Autophagy is an evolutionarily conserved catabolic process involved in several physiological and pathological processes1,2. Although primarily cytoprotective, autophagy can also contribute to cell death; it is thus important to understand what distinguishes the life or death decision in autophagic cells3. Here, we report that induction of autophagy is coupled to reduction of histone H4 lysine 16 acetylation (H4K16ac) through downregulation of the histone acetyltransferase hMOF/KAT8/MYST1, and demonstrate that this histone modification regulates the outcome of autophagy. At a genome-wide level we find that H4K16 deacetylation is associated predominantly with the downregulation of autophagy-related genes. Antagonizing H4K16ac downregulation upon autophagy induction results in the promotion of cell death. Our findings establish that alteration in a specific histone posttranslational modification during autophagy, affects the transcriptional regulation of autophagy-related genes and initiates a regulatory feedback loop, which serves as a key determinant of survival versus death responses upon autophagy induction.

BACKGROUNDSubfertility affects approximately 15% of all couples, and a severe male factor is identified in 17% of these couples. While the etiology of a severe male factor remains largely unknown, prior gonadotoxic treatment and genomic aberrations have been associated with this type of subfertility. Couples with a severe male factor can resort to ICSI, with either ejaculated spermatozoa (in case of oligozoospermia) or surgically retrieved testicular spermatozoa (in case of azoospermia) to generate their own biological children. Currently there is no direct treatment for azoospermia or oligozoospermia. Spermatogonial stem cell (SSC) autotransplantation (SSCT) is a promising novel clinical application currently under development to restore fertility in sterile childhood cancer survivors. Meanwhile, recent advances in genomic editing, especially the clustered regulatory interspaced short palindromic repeats-associated protein 9 (CRISPR-Cas9) system, are likely to enable genomic rectification of human SSCs in the near future.OBJECTIVE AND RATIONALEThe objective of this review is to provide insights into the prospects of the potential clinical application of SSCT with or without genomic editing to cure spermatogenic failure and to prevent transmission of genetic diseases.SEARCH METHODSWe performed a narrative review using the literature available on PubMed not restricted to any publishing year on topics of subfertility, fertility treatments, (molecular regulation of) spermatogenesis and SSCT, inherited (genetic) disorders, prenatal screening methods, genomic editing and germline editing. For germline editing, we focussed on the novel CRISPR-Cas9 system. We included papers written in English only.OUTCOMESCurrent techniques allow propagation of human SSCs in vitro, which is indispensable to successful transplantation. This technique is currently being developed in a preclinical setting for childhood cancer survivors who have stored a testis biopsy prior to cancer treatment. Similarly, SSCT could be used to restore fertility in sterile adult cancer survivors. In vitro propagation of SSCs might also be employed to enhance spermatogenesis in oligozoospermic men and in azoospermic men who still have functional SSCs albeit in insufficient numbers. The combination of SSCT with genomic editing techniques could potentially rectify defects in spermatogenesis caused by genomic mutations or, more broadly, prevent transmission of genomic diseases to the offspring. In spite of the promising prospects, SSCT and germline genomic editing are not yet clinically applicable and both techniques require optimization at various levels.WIDER IMPLICATIONSSSCT with or without genomic editing could potentially be used to restore fertility in cancer survivors to treat couples with a severe male factor and to prevent the paternal transmission of diseases. This will potentially allow these couples to have their own biological children. Technical development is progressing rapidly, and ethical reflection and societal debate on the use of SSCT with ...

Testicular tissue can be cryopreserved before long-term culture without modifying its outcome, which encourages implementation of testicular tissue banking for fertility preservation. However, because of the limited numbers of SSCs available after 2 months, further exploration and optimization of the culture system is needed.

Current cancer treatment regimens do not only target tumor cells, but can also have devastating effects on the spermatogonial stem cell pool, resulting in a lack of functional gametes and hence sterility. In adult men, fertility can be preserved prior to cancer treatment by cryopreservation of ejaculated or surgically retrieved spermatozoa, but this is not an option for prepubertal boys since spermatogenesis does not commence until puberty. Cryopreservation of a testicular biopsy taken before initiation of cancer treatment, followed by in vitro propagation of spermatogonial stem cells and subsequent autotransplantation of these stem cells after cancer treatment, has been suggested as a way to preserve and restore fertility in childhood cancer survivors. This strategy, known as spermatogonial stem cell transplantation, has been successful in mice and other model systems, but has not yet been applied in humans. Although recent progress has brought clinical application of spermatogonial stem cell autotransplantation in closer range, there are still a number of important issues to address. In this paper, we describe the state of the art of spermatogonial stem cell transplantation and outline the hurdles that need to be overcome before clinical implementation.

This study aimed at validating the previously published association between TGF-β1 single nucleotide polymorphisms and a reduced risk for radiation-induced lung toxicity. We were not able to confirm the reported association, neither using maximum dyspnea score nor after correction for baseline dyspnea score.

Autologous transplantation of spermatogonial stem cells is a promising new avenue to restore fertility in infertile recipients. Expansion of the initial spermatogonial stem cell pool through cell culturing is a necessary step to obtain enough cells for effective repopulation of the testis after transplantation. Since in vitro propagation can lead to (epi-)genetic mutations and possibly malignant transformation of the starting cell population, we set out to investigate genome-wide DNA methylation status in uncultured and cultured primary testicular ITGA6+ sorted cells and compare them with germ cell tumor samples of the seminoma subtype. Seminomas displayed a severely global hypomethylated profile, including loss of genomic imprinting, which we did not detect in cultured primary testicular ITGA6+ cells. Differential methylation analysis revealed altered regulation of gamete formation and meiotic processes in cultured primary testicular ITGA6+ cells but not in seminomas. The pivotal POU5F1 marker was hypomethylated in seminomas but not in uncultured or cultured primary testicular ITGA6+ cells, which is reflected in the POU5F1 mRNA expression levels. Lastly, seminomas displayed a number of characteristic copy number variations that were not detectable in primary testicular ITGA6+ cells, either before or after culture. Together, the data show a distinct DNA methylation patterns in cultured primary testicular ITGA6+ cells that does not resemble the pattern found in seminomas, but also highlight the need for more sensitive methods to fully exclude the presence of malignant cells after culture and to further study the epigenetic events that take place during in vitro culture. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0230253 March 16, 2020 1 / 18 OPEN ACCESS Citation: Struijk RB, Dorssers LCJ, Henneman P, Rijlaarsdam MA, Venema A, Jongejan A, et al. (2020) Comparing genome-scale DNA methylation and CNV marks between adult human cultured ITGA6+ testicular cells and seminomas to assess in vitro genomic stability. PLoS ONE 15(3): e0230253. https://doi.org/10.

In this Letter, during the preparation of Figs 1b and 3b, and Supplementary Figs 3c and 10a, the digital western blot scans were processed to remove irrelevant lanes from single-blot images. Although all excisions/mergers originated from the same gel, these figure constructions should have been explicitly pointed out. We now include the unprocessed scans of the corresponding blots as Supplementary Information to this Corrigendum. In addition, the original GRO-seq data have been uploaded at ArrayExpress with the accession number E-MTAB-5490. The original Letter has not been corrected.

1. DNA barcodes are useful for species-level sorting of specimen samples, but rarely used in time-sensitive projects that require species richness estimates or identification of pest or invasive species within hours. The main reason is that existing express barcoding workflows are either too expensive or can only be carried out in very well equipped laboratories by highly trained staff. 2. We here introduce a simple workflow that combines rapid DNA extraction with HotSHOT, amplicon production with the aid of NextGenPCR thermocyclers, and sequencing with low-cost MinION sequencers. 3. We demonstrate the power of the approach by generating and identifying 250 barcodes for 285 specimens within 6 hours. The workflow only required the following major equipment that easily fits onto a lab bench: Conventional thermocycler, NextGenPCR thermocycler, microplate sealer, Qubit, and MinION. 4. We argue that species-level sorting with simplified barcoding workflows is now faster, more accurate, and sufficiently cost-effective that it can and should replace morpho-species sorting in many projects.