High Mitochondrial Potential Research Articles

Reconstituted CD74+ NK cells trigger chronic graft versus host disease after allogeneic bone marrow transplantation

Chronic graft-versus-host disease (cGVHD) is the most common long-term complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The patients with pulmonary cGVHD in particular have a very poor prognosis. NK cells are the first reconstituted lymphocyte subset after allo-HSCT; however, the impact of reconstituted NK cells on cGVHD is unclear. Here, we found allogeneic recipients showed obvious pulmonary cGVHD. Surprisingly, deletion of reconstituted NK cells resulted in maximal relief of pulmonary cGVHD. Mechanistically, reconstituted NK cells with donor profiles modulated the pulmonary inflammatory microenvironment to trigger cGVHD. Reconstituted NK cells secreted IFN-γ and TNF-α to induce CXCL10 production by epithelial cells, which recruited macrophages and CD4+ T cells to the lungs. Then macrophages and CD4+ T cells were activated by the inflammatory microenvironment, thereby mediating lung injury. Through assessment of differences in cellular energy, we found that CD74+ NK cells with high mitochondrial potential and pro-inflammatory activity triggered pulmonary cGVHD. Furthermore, targeted elimination of CD74+ NK cells using the anti-CD74 antibody significantly alleviated pulmonary cGVHD but preserved the CD74− NK cells to exert graft-versus-leukemia (GVL) effects. Data from human samples corroborated our findings in mouse models. Collectively, our results reveal that reconstituted CD74+ NK cells trigger pulmonary cGVHD and suggest that administration of CD74 antibody was a potential therapeutic for patients with cGVHD.

Single-Cell Metabolic Profiling Integrated with Extracellular Vesicle Analysis Reveals Novel Metabolic Vulnerabilities and Prognostic Biomarkers in Acute Myeloid Leukemia

Introduction Acute myeloid leukemia (AML) is an aggressive disease for which less invasive tools are needed to explore disease dynamics. Changes in cell metabolism and metabolic adaptation are hallmark features for AML, thus emerging as promising therapeutic targets. However, it is still poorly elucidated whether and which extrinsic microenvironment signals may regulate the metabolic reprogramming occurring in AML. In this regard, Extracellular Vesicles (EVs) represent a promising tool for non-invasive liquid biopsy and may reveal a novel role in energy metabolism as well as clinically relevant biomarkers for AML. Along with EV profiling from peripheral blood (PB), we mapped the metabolic signature of leukemic stem cells (LSCs) and immune cell subsets to identify metabolic vulnerabilities and novel prognostic biomarkers. Methods PB (and paired bone marrow) were collected from AML patients at diagnosis (n=98) and healthy donors (HD, n=12). EVs were purified from platelet-free PB plasma of AML patients by size-exclusion chromatography followed by ultrafiltration. We have submitted all relevant data of our EV experiments to the EV-TRACK knowledgebase (EV-TRACK ID: EV230004). MACSPlex Exosome Kit was used for screening up to 37 surface EV markers. Western blot analysis was also performed. Energy cell metabolism was explored by Single Cell ENergetic metabolism by profilIng Translation inHibition (SCENITH TM) in LSC-like cells (CD34 +CD38 low/-)and immune cell subsets (CD3 +/CD4 +/CD8 +/T regulatory cells) using conventional/spectral flow-cytometry. Results Here, we developed a novel method exploiting both LSCs and EVs from AML patients using fresh whole blood for metabolic exploration. Firstly, we observed that LSC-like cells display low reactive oxygen species (ROS) levels with both high glutathione (GSH, as antioxidant molecule) levels and mitochondrial functionality suggesting a more resistant phenotype. Consistently, poor clinical outcomes were experienced by AML patients treated with conventional chemotherapy and with high GSH levels and mitochondrial potential in LSC-like cells (log-rank p=0.04). We also found high dependence on glucose and a preferential skewing toward glycolysis in LSC-like cells revealing a distinct metabolic status for LSCs in circulation. However, according to European LeukemiaNet (ELN) 2022 risk classification, a more prominent mitochondrial dependence on LSC-like cells was reported for intermediate- or adverse-risk AML patients revealing a prognostic relevance. By contrast, exploring the immunometabolic reprogramming in circulation, we revealed a significant decrease in glucose dependence for immune cells (CD4 + and CD8 + T cells) in comparison to LSCs proving the presence of a complex metabolic network in AML. Interestingly, we investigated the potential metabolic effects of EVs on LSCs. Indeed, CD34 + LSC-like cells co-cultured with circulating EVs enhanced their GSH levels and mitochondrial functionality towards a more aggressive phenotype. Accordingly, we discovered the presence of the antioxidant enzyme, glutathione peroxidases 3 (GPx-3), in AML EVs. Then, we profiled the surface proteins of isolated EVs to detect their cell origins and provide a reference map for clinical prognosis. We found that circulating AML EVs were significantly enriched in CD4 (helper T cell marker), CD14 (monocyte marker), CD40 (B-cell associated marker), CD44 and CD133-1 (stem cell markers), CD105 (stromal cell marker) and HLA-II (antigen-presenting cell marker) compared to HD EVs. In particular, we found that intermediate-risk AML patients showed a strong depletion in the expression of EV markers including T cell markers (CD2 and CD8) and mesenchymal markers (CD49e and CD146) in comparison to favorable and adverse-risk patients. Interestingly, AML patients who had been treated not intensively and showed low expression of CD40 (HR=0.23, 95% CI, 0.05−0,99, p=0.04) or CD62P (platelet activation marker, HR=0.24, 95% CI, 0.05−1.02, p=0.05) on EVs experienced poor outcomes suggesting that dedifferentiated phenotype on EVs might be associated with worse prognosis. Conclusion Overall, towards a new redefined ‘metabolic’ stratification for AML patients, we identified novel prognostic biomarkers for AML patients that might reveal novel metabolic vulnerabilities by exploiting in parallel single-cell metabolic profile and EV-based liquid biopsy.

Influence of the coincubation of post-thawed bull semen with elevated β-hydroxybutyrate concentrations on sperm characteristics.

In this study, the relationships between post-thaw bull sperm characteristics and hyperketonemic conditions after coincubation with cow plasma or media were determined to investigate if such a condition could affect bull sperm characteristics. Two experiments were conducted. In experiment 1, blood samples were collected from 31 cows to prepare plasma. Cows were independently categorized into two groups according to plasma β-hydroxybutyrate (BHB) concentrations (above or below 1.2 mM). Thawed bull semen was diluted and incubated with diluted plasma; motility parameters were evaluated using Computer Assisted Semen Analysis (CASA). In experiment 2, a pooled sample of thawed semen was diluted and divided into three aliquots: without BHB (control) and treated with either 1.2 mM (1.2) or 3 mM (3) BHB. In addition to motility, flow cytometric analyses were carried out. In experiment 1, the overall motility decreased significantly in plasma containing high (≥1.2 mM) BHB compared to plasma containing low (<1.2 mM) BHB. In experiment 2, the overall motility tended to be lower in BHB (3 mM)-supplemented samples. The supplementation of 3 mM BHB increased the proportion of live superoxide-positive sperm and sperm with high mitochondrial potential, while the DNA fragmentation index decreased.

Effects of gelatin and oxytocin supplementation in a long-term semen extender on boar semen quality and fertility potential.

This study investigated the efficacy of different concentrations of gelatin supplementation in long-term semen extender on boar semen quality during storage for 10 days at 17°C. Additionally, oxytocin was added to stored semen to enhance fertility. In Experiment 1, boar semen was collected, diluted with gelatin at concentrations between 0% and 2.5% (w/v) and mixed with a semen extender. Then, it was kept in a refrigerator at 17°C and stored for 10 days. In Experiment 2, the sperm quality was examined after adding 0, 5, and 10 IU oxytocin per artificial insemination dose to the most effective semen extender from Experiment 1 and placing it in a refrigerator at 17°C for 10 days. In Experiment 3, the fertility potential in terms of non-return rate and litter size was determined using the most effective solid-stored semen supplemented with oxytocin. The results indicated that sperm quality decreased with increasing storage time (p<0.05). The sperm quality in terms of total motility, progressive motility, and viable sperm with intact acrosomes and high mitochondrial potential was the highest with 1.5% gelatin supplementation (p<0.001) on all days of storage. Treatment with oxytocin did not affect sperm quality (p>0.05). The non-return rate and litter size after insemination with semen supplemented with 1.5% gelatin and 10 IU of oxytocin after 8 to 10 days of storage were comparable to those of the control group (p>0.05). A semen extender as a solid medium supplemented with 1.5% gelatin successfully preserved boar semen for a long storage duration. Treatment with oxytocin did not affect sperm quality. In addition, the fertility capacity using 1.5% gelatin with 10 IU oxytocin and stored for 8 to 10 days was acceptable and comparable to that of short-term storage.

The morphology, morphometry and functionality of fresh and cryopreserved wisent (Bison bonasus) epididymal spermatozoa

Epididymal spermatozoa obtained post mortem are considered a valuable source of genetic material which is often irrevocably lost. This makes these gametes constitute a key element in protection and restitution programs. The wisent (Bison bonasus, Linnaeus 1758) is a species that survived in zoos after extinction from its natural habitat. This resulted in a narrowing of the genetic pool of the whole population, which is at present derived from only 12 ancestors. Currently, wisent protection programs are aimed at preserving the genetic diversity by establishing a germplasm bank. The objective of this study was to comprehensively characterize the morphology, morphometry and functionality of wisent epididymal spermatozoa and evaluate the effectiveness of their cryopreservation in extender based on Tris buffer and chicken egg yolk. The median total number of spermatozoa obtained from one individual was 1985.0 × 106 (62.5 × 106–7452.0 × 106). These gametes were characterized by median: 40.0% (0.5–70.0%) subjective motility, 69.8% (32.5–90.0%) viability and 54.3% (10.5–83.3%) normal morphology. The sperm head had a median size of 5.0 μm (3.5–6.7 μm) width, 8.5 μm (6.4–11.3 μm) length and 36.9 μm2 (23.7–48.6 μm2) surface area. The viable population of the obtained gametes was characterized by median values 53.2% (4.5–80.3%) of intact sperm membrane, 50.8 (26.0–76.6%) of intact acrosome, 0.4% (0–98.7%) of fragmented chromatin, 5.9% (0.0–88.8%) of cells with high mitochondrial potential and 42.1% (8.3–63.7%) without lipid peroxidation. The viable population of the frozen/thawed gametes was characterized by median values: 18.4% (2.4–57.9%) of intact sperm membrane, 35.1 (11.9–56.7%) of intact acrosome, 0.07% (0–89.2%) of fragmented chromatin, 12.8% (0.0–49.7%) of cells with high mitochondrial potential and 16.3% (2.2–53.6%) without lipid peroxidation. Due to the material originating from a relatively large number of wild individuals, the research presented here contributed to the description of certain species standards for the assessment of wisent epididymal spermatozoa. The presented effect of cryopreservation on these gametes justifies the use of an extender based on Tris buffer with the addition of chicken egg yolk. The obtained effects are satisfactory from the point of view of preserving valuable genetic material and their use in ART.

Abstract PR016: Systemic T cell metabolic and effector function changes following treatment with PD1 and CTLA4 in patients with kidney cancer

Abstract Background: We have previously shown that dysfunctional renal cell carcinoma (RCC) tumor infiltrating lymphocytes (TIL) have glycolytic insufficiencies, and effector function can be rescued by bypassing glycolysis and modulating mitochondrial fitness (Beckermann et al., 2020). We have also shown that RCC TIL biology may be captured in a subset of the peripheral blood T cells, providing an opportunity to assess the tumor immune landscape in noninvasive liquid biopsy from peripheral blood samples (Siska et al., 2018). Methods: We evaluated the peripheral blood of twenty patients with RCC undergoing systemic therapy with PD1 and CTLA4, ten of whom had primary progressive disease and ten who had clinical benefit (SD, PR, CR for 6 months or greater), studying samples before and after three weeks on treatment. Single Cell mRNA gene expression and TCR clonal analysis was assessed in a subset of patients as well as ArcherDx V(D)J sequencing on matched tumor tissue. To assess the impact of mitochondrial membrane potential on T cell responses in patients with ccRCC we flow sorted viable, CD3+ PBMCs with high or low mitochondrial potential. The peripheral blood was analyzed for protein changes using a 44-plex labeled CyTOF antibody panel focused on T cells surface markers, as well as effector and metabolic function. Results: From peripheral blood of patients with ccRCC we find that CD3+ T cells are predominantly composed of subgroups with mitochondrial high membrane potential and expand in number after αPD1+αCTLA4 therapy. Peripheral T cells with low mitochondrial membrane potential are enriched for gene expression pathways associated with cytotoxicity. T cells with mitochondrial low potential also tended to have oligoclonal TCR expansion that were frequently shared between tumor and blood compared to that of mitochondrial high potential T cells. Mitochondrial low T cells were enriched for genes associated with cytotoxicity including CTSW, CD8, KLRK1, and KLRD. The tumor T cell repertoire demonstrated the greatest similarity with peripheral T cells that had low mitochondrial membrane potential. Shared T cells between the tumor and periphery are enriched for chemotaxis, antigen binding, and cytotoxicity signaling pathways. At the protein level, patients with response have lower metabolic activity and greater CD4+ effector T cells, consistent with the scRNA-seq data, while patients with progressive disease have more metabolically active profiles. Conclusions: Single cell gene expression and mass cytometry analysis shows that systemic changes occur in patients with kidney cancer undergoing αPD1 and αCTLA4 treatment. Shared TCR from TIL exist in oligoclonally expanded T cells in the peripheral blood. These shared T cells are enriched in subsets with low mitochondrial membrane potential and express markers of effector function and upregulate cytotoxic T cell pathways. Citation Format: Dalton Greenwood, Paul Lindau, Caroline Roe, Madelyn Landis, Rachel Hongo, Brian Rini, Jonathan Irish, W. Kimryn Rathmell, Jeffrey Rathmell, Kathryn Beckermann. Systemic T cell metabolic and effector function changes following treatment with PD1 and CTLA4 in patients with kidney cancer [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr PR016.

Abstract 572: Netrin-1 Induces Cytoskeletal-mediated Rewiring Of Mitochondrial Metabolism And Immunity

Background: Cardiometabolic diseases are characterized by maladaptive immune infiltration in metabolic tissues. This results in unresolved inflammation, mediated by macrophages (M∅). Netrin-1 (Ntn1) causes macrophage retention by inhibiting cytoskeletal activity and induces a pro-inflammatory phenotype through receptor Unc5B. Emerging evidence suggests that cellular mechanics and metabolism are reciprocally regulated, but whether this plays a role in macrophage immunometabolism has not been explored. We hypothesized that Ntn1 stimulates a cytoskeletal-mediated rewiring of cellular metabolism toward a pro-inflammatory phenotype in macrophages. Methods/Results: We report that mechanical stress stimulates Ntn1 and Unc5b expression in macrophages along with proinflammatory genes known to promote atherosclerosis. RNA-sequencing analysis comparing control (M∅ WT ) with Ntn1 -silenced macrophages (M∅ Δ Ntn1 ) under high mechanical stress revealed a transcriptional signature associated with decreased biomechanical sensing and increased energy metabolism. This was confirmed by extracellular flux assays showing higher mitochondrial respiration in M∅ Δ Ntn1 . In addition, flow cytometry and live-cell imaging showed cytoskeletal remodelling and improved mitochondrial functionality in M∅ Δ Ntn1 as measured by higher mitochondrial potential, membrane integrity and network complexity. Importantly, incubation with recombinant Ntn1 reversed the effects of genetic loss of Ntn1 , but not that of Unc5b , suggesting receptor dependency. Furthermore, as Ntn1 is tied to cytoskeletal reorganization via Rho-associated kinase (ROCK) inhibition, we tested the effects of ROCK signaling on mitochondrial metabolism. Small molecule-mediated ROCK pathway activation raised mitochondrial membrane potential in M∅ WT , mimicking loss of Ntn1 , whereas ROCK inhibition restored mitochondrial membrane potential in M∅ Δ Ntn1 to wild type level. Conclusion: Taken together, our data shows that Ntn1, through Unc5B, decreases mitochondrial function through ROCK-mediated cytoskeletal reorganization. This suggests that Ntn1 perpetuates inflammation in cardiometabolic diseases through a cytoskeletal regulation of immunometabolism in macrophages.

Impact of cryopreservation protocols (one- and two-step) on boar semen quality at 5 °C and post-thawing

The two-step protocol (2 S) is currently used for boar semen cryopreservation. In this method, the cryoprotectant penetrant agents (CPAs) are added at 5 °C to reduce the toxicity of CPAs. An alternative is the one-step protocol (1 S), which is easier, cheaper, and reduces the necessity of equipment, but could increase the toxicity of CPAs. Currently, there are no studies that compared both protocols for boar semen cryopreservation. This experiment aimed to study the effect of cryopreservation protocol (1 S vs 2 S) on boar spermatozoa. In the one-step protocol, after centrifugation, the spermatozoa pellet was resuspended at 17 °C in the extender containing CPAs to achieve a concentration of 1 × 109 spermatozoa/mL and then submitted to cryopreservation. For the two-step protocol, the sperm pellet was resuspended in fraction A at 17 °C to achieve a concentration of 1.5 × 109 spermatozoa/ mL, and then allowed to cool to 5º C before fraction B with CPA was added to the sample to achieve a final concentration of 1 × 109 spermatozoa/mL and followed by freezing. The cryopreservation protocol did not impact total motility at 5 °C (1 S: 78.5 % vs 2 S: 79 %, p > 0.05). After thawing, the two-step protocol improved (p < 0.05) total (1 S: 18.2 % vs 2 S: 29.5 %) and progressive motility (1 S: 9 % vs 2 S: 15%). Further, the 2 S protocol increased (p < 0.05) the percentage of rapid spermatozoa (1 S: 8.7 % vs 2 S: 14.6 %) and spermatozoa with intact plasma and acrosomal membrane (IAIP) (1 S: 40.5 % vs 2 S: 61.5 %), and increased (p < 0.05) live sperm cells with high mitochondrial potential (MHIP) (1 S: 42.9 % vs 2 S: 60 %). The boar semen cryopreservation method (TRT) did not (p > 0.05) alter membrane lipid disorder, lipid peroxidation, and superoxide anion. Thus, the best method for boar semen cryopreservation is the two-step protocol.

P-158 Beneficial effects of platelet rich plasma for human germinal vesicle oocyte in vitro maturation

Abstract Study question Can platelet rich plasma (PRP) supplementation to the medium improve outcomes of in vitro maturation of germinal vesicle (GV) oocytes? Summary answer PRP as a component of in vitro maturation medium benefits the GV oocyte maturation rate, the mitochondrial membrane potential and the distribution of lipid droplets. What is known already The European Society of Human Reproduction and Embryology presents several strategies for maintaining fertility in women, one of which is in vitro maturation (IVM) of oocytes. Despite more than 5,000 children have been born after using the IVM method, the mechanisms involved in meiotic arrest and resumption in oocytes are not fully understood. Hormones and growth factors are components of a complex regulation system which play a mediator role in ovarian function and are involved in meiotic resumption. PRP is a rich source of growth factors and can be effectively used to supplement the medium for in vitro oocyte maturation. Study design, size, duration Oocyte maturity was assessed after denudation, and immature gametes at the GV stage (n = 84) were randomly divided into 4 groups for IVM (24 - 48h): 1- without cumulus cells (CC) and PRP, 2 – with PRP without CC, 3 - with CC without PRP, 4 – with CC and PRP. The maturation rate of the oocytes was evaluated in 24 or 48h. The study was carried out between January 2020 to December 2021. Participants/materials, setting, methods This prospective study included 30 female patients 33±3.6 years old. Women received exogenous gonadotropins as part of a short protocol of superovulation induction. About 15% oocytes were at the germinal vesicle stage after denudation of retrieved gametes. PRP was prepared by two-step centrifugation method and was added (5%) to the maturation media. Primary endpoints were oocyte maturation rate, mitochondrial membrane potential and lipid droplets distribution evaluated by using JC-1 and Nile Red staining respectively. Main results and the role of chance The highest maturation rate was in group 4 (85%) compared with groups 1-3, where the rates were 9.5; 36.4 and 47.6, respectively (p &amp;lt; 0.05). The biggest number of cells with high mitochondrial potential was in oocytes matured with PRP and cumulus cells (4.5 ± 0.7) compared with other groups (1.3 ± 0.3; 3.0 ± 0.5 and 2.7 ± 0.4 for groups 1-3, respectively) (p &amp;lt; 0.05). The distribution of lipid droplets, typical of in vivo matured metaphase II oocytes, was the largest in group 1 (75%) (p &amp;lt; 0.05). There were no differences in this parameter between the other groups. Limitations, reasons for caution Limited number of GV oocytes in the study group. Further studies are recommended and should include group of patients with different age range. Wider implications of the findings PRP injection into ovarian tissue causes its rejuvenation. Our results confirm for the first time that PRP supplementation to the medium of oocyte in vitro maturation can increase the maturation rate, mitochondrial activity, and improve lipid droplets distribution in human oocytes. These finding are valuable for improvement of IVM medium. Trial registration number Not applicable

Coenzyme Q10 and melatonin protect cryopreserved equine sperm against lipoperoxidation

The objective of the experiment was to evaluate the effect of the addition of different concentrations of the antioxidants Coenzyme Q10 (CoQ10) and melatonin to equine semen freezing diluent, alone or in combination, during the cryopreservation process. Twenty ejaculates (n = 5 stallions) were divided in groups: Control (C, without the addition of antioxidants), melatonin 0.75 mM (MEL1), melatonin 1.5 mM (MEL2), CoQ10 40 μg/mL (Q1), CoQ10 200 μg/mL (Q2), and CoQ10 40 μg/mL+ 0.75 mM melatonin (Q1 +MEL1). Q1 and Q2 groups demonstrated intact plasma membrane and high mitochondrial membrane potential after 30 (M-30) and 60 (M-60) min of incubation compared with the control group (Q1: 64.8 % ± 9.9 %, Q2: 65.2 % ± 10.5 %, C: 55.1 % ± 10.0 %; M-30 and Q1: 63.3 % ± 10.4 %, Q2: 64.6 % ± 10.8 %, C: 53.1 ± 10.6 %; M-60; P < 0.05). Melatonin conferred greater membrane stability at all evaluated times compared with the control group (MEL1: 42.1 % ± 6.0 %; MEL2: 44.0 % ± 6.7 %, C: 35.9 % ± 5.9 %; M-0; MEL1: 40.8 % ± 5.6 %; MEL2: 42.6 % ± 7.2 %, C: 33.1 % ± 6.6 %; M-30 and MEL1: 37.5 % ± 7.4 %; MEL2: 39.1 % ± 7.2 %; C: 31.3 % ± 6.5 %; M-60; P < 0.05). The use of antioxidants alone or in combination resulted in lower levels of lipoperoxidation at all times evaluated compared with in the control group (P < 0.05). In conclusion, CoQ10 and melatonin were effective in the cryopreservation of equine semen by decreasing lipoperoxidation and promoting a higher percentage of spermatozoa with a high mitochondrial potential, total and progressive motility, and prevention of membrane lipid disorder.

Effect of supplemental trace minerals on standard and novel measures of bull fertility

Two studies were conducted to evaluate the effects of trace mineral supplementation on traditional and novel measures of bull fertility. In Experiment 1, 37 mature bulls received one of three dietary supplements daily for 71 d: 1) Supplement without Cu, Zn, and Mn (CON); 2) Supplement with Cu, Zn, and Mn sulfate (SULF); and 3) Supplement with basic Cu chloride, and Zn and Mn hydroxychloride (CHLR). In Experiment 2, 128 Angus or Angus-Hereford bull calves were maintained on a growing diet for 75 d (year 1) or 119 d (year 2) in Calan gate equipped pens without mineral supplementation. Bulls (n = 32 head/treatment) received one of four trace mineral supplements daily for 84 d: 1) Zn with no Cu (ZN), 2) Cu with no Zn (CU), 3) Cu and Zn (ZNCU), or 4) no Cu or Zn (CON). Bull fertility measures included a breeding soundness evaluation (BSE) and novel fertility measures conducted using flow cytometry. In mature bulls, final liver Zn concentration was positively correlated (P = 0.02) with sperm concentration (r = 0.31) and tended (P = 0.06) to be negatively correlated with acrosome damage (r = −0.39). Peripubertal bulls receiving ZNCU had greater ADG than bulls in the CU group (P = 0.05). Each BSE and novel fertility component improved from Day 0–84 in peripubertal bulls and were not affected (P > 0.10) by mineral supplementation. Bulls that received no supplement (CON) had greater (P < 0.01) percentage of sperm with distal midpiece reflex (6.9 vs 4.0% for CON and TM supplement, respectively) and Dag or Dag-like defect (2.6 vs 1.4% for CON and TM supplement, respectively) in their ejaculates. Sperm viability after 30 min of incubation were not affected by trace mineral supplementation, but after 3 h incubation, sperm viability tended to differ (P = 0.06) between treatments and tended to be less for CON bulls (48.5%) compared to ZNCU bulls (55.1%). Among contrast comparisons, trace mineral supplemented bulls had greater (P < 0.05) percentage of viable sperm at 3 h post collection and reactive oxygen resistant sperm than CON bulls. Addition of Zn to trace mineral containing Cu (ZNCU) improved (P < 0.05) percentage of sperm in the ejaculate with high mitochondrial energy potential and viable sperm with intact acrosome membrane. In summary, it appears the homeostasis mechanisms for bull trace mineral maintenance are extremely efficient and mineral supplementation of mature and peripubertal bulls did not have major improvements in any laboratory or chute-side measures of bull fertility, however bulls exposed to breeding or in environments with diet antagonists might respond differently.

Dual function of Bim is switched by ANT2 (SLC25A5) to balance apoptotic and effective signals in CD8+ T cells

Abstract The immune responses to anti-PD-1 therapy in cancer patients are not completely defined due to lack of reliable biomarkers that identifies responsive and functional T cells. Bim, a molecule of the Bcl-2 family, was recently identified as a downstream signaling molecule of PD-1 pathway in CD8+ T cells and has both pro-apoptotic and effective roles in CD8 T cells. Our clinical data shown that high level of Bim in CD8+ T cells (before checkpoint blockade) was predictive of response in metastatic melanoma whereas in colorectal cancer, low level of Bim was associated with treatment response. Using co-immunoprecipitation, high resolution microscopy and FRET we identified ANT2 (Adenine Nucleotide Translocase 2, an inner membrane protein of mitochondria) as a protein interacting with Bim. Accordingly, we found CD8+ T cells with low and high mitochondrial potential demonstrated different ANT2/Bim ratio, and high ANT2/Bim ratio fall in effector T cells with low mitochondrial potential but high cytotoxic activity. Given the pro-survival of ANT2, our results indicate that ANT2 may function to balance the pro-apoptotic and effective role of Bim in mitochondria in order to preserve effector T cells before contraction. Understanding the molecular mechanism of Bim and ANT2 interaction in CD8+ T cells may provide a novel marker to identify resilient CD8+ T cells responsive to anti-PD-1 therapy, and predict clinical response to the therapy.

Lipid peroxidation in bull semen influences sperm traits and oxidative potential of Percoll®-selected sperm.

Although bovine embryo in vitro production (IVP) is a common assisted reproductive technology, critical points warrant further study, including sperm traits and oxidative status of sperm for in vitro fertilization (IVF). Our aim was to evaluate whether the lipid peroxidation index of commercial bull semen is influenced by sperm traits and oxidative status of sperm populations selected using Percoll® gradient. Semen straws from 48 batches from 14 Nelore bulls were thawed individually, analyzed for motility and subjected to Percoll selection. After Percoll, the lipid peroxidation index of the extender was evaluated, whereas selected sperm were analyzed for motility, acrosome and membrane integrity, mitochondrial membrane potential, chromatin resistance and oxidative potential under IVF conditions. Batches were divided retrospectively in four groups according to lipid peroxidation index. Sperm from Group 4 with the lowest index of lipid peroxidation had, after Percoll selection, greater plasma membrane integrity (81.3%; P = 0.004), higher mitochondrial potential (81.1%; P = 0.009) and lower oxidative potential (135.3 ng thiobarbituric acid reactive substances (TBARS)/ml; P = 0.026) compared with Group 1 with highest lipid peroxidation index (74.3%, 73% and 213.1 ng TBARS/ml, respectively). Furthermore, we observed negative correlations for the lipid peroxidation index with motility, membrane integrity and mitochondrial potential, and positive correlations with oxidative potential. In conclusion, oxidative stress in semen straws, as determined using lipid peroxidation in the extender, is associated with sperm traits and their oxidative potential under IVF conditions. These results provided further insights regarding the importance of preventing oxidative stress during semen handling and cryopreservation, as this could affect sperm selected for IVF. Finally, Percoll selection did not completely remove sperm with oxidative markers.

Strategy of Isolating 'Primed' Tumor Initiating Cells Based on Mitochondrial Transmembrane Potential.

Various stem cells have been found to be dependent on mitochondrial energetics. The role of mitochondria in regulating the self-renewal of normal stem cells and stem-like tumor initiating cells (TICs) is increasingly being appreciated. We proposed that TIC populations have a sub population of cells that are "primed" by mitochondria for self-renewal. Using ovarian cancer model, we have developed a protocol to identify and isolate these "primed" cells using Fluorescence-Assisted Cell Sorting (FACS). We combined live cell stains for a functional marker of TICs and for mitochondrial transmembrane potential to enrich TICs with higher mitochondrial potential that form in vitro spheroids 10-fold more than the other TICs with lower mitochondrial potential. This protocol can be directly used or modified to be used in various cell types. Thus, this protocol is anticipated to be invaluable for the basic understanding of mitochondrial and energetic heterogeneity within stem cell population, and may also prove valuable in translational studies in regenerative medicine and cancer biology.

Abstract A53: Energetic regulation of the Cyclin E oncoprotein in mitochondria-dependent ovarian tumor initiating cells

Abstract Study Purpose: Ovarian tumor-initiating (stem) cells (ovTICs) contribute to EOC chemoresistance. Thus, understanding their vulnerabilities may reveal novel therapeutic strategies. Overactivation of the cell cycle regulator Cyclin E is linked to chemoresistance of a subpopulation of epithelial ovarian carcinoma (EOC). However, role of Cyclin E in ovTIC maintenance is not clear. Energetics of TICs are rewired and Cyclin E function is uniquely linked to energetics and metabolism, which has not been tested in EOC. In nontumorigenic models, we reported that protein levels of Cyclin E (and certain stem cell markers) are elevated by boost in mitochondrial energetics caused by repression of the mitochondrial fission protein, Drp1. In EOC cells, Drp1 repression elevates the functional ovTIC marker Aldh, while active ovTICsAldh+ is dependent on mitochondrial energetics unlike the bulk tumor cells (BTCs Aldh-). Moreover, ovTICAldh+ potency is higher in cells with higher mitochondrial transmembrane potential. Therefore, we are investigating how mitochondrial energetics modulated by Drp1 regulates Cyclin E for ovTIC maintenance, which may reveal energetic vulnerabilities of ovTICs. Experimental Procedures: We sort 4 cell populations based on Aldh activity and mitochondrial membrane potential and then study mitochondrial and Cyclin E properties. Here, we use biochemical and cell biologic techniques, including our unique high-resolution microscopy-based techniques. We isolate mitochondria by biochemical cell fractionation. We manipulate genes by shRNA mediated knockdown. Unpublished Data: First, we confirmed the existence of the Aldh+ cell population with higher or lower mitochondrial membrane potential in mouse xenografts and patient EOC cells, and also confirmed a noncanonical mitochondrial pool of Cyclin E in EOC cells and xenografts as we reported for other cells. Interestingly, chemoresistance related ovTICAldh+ enrichment happens with increase in Cyclin E protein levels only when Drp1 is repressed to allow boost in mitochondrial energetics. Indeed, Cyclin E levels are higher in isolated quiescent ovTICsAldh+ than the ovBTCs Aldh-. More importantly, activation of TIC properties maintains the elevated Cyclin E levels in the more potent ovTICsAldh+ with higher mitochondrial potential, but not in the less potent ovTICsAldh+ with lower mitochondrial potential. This Cyclin E dependence on mitochondrial energetics in ovTICsAldh+ may be the underlying mechanism of the attenuation of chemoresistance with mitochondrial inhibitors, as we observed. Conclusions: We propose the novel concept that ovTICsAldh+ “primed” by Drp1 regulated mitochondrial energetics maintain elevated Cyclin E levels, which may involve mitochondrial translocation and release of Cyclin E. We speculate that inclusion of specific mitochondrial inhibitors in the chemotherapeutic regime may eliminate mitochondria dependent ovTICAldh+ that are maintained by mitochondria regulated Cyclin E. Citation Format: Kasturi Mitra, Brian Spurlock. Energetic regulation of the Cyclin E oncoprotein in mitochondria-dependent ovarian tumor initiating cells [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A53.

Sodium caseinate improves longevity and fertility of frozen bull semen

This study aimed to evaluate the effect of sodium caseinate added into freezing extender on the sperm parameters of cryopreserved bull semen and in vitro and in vivo fertility. One ejaculate of 30 bulls was used and processed using Botu-Bov (Botupharma, Botucatu, Brazil) with the addition of 20% egg yolk (EY) or 15% egg yolk with 2% sodium caseinate (EY + SC), subsequently submitted to freezing. Semen from both groups were evaluated immediately after thawing (T0) and after thermic stress at 37 °C for 90 min (T90), for sperm kinetics, by CASA method, and plasma membrane integrity (PMI), superoxide (O2−) concentration and high mitochondrial potential (HMP) by flow cytometry. In vitro fertilization (IVF) was performed to assess embryo cleavage rate on day 3, and blastocyst rate on day 8. The in vivo fertility test was performed using fixed-time artificial insemination (FTAI). In sperm evaluation, trajectory velocity, linear velocity, curvilinear velocity, and lateral head movement were higher (P < 0.05) in EY + SC at T0. At T90, while rectilinearity and linearity did not differ between EY and EY + SC (P > 0.05), the other parameters evaluated were higher in EY + SC. Similarly, the integrity of the plasma and acrosomal membranes (iPAM) was higher (P < 0.05) at T90 in EY + SC, but did not differ (P > 0.05) between the groups at T0. For O2− and HMP, the values were lower (P < 0.05) in EY + SC group in both moments; furthermore, EY + SC showed higher cleavage and blastocyst rates in IVF. Likewise, pregnancy rates by FTAI were higher (P < 0.05) in the EY + SC group. In conclusion, the addition of sodium caseinate into freezing extender improves sperm parameters of frozen-thawed bull semen and fertility rates on during in vitro and in vivo tests.

ANT2 (SLC25A5) balances the pro-apoptotic vs. effector signals of Bim in CD8 T cells

Abstract The immune response to anti-PD-1 therapy in cancer patients is not completely defined due to lack of reliable biomarkers that can determine T cell function. Bim, a member of the Bcl-2 family, was recently identified as a downstream signaling molecule in the PD-1 pathway. Within CD8 T cells, Bim appears to have a dual function, and can be pro-apoptotic or promote effector activity. Our clinical data has shown that high levels of Bim in CD8 T cells are predictive of response to anti-PD-1 therapy in metastatic melanoma whereas in colorectal cancer, a low level of Bim is associated with treatment response. Thus, we sought to determine what molecular partners might influence the role of Bim. Using co-immunoprecipitation, high resolution microscopy and FRET we identified ANT2 (Adenine Nucleotide Translocase 2), an inner membrane protein of mitochondria, as a protein that interacts with Bim. Accordingly, we found CD8 T cells with low and high mitochondrial potential demonstrated different ANT2/Bim ratios, and a low ANT2/Bim ratio was present in effector T cells with low mitochondrial potential but high cytotoxic activity. Given the pro-survival function of ANT2, our results indicate that ANT2 may balance the pro-apoptotic and effector roles of Bim in mitochondria in order to preserve effector T cells before contraction. Understanding the molecular mechanism of Bim and ANT2 interactions in CD8 T cells may provide a novel marker to predict clinical response to anti-PD-1 therapy.

Increased quality of in natura and cryopreserved semen of water buffaloes supplemented with saturated and unsaturated fatty acids from the palm oil industry.

Ruminant energy supplementation with vegetable oils or fats has been standing out worldwide and oil palm processing has been receiving growing interest. This study assessed the effect of supplementation with saturated and unsaturated fatty acids from the palm oil industry on the lipid profile of seminal plasma and of the sperm membrane, as well as on the morphological and functional characteristics of raw and cryopreserved buffalo semen. Twelve purebred Murrah bulls (Bubalus bubalis) were assigned to the experimental groups and fed diets for 120 days with no added lipids (CONT, four bulls), or with an extra amount of 3% lipids from crude palm oil (PALM, four bulls), or from palm oil deodorizer distillate (PODD, four bulls). Semen was collected and cryopreserved every 15 days. The lipid composition of membranes and semen quality were determined after collections. Lipid supplementation did not impact feed intake (P>0.05). Diet enrichment with PALM increased the linoleic acid (C18:2,ω6) in seminal plasma. Lipid supplementation did not increase the polyunsaturated fatty acids in the sperm membrane composition, but significantly increased the lignoceric acid (C24:0). Cryopreserved semen of the supplemented bulls presented higher progressive motility (60.2 vs. 67.9 vs. 65.2%; P<0.05) and sperm viability detected by eosin-nigrosin staining (61.1 vs. 69.4 vs. 67.8%; P<0.05). Palm oil reduced major sperm defects in both raw (12.2 vs. 9.3 vs. 13.2%; P<0.0001) and cryopreserved semen (12.4 vs. 9.4 vs. 11.2%; P<0.0001). The lipids added to the diet did not impact the population of spermatozoa with intact plasma and acrosomal membranes (PI-/PSA-), but significantly increased the percentage of spermatozoa with high mitochondrial potential (25.6 vs. 31.5 vs. 32.0%; P=0.008). The results suggest that lipid supplementation based on crude palm oil or palm oil deodorizer distillate can be safely used to feed buffalo bulls and may increase sperm attributes related to male fertility.

Superoxide Anion Is Reduced in Gradient Selected Cryopreserved Stallion Semen Despite High Mitochondrial Potential

Superoxide Anion Is Reduced in Gradient Selected Cryopreserved Stallion Semen Despite High Mitochondrial Potential

P-235 - Selective elimination of senescent cells by mitochondrial targeting is regulated via ANT2

Cellular senescence is stable cell cycle arrest limiting proliferative potential of cells. Inability of immune cells to eliminate senescent cells from the organism may lead to development of age-related diseases. We have developed several mitocans, mitochondrially targeted agents inducing apoptosis of cancer cells, whose mitochondrial uptake is driven by high mitochondrial potential of those cells. This efficacy of mitocans to target cells with increased mitochondrial potential, such as senescent cells, makes them candidates for senolytic agents. Mitochondrial targeted tamoxifen (MitoTam), unlike other anti-cancer agents, not only kills cancer cells without inducing senescence, but also selectively eliminates both malignant and non-cancerous senescent cells. In naturally aged mice, MitoTam treatment resulted in decrease of senescent markers in all tested organs. We found a role of adenine nucleotide translocator 2 (ANT2) in the survival of MitoTam-treated cells. Restoration of ANT2 in senescent cells caused resistance to MitoTam, while its downregulation in control cells promoted MitoTam-induced elimination. The ability of MitoTam to eliminate senescent cells results in new strategy for treatment of age-related pathologies and senescence-associated inflammation or tumorigenesis.