Cryoprotection of humanin-like peptides in seminal plasma for ejaculated spermatozoa of crossbred bulls

BACKGROUND

Cryopreservation process negatively affects spermatozoa functions. Humanin, a small polypeptide encoded in the mitochondrial genome, is well known for its role in cell survival.

OBJECTIVE

To quantify the endogenous levels of humanin in seminal plasma of crossbred Frieswal bulls and to study its role in cryoprotection. The presence of humanin in bull spermatozoa was also investigated.

MATERIALS AND METHODS

A total of 40 semen samples were separated into two groups based on the initial progressive motility (IPM): Good (IPM >70%) and Poor (IPM <50%) groups; and/or based on the post-thaw motility (PTM): Freezable (PTM>50%) and Non-freezable (PTM < 50%) groups. Humanin concentration in seminal plasma (SP-HN) was quantified using ELISA.

RESULTS

SP-HN concentration ranged from undetectable to 67.6 pg/mL with a median level of 35.2 pg/mL. SP-HN level was significantly higher in the good quality semen group than in the poor quality semen group (p<0.001), and also significantly higher in the freezable group than in the non-freezable group (p<0.001). SP-HN level was positively correlated with initial progressive motility, post-thaw semen motility, viability, acrosome intactness and plasma membrane integrity, but negatively correlated the level of reactive oxygen species and malondialdehyde content. Immunochemical localization showed the presence of humanin in the proximal region of the middle piece of spermatozoa.

CONCLUSION

Endogenous humanin level had significant correlation with semen quality and might protect sperm cells against freeze-induced oxidative stress. doi.org/10.54680/fr22510110712.

Cryoprotectant with a mitochondrial derived peptide, humanin, improves post-thaw quality of buffalo spermatozoa

BACKGROUND

Semen cryopreservation results in deleterious effects on spermatozoa, including lipid peroxidation and a reduction in the total antioxidant components of seminal plasma. The ultimate outcome of these changes is a reduction in post-thaw semen quality. A mitochondrial derived peptide, humanin, a potent cytoprotective and antioxidant agent was used in the present study.

OBJECTIVE

To evaluate the efficacy of a mitochondrial-derived peptide, humanin to improve the post-thaw quality of buffalo spermatozoa.

MATERIALS AND METHODS

A total of 18 ejaculates from three Murrah buffalo bulls (n=6 each) were collected. Each ejaculate was divided into four aliquots. The first aliquot was diluted with standard EYTG dilutor (Group I, control), whereas the other three aliquots were diluted with EYTG supplemented with 2 µM (Group II), 5 µM (Group III) and 10 µM humanin (Group IV), respectively. Semen was evaluated for physico-morphological and functional attributes such as progressive motility, viability, abnormality, acrosome integrity, plasmamembrane integrity of fresh samples, pre-freeze and post-thaw stages. Oxidative stress parameters [lipid peroxidation (LPO) and total antioxidant capacity (TAC)] were also measured at the pre-freeze and post-thaw stages.

RESULTS

Humanin supplementation resulted in significantly higher (p < 0.05) post-thaw motility in all treatment groups and, higher (p < 0.05) viability in Groups III and IV in comparison to the control at the post-thaw stage. Spermatozoa with intact acrosome and plasma membrane were higher (p < 0.05) in Groups III and IV as compared to Groups I and II. The LPO levels at the post-thaw stage were found to be lower (p < 0.05) in all treatment groups versus the control group, whereas, higher (p≤0.05) TAC values were recorded in Groups III and IV in comparison to the control and Group II.

CONCLUSION

Humanin supplementation in the extender improved the freezabilty of buffalo spermatozoa.

Effect of Mito-TEMPO Incorporated Semen Extender on Physico-morphological Attributes and Functional Membrane Integrity of Frozen Thawed Buffalo Spermatozoa

BACKGROUND

Sperm mitochondria are the major site of reactive oxygen species (ROS) production and excess production during freezing-thawing process inflicts oxidative damages to spermatozoa. Buffalo spermatozoa are more prone to oxidative damage due to inherently more polyunsaturated fatty acids and low cholesterol to phospholipids ratio in the plasma membrane. A mitochondrial targeted antioxidant, Mito-TEMPO was used in this study.

OBJECTIVE

To study the effect of Mito-TEMPO incorporated semen extender on the post-thaw semen quality in buffalo.

MATERIALS AND METHODS

A total of 18 ejaculates from three murrah buffalo bulls with ≥70% individual progressive motility were utilized for the study. Each semen sample was equally divided and extended with five groups: Group I (Control, without Mito-TEMPO addition); Group II (10 µM Mito-TEMPO); Group III (50 µM Mito-TEMPO); Group IV (100 µM Mito-TEMPO); Group V (500 µM Mito-TEMPO) to have 80×10⁶ progressive motile sperm/mL of extender, filled and sealed in French mini straws (0.25 mL) and frozen following equilibration. The effect of Mito-TEMPO was assessed at fresh/post-dilution and post-thaw stages by evaluating physico-morphological attributes and functional membrane integrity such as hypo-osmotic swelling test (HOST).

RESULTS

Initial progressive motility, viability, acrosomal integrity and HOS response was significantly (p<0.05) improved and sperm abnormality was significantly (p<0.05) reduced in extended semen with Mito-TEMPO (50 µM) compared to control at post-thaw stage, although improvement was also observed at 10 and 100 µM in post-thaw samples.

CONCLUSION

Mito-TEMPO incorporated semen extender at 50 µM concentration, could be part of a rationale for improving post-thaw semen quality in buffalo.

Incubation with Cholesterol-loaded Cyclodextrin and Subsequent Dilution in Partially Deoxygenated Extender Improves the Freezability of Cross-bred Bull Sperm

BACKGROUND

The cryopreservation process induces osmotic stress, membrane changes and production of reactive oxygen species resulting in damage to the spermatozoa. Together, the presence of oxygen in the extender aggravates the oxidative stress that further reduces the cryosurvival rate of sperm cells.

OBJECTIVE

To study the combined effect of cholesterol loaded cyclodextrin (CLC) and partial deoxygenation on post-thaw semen quality in crossbred bulls.

MATERIALS AND METHODS

A total of 18 ejaculates from three crossbred bulls with >3+ mass motility and >70% individual progressive motility were utilized for the study. Each semen sample was divided into four groups: Group I (containing extender without partial deoxygenation or CLC addition); Group II (extender containing 3 mg CLC/120X10⁶ spermatozoa); Group III (extender containing 3 mg CLC/120X10⁶ spermatozoa and 4 ppm dissolved oxygen (DO) level); Group IV (extender containing 3 mg CLC/120X10⁶ spermatozoa and 6 ppm DO level). The samples in each group were finally extended to have 80×10⁶ progressive motile sperm/mL of extender, filled and sealed in French mini straws (0.25 mL) and frozen following equilibration. The effect of CLC addition and partial deoxygenation was assessed at fresh (post-dilution), pre-freeze and post-thaw stages by evaluating various variables [sperm motility, viability, hypo-osmotic swelling (HOS) response, acrosomal integrity, capacitation status and mitochondrial membrane potential (MMP)].

RESULTS

The sperm population was significantly more positive for motility, viability, HOS response, acrosome intactness, high MMP and had less capacitation-like changes in groups supplemented with CLC and partially deoxygenation. However, the positive effect was most pronounced in the group that had extender with CLC+4 ppm DO.

CONCLUSION

Partial deoxygenation of extender, and CLC addition in combination, could be part of a rationale for improving post-thaw semen quality in cross-bred bulls.

Effect of Liquid Nitrogen Flushing of Extender on Seminal Antioxidant Profile of Murrah Buffalo during Cryopreservation

BACKGROUND

The dissolved oxygen in the extender may act as a source for the production of reactive oxygen species that may lead to reduced seminal antioxidant profile which in turn may be responsible for impaired frozen thawed sperm quality and fertility.

OBJECTIVE

To study the effect of adding liquid nitrogen into the extender on semen freezability and seminal antioxidant profile in buffalo.

MATERIALS AND METHODS

Semen extender was prepared freshly and divided into two sub extenders namely, Extender I: control (non deoxygenated) and Extender II: partially deoxygenated by using LN₂ flushing). The estimation of dissolved oxygen (DO) level was done in both extenders. Semen samples with mass motility of ≥ 3+ and individual progressive motility of 70% and above, collected from murrah buffalo bulls were utilized for the present study. Each semen sample was split into two group's viz., group I: diluted with extender I and group II: diluted with extender II up to 60×10⁶ sperm/mL. The diluted semen samples were packed into French mini straws (0.25 mL), sealed with polyvinyl alcohol powder, kept for 3 h at 5°C for equilibration and then kept in automatic programmable freezer until temperature of straws reached -145°C followed by plunging into liquid nitrogen (-196°C). The evaluation of semen samples was carried out for various seminal attributes (sperm motility, live sperm count, acrosomal integrity, and hypo-osmotic swelling (HOS) response) and antioxidant profile (superoxide dismutase (SOD), glutathione peroxidase (GPx) and total antioxidant capacity (TAC)) at pre freeze and post thaw stage.

RESULTS

Sperm motility, live sperm count, acrosomal integrity, HOS response were significantly (P<0.05) higher in group II as compared to group I. The average seminal SOD, GPx and TAC levels were significantly (P<0.05) higher in group II as compared to group I at pre freeze and post thaw stage.

CONCLUSION

It is concluded that partial deoxygenation of the extender prior to its addition to semen enhances sperm quality in terms of sperm motility, live sperm count, acrosomal integrity, and hypo-osmotic swelling (HOS) response and also improves seminal antioxidant profile (superoxide dismutase (SOD), glutathione peroxidase (GPx) and total antioxidant capacity (TAC).

Effect of incubation on freezability of cholesterol-loaded cyclodextrin treated buffalo (Bubalus bubalis) spermatozoa

Aim:

The aim of this study was to investigate the effect of incubation on freezability of cholesterol loaded cyclodextrin (CLC) treated buffalo spermatozoa.

Materials and Methods:

Semen samples with mass motility of 3+ and greater, collected from Murrah buffalo bulls were utilized. Immediately after collection, four equal groups of semen sample were made. Group I was kept as control and diluted with Tris upto concentration of 60×10⁶ sperm/ml, where as Groups II, III, and IV were treated with CLC at 3 mg/120× 10⁶ spermatozoa, incubated at 37°C for action of CLC for 10, 15 and 20 min, respectively, and diluted with tris upto concentration of 60×10⁶ sperm/ml. All groups were subjected to equilibration and freezing. The evaluation of semen samples from all groups was carried out at fresh, pre-freeze and post-thaw stage for progressive motility, viability and hypo-osmotic swelling response (HOS response).

Results:

At the pre-freeze stage, significantly (p<0.05) higher percentage of progressive motility and viability was observed in treatment groups as compared to control with no significant difference among treatment groups. HOS response was significantly (p<0.05) higher in treatment groups as compared to control at pre-freeze stage. At post-thaw stage, significantly (p<0.05) higher percentage of progressive motility, viability and HOS response was recorded in Group II as compared to control and other treatment groups (III and IV). Group II retained significant post-thaw motility and viability at various post-thaw incubation periods.

Conclusion:

Incubation period of 10 min for CLC treated buffalo spermatozoa yielded significantly higher results in terms of freezability as compared to incubation for 15 and 20 min.

Complete sequence of RNA3 of Cucumber mosaic virus isolates infecting Gerbera jamesonii suggests its grouping under IB subgroup

The complete RNA3 genome of Cucumber mosaic virus (CMV) was amplified by RT-PCR from three infected gerbera (Gerbera jamesonii) leaf samples exhibiting severe chlorotic mosaic and flower deformation symptoms. The amplicons obtained were cloned sequenced and deposited in GenBank under the accessions JN692495, JX913531 (from cv. Zingaro) and JX888093 (from cv. Silvester). These sequences shared 98-99 % identities to each other and with a strain of CMV-Banana reported from India, and 90-95 % identities with various strains of CMV reported worldwide. Phylogenetic analysis revealed their closest affinity with CMV-Banana strain, and close relationships with several other strains of CMV of subgroup IB. This study provides evidence of subgroup IB CMV causing severe chlorosis and flower deformation in two cultivars (Zingaro and Silvester) of G. jamesonii in India.

Potent antifungal activity of garlic (allium sativum) against experimental murine dissemenated cryptococcosis

The adequate management of cryptococcosis is difficult with the available armamentarium of synthetic antifungals. We made an effort to evaluate fresh extracts of garlic ( Allium sativum L.) to assess potential therapeutic use of this herb as an anticryptococcal agent. The in vitro antifungal activity in broth showed greatest activity in the aqueous extract (MIC 125-250 µg/ml; MFC 250 to = 500 µg/ml) compared to the alcoholic, crude or commercial extracts. Treatment of Balb/c mice with garlic extracts in mice (orally) showed that alcoholic extracts (5 mg/kg, q.i.d.) provided 100% protection of mice against disseminated cryptococcosis. A concomitant increase in MST (&gt; 35 days) was observed, along with a significant reduction in cfu (log 10 ) burden of cryptococci in visceral (liver, spleen, kidney, lung and heart) tissues, especially brain (&gt; 4.5 log 10 ). The efficacy of extracts was also evident in the sera of mice. Thus, alcoholic extracts of fresh garlic elicit potential anticryptococcal activity against murine disseminated cryptococcosis.

Cryptococcosis associated with HIV negative Indian patients and HIV positive Indian blood donors

Cryptococcosis, particularly cryptococcal meningitis (CM), has become an increasing problem globally in the AIDS era. In the present investigation we have made an effort for the first time to study Indian cases (100) both HIV-positive (23 cases, male, mostly Indian professional blood donors, PBDs') confirmed by an ELISA test and Western Blot but asymptomatic for CM and HIV-negative (77:49 male and 28 female) asymptomatic or symptomatic. These subjects were patients from the Lucknow hospitals admitted during the period between February, 1991 to February, 1994, for suspected cryptococcosis or CM. Of those cases, 10% were positive for cryptococcosis or CM. Meningoencephalitis was the dominant clinical manifestation in four (HIV-negative) cases of CM. CT scanning of the head of those cases revealed a noncommunicating hydrocephalus due to aqueductal stenosis (in 2 cases) and a communicating hydrocephalus with granuloma (by MRI) in another case. The latex agglutination test (LAT) of the sera was positive for Cryptococcus antigen in 6 (26%) of the (HIV-positive) patients and 4 (5%), of the HIV-negative cases. In the cases of CM, there was a lower antigen titre in CSF than in the pronase-treated sera. The LAT was found to be useful in diagnosis of cryptococcosis, especially in asymptomatic cases. The CSF of CM-positive cases revealed low levels of glucose, reduced cell count and high proteins. Among the HIV-negative cases, the onset of meningitis in 4 cases was preceded by the presence of encapsulated budding yeast cells in CSF India ink smear, or cryptococci in a direct urine smear in one case. The CSF culture of 3 cases was positive for mucoid Cryptococcus neoformans, showing brown colour effect (BCE) on Staib agar (syn. Guizotia abyssinica creatinine agar, bird seed agar). The isolated yeast strains were identified as C. neoformans var. neoformans by physiological tests. The pathogenicity test of strains revealed virulence to BALB/c mice evidenced by a high mortality of mice and significantly (p < 0.05) high CN burden (> 4-5 mean log(10) cfu), in the brain followed by other visceral organs (lung, liver, spleen, kidney and heart). The in-vitro susceptibility (MIC mu gmL(-1)) of strains.