Ultrastructural organization of replicating chromatin in prematurely condensed chromosomes

Aim. The ultrastructural aspect of replicating chromatin organization is a matter of dispute. Here, we have analyzed the ultrastructural organization of replication foci using prematurely condensed chromosomes (PCC). Methods. To investigate the ultrastructure of replicating chromatin, we have used correlative light and electron microscopy as well as immunogold staining. Results. Replication in PCC occurs in the gaps between condensed chromatin domains. Using correlative light and electron microscopy, we observed that the replication foci contain decondensed chromatin as well as 80 and 130 nm globules, those were also found in condensed non-replicating chromatin domains. Using immunogolding, we demonstrated that DNA replication in S-phase PCC occurs in loose chromatin on the periphery of dense chromatin domains. Conclusion. Replication in PCC occurred in the decondensed chromatin neighboring the condensed chromatin without formation of special structures

Ultrastructural organization of replicating chromatin in prematurely condensed chromosomes

Aim. The ultrastructural aspect of replicating chromatin organization is a matter of dispute. Here, we have analyzed the ultrastructural organization of replication foci using prematurely condensed chromosomes (PCC). Methods. To investigate the ultrastructure of replicating chromatin, we have used correlative light and electron microscopy as well as immunogold staining. Results. Replication in PCC occurs in the gaps between condensed chromatin domains. Using correlative light and electron microscopy, we observed that the replication foci contain decondensed chromatin as well as 80 and 130 nm globules, those were also found in condensed non-replicating chromatin domains. Using immunogolding, we demonstrated that DNA replication in S-phase PCC occurs in loose chromatin on the periphery of dense chromatin domains. Conclusion. Replication in PCC occurred in the decondensed chromatin neighboring the condensed chromatin without formation of special structures

Genetically determined patozoospermia. Literature review and research results

Genetic factors (chromosomal aberrations and point mutations) are the cause of infertility in 10–15 % of men with impaired fertility. Homogeneous structural and functional defects in the sperm or the total terato-, asthenozoospermia – rare cases of genetically determined male infertility, are autosomal recessive diseases. Currently, described 4 types of «syndromic» spermopatology. 1. Primary ciliary dyskinesia (PCD) in men with total asthenozoospermia. Affects axoneme structures (microtubules, dynein arms, radial spokes). It identified more than 20 chromosomal loci responsible for the development of the PCD. 2. Dysplasia of the fibrous sheath of sperm tail in men with asthenozoospermia. The shortened and thickened sperm tail observed with disorganization of vertical columns and cross ribs of the fibrous sheath. Candidate genes – genes family ACAP. 3. Globozoospermia in men with teratozoospermia characterized by the presence of sperm with round heads, primary lack of acrosome and disorganization middle part of the flagellum. Found mutations or deletions of genes SPATA16, PICK1 and DPY19L2. 4. Syndrome decapitated spermatozoa in men with teratozoospermia (microcephaly). Abnormalities in the spermiogenesis development of connecting part jf the tail and proximal (morphologically normal) centrioles.In 2012–2014 years we have studied the ultrastructure of 2267 semen samples of men with impaired fertility. Globozoospermia revealed in 7 patients, dysplasia of the fibrous sheath – 13, decapitated sperm – in one. PCD was revealed in 4 patients (lack of axoneme dynein arms was found in 1 patient, absence of axoneme radial spokes – in 3 patients.The problem of genetically determined patozoospermya must be taken into account when the assisted reproductive technologies practises. There are few cases of successful assisted reproductive technologies with sperm of these patients. We don»t know the etiological factors of syndromic spermopatologe, so we cannot determine the degree of genetic risk

Sperm DNA fragmentation in men of different age

The study objective is to analyze the content of spermatozoa with single and double-stranded DNA breaks in different age groups.Materials and methods. The level of DNA fragmentation was studied in 300 ejaculate samples obtained from 266 sub- or infertile men. The group 1 included 150 samples obtained from 131 patients under the age of 45 (21–44 years), the group 2 included 150 samples obtained from 135 patients above the age of 45 (45–68 years). Mean ages were 34.8 ± 3.9 and 48.6 ± 3.1 years, respectively. The number of sperm with fragmented DNA was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method on ejaculate smears. The number of spermatozoa with >15 % of fragmented DNA was considered elevated. Standard semen analysis was performed in 117 and 97 men from the groups 1 and 2, respectively.Results. The number of sperm with fragmented DNA varied in ejaculated samples from 1.5 to 64.5 %. Mean number of sperm with DNA breaks in the group 1 (12.0 ± 6.0 %) was significantly lower than in the group 2 (16.1 ± 8.3 %, p <0.05). Mean sperm count in the ejaculate of the group 1 (267.0 ± 198.7 million) was significantly higher than in the group 2 (201.0 ± 162.9 million, p = 0.02).Conclusion. We revealed that in men over the age of 45 years, the percentage of spermatozoa with DNA fragmentation is higher than in men under 45 years of age, it may indirectly indicate an increased level of reactive oxygen species in the seminal plasma in older patients

DNA fragmentation in spermatozoa and its relationship with impaired spermatogenesis

Sperm cells DNA fragmentation is one of the factors of male sub-/infertility discovered recently. At present, pathophysiological mechanisms that cause DNA fragmentation have not been studied completely. It is suggested that they may be caused with defects of chromatin remodeling, apoptosis, and oxidative stress. Spermiological examination was performed in 461 infertile men. With 23 % of the patients examined, the frequency of sperm cells DNA fragmentation comprises over 15 %, with that, 18 % of the patients demonstrated its range from 15.1 to 30 %, and with 5 % of patients, it exceeded 30 %. We found that the amount of sperm cells with fragmented DNA with severe forms of pathozoospermia is higher that with less manifested disturbances of spermatogenesis. Negative dynamics was revealed regarding the change in sperm concentration in men that have increased frequency of DNA fragmentation. Obtained results confirm the suggestion of the correlation between some semen parameters (concentration, motility, and morphology) and sperm DNA fragmentation. Thus, one can state that the DNA fragmentation parameter of sperm cells has a certain diagnostic and forecasting value for married couples with reproduction disorders.</p

DNA fragmentation in spermatozoa and its relationship with impaired spermatogenesis

Sperm cells DNA fragmentation is one of the factors of male sub-/infertility discovered recently. At present, pathophysiological mechanisms that cause DNA fragmentation have not been studied completely. It is suggested that they may be caused with defects of chromatin remodeling, apoptosis, and oxidative stress. Spermiological examination was performed in 461 infertile men. With 23 % of the patients examined, the frequency of sperm cells DNA fragmentation comprises over 15 %, with that, 18 % of the patients demonstrated its range from 15.1 to 30 %, and with 5 % of patients, it exceeded 30 %. We found that the amount of sperm cells with fragmented DNA with severe forms of pathozoospermia is higher that with less manifested disturbances of spermatogenesis. Negative dynamics was revealed regarding the change in sperm concentration in men that have increased frequency of DNA fragmentation. Obtained results confirm the suggestion of the correlation between some semen parameters (concentration, motility, and morphology) and sperm DNA fragmentation. Thus, one can state that the DNA fragmentation parameter of sperm cells has a certain diagnostic and forecasting value for married couples with reproduction disorders

Mechanisms and Treatment of Light-Induced Retinal Degeneration-Associated Inflammation: Insights from Biochemical Profiling of the Aqueous Humor

Ocular inflammation contributes to the pathogenesis of blind-causing retinal degenerative diseases, such as age-related macular degeneration (AMD) or photic maculopathy. Here, we report on inflammatory mechanisms that are associated with retinal degeneration induced by bright visible light, which were revealed while using a rabbit model. Histologically and electrophysiologically noticeable degeneration of the retina is preceded and accompanied by oxidative stress and inflammation, as evidenced by granulocyte infiltration and edema in this tissue, as well as the upregulation of total protein, pro-inflammatory cytokines, and oxidative stress markers in aqueous humor (AH). Consistently, quantitative lipidomic studies of AH elucidated increase in the concentration of arachidonic (AA) and docosahexaenoic (DHA) acids and lyso-platelet activating factor (lyso-PAF), together with pronounced oxidative and inflammatory alterations in content of lipid mediators oxylipins. These alterations include long-term elevation of prostaglandins, which are synthesized from AA via cyclooxygenase-dependent pathways, as well as a short burst of linoleic acid derivatives that can be produced by both enzymatic and non-enzymatic free radical-dependent mechanisms. The upregulation of all oxylipins is inhibited by the premedication of the eyes while using mitochondria-targeted antioxidant SkQ1, whereas the accumulation of prostaglandins and lyso-PAF can be specifically suppressed by topical treatment with cyclooxygenase inhibitor Nepafenac. Interestingly, the most prominent antioxidant and anti-inflammatory benefits and overall retinal protective effects are achieved by simultaneous administrating of both drugs indicating their synergistic action. Taken together, these findings provide a rationale for using a combination of mitochondria-targeted antioxidant and cyclooxygenase inhibitor for the treatment of inflammatory components of retinal degenerative diseases