‐esteem was significantly improved and depression scores were significantly lower at week 13. There was no significant difference in family or social functioning at week 13.
Conclusions
While the findings provide some evidence for the integration of music therapy into clinical practice, differences relating to subgroups and secondary outcomes indicate the need for further study. ISRCTN Register; ISRCTN96352204.
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