Induction of mitochondrial recycling reverts age-associated decline of the hematopoietic and immune systems

Aging compromises hematopoietic and immune system functions, making older adults especially susceptible to hematopoietic failure, infections and tumor development, and thus representing an important medical target for a broad range of diseases. During aging, hematopoietic stem cells (HSCs) lose their blood reconstitution capability and commit preferentially toward the myeloid lineage (myeloid bias)1,2. These processes are accompanied by an aberrant accumulation of mitochondria in HSCs3. The administration of the mitochondrial modulator urolithin A corrects mitochondrial function in HSCs and completely restores the blood reconstitution capability of 'old' HSCs. Moreover, urolithin A-supplemented food restores lymphoid compartments, boosts HSC function and improves the immune response against viral infection in old mice. Altogether our results demonstrate that boosting mitochondrial recycling reverts the aging phenotype in the hematopoietic and immune systems.

Kinesin-2 transports Orco into the olfactory cilium of Drosophila melanogaster at specific developmental stages

The cilium, the sensing centre for the cell, displays an extensive repertoire of receptors for various cell signalling processes. The dynamic nature of ciliary signalling indicates that the ciliary entry of receptors and associated proteins must be regulated and conditional. To understand this process, we studied the ciliary localisation of the odour-receptor coreceptor (Orco), a seven-pass transmembrane protein essential for insect olfaction. Little is known about when and how Orco gets into the cilia. Here, using Drosophila melanogaster, we show that the bulk of Orco selectively enters the cilia on adult olfactory sensory neurons in two discrete, one-hour intervals after eclosion. A conditional loss of heterotrimeric kinesin-2 during this period reduces the electrophysiological response to odours and affects olfactory behaviour. We further show that Orco binds to the C-terminal tail fragments of the heterotrimeric kinesin-2 motor, which is required to transfer Orco from the ciliary base to the outer segment and maintain within an approximately four-micron stretch at the distal portion of the ciliary outer-segment. The Orco transport was not affected by the loss of critical intraflagellar transport components, IFT172/Oseg2 and IFT88/NompB, respectively, during the adult stage. These results highlight a novel developmental regulation of seven-pass transmembrane receptor transport into the cilia and indicate that ciliary signalling is both developmentally and temporally regulated.

Multielemental Analysis of Low-Volume Samples Reveals Cancer-Specific Profile in Serum and Sorted Immune Cells

We developed and validated a reliable, robust, and easy-to-implement quantitative method for multielemental analysis of low-volume samples. Our ICP-MS-based method comprises the analysis of 20 elements (Mg, P, S, K, Ca, V, Cr, Mn, Fe, Co, Cu, Zn, Se, Br, Rb, Sr, Mo, I, Cs, and Ba) in 10 μL of serum and 12 elements (Mg, S, Mn, Fe, Co, Cu, Zn Se, Br, Rb, Mo, and Cs) in less than 250 000 cells. As a proof-of-concept, we analyzed the elemental profiles of serum and sorted immune T cells derived from naı̈ve and tumor-bearing mice. The results indicate a tumor systemic effect on the elemental profiles of both serum and T cells. Our approach highlights promising applications of multielemental analysis in precious samples such as rare cell populations or limited volumes of biofluids that could provide a deeper understanding of the essential role of elements as cofactors in biological and pathological processes.

The NAD-Booster Nicotinamide Riboside Potently Stimulates Hematopoiesis through Increased Mitochondrial Clearance

It has been recently shown that increased oxidative phosphorylation, as reflected by increased mitochondrial activity, together with impairment of the mitochondrial stress response, can severely compromise hematopoietic stem cell (HSC) regeneration. Here we show that the NAD⁺-boosting agent nicotinamide riboside (NR) reduces mitochondrial activity within HSCs through increased mitochondrial clearance, leading to increased asymmetric HSC divisions. NR dietary supplementation results in a significantly enlarged pool of progenitors, without concurrent HSC exhaustion, improves survival by 80%, and accelerates blood recovery after murine lethal irradiation and limiting-HSC transplantation. In immune-deficient mice, NR increased the production of human leucocytes from hCD34+ progenitors. Our work demonstrates for the first time a positive effect of NAD⁺-boosting strategies on the most primitive blood stem cells, establishing a link between HSC mitochondrial stress, mitophagy, and stem-cell fate decision, and unveiling the potential of NR to improve recovery of patients suffering from hematological failure including post chemo- and radiotherapy.

Measurement of Mitochondrial Mass and Membrane Potential in Hematopoietic Stem Cells and T-cells by Flow Cytometry

A fine balance of quiescence, self-renewal, and differentiation is key to preserve the hematopoietic stem cell (HSC) pool and maintain lifelong production of all mature blood cells. In recent years cellular metabolism has emerged as a crucial regulator of HSC function and fate. We have previously demonstrated that modulation of mitochondrial metabolism influences HSC fate. Specifically, by chemically uncoupling the electron transport chain we were able to maintain HSC function in culture conditions that normally induce rapid differentiation. However, limiting HSC numbers often precludes the use of standard assays to measure HSC metabolism and therefore predict their function. Here, we report a simple flow cytometry assay that allows reliable measurement of mitochondrial membrane potential and mitochondrial mass in scarce cells such as HSCs. We discuss the isolation of HSCs from mouse bone marrow and measurement of mitochondrial mass and membrane potential post ex vivo culture. As an example, we show the modulation of these parameters in HSCs via treatment with a metabolic modulator. Moreover, we extend the application of this methodology on human peripheral blood-derived T cells and human tumor infiltrating lymphocytes (TILs), showing dramatic differences in their mitochondrial profiles, possibly reflecting different T cell functionality. We believe this assay can be employed in screenings to identify modulators of mitochondrial metabolism in various cell types in different contexts.

Tumour-derived PGD2 and NKp30-B7H6 engagement drives an immunosuppressive ILC2-MDSC axis

Group 2 innate lymphoid cells (ILC2s) are involved in human diseases, such as allergy, atopic dermatitis and nasal polyposis, but their function in human cancer remains unclear. Here we show that, in acute promyelocytic leukaemia (APL), ILC2s are increased and hyper-activated through the interaction of CRTH2 and NKp30 with elevated tumour-derived PGD2 and B7H6, respectively. ILC2s, in turn, activate monocytic myeloid-derived suppressor cells (M-MDSCs) via IL-13 secretion. Upon treating APL with all-trans retinoic acid and achieving complete remission, the levels of PGD2, NKp30, ILC2s, IL-13 and M-MDSCs are restored. Similarly, disruption of this tumour immunosuppressive axis by specifically blocking PGD2, IL-13 and NKp30 partially restores ILC2 and M-MDSC levels and results in increased survival. Thus, using APL as a model, we uncover a tolerogenic pathway that may represent a relevant immunosuppressive, therapeutic targetable, mechanism operating in various human tumour types, as supported by our observations in prostate cancer.Group 2 innate lymphoid cells (ILC2s) modulate inflammatory and allergic responses, but their function in cancer immunity is still unclear. Here the authors show that, in acute promyelocytic leukaemia, tumour-activated ILC2s secrete IL-13 to induce myeloid-derived suppressor cells and support tumour growth.

Single-cell analyses identify bioengineered niches for enhanced maintenance of hematopoietic stem cells

The in vitro expansion of long-term hematopoietic stem cells (HSCs) remains a substantial challenge, largely because of our limited understanding of the mechanisms that control HSC fate choices. Using single-cell multigene expression analysis and time-lapse microscopy, here we define gene expression signatures and cell cycle hallmarks of murine HSCs and the earliest multipotent progenitors (MPPs), and analyze systematically single HSC fate choices in culture. Our analysis revealed twelve differentially expressed genes marking the quiescent HSC state, including four genes encoding cell–cell interaction signals in the niche. Under basal culture conditions, most HSCs rapidly commit to become early MPPs. In contrast, when we present ligands of the identified niche components such as JamC or Esam within artificial niches, HSC cycling is reduced and long-term multipotency in vivo is maintained. Our approach to bioengineer artificial niches should be useful in other stem cell systems.

Haematopoietic stem cell (HSC) self-renewal is not sufficiently understood to recapitulate in vitro. Here, the authors generate gene signature and cell cycle hallmarks of single murine HSCs, and use identified endothelial receptors Esam and JamC as substrates to enhance HSC growth in engineered niches.

The C-terminal tails of heterotrimeric kinesin-2 motor subunits directly bind to α-tubulin1: Possible implications for cilia-specific tubulin entry

The assembly of microtubule-based cytoskeleton propels the cilia and flagella growth. Previous studies have indicated that the kinesin-2 family motors transport tubulin into the cilia through intraflagellar transport. Here, we report a direct interaction between the C-terminal tail fragments of heterotrimeric kinesin-2 and α-tubulin1 isoforms in vitro. Blot overlay screen, affinity purification from tissue extracts, cosedimentation with subtilisin-treated microtubule and LC-ESI-MS/MS characterization of the tail-fragment-associated tubulin identified an association between the tail domains and α-tubulin1A/D isotype. The interaction was confirmed by Forster's resonance energy transfer assay in tissue-cultured cells. The overexpression of the recombinant tails in NIH3T3 cells affected the primary cilia growth, which was rescued by coexpression of a α-tubulin1 transgene. Furthermore, fluorescent recovery after photobleach analysis in the olfactory cilia of Drosophila indicated that tubulin is transported in a non-particulate form requiring kinesin-2. These results provide additional new insight into the mechanisms underlying selective tubulin isoform enrichment in the cilia.

Sudden onset abdominal pain and distension: an imaging sparkler

We present a case of a middle-aged patient presenting with acute onset abdominal pain and distension who had signs of bowel obstruction on physical exam. He was afebrile, hemodynamically stable with no peritoneal signs. Abdominal radiograph and CT scan were pathognomic for sigmoid volvulus. Through this case report we want to discuss the presentation, diagnosis, management options for sigmoid volvulus and importance of features suggestive of ischemic bowel that necessitates different management options.

Automated analysis of single stem cells in microfluidic traps

We report a reliable strategy to perform automated image cytometry of single (non-adherent) stem cells captured in microfluidic traps. The method rapidly segments images of an entire microfluidic chip based on the detection of horizontal edges of microfluidic channels, from where the position of the trapped cells can be derived and the trapped cells identified with very high precision (>97%). We used this method to successfully quantify the efficiency and spatial distribution of single-cell loading of a microfluidic chip comprised of 2048 single-cell traps. Furthermore, cytometric analysis of trapped primary hematopoietic stem cells (HSC) faithfully recapitulated the distribution of cells in the G1 and S/G2-M phase of the cell cycle that was measured by flow cytometry. This approach should be applicable to automatically track single live cells in a wealth of microfluidic systems.

Penile cancer in India: a clinicoepidemiological study

INTRODUCTION

Penile cancer is one of the most common genitourinary cancers encountered in developing countries like India. The incidence of carcinoma of the penis varies according to circumcision practice, hygienic standard, phimosis, the number of sexual partners, HPV infection, exposure to tobacco products, and other factors. The aim of the study was to study the clinic-epidemiological profile of penile cancer.

MATERIALS AND METHODS

54 patients were enrolled and studied from May 2005 to June 2006. Clinicoepidemiologic profile and patients' characteristics were assessed in a questionnaire including demographic data, presence of risk factors like smoking, phimosis, circumcision, history of promiscuity, history of sexually transmitted disease etc., clinical features, pathological features of tumor like size, site, appearance, histological type, grade, presence of lymph nodes, treatment performed and response. 5 year survival rates were also calculated.

RESULTS

Of the 54 patients, about three-fourths patients were older than 50. About one quarter patients presented with phimosis and 20% patients had undergone circumcision after attaining adulthood. 70% patients were found to be smokers. Most patients presented with T2 disease whereas lymphadenopathy, both benign and malignant, was present in 55.5% and 76% patients in T1 and T2 patients respectively. 5 year survival rates were found to be 87% and 60% respectively in stage I and II respectively.

CONCLUSION

penile cancer is one of the most common genitourinary cancer affecting mostly aged, uncircumcised males with history of smoking.Most patients present at advanced age and hence a national awareness campaign against this disease should be promoted.

Interaction with a kinesin-2 tail propels choline acetyltransferase flow towards synapse

Bulk flow constitutes a substantial part of the slow transport of soluble proteins in axons. Though the underlying mechanism is unclear, evidences indicate that intermittent, kinesin-based movement of large protein-aggregates aids this process. Choline acetyltransferase (ChAT), a soluble enzyme catalyzing acetylcholine synthesis, propagates toward the synapse at an intermediate, slow rate. The presynaptic enrichment of ChAT requires heterotrimeric kinesin-2, comprising KLP64D, KLP68D and DmKAP, in Drosophila. Here, we show that the bulk flow of a recombinant Green Fluorescent Protein-tagged ChAT (GFP::ChAT), in Drosophila axons, lacks particulate features. It occurs for a brief period during the larval stages. In addition, both the endogenous ChAT and GFP::ChAT directly bind to the KLP64D tail, which is essential for the GFP::ChAT entry and anterograde flow in axon. These evidences suggest that a direct interaction with motor proteins could regulate the bulk flow of soluble proteins, and thus establish their asymmetric distribution.

Novel medical therapies of recurrent and metastatic gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors (NETs) of the gastrointestinal tract and pancreas are slow-growing but commonly advanced malignancies with increasing incidence and prevalence. While locoregional disease can be effectively managed with resection, treatment of recurrent, progressive or metastatic disease has until recently been limited to palliative embolization and cytoreducitve surgery, with cytotoxic chemotherapeutic agents being the last resort. However, novel molecular targeted therapies inhibiting malignant cell proliferation and neoangiogenesis, as well as new cytotoxic chemotherapy drugs and somatostatin analogues, are all being investigated for their potential use in advanced neuroendocrine tumors. Long-acting release forms of octreotide have been shown to not only improve symptoms in carcinoid syndrome but to also delay progression of gastrointestinal NETs. On the other hand, phase III trials have demonstrated everolimus (with octreotide) and sunitinib to increase progression-free survival in pancreatic NETs. Use of bevacizumab has also shown promise in a phase II study, and results of an ongoing phase III trial comparing it to interferon are eagerly expected. Use of radiolabeled somatostatin analogues is still under investigation, though several phase II studies are encouraging. New cytotoxic agents, most notably temozolomide and capecitabine, are already in use, but their relative effectiveness compared to streptozocin in pancreatic NETs is yet to be determined.

Heterotrimeric kinesin-II is necessary and sufficient to promote different stepwise assembly of morphologically distinct bipartite cilia in Drosophila antenna

Structurally diverse sensory cilia have evolved from primary cilia, a microtubule-based cellular extension engaged in chemical and mechanical sensing and signal integration. The diversity is often associated with functional specialization. The olfactory receptor neurons in Drosophila, for example, express three distinct bipartite cilia displaying different sets of olfactory receptors on them. Molecular description underlying their assembly and diversification is still incomplete. Here, we show that the branched and the slender olfactory cilia develop in two distinct step-wise patterns through the pupal stages before the expression of olfactory receptor genes in olfactory neurons. The process initiates with a thin procilium growth from the dendrite apex, followed by volume increment in successive stages. Mutations in the kinesin-II subunit genes either eliminate or restrict the cilia growth as well as tubulin entry into the developing cilia. Together with previous results, our results here suggest that heterotrimeric kinesin-II is the primary motor engaged in all type-I sensory cilia assembly in Drosophila and that the cilia structure diversity is achieved through additional transports supported by the motor during development.

Desmoplastic small round cell tumor with primary ovarian involvement: case report and review

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive, malignant neoplasm that has recently been characterized. It has not been associated with a primary visceral organ. In women, cases are even more rare and often have some ovarian involvement.

CASE

An 11-year-old girl presented with abdominal pain, nausea, and vomiting. A CT scan revealed a large heterogeneous pelvic mass with cystic components and an 8-cm midabdominal mass. During exploratory laparotomy, the patient was found to have a pelvic mass measuring 12. 9 cm replacing normal ovarian tissue. The midabdominal mass was also removed. Pathology, cytology, and immunohistochemistry confirmed a desmoplastic small round cell tumor. Even with aggressive surgical and medical intervention, the patient died 11 months after initial diagnosis.

CONCLUSION

We present a rare small cell tumor that is associated with ovarian involvement. The prognosis in these patients is extremely poor and very few survivals have been reported.

IgA antibodies to the 27-kDa heat-shock protein in the genital tracts of women with gynecologic cancers

Heat-shock proteins promote cell survival under adverse environmental conditions. Synthesis of the 27-kDa (HSP27), 70-kDa (HSP70), and 90-kDa (HSP90) heat-shock proteins is increased in malignantly transformed cells and has been associated with tumor proliferation, metastasis, and resistance to chemotherapeutic agents. The increased expression of heat-shock proteins and their association with tumor-specific antigens may result in local immunity to the heat-shock proteins. We examined the occurrence of IgA antibodies to HSP27, HSP70, and HSP90 in the lower genital tracts of women with possible gynecologic cancers. Cervical samples were obtained from 119 consecutive women being evaluated for a gynecologic malignancy or returning for a follow-up examination following cancer treatment. Aliquots were tested for IgA anti-heat-shock protein antibodies by ELISA. Aliquots were also tested for IgG antibodies to HSP27 as well as for human papillomavirus. Anti-HSP27 IgA was detected in 85.7% of 21 women with endometrial cancer tested prior to diagnosis and in 41.1% of 17 women tested after treatment. In women with ovarian cancer, 77.8% of 9 women tested prior to diagnosis and 75.0% of 24 women evaluated after treatment were anti-HSP27 IgA-positive. Of 6 women with cervical cancer tested prior to diagnosis, 5 were positive for this antibody. None of 25 women with benign diagnoses or 46 healthy women were cervical IgA anti-HSP27-positive (P < 0.0001). In contrast, anti-HSP27 IgG was not associated with a gynecologic malignancy. HSP27 cervical antibodies were not associated with the presence of human papillomavirus. Cervical IgA antibodies to HSP90 were associated with ovarian cancer; antibodies to HSP70 were not cancer-associated. We conclude that cervical IgA antibodies to HSP27 may be indicators of a gynecologic malignancy.

Serum antibodies to the 27-kd heat shock protein in women with gynecologic cancers

OBJECTIVES

Among women the association between heat shock protein immunity and cancer has been examined primarily for breast cancer. Autoantibodies to the 27-kd heat shock protein were detected in some patients with breast cancer but not in control subjects, and the presence of these antibodies was correlated with improved survival. We examined the relationship between autoimmunity to heat shock proteins and the diagnosis of malignancies of the female genital tract.

STUDY DESIGN

Serum samples from women seen for possible gynecologic malignancies or returning for evaluation after surgery, radiation, chemotherapy, or a combination for gynecologic cancers were tested for immunoglobulin G antibodies to the 27-kd, 60-kd, 70-kd, and 90-kd heat shock proteins by enzyme-linked immunosorbent assay with the purified recombinant proteins bound to wells of a microtiter plate. Serum samples from women with no history of malignancies served as control preparations.

RESULTS

Antibodies to the 27-kd heat shock protein were detected in only 1 of 29 healthy control subjects (3.4%) and 1 of 23 women whose lesions were benign (4.3%). In marked contrast, 39 of 96 women with gynecologic cancers (40.6%) had positive antibody detection (P =.0004 vs benign). The percentages of positive results seen for ovarian (17/34, 50%), endometrial (13/34, 38.2%), cervical and uterine (3/10, 30%), vaginal and vulvar (3/5, 60%), and other (3/13, 23.1%) cancers were not significantly different from each other. Similar prevalences of antibodies to the 27-kd heat shock protein were seen among patients with cancer who had untreated active disease and after treatment. Unlike the results with antibodies to the 27-kd heat shock protein there was no relationship between antibodies to the other heat shock proteins and any gynecologic cancer.

CONCLUSION

Circulating autoantibodies to the 27-kd heat shock protein were found to be associated with malignancies of the female genital tract.