Phages are the obligate parasite of bacteria and have complex interactions with their hosts. Phages can live in, modify, and shape bacterial communities by bringing about changes in their abundance, diversity, physiology, and virulence. In addition, phages mediate lateral gene transfer, modify host metabolism and reallocate bacterially-derived biochemical compounds through cell lysis, thus playing an important role in ecosystem. Phages coexist and coevolve with bacteria and have developed several antidefense mechanisms in response to bacterial defense strategies against them. Phages owe their existence to their bacterial hosts, therefore they bring about alterations in their host genomes by transferring resistance genes and genes encoding toxins in order to improve the fitness of the hosts. Application of phages in biotechnology, environment, agriculture and medicines demands a deep insight into the myriad of phage-bacteria interactions. However, to understand their complex interactions, we need to know how unique phages are to their bacterial hosts and how they exert a selective pressure on the microbial communities in nature. Consequently, the present review focuses on phage biology with respect to natural selection of bacterial populations. (www.actabiomedica.it)

Lipedema is an often underdiagnosed chronic disorder that affects subcutaneous adipose tissue almost exclusively in women, which leads to disproportionate fat accumulation in the lower and upper body extremities. Common comorbidities include anxiety, depression, and pain. The correlation between mood disorder and subcutaneous fat deposition suggests the involvement of steroids metabolism and neurohormones signaling, however no clear association has been established so far. In this study, we report on a family with three patients affected by sex-limited autosomal dominant nonsyndromic lipedema. They had been screened by whole exome sequencing (WES) which led to the discovery of a missense variant p.(Leu213Gln) in AKR1C1, the gene encoding for an aldo-keto reductase catalyzing the reduction of progesterone to its inactive form, 20-α-hydroxyprogesterone. Comparative molecular dynamics simulations of the wild-type vs. variant enzyme, corroborated by a thorough structural and functional bioinformatic analysis, suggest a partial loss-of-function of the variant. This would result in a slower and less efficient reduction of progesterone to hydroxyprogesterone and an increased subcutaneous fat deposition in variant carriers. Overall, our results suggest that AKR1C1 is the first candidate gene associated with nonsyndromic lipedema.

To report visual outcomes and rate of retinal pigment epithelium (RPE) atrophy progression in patients with extensive macular atrophy with pseudodrusen-like appearance (EMAP). Retrospective, observational study. Patients with EMAP and symptom onset before 55 years of age, at least 12 months of follow-up using Spectralis blue-light fundus autofluorescence (BAF) and OCT and with no other ocular or systemic conditions. Best-corrected visual acuity (BCVA), BAF, and OCT images were reviewed at baseline and at each annual visit until the last available follow-up. Atrophy was measured by 2 graders using the region finder software on Heidelberg Explorer and confirmed using OCT scans covering the entire atrophic lesion. The following imaging biomarkers were analyzed at each visit: foveal atrophy, vitreomacular traction, outer retinal tubulations, choroidal caverns and subfoveal choroidal thickness, border autofluorescence pattern (hyper-autofluorescent or iso-autofluorescent), and border irregularity as expressed by circularity index (CI). Primary outcomes were annual rate of atrophy enlargement and BCVA loss in EMAP patients. Secondary outcomes included the assessment of potential factors able to predict disease progression. Thirty-six eyes from 18 patients with EMAP (6 men [33%]; mean age at symptom onset, 48.1 ± 1.7 years) were included. Mean follow-up lasted 32.8 ± 14.3 months. RPE atrophy increased from 10.8 ± 6.3 mm² at baseline to 18.1 ± 8.3 mm² at the end of follow-up, with a rate of 2.91 ± 1.09 mm²/year. Faster progression was associated with smaller CI at baseline (P = 0.02) and with iso-autofluorescent lesion borders (P = 0.01). Visual acuity declined progressively at a rate of 7.4 ± 5.8 letters per year, with 57% of eyes showing vision of 20/200 Snellen or worse at the 4-year follow-up. Worse visual outcomes were observed in patients with early foveal involvement at baseline (P = 0.02). Patients affected by EMAP present a rapid expansion of RPE atrophy that is comparable with the diffuse-trickling form of geographic atrophy. More irregular and iso-autofluorescent lesion borders seem to predict faster progression. Our findings may provide relevant information for patient counseling and future interventional approaches to select the best candidates and proper clinical outcomes.

Lipedema is a disabling disease characterized by symmetric enlargement of the lower and/or upper limbs due to deposits of subcutaneous fat, that is easily misdiagnosed. Lipedema can be primary or syndromic, and can be the main feature of phenotypically overlapping disorders. The aim of this study was to design a next-generation sequencing (NGS) panel to help in the diagnosis of lipedema by identifying genes specific for lipedema but also genes for overlapping diseases, and targets for tailored treatments. We developed an NGS gene panel consisting of 305 genes potentially associated with lipedema and putative overlapping diseases relevant to lipedema. The genomes of 162 Italian and American patients with lipedema were sequenced. Twenty-one deleterious variants, according to 3 out of 5 predictors, were detected in PLIN1, LIPE, ALDH18A1, PPARG, GHR, INSR, RYR1, NPC1, POMC, NR0B2, GCKR, PPARA in 17 patients. This extended NGS-based approach has identified a number of gene variants that may be important in the diagnosis of lipedema, that may affect the phenotypic presentation of lipedema or that may cause disorders that could be confused with lipedema. This tool may be important for the diagnosis and treatment of people with pathologic subcutaneous fat tissue accumulation.

TIE1 is a cell surface protein expressed in endothelial cells. Involved in angiogenesis and lymphangiogenesis, including morphogenesis of lymphatic valves, TIE1 is important for lymphatic system functional integrity. The main purpose of this study was to identify different variants in the TIE1 gene that could be associated with lymphatic malformations or dysfunction and predisposition for lymphedema. In a cohort of 235 Italian lymphedema patients, who tested negative for variants in known lymphedema genes, we performed a further test for new candidate genes, including TIE1. Three probands carried different variants in TIE1. Two of these segregated with lymphedema or lymphatic dysfunction in familial cases. Variants in TIE1 could contribute to the onset of lymphedema. On the basis of our findings, we propose TIE1 as a candidate gene for comprehensive genetic testing of lymphedema.

Background: Up to 15% of couples are infertile and male factor infertility accounts for approximately 50% of these cases. Male infertility is a multifactorial pathological condition. The genetic of male infertility is very complex and at least 2000 genes are involved in its etiology. Genetic testing by next-generation sequencing (NGS) technologies can be relevant for its diagnostic value in male infertile patients. Therefore, the aim of this study was to implement the diagnostic offer with the use of an NGS panel for the identification of genetic variants. Methods: We developed an NGS gene panel that we used in 22 male infertile patients. The panel consisted of 110 genes exploring the genetic causes of male infertility; namely spermatogenesis failure due to single-gene mutations, central hypogonadism, androgen insensitivity syndrome, congenital hypopituitarism, and primary ciliary dyskinesia. Results: NGS and a subsequent sequencing of the positive pathogenic or likely pathogenic variants, 5 patients (23%) were found to have a molecular defect. In particular, pathogenic variants were identified in TEX11, CCDC39, CHD7, and NR5A1 genes. Moreover, 14 variants of unknown significance and 7 novel variants were found that require further functional studies and family segregation. Conclusion: This extended NGS-based diagnostic approach may represent a useful tool for the diagnosis of male infertility. The development of a custom-made gene panel by NGS seems capable of reducing the proportion of male idiopathic infertility.