Transplanting old organs promotes senescence in young recipients.

In clinical organ transplantation, donor and recipient ages may differ substantially. Old donor organs accumulate senescent cells that have the capacity to induce senescence in naïve cells. We hypothesized that the engraftment of old organs may induce senescence in younger recipients, promoting age-related pathologies. When performing isogeneic cardiac transplants between age-mismatched C57BL/6 old donor (18 months) mice and young and middle-aged C57BL/6 (3- or 12- month-old) recipients , we observed augmented frequencies of senescent cells in draining lymph nodes, adipose tissue, livers, and hindlimb muscles 30 days after transplantation. These observations went along with compromised physical performance and impaired spatial learning and memory abilities. Systemic levels of the senescence-associated secretory phenotype factors, including mitochondrial DNA (mt-DNA), were elevated in recipients. Of mechanistic relevance, injections of mt-DNA phenocopied effects of age-mismatched organ transplantation on accelerating aging. Single treatment of old donor animals with senolytics prior to transplantation attenuated mt-DNA release and improved physical capacities in young recipients. Collectively, we show that transplanting older organs induces senescence in transplant recipients, resulting in compromised physical and cognitive capacities. Depleting senescent cells with senolytics, in turn, represents a promising approach to improve outcomes of older organs.

The medical cost and outcome of desensitization protocol in kidney transplantation recipients with high immunological risks.

BACKGROUND: Kidney transplantation is a well-established alternative in renal replacement therapy. Compared with hemodialysis, low-immunological-risk kidney transplantation can reduce the medical treatment costs associated with end-stage renal disease. However, there are few reports on whether high-immunological-risk kidney transplantation reduces the financial burden on governments. We investigated the medical costs of high-immunological-risk kidney transplantation in comparison with the cost of hemodialysis in Japan. METHODS: We compared the medical costs of high-immunological-risk kidney transplantation with those of hemodialysis. 15 patients who underwent crossmatch-positive and/or donor-specific antibody-positive kidney transplantations between 2020 and 2021 were enrolled in this study. The patients received intravenous immunoglobulin, plasmapheresis, and rituximab as desensitizing therapy. RESULTS: Acute antibody-mediated rejection was detected in nine (60%) recipients, while there were no indications of graft function deterioration during the follow-up. For each patient, the transplant hospitalization cost was 38 428 ± 8789 USD. However, the cumulative costs were 59 758 ± 10 006 USD and 79 781 ± 16 366 USD, at 12 and 24 months, respectively. Compared with hemodialysis (34 286 USD per year), high-immunological-risk kidney transplantation tends to be expensive in the first year, but the cost is likely to be lower than that of hemodialysis after 3 years. CONCLUSIONS: Although kidney transplantation is initially expensive compared with hemodialysis, the medical cost becomes advantageous after 3 years even in kidney transplant recipients with high immunological risk.

The Impact of FGFR3 Alterations on the Tumor Microenvironment and the Efficacy of Immune Checkpoint Inhibitors in Bladder Cancer.

BACKGROUND: Currently, only limited knowledge is available regarding the phenotypic association between fibroblast growth factor receptor 3 (FGFR3) alterations and the tumor microenvironment (TME) in bladder cancer (BLCA). METHODS: A multi-omics analysis on 389 BLCA and 35 adjacent normal tissues from a cohort of OMPU-NCC Consortium Japan was retrospectively performed by integrating the whole-exome and RNA-sequence dataset and clinicopathological record. A median follow-up duration of all BLCA cohort was 31 months. RESULTS: FGFR3 alterations (aFGFR3), including recurrent mutations and fusions, accounted for 44% of non-muscle invasive bladder cancer (NMIBC) and 15% of muscle-invasive bladder cancer (MIBC). Within MIBC, the consensus subtypes LumP was significantly more prevalent in aFGFR3, whereas the Ba/Sq subtype exhibited similarity between intact FGFR3 (iFGFR3) and aFGFR3 cases. We revealed that basal markers were significantly increased in MIBC/aFGFR3 compared to MIBC/iFGFR3. Transcriptome analysis highlighted TIM3 as the most upregulated immune-related gene in iFGFR3, with differential immune cell compositions observed between iFGFR3 and aFGFR3. Using EcoTyper, TME heterogeneity was discerned even within aFGFR cases, suggesting potential variations in the response to checkpoint inhibitors (CPIs). Among 72 patients treated with CPIs, the objective response rate (ORR) was comparable between iFGFR3 and aFGFR3 (20% vs 31%; p = 0.467). Strikingly, a significantly higher ORR was noted in LumP/aFGFR3 compared to LumP/iFGFR3 (50% vs 5%; p = 0.022). This trend was validated using data from the IMvigor210 trial. Additionally, several immune-related genes, including IDO1, CCL24, IL1RL1, LGALS4, and NCAM (CD56) were upregulated in LumP/iFGFR3 compared to LumP/aFGFR3 cases. CONCLUSIONS: Differential pathways influenced by aFGFR3 were observed between NMIBC and MIBC, highlighting the upregulation of both luminal and basal markers in MIBC/aFGFR3. Heterogeneous TME was identified within MIBC/aFGFR3, leading to differential outcomes for CPIs. Specifically, a favorable ORR in LumP/aFGFR3 and a poor ORR in LumP/iFGFR3 were observed. We propose TIM3 as a potential target for iFGFR3 (ORR: 20%) and several immune checkpoint genes, including IDO1 and CCL24, for LumP/iFGFR3 (ORR: 5%), indicating promising avenues for precision immunotherapy for BLCA.

Tertiary lymphoid structure and neutrophil-lymphocyte ratio coordinately predict outcome of pembrolizumab.

Emerging evidence suggests that the presence of tertiary lymphoid structures (TLS) and neutrophil-lymphocyte ratio (NLR) in peripheral blood is associated with the treatment response to checkpoint inhibitors (CPIs), whereas there is limited knowledge regarding whether these factors reciprocally impact the treatment outcomes of CPIs in metastatic urothelial carcinoma (mUC). Herein, we investigated treatment outcomes of platinum-refractory mUC patients (50 cases with whole-exome and transcriptome sequencing) treated with pembrolizumab. The pathological review identified 24% of cases of TLS in the specimens. There was no significant difference in the NLR between the TLS- and TLS+ groups (p = 0.153). In the lower NLR group, both overall survival and progression-free survival were significantly longer in patients with TLS than in those without TLS, whereas the favorable outcomes associated with TLS were not observed in patients in the higher NLR group. We explored transcriptomic differences in UC with TLS. The TLS was comparably observed between luminal (20%) and basal (25%) tumor subtypes (p = 0.736). Exploring putative immune-checkpoint genes revealed that ICOSLG (B7-H2) was significantly increased in tumors with lower NLR. KRT expression levels exhibited higher basal cell markers (KRT5 and KRT17) in the higher NLR group and lower differentiated cell markers (KRT8 and KRT18) in patients with TLS. In conclusion, the improved outcomes of pembrolizumab treatment in mUC are restricted to patients with lower NLR. Our findings begin to elucidate a distinct molecular pattern for the presence of TLS according to the NLR in peripheral blood.

Nephron-sparing ureteroscopic surgery vs. radical nephroureterectomy: comparable survival-outcomes in upper tract urothelial carcinoma.

PURPOSE: This study investigates the utility of ureteroscopic surgery (URS) as an alternative to radical nephroureterectomy (RNU) in managing upper tract urothelial carcinoma (UTUC), with a focus on survival outcomes and re-evaluation of current the European Association of Urology guidelines criteria. METHODS: We conducted a retrospective, multi-institutional review of 143 UTUC patients treated with URS (n = 35) or RNU (n = 108). Clinicopathological factors were analyzed, and survival outcomes were assessed using Kaplan-Meier analysis and Cox proportional-hazards models. RESULTS: The median follow-up period was 27 months. Overall survival (OS) and radiographic progression-free survival (rPFS) were comparable between the URS and RNU groups (OS: HR 2.42, 95% CI 0.63-9.28, P = 0.0579; rPFS: HR 1.82, 95% CI 0.60-5.47, P = 0.1641). URS conferred superior renal function preservation. In patients characterized by factors such as radiographically invisible lesions, negative cytology, pTa stage, low-grade tumors, and multiple lesions, the OS outcomes with URS were comparable to those with RNU as follows: radiographically invisible lesions (P = 0.5768), negative cytology (P = 0.7626), pTa stage (P = 0.6694), low-grade tumors (P = 0.9870), and multiple lesions (P = 0.8586). CONCLUSION: URS offers survival outcomes similar to RNU, along with better renal function preservation, especially in low-risk UTUC patients. These findings underscore the urgency of re-evaluating the current EAU guidelines and encourage further research into determining the ideal patient selection for URS in UTUC treatment.

CTLA4-Ig prolongs graft survival specifically in young but not old mice.

Elderly organ transplant recipients have remained underrepresented in clinical trials, despite representing a rapidly growing population. Here, we assessed age-specific effects of CTLA4-Ig (cytotoxic T-lymphocyte antigen 4-Ig), a fusion protein blocking costimulatory signaling between antigen-presenting cells and T cells through CD28. Cardiac allografts in young mice (2-3 months) treated with CTLA4-Ig survived indefinitely, whereas 80% of old recipients (18 months) had lost their graft after 100 days. CTLA4-Ig was also significantly less effective in older recipients of skin transplants. CTLA4-Ig reduced CD4+ central memory and effector memory T cells and diminished systemic interferon-gamma levels only in young recipients. These differences corresponded to a reduced expression of CD28 on antigen-experienced CD4+ T cells in old mice. In support, adoptive transfer of old CD4+ T cells that were transfected with a lentiviral vector inducing constant expression of CD28 accelerated the rejection of allogeneic skin grafts in young RAG2-/- recipient mice. Regulatory T cells (Tregs), in contrast, demonstrated an increased expression of CD28 with aging and CTLA4-Ig treatment in old recipients resulted in reduced frequencies, compromised proliferation, and diminished suppressive capacity of Tregs. These findings may prove to have unique clinical consequences for immunosuppression in the growing population of elderly transplant recipients.

Recipient sex and estradiol levels affect transplant outcomes in an age-specific fashion.

Sex-specific influences have been shown for a variety of diseases. Whether donor or recipient sex and sex hormone levels impact alloimmune responses remains unclear. In unifactorial and multifactorial analyses of more than 400 000 SRTR listed kidney transplant patients, we found that younger female recipients had an inferior death-censored graft survival that was independent of donor sex. In contrast, graft survival was superior in older female recipients, suggesting the impact of recipient sex hormones over chromosomal sex mismatches. Those clinical changes were delineated in experimental skin and heart transplant models showing a prolongation of graft survival in ovariectomized young female recipients. In contrast, graft survival was comparable in ovariectomized and naïve old female recipients. Young ovariectomized mice showed reduced amounts and a compromised T cell proliferation. Deprivation of female hormones dampened the production of interferon (IFN)-γ and interleukin (IL)-17+ by CD4+ T cells while augmenting systemic counts of Tregs. Increasing estradiol concentrations in vitro promoted the switch of naïve CD4+ T cells into Th1 cells; high physiological estradiol concentrations dampening Th1 responses, promoted Tregs, and prolonged graft survival. Thus, clinical observations demonstrate age-specific graft survival patterns in female recipients. Estrogen levels, in turn, impact the fate of T cell subsets, providing relevant and novel information on age- and sex-specific alloimmunity.

Risk stratification for the prediction of overall survival could assist treatment decision-making at diagnosis of castration-resistant prostate cancer: a multicentre collaborative study in Japan.

OBJECTIVES: To assess whether a new risk stratification system according to predictors for overall survival (OS) at the diagnosis of metastatic castration-resistant prostate cancer (mCRPC) could determine treatment outcomes and assist in treatment decision-making. PATIENTS AND METHODS: Two independent clinical cohorts of patients, treated with androgen signalling inhibitors (ASIs: abiraterone and enzalutamide) or docetaxel as a first-line treatment for mCRPC, were used in this study: a derivation cohort (196 patients with mCRPC) and an external validation cohort (211 patients with mCRPC). RESULTS: Three independent predictors for OS, including duration of initial androgen deprivation therapy <12 months before mCRPC diagnosis, alkaline phosphatase level >350 U/dL and haemoglobin level <11 g/dL at the diagnosis of mCRPC, were defined as risk factors. Patients with zero, one and multiple risk factors were assigned to a favourable-, intermediate- and poor-risk group, respectively. The median OS values in each risk group were well separated in the derivation cohort (P < 0.001) as well as in the validation cohort (P < 0.001). Of a total of 407 patients with mCRPC, 84 were assigned to the poor-risk group with the median OS of 12 months. In this group, a trend towards longer OS favouring docetaxel compared to ASIs as the first-line treatment (medians of 17 and 12 months, respectively) was observed. CONCLUSION: The new risk group stratification system could predict patient survival at the diagnosis of mCRPC. Given the convenience of these risk definitions, physicians may be encouraged to consider these risk groups in daily practice.

Association between response to rituximab and antibody-mediated rejection in ABO-incompatible living kidney transplantation.

OBJECTIVES: To examine the association of response to rituximab and the incidence of antibody-mediated rejection in preconditioning of rituximab and plasma exchange without post-transplant plasmapheresis in patients undergoing ABO-incompatible living kidney transplantation. METHODS: A total of 115 patients who underwent ABO-incompatible living kidney transplantation at Tokyo Women's Medical University Hospital, Tokyo, Japan, were divided into two groups based on the response to rituximab: good response (n = 75) or poor response (n = 40). The rituximab good response and poor response patients were defined as patients whose CD19+ cells were non-detected (0%) and detected on the day of transplantation (2-5 days, median 3 days, after rituximab administration), respectively. RESULTS: Rituximab response and anti-A/B blood antibody titer after plasmapheresis were significant risk factors for antibody-mediated rejection (P = 0.036, 0.045, respectively). The occurrence of antibody-mediated rejection was higher in the poor response group than in the good response group (22.5% vs 8.0%; P = 0.028). The 14-day, 3-month and 1-year cumulative incidence of antibody-mediated rejection was 2.7%, 5.3% and 8.0% in the good response group, and 17.5%, 20.0% and 22.5% in the poor response group after ABO-incompatible living kidney transplantation. The patient survival was not significantly different between the two groups. However, graft survival 1 month after transplantation was lower in the poor response group. There is no significant difference in graft function and in the incidence of complications, including infection, after transplantation between the two groups. CONCLUSIONS: Antibody-mediated rejection after ABO-incompatible living kidney transplantation was significantly associated with the response to rituximab in our preconditioning protocol.

Cardiovascular disease in kidney transplant recipients: Japan Academic Consortium of Kidney Transplantation (JACK) cohort study.

BACKGROUND: The number of kidney transplant recipients (KTRs) from diabetic nephropathy (DN) and with cardiovascular disease (CVD) history has increased worldwide. Nevertheless, epidemiologic evidence of CVD in KTRs remains limited. METHODS: We investigated post-transplant CVD in 1614 adult KTRs between 1990 and 2014. CVD was defined according to the international classification of diseases (ICD-10). All-cause mortality was also investigated. Final follow-up was performed in March 2016. The KTRs were categorized into four groups according to DN and CVD at surgery. RESULTS: During the follow-up period, 309 KTRs experienced CVDs and 124 KTRs died. The 15-year cumulative CVDs rate was 87% in KTRs with both DN and CVD history, and the rate in KTRs without those was 22.3%. DN and CVD were associated with increased risk of post-transplant CVD [hazard ratio (HR), 3.44; 95% confidence interval (CI), 2.03-5.82; P < 0.001], and the impact marked increased after 7.5 years follow-up period (HR, 16.56; 95% CI, 6.56-41.8; P < 0.001). DN and CVD in KTRs were associated with mortality (HR, 3.32; 95% CI, 1.34-8.22; P = 0.009), and post-transplant CVD was the leading cause (35.5%) of overall death. However, DN and CVD were not associated with increased graft failure rate. CONCLUSIONS: The risk of post-transplant CVDs incidence in KTRs with DN and CVD history is high, and it increases during the late transplant period. Appropriate routine cardiovascular screening and evaluation are needed to reduce late-onset CVD incidence.

[A Case of Retroperitoneal Teratoma Difficult to Distinguish from Adrenal Tumor].

Retroperitoneal tumor is a rare tumor, with an incidence of 0.2 to 0.8%. Among such tumors, the frequency of teratomas ranges from 6 to 18%, and adult cases are extremely rare. We report a mature teratoma that occurred in the retroperitoneum of 43-year-old woman. She experienced back pain and a left adrenal gland mass was detected on computed tomography. Computed tomography and magnetic resonance imaging findings showed a cyst made of fat and calcification, but it was difficult to distinguish retroperitoneal teratoma from adrenal tumor in this case. The tumor was removed, and was mainly composed of a hair ball and fat. Pathological examination showed that the tumor was composed of stratified squamous epithelium, keratinizing component, cartilage, and bronchial epithelium, while no continuity with the adrenal gland was observed. Therefore, the tumor was diagnosed as a retroperitoneal teratoma.

[A CASE OF ADVANCED BLADDER NEUROENDOCRINE CARCINOMA (SMALL CELL CARCINOMA) SIGNIFICANTLY IMPROVED BY LOW DOSE OF ORAL TEGAFUR-URACIL].

A 81-old-woman underwent a transurethral resection of bladder tumor (TURBT) at a nearby hospital in April 2011. The diagnosis was invasive urothelial carcinoma, G3 with a component of bladder small cell carcinoma, T1 or more. She was recommended to visit our hospital for combined modality therapy of bladder cancer, but she refused the treatment for over one year. In May 2012, she came to our hospital with the chief complaint of pain at urination. Cystoscopy revealed non-papillary sessile tumor in the top of the bladder, and CT scan demonstrated the presence of the right obturator lymph nodes swollen up to 1.2 cm in size. The second TURBT was performed and the diagnosis was bladder small cell carcinoma (pT3N2M0) according to urothelial cancer guidelines of the Japanese Urological Association (JUA). Because she strongly refused hospitalization anymore, we started daily oral intake of low dose Tegafur-Uracil (100 mg) for the treatment. After one month, the serum Neuron-Specific Enolase (NSE; tumor maker of small cell cancer) level was elevated to 27.6 ng/ml and the right obturator lymph node was enlarged up to 1.9 cm. Therefore, the Trgafur-Uracil dose was increased to 200 mg daily. After then, the serum NSE level was decreased to 15.5 ng/ml following reduction in size of the obturator lymph nodes with partial response in December 2013. After two years of follow-up period, her regular urine test showed normal findings, and no apparent recurrence was detected on urinary bladder with MRI and Cystoscopy. This is a case of advanced bladder small cell carcinoma significantly improved by oral administration of Tegafur-Uracil 200 mg/day for over 2 years.

Sex difference and immunosenescence affect transplantation outcomes.

Kidney transplantation is a well-established alternative to renal replacement therapy. Although the number of patients with end-stage renal disease (ESRD) is increasing, the availability of kidney for transplantation is still insufficient to meet the needs. As age increases, the prevalence of ESRD increases; thus, the population of aged donors and recipients occupies large proportion. Accumulated senescent cells secrete pro-inflammatory factors and induce senescence. Additionally, it is gradually becoming clear that biological sex differences can influence aging and cause differences in senescence. Here, we review whether age-related sex differences affect organ transplant outcomes and what should be done in the future.

Usefulness of Dietary Salt Restriction in Kidney Transplant Recipients: Analysis of Blood Pressure Levels Depending on the Differences in the Levels of Salt Intake.

BACKGROUND: Sodium retention causes post-transplant hypertension, and sodium restriction is recommended in kidney transplantation recipients. We investigated the changes in salt intake and age-specific differences in salt intake over the post-transplant periods and considered what guidance is important for salt reduction tailored to individual recipients. METHODS: We calculated salt intake for 38 recipients who underwent kidney transplantation from August 2013 to August 2018 using Tanaka's equation and extracted their blood pressure (BP) levels. RESULTS: The rate of achieving the desired level of salt intake (<6 g/d) was 7.9%. The average salt intake was 7.8 ± 1.4 g. Average BP by salt intake was as follows: <6 g/d, 109/71 mm Hg; 6 to <7 g/d, 127/84 mm Hg; 7 to <8 g/d, 124/79 mm Hg, 8 to <9 g/d, 130/73 mm Hg; 9 to <10 g/d, 133/83 mm Hg; and >10g/d, 137/81 mm Hg. DISCUSSION: Awareness of the need for salt restriction diminishes as time passes after transplantations, leading to increased salt uptake; therefore, regular guidance for keeping salt intake low is necessary for patients to maintain the awareness of salt restriction. The recipients with higher salt intake had higher blood pressure, suggesting the need for managing salt reduction. CONCLUSIONS: Dietary counseling showed a short-term efficacy for reducing sodium intake and clinically relevant BP improvement in renal allograft recipients.

Real-world survival outcome comparing abiraterone acetate plus prednisone and enzalutamide for nonmetastatic castration-resistant prostate cancer.

BACKGROUND: There is little evidence of abiraterone acetate (AA) plus prednisone for patients with non-metastatic castration-resistant prostate cancer (nmCRPC). In this study, we conducted a comparative analysis of real-world survival outcomes between AA plus prednisone and enzalutamide (Enz) in patients with nmCRPC, utilizing our consortium dataset. MATERIALS AND METHODS: The clinical records of 133 nmCRPC patients treated with first-line Enz or AA plus prednisone were analyzed. The primary endpoints of the study were overall survival (OS) and cancer-specific survival (CSS). Cumulative incidence function (CIF) using Fine and Gray models was also utilized to assess non-cancer-caused death considering the competing risk of cancer-caused death. RESULTS: During a median follow-up of 36 months, 34 patients (25.6%) had deceased, with a median OS of 99 months in the entire cohort. There were no significant differences in comorbidities between the Enz and AA groups. Time to PSA progression (TTPP: HR 0.81, 95% CI 0.51-1.30, P = 0.375) and CSS (HR 1.32, 95% CI 0.55-3.44, P = 0.5141) were comparable between the two groups. However, intriguingly, there was a trend towards shorter OS in patients treated with AA plus prednisone compared to Enz (HR 0.57, 95% CI 0.29-1.12, P = 0.0978, median of 99 and 69 months in Enz and AA groups, respectively). CIF analysis revealed that nmCRPC patients treated with AA plus prednisone were more likely to result in non-cancer-caused death than those treated with Enz (HR 5.22, 95% CI 1.88-14.50, P = 0.0014). CONCLUSIONS: Our real-world survival analysis suggests that while AA plus prednisone may demonstrate comparable treatment efficacy to Enz in the context of nmCRPC, there may be an increased risk of non-cancer-caused death. Physicians should take into consideration this information when making treatment decisions for patients with nmCRPC.

Unplanned hemodialysis initiation and low geriatric nutritional risk index scores are associated with end-stage renal disease outcomes.

Patients with end-stage renal disease (ESRD) have a low nutritional status and a high mortality risk. The geriatric nutritional risk index (GNRI) is a predictive marker of malnutrition. However, the association between unplanned hemodialysis (HD) and GNRI with mortality remains unclear. In total, 162 patients underwent HD at our hospital. They were divided into two groups: those with unplanned initiation with a central venous catheter (CVC; n = 62) and those with planned initiation with prepared vascular access (n = 100). There were no significant differences in sex, age, malignant tumor, hypertension, and vascular disease, while there were significant differences in the times from the first visit to HD initiation (zero vs. six times, p < 0.001) and days between the first visit and HD initiation (5 vs. 175 days, p < 0.001). The CVC insertion group had significantly lower GNRI scores at initiation (85.7 vs. 99.0, p < 0.001). The adjusted hazard ratios were 4.002 and 3.018 for the GNRI scores and frequency, respectively. The 3-year survival rate was significantly lower in the CVC + low GNRI group (p < 0.0001). The GNRI after 1 month was significantly inferior in the CVC insertion group. Inadequate general management due to late referral to the nephrology department is a risk factor for patients with ESRD.

Hemodialysis Initiation in Oldest-Old Patients: A Case Series.

With an increase in the number of older adults worldwide, the oldest-old population, defined as individuals over the age of 90, is also growing. Japan is now facing the problem of a "super-aged society" in which over 21% of the population is aged over 65. The oldest-old constituted 1.8% (2.31 million) of the Japanese population in 2019. Such individuals have special health-care needs. In cases of acute or chronic (or both) renal failure in the oldest-old, it becomes difficult to decide whether dialysis should be initiated. The issue is controversial, and there is some debate on whether dialysis should be avoided in elderly people because of their frailty or if it should be initiated to enable them to spend their remaining years with their families by improving their quality of life. Herein, we describe our experience in 4 cases of hemodialysis initiated in patients over the age of 90. In our experience, dialysis enabled them to spend the rest of their lives with their families, which could not have been possible without it. Although further studies are needed, we concluded that oldest-old individuals in good general health could be eligible for and benefit from hemodialysis.

Targeting age-specific changes in CD4+ T cell metabolism ameliorates alloimmune responses and prolongs graft survival.

Age impacts alloimmunity. Effects of aging on T-cell metabolism and the potential to interfere with immunosuppressants have not been explored yet. Here, we dissected metabolic pathways of CD4+ and CD8+ T cells in aging and offer novel immunosuppressive targets. Upon activation, CD4+ T cells from old mice failed to exhibit adequate metabolic reprogramming resulting into compromised metabolic pathways, including oxidative phosphorylation (OXPHOS) and glycolysis. Comparable results were also observed in elderly human patients. Although glutaminolysis remained the dominant and age-independent source of mitochondria for activated CD4+ T cells, old but not young CD4+ T cells relied heavily on glutaminolysis. Treating young and old murine and human CD4+ T cells with 6-diazo-5-oxo-l-norleucine (DON), a glutaminolysis inhibitor resulted in significantly reduced IFN-γ production and compromised proliferative capacities specifically of old CD4+ T cells. Of translational relevance, old and young mice that had been transplanted with fully mismatched skin grafts and treated with DON demonstrated dampened Th1- and Th17-driven alloimmune responses. Moreover, DON diminished cytokine production and proliferation of old CD4+ T cells in vivo leading to a significantly prolonged allograft survival specifically in old recipients. Graft prolongation in young animals, in contrast, was only achieved when DON was applied in combination with an inhibition of glycolysis (2-deoxy-d-glucose, 2-DG) and OXPHOS (metformin), two alternative metabolic pathways. Notably, metabolic treatment had not been linked to toxicities. Remarkably, immunosuppressive capacities of DON were specific to CD4+ T cells as adoptively transferred young CD4+ T cells prevented immunosuppressive capacities of DON on allograft survival in old recipients. Depletion of CD8+ T cells did not alter transplant outcomes in either young or old recipients. Taken together, our data introduce an age-specific metabolic reprogramming of CD4+ T cells. Targeting those pathways offers novel and age-specific approaches for immunosuppression.

Increased BUB1B/BUBR1 expression contributes to aberrant DNA repair activity leading to resistance to DNA-damaging agents.

There has been accumulating evidence for the clinical benefit of chemoradiation therapy (CRT), whereas mechanisms in CRT-recurrent clones derived from the primary tumor are still elusive. Herein, we identified an aberrant BUB1B/BUBR1 expression in CRT-recurrent clones in bladder cancer (BC) by comprehensive proteomic analysis. CRT-recurrent BC cells exhibited a cell-cycle-independent upregulation of BUB1B/BUBR1 expression rendering an enhanced DNA repair activity in response to DNA double-strand breaks (DSBs). With DNA repair analyses employing the CRISPR/cas9 system, we revealed that cells with aberrant BUB1B/BUBR1 expression dominantly exploit mutagenic nonhomologous end joining (NHEJ). We further found that phosphorylated ATM interacts with BUB1B/BUBR1 after ionizing radiation (IR) treatment, and the resistance to DSBs by increased BUB1B/BUBR1 depends on the functional ATM. In vivo, tumor growth of CRT-resistant T24R cells was abrogated by ATM inhibition using AZD0156. A dataset analysis identified FOXM1 as a putative BUB1B/BUBR1-targeting transcription factor causing its increased expression. These data collectively suggest a redundant role of BUB1B/BUBR1 underlying mutagenic NHEJ in an ATM-dependent manner, aside from the canonical activity of BUB1B/BUBR1 on the G2/M checkpoint, and offer novel clues to overcome CRT resistance.

Restored TDCA and valine levels imitate the effects of bariatric surgery.

Background: Obesity is widespread and linked to various co-morbidities. Bariatric surgery has been identified as the only effective treatment, promoting sustained weight loss and the remission of co-morbidities. Methods: Metabolic profiling was performed on diet-induced obese (DIO) mice, lean mice, and DIO mice that underwent sleeve gastrectomies (SGx). In addition, mice were subjected to intraperitoneal (i.p.) injections with taurodeoxycholic acid (TDCA) and valine. Indirect calorimetry was performed to assess food intake and energy expenditure. Expression of appetite-regulating hormones was assessed through quantification of isolated RNA from dissected hypothalamus tissue. Subsequently, i.p. injections with a melanin-concentrating hormone (MCH) antagonist and intrathecal administration of MCH were performed and weight loss was monitored. Results: Mass spectrometric metabolomic profiling revealed significantly reduced systemic levels of TDCA and L-valine in DIO mice. TDCA and L-valine levels were restored after SGx in both human and mice to levels comparable with lean controls. Systemic treatment with TDCA and valine induced a profound weight loss analogous to effects observed after SGx. Utilizing indirect calorimetry, we confirmed reduced food intake as causal for TDCA/valine-mediated weight loss via a central inhibition of the MCH. Conclusions: In summary, we identified restored TDCA/valine levels as an underlying mechanism of SGx-derived effects on weight loss. Of translational relevance, TDCA and L-valine are presented as novel agents promoting weight loss while reversing obesity-associated metabolic disorders. Funding: This work has been supported in part by a grant from NIH (UO-1 A1 132898 to S.G.T., DP and MA). M.Q. was supported by the IFB Integrated Research and Treatment Centre Adiposity Diseases (Leipzig, Germany) and the German Research Foundation (QU 420/1-1). J.I. was supported by the Biomedical Education Program (BMEP) of the German Academic Exchange Service (DAAD). T.H. (HE 7457/1-1) and F.K. (KR 4362/1-1) were supported by the German Research Foundation (DFG). H.R.C.B. was supported the Swiss Society of Cardiac Surgery. Y.N. was supported by the Chinese Scholarship Council (201606370196) and Central South University. H.U., T.M. and R.M. were supported by the Osaka Medical Foundation. C.S.F. was supported by the German Research Foundation (DFG, SFB738, B3).