Role of HOX genes in cancer progression and their therapeutical aspects

HOX genes constitute a family of evolutionarily conserved transcription factors that play pivotal roles in embryonic development, tissue patterning, and cell differentiation. These genes are essential for the precise spatial and temporal control of body axis formation in vertebrates. In addition to their developmental functions, HOX genes have garnered significant attention for their involvement in various diseases, including cancer. Deregulation of HOX gene expression has been observed in numerous malignancies, where they can influence tumorigenesis, progression, and therapeutic responses. This review provides an overview of the diverse roles of HOX genes in development, disease, and potential therapeutic targets, highlighting their significance in understanding biological processes and their potential clinical implications.

Awareness data on cervical cancer among females of rural and urban areas of Haryana, India

A cross-sectional study was done to assess the degree of current awareness and behaviors about cervical cancer among females in urban and rural areas of North India. This survey was conducted on one thousand females (500 rural and 500 urban). A well-structured questionnaire was designed to collect information about participants' knowledge on cancer of cervix uteri such as age, height and weight measurements, marital status, menstrual status, personal hygiene, age at menarche, sexual history, pregnancy and abortion history, use of contraceptive pills for birth-control, smoking, alcohol consumption, and other relevant information. The data was collected by conducting face-to-face interviews after obtaining the verbal consent of the participants. The data has the potential to reduce disease burden by spreading awareness about symptoms and risk factors of cervical cancer as well as implementation of effective early screening strategies.

A rare optineurin mutation in an Indian family with coexistence of JOAG and PCG

Purpose

This study focused on the genetic screening of Myocilin (MYOC), Cytochrome P450 family 1 subfamily B member 1 (CYP1B1), Optineurin (OPTN), and SIX homeobox 6 (SIX6) genes in a family with coexistence of primary congenital glaucoma (PCG) and juvenile open-angle glaucoma (JOAG).

Methods

Sanger sequencing was used to examine the coding region of all four genes. Six different online available algorithms were used for the pathogenicity prediction of missense variant. Structural analysis was done using Garnier-Osguthorpe-Robson (GOR), PyMol, ChimeraX, and Molecular Dynamic (MD) Simulations (using Graphics Processing Unit (GPU)-enabled Desmond module of Schrödinger).

Results

There were a total of three sequence variants within the family. All seven algorithms determined that a single mutation, G538E, in the OPTN gene is pathogenic. The loops connecting the strands became more flexible, as predicted structurally and functionally by pathogenic mutations. Mutations create perturbations and conformational rearrangements in proteins, hence impairing their functioning.

Conclusion

In this study, we describe a North Indian family in which members were having JOAG and PCG due to a rare homozygous/heterozygous mutation in OPTN. The coexistence of two types of glaucoma within a single pedigree suggests that certain OPTN mutations may be responsible for the onset of different glaucoma phenotypes.

Artificial Intelligence Literacy: Developing a Multi-institutional Infrastructure for AI Education

RATIONALE AND OBJECTIVES

To evaluate the effectiveness of an artificial intelligence (AI) in radiology literacy course on participants from nine radiology residency programs in the Southeast and Mid-Atlantic United States.

MATERIALS AND METHODS

A week-long AI in radiology course was developed and included participants from nine radiology residency programs in the Southeast and Mid-Atlantic United States. Ten 30 minutes lectures utilizing a remote learning format covered basic AI terms and methods, clinical applications of AI in radiology by four different subspecialties, and special topics lectures on the economics of AI, ethics of AI, algorithm bias, and medicolegal implications of AI in medicine. A proctored hands-on clinical AI session allowed participants to directly use an FDA cleared AI-assisted viewer and reporting system for advanced cancer. Pre- and post-course electronic surveys were distributed to assess participants' knowledge of AI terminology and applications and interest in AI education.

RESULTS

There were an average of 75 participants each day of the course (range: 50-120). Nearly all participants reported a lack of sufficient exposure to AI in their radiology training (96.7%, 90/93). Mean participant score on the pre-course AI knowledge evaluation was 8.3/15, with a statistically significant increase to 10.1/15 on the post-course evaluation (p= 0.04). A majority of participants reported an interest in continued AI in radiology education in the future (78.6%, 22/28).

CONCLUSION

A multi-institutional AI in radiology literacy course successfully improved AI education of participants, with the majority of participants reporting a continued interest in AI in radiology education in the future.

Molecular genetics of primary open-angle glaucoma

Glaucoma is a series of linked optic diseases resulting in progressive vision loss and total blindness due to the acquired loss of retinal ganglion cells. This harm to the optic nerve results in visual impairment and, ultimately, total blindness if left untreated. Primary open-angle glaucoma (POAG) is the most frequent variety within the large family of glaucoma. It is a multifaceted and heterogeneous condition with several environmental and genetic variables aiding in its etiology. By 2040, there will be 111.8 million glaucoma patients globally, with Asia and Africa accounting for the vast majority. The goal of this review is to elaborate on the role of genes (nuclear and mitochondrial) as well as their variants in the pathogenesis of POAG. PubMed and Google Scholar databases were searched online for papers until September 2022. Prevalence and inheritance patterns vary significantly across different ethnic and geographic populations. Numerous causative genetic loci may exist; however, only a few have been recognized and characterized. Further investigation into the genetic etiology of POAG is expected to uncover novel and intriguing causal genes, allowing for a more precise pathogenesis pattern of the disease.

Long non-coding RNAs as critical regulators and novel targets in cervical cancer: current status and future perspectives

Cervical cancer is among the leading causes of cancer-associated mortality in women. In spite of vaccine availability, improved screening procedures, and chemoradiation therapy, cervical cancer remains the most commonly diagnosed cancer in 23 countries and the leading cause of cancer deaths in 36 countries. There is, therefore, a need to come up with novel diagnostic and therapeutic targets. Long non-coding RNAs (lncRNAs) play a remarkable role in genome regulation and contribute significantly to several developmental and disease pathways. The deregulation of lncRNAs is often observed in cancer patients, where they are shown to affect multiple cellular processes, including cell cycle, apoptosis, angiogenesis, and invasion. Many lncRNAs are found to be involved in the pathogenesis as well as progression of cervical cancer and have shown potency to track metastatic events. This review provides an overview of lncRNA mediated regulation of cervical carcinogenesis and highlights their potential as diagnostic and prognostic biomarkers as well as therapeutic targets for cervical cancer. In addition, it also discusses the challenges associated with the clinical implication of lncRNAs in cervical cancer.

Genetic dissection of non-syndromic retinitis pigmentosa

Retinitis pigmentosa (RP) belongs to a group of pigmentary retinopathies. It is the most common form of inherited retinal dystrophy, characterized by progressive degradation of photoreceptors that leads to nyctalopia, and ultimately, complete vision loss. RP is distinguished by the continuous retinal degeneration that progresses from the mid-periphery to the central and peripheral retina. RP was first described and named by Franciscus Cornelius Donders in the year 1857. It is one of the leading causes of bilateral blindness in adults, with an incidence of 1 in 3000 people worldwide. In this review, we are going to focus on the genetic heterogeneity of this disease, which is provided by various inheritance patterns, numerosity of variations and inter-/intra-familial variations based upon penetrance and expressivity. Although over 90 genes have been identified in RP patients, the genetic cause of approximately 50% of RP cases remains unknown. Heterogeneity of RP makes it an extremely complicated ocular impairment. It is so complicated that it is known as “fever of unknown origin”. For prognosis and proper management of the disease, it is necessary to understand its genetic heterogeneity so that each phenotype related to the various genetic variations could be treated.

Genetic association of ARID5B with the risk of colorectal cancer within Jammu and Kashmir, India

Colorectal cancer (CRC), which includes the development of cancer from the colon or rectum, is one of the highly prevalent cancers in the populations of Jammu and Kashmir (J&K) in India. However, case-control genetic association studies on CRC are lacking in this population. Various genome-wide association studies have previously shown that single-nucleotide polymorphisms (SNPs) of the AT-rich interaction domain 5B (ARID5B) gene located on chromosome 10q21.2 contribute substantially to the development of colorectal cancer. The association between ARID5B and CRC risk in north Indian population groups is still unknown. To understand the role of ARID5B SNPs in CRC in the population of J&K, we designed a case-control study to investigate the association of the cancer susceptibility variant rs10740055 of ARID5B with CRC in the population of J&K. The study included 180 cases and 390 healthy controls. Genotyping of the rs10740055 variant was performed by RT-PCR using the TaqMan assay technique. Hardy-Weinberg equilibrium of the variant was assessed using the chi-squared test. The allele- and genotype-specific risks were estimated by odds ratios (ORs) with 95% confidence intervals (CIs). The rs10740055 variant showed a higher risk for colorectal cancer with an OR of 3.35 (1.99-5.65 at 95% CI) and P = 0.000005 corrected for age, gender, ethnicity, BMI, alcohol intake and smoking. Our results indicate that the A allele of rs10740055 imparts risk to the population and also that a larger sample size is needed for further statistical validation. The association of other variants in other ARID family genes should also be tested as their role cannot be ruled out.

Polymorphism in the TP63 gene imparts a potential risk for leukemia in the North Indian population

BACKGROUND

The role of single nucleotide polymorphism rs10937405 (C>T) of the TP63 gene in cancer including leukemia has previously been studied in different world populations; however, the role of this variant in leukemia in the North Indian population of Jammu and Kashmir is still unknown.

OBJECTIVES

In the present study, we investigated the association of genetic variant rs10937405 with leukemic in the Jammu and Kashmir population.

METHODS

A total of 588 subjects, (188 cases and 400 controls) were recruited for the study. The rs10937405 variant was genotyped by using the real-time based TaqMan assay.

RESULTS

A statistically significant association was observed between the rs10937405 and leukemia [OR of 1.94 (95% CI 1.51-2.48), p=1.2x10-6].

CONCLUSION

The current study concludes that the rs10937405 variant is a risk factor for the development of leukemia in the population of Jammu and Kashmir, North India. However, it would be interesting to explore the contribution of this variant in other cancers as well. Our findings will help in the development of diagnostic markers for leukemia in the studied population and potentially for other North Indian populations.

Homozygosity Mapping and Genetic Analysis of Autosomal Recessive Retinal Dystrophies in 144 Consanguineous Pakistani Families

Purpose

The Pakistan Punjab population has been a rich source for identifying genes causing or contributing to autosomal recessive retinal degenerations (arRD). This study was carried out to delineate the genetic architecture of arRD in the Pakistani population.

Methods

The genetic origin of arRD in a total of 144 families selected only for having consanguineous marriages and multiple members affected with arRD was examined. Of these, causative mutations had been identified in 62 families while only the locus had been identified for an additional 15. The remaining 67 families were subjected to homozygosity exclusion mapping by screening of closely flanking microsatellite markers at 180 known candidate genes/loci followed by sequencing of the candidate gene for pathogenic changes.

Results

Of these 67 families subjected to homozygosity mapping, 38 showed homozygosity for at least one of the 180 regions, and sequencing of the corresponding genes showed homozygous cosegregating mutations in 27 families. Overall, mutations were detected in approximately 61.8 % (89/144) of arRD families tested, with another 10.4% (15/144) being mapped to a locus but without a gene identified.

Conclusions

These results suggest the involvement of unmapped novel genes in the remaining 27.8% (40/144) of families. In addition, this study demonstrates that homozygosity mapping remains a powerful tool for identifying the genetic defect underlying genetically heterogeneous arRD disorders in consanguineous marriages for both research and clinical applications.

Novel occurrence of axenfeld: Rieger syndrome in a patient with blepharophimosis ptosis epicanthus inversus syndrome

Blepharophimosis ptosis epicanthus inversus syndrome (BPES) is a complex eyelid malformation characterized by the classical tetrad of blepharophimosis, telecanthus, ptosis, and epicanthus inversus. It has been reported to be associated with other ocular anomalies such as euryblepharon, strabismus, nystagmus, amblyopia, microphthalmos, lacrimal drainage apparatus abnormality, extra ocular muscle abnormalities, microcornea, trabecular dysgenesis, optic nerve hypoplasias, and colobomas of the optic disk. We describe a case of BPES with Axenfeld-Rieger syndrome, a neurocristopathy characterized by maldevelopment of the anterior segment with predisposition to development of glaucoma. Interestingly, both syndromes are caused by mutations in the same class of genes, namely the winged-helix/forked transcription factors (FOX) involved in a variety of developmental processes.

Mitochondrial DNA nucleotide changes in primary congenital glaucoma patients

PURPOSE

Primary congenital glaucoma (PCG) is the second most common cause of blindness, accounting for 0.01%-0.04% of total blindness worldwide. Most congenital glaucoma cases are mapped to the GLC3A locus, and many aspects of PCG are still unknown. Recent studies have reported an increased frequency of mitochondrial DNA (mtDNA) sequence changes in primary open-angle glaucoma, primary angle-closure glaucoma, and pseudoexfoliation glaucoma compared to controls. Thus, this study was planned with the aim of detecting mitochondrial DNA variations in PCG cases.

METHODS

Twenty primary congenital glaucoma cases were selected from Dr. R. P. Centre for Ophthalmic Sciences of All India Institute of Medical Sciences (AIIMS), New Delhi, India. DNA was isolated from whole blood samples. The entire coding region of the mitochondrial genome was amplified by PCR in 20 patients and 20 controls. The full mtDNA genome was sequenced and analyzed against mitochondrial reference sequence NC_012920.

RESULTS

MtDNA sequencing revealed a total of 195 nucleotide variations in PCG patients and 58 in controls. Of the 195 changes, 43 (22.05%) were nonsynonymous, 82 (42.05%) were synonymous, and 30 were in RNA genes. A total of 39/195 (20.00%) variations were observed in the D-loop (hypervariable region), 19/195 (9.74%) in different ribosomal RNA (rRNAs), 11/195 (5.64%) in transfer RNA (tRNAs), 66/195 (33.84%) in complex I, 17/195 (8.71%) in complex III, 27/195 (13.84%) in complex IV, and 15/195 (7.69%) in complex V. Of 58 variations in the controls, 14 were nonsynonymous changes. The Sorting Intolerant from Tolerant and Polymorphism Phenotyping analyses of all nonsynonymous changes from patients revealed two pathogenic changes in NADH-ubiquinone oxidoreductase chain 2 (ND2) and cytochrome oxidase subunit III (COXIII) subunits. In one of the patients, the insertion of cytosine introduced a frame shift change (p.Ile104AsnfsX26) in the cytochrome b (CYB) subunit of the electron transport chain. In another patient, a variation (G8572A) in ATP synthase 8 (ATpase8) led to the introduction of a stop codon or termination at amino acid position 69. Haplogroup/phylogenetic analysis of mtDNA showed that primary congenital glaucoma patients belong to three macrohaplogroups: M (4), N (15), and L (1). Fifty percent of the patients belonged to the H2a2a lineage of the N-derived haplogroup.

CONCLUSIONS

Although several mutations were found at a higher frequency among our population, there is a need to complement this study with functional studies and to analyze a large number of samples in different populations of different haplogroups, as penetrance varies among haplogroups.

Screening of the LTBP2 gene in a north Indian population with primary congenital glaucoma

PURPOSE

Primary congenital glaucoma (PCG), a severe form of glaucoma that presents early in life, is an autosomal recessive eye disorder that results from defects in anterior eye segment. Null mutations in LTBP2 were reported in patients with PCG in Pakistani and Iranian families. This study was aimed to identify the mutation profile of the LTBP2 gene in north Indian patients with PCG.

METHODS

After ethical clearance, 54 unrelated patients with PCG who were either negative or heterozygous for MYOC, CYP1B1, and FOXC1 mutations and 50 ethnically matched non-glaucomatous controls were recruited for the study. PCG diagnosis was established by the presence of buphthalmos in at least one affected eye and associated high intraocular pressure before the age of 3 years. LTBP2 was screened in genomic blood DNA for mutations, with PCR and direct sequencing of PCR amplified fragments.

RESULTS

We observed one intronic single nucleotide polymorphism (rs3742793) between exons 6 and 7 in the LTBP2 gene in 18 patients with PCG. This nucleotide change resulted in cytosine (C) being replaced by guanosine (G) at position g.75070493. No pathogenic variants were identified in the LTBP2 gene in our cohort of patients.

CONCLUSIONS

LTBP2 gene mutations are not involved in the pathogenesis of primary congenital glaucoma in our patients. Thus, it is important to screen other glaucoma-associated loci and genes for involvement in congenital glaucoma in cases that are either negative or heterozygous for MYOC, CYP1B1, and FOXC1 mutations to have better insight into the disease pathogenesis.

Preventive effect of Sphaeranthus indicus during progression of glucocorticoid-induced insulin resistance in mice

CONTEXT

The whole plant of Sphaeranthus indicus Linn. (Asteraceae) is traditionally used in the treatment of diabetes mellitus.

OBJECTIVE

The present study investigated the effect of the methanol extract of Sphaeranthus indicus whole plant in dexamethasone-induced insulin resistance in mice.

MATERIALS AND METHODS

The mice were treated with dexamethasone for 22 days and effects on plasma glucose level, serum triglyceride level, glucose uptake, levels of hepatic enzymes like glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), lipid peroxidase (LPO), and body weight was observed.

RESULTS

The Sphaeranthus indicus extract (SI) showed significant decrease in plasma glucose and serum triglyceride levels (p <0.01) at doses, of 400 and 800 mg/kg, p.o., and stimulated insulin assisted and non-insulin assisted glucose uptake in skeletal muscle. The levels of antioxidant enzymes GSH, SOD, and CAT were significantly increased (p <0.01) and there was a significant decrease in level of LPO (p <0.01). SI significantly restored (p <0.01) dexamethasone induced body weight loss.

DISCUSSION AND CONCLUSION

Sphaeranthus indicus may prove to be effective in the treatment of type II diabetes mellitus owing to its ability to decrease insulin resistance.

VSX1 gene analysis in keratoconus

PURPOSE

To screen the visual system homeobox 1 (VSX1) gene in keratoconus patients.

METHODS

The enntire coding region of VSX1, including intron-exon boundaries were amplified in keratoconus cases (n=50) and controls (n=50). All sequences were analyzed against the ensemble sequence (ENSG00000100987) for VXS1.

RESULTS

Sequencing analysis showed four alterations (p.A182A, p.R217H, p.P237P, and g.25059612C>T) in VSX1 of which g.25059612C>T (in intron 2) was found to be novel. Of these four, p.A182A and p.P237P were present in both cases as well as controls while p.R217H and g.25059612C>T were limited to cases only. All these changes were non-pathogenic.

CONCLUSIONS

In our study no pathogenic VSX1 mutation was identified. The role of VSX1 in the pathogenesis of keratoconus is still controversial. VSX1 mutations are responsible for a very small fraction of all observed keratoconus cases. The absence of pathogenic mutations in VSX1 in our patients indicates that other genetic loci like 13q32 as suggested by a recent study may be involved in the pathogenesis of this disorder.

MYOC and FOXC1 gene analysis in primary congenital glaucoma

PURPOSE

To screen the myocilin (MYOC) and forkhead box protein C1 (FOXC1) genes for sequence variations in primary congenital glaucoma (PCG).

METHODS

Seventy five PCG patients were screened for MYOC variations and 54 cases (negative or heterozygous for cytochrome P4501B1 mutations) for FOXC1 mutations by polymerase chain reaction (PCR) and DNA sequencing.

RESULTS

Five single nucleotide polymorphisms (SNPs; -126T>C, -83G>A, p.R76K, IVS2+35G>A, and p.Y347Y) were identified in MYOC and two sequence variations (GGC375ins and GGC447ins) in FOXC1. No pathogenic variations were identified in MYOC and FOXC1 in our patients.

CONCLUSIONS

MYOC and FOXC1 mutations are not involved in pathogenesis of primary congenital glaucoma in our patients. Thus, it is important to screen other loci for involvement in congenital glaucoma in cases which are negative or heterozygous for CYP1B1 mutations to have a better insight in to disease pathogenesis.

Comet assay: a prognostic tool for DNA integrity assessment in infertile men opting for assisted reproduction

BACKGROUND & OBJECTIVES

The growing concern on transmission of genetic diseases in assisted reproduction technique (ART) and the lacunae in the conventional semen analysis to accurately predict the semen quality has led to the need for new techniques to identify the best quality sperm that can be used in assisted procreation techniques. This study analyzes the sperm parameters in the context of DNA damage in cytogenetically normal, AZF non deleted infertile men for DNA damage by comet assay.

METHODS

Seventy infertile men and 40 fertile controls were evaluated for the semen quality by conventional semen parameters and the sperms were also analyzed for DNA integrity by comet assay. The patients were classified into oligozoospermic (O), asthenozoospermic (A), teratozoospermic (T), oligoasthenoteratozoospermic (OAT) categories and infertile men with normal semen profile. The extent of DNA damage was assessed by visual scoring method of comets.

RESULTS

Idiopathic infertile men with normal semen profile (n=18) according to conventional method and patients with history of spontaneous abortions and normal semen profile (n=10) had high degree of DNA damage (29 and 47% respectively) as compared to fertile controls (7%). The O, A, T and OAT categories of patients had a variably higher DNA damage load as compared to fertile controls.

INTERPRETATION & CONCLUSION

The normal range and threshold for DNA damage as a predictor of male fertility potential and technique which could assess the sperm DNA damage are necessary to lower the trauma of couples experiencing recurrent spontaneous abortion or failure in ART.

Identification of novel mitochondrial mutations in Leber's hereditary optic neuropathy

PURPOSE

To screen mitochondrial DNA (mtDNA) variations in Leber hereditary optic neuropathy (LHON).

METHODS

Ten LHON patients were selected from neuro-ophthalmology clinics of All India Institute of Medical Sciences (AIIMS), New Delhi, India. Clinical evaluation included slit-lamp biomicroscopy, fundus examination, and neuroimaging. DNA was isolated from whole blood samples. The entire coding region of the mitochondrial genome was amplified by PCR in ten patients and 20 controls. The full mtDNA genome except D-loop was sequenced. All sequences were analyzed against mitochondrial reference sequence NC_012920.

RESULTS

MtDNA sequencing revealed a total of 30 nucleotide variations in the ten LHON patients and 29 in the 20 controls. Of 30 changes, 30.00% (9/30) were nonsynonymous, and the remaining 70.00% (21/30) were synonymous. In controls, a total of five changes were nonsynonymous. Out of the total 14 nonsynonymous changes observed in cases and controls, four (p.A52T in nicotinamide adenine dinucleotide [NADH] dehydrogenase [ND1] protein; p.L128Q in ND2; p.W48R in ATPase6; p.R340H in ND4 protein) were pathogenic. Four patients were positive for either of pathogenic changes. In total, 16.66% (5/30) variations were novel out of which 40.00% (2/5) were nonsynonymous. All novel variations were submitted to the GenBank database, and accession numbers were obtained. Primary LHON mutations in complex I genes have been considered a hallmark feature of LHON patients, and primary LHON mutations were present in two cases in this study. Mutations in complex I genes (ND genes) account for 50%-90% of LHON pedigrees in different ethnic pedigrees. In this study the highest numbers of changes were also present in complex I genes (46.66%; 14/30) followed by complex IV (30.00%; 9/30), complex III (16.66%; 5/30), and then complex V (6.66%; 2/30). Complex I had 5/30 (16.66%) nonsynonymous changes, complex III had 1/30 (3.33%), complex IV had 1/30 (3.33%), and complex V had 2/30 (6.66%) nonsynonymous changes. Nonsynonymous mutations in cytochrome c oxidase (COX) genes have been reported previously in LHON patients. Nonsynonymous mtDNA variations may adversely affect the respiratory chain and impair the oxidative phosphorylation (OXPHOS) pathway, resulting in low ATP production and elevated reactive oxygen species (ROS) levels, which cause oxidative stress. It has previously been reported that oxidative stress (OS) leads to oxidative damage of cellular macromolecules, such as mitochondrial and nuclear DNA, proteins, and lipids along with energy depletion and a local imbalance of calcium homeostasis, resulting in neuronal degeneration. OS is the underlying etiology in several ocular diseases and also plays an essential role in LHON.

CONCLUSIONS

A total of five novel mtDNA variations were identified in this study. Nonsynonymous mtDNA variations may adversely affect the respiratory chain and impair the OXPHOS pathway, resulting in low ATP production and elevated ROS levels. OS further damages both nuclear and mtDNA. This preliminary study describes mtDNA sequence variations in a relatively small number of LHON patients of north Indian ethnic origin. However, these results should be confirmed in other populations. Early diagnosis of mtDNA variations and prompt anti-oxidant administration in these cases may delay OS-induced injury to retinal ganglion cells (RGCs) and hence improve visual prognosis.

Mitochondrial DNA analysis in primary congenital glaucoma

PURPOSE

To screen mitochondrial DNA (mtDNA) for nucleotide variations in primary congenital glaucoma (PCG).

METHODS

The entire coding region of the mitochondrial genome was amplified by polymerase chain reaction from 35 PCG patients and 40 controls. The full mtDNA genome except the D-loop was sequenced. All sequences were analyzed against mitochondrial reference sequence NC_012920.

RESULTS

MtDNA sequencing revealed a total of 132 and 58 nucleotide variations in PCG and controls, respectively. Of 132 nucleotide variations, 42 (31.81%) were non-synonymous and 82 (62.12%) were synonymous changes, and 8 were in RNA genes. The highest number of nucleotide variations were recorded in complex I followed by complex IV, then complex V. Eight patients (22.85%) had potentially pathogenic mtDNA nucleotide changes and twenty (57.14%) had mtDNA sequence changes associated with elevated reactive oxygen species (ROS) production. Mitochondria not only constitute the energy-generating system in the cell, but are also critically involved in calcium signaling and apoptosis. Mitochondrial function can be affected by mutations in mitochondrial and nuclear DNA, chemical insults to components of the electron transport chain, and a lack of substrates such as oxygen. Mitochondrial dysfunction results in an excessive generation of free radicals and reduced mitochondrial respiration. Developing trabecular meshwork (TM) is deficient in antioxidant enzymes, and thus is more susceptible to oxidative stress (OS) induced damage. Previous studies have documented certain mtDNA sequence variations associated with elevated ROS levels and OS. Three such changes (G10398A, A12308G, and G13708A) were present in our patients. Elevated ROS may cause OS. This OS may further damage mtDNA and may cause decreased mitochondrial respiration. This may lead to impaired growth, development and differentiation of TM and consequently trabecular-dysgenesis, which is a characteristic feature of PCG. OS affects both TM and retinal ganglion cells (RGCs) and may be involved in the neuronal death affecting the optic nerve in glaucoma. There are several studies which point to mitochondrial dysfunction in different types of glaucoma and critically participate in RGC death. Recent studies also implicate mitochondrial dysfunction-associated OS as a risk factor for glaucoma patients. It has been reported that elevated hydrostatic pressure causes breakdown of the mitochondrial network by mitochondrial fission and induce cristae depletion and cellular ATP reduction in differentiated RGC-5 cells in vitro as well as in vivo.

CONCLUSIONS

A total of 44 novel mtDNA variations were identified in this study. Non-synonymous mtDNA variations may adversely affect respiratory chain, impair OXPHOS pathway result in low ATP production, high ROS production and impair growth, development and differentiation of TM lead to trabecular-dysgenesis and consequently RGC's death. Such cases with mtDNA variations and consequent OS may benefit by early diagnosis and prompt management by antioxidant therapy. This may delay OS induced injury to TM and RGCs and hence improve visual prognosis.

Mutation spectrum of CYP1B1 in North Indian congenital glaucoma patients

PURPOSE

Mutations in Cytochrome P450 (CYP1B1) are a predominant cause of congenital glaucoma. This study was planned with the aim to identify the mutation profile of CYP1B1 in North Indian primary congenital glaucoma (PCG) patients.

METHODS

After ethical clearance, 50 congenital glaucoma patients and 50 ethnically matched controls were recruited in this study. Genomic DNA was isolated from the blood and trabecular meshwork, and CYP1B1 was screened for the six most prevalent mutations (termination at 223 [Ter@223], Gly61Glu, Pro193Leu, Glu229Lys, Arg368His, and Arg390Cys) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). DNA sequencing was done to identify other mutations and for confirmation of RFLP positive samples.

RESULTS

On PCR-RFLP, 21/50 cases (42%) were found positive for one or more of these mutations. However, on sequencing, we found that 23/50 (46%) harbored the CYPIB1 mutations. Ter@223 was found in 18%, p.R390H in 16%, and p.R368H in 8% of cases. Three novel mutations, p.L24R, p.F190L, and p.G329D, were identified by DNA sequencing. Leucine, phenylalanine, and glycine are conserved at the 24th, 190th, and 329th position in the CYP1B1 protein in different species, suggestive of important functions at these loci. Ter@223 was found to be the most prevalent mutation in our patients while p.R368H was most prevalent in southern India. The difference in frequency and mutation profile may be due to the heterogeneous Indian population. Pathogenic CYP1B1 mutations impair anterior chamber development and differentiation by blocking the aqueous outflow and raising intraocular pressure (IOP).

CONCLUSIONS

Three novel mutations were identified in this study. Studies of pathogenic sequence variants in CYP1B1 in different populations may contribute to a better understanding of the disease pathogenesis. This may lead to the development of novel therapeutic approaches in the near future.

Oxidative stress and sperm mitochondrial DNA mutation in idiopathic oligoasthenozoospermic men

Physiological function of reactive oxygen species (ROS) has been known since a long, but recently toxic effects of ROS on spermatozoa have gained much importance in male infertility. Mitochondrial DNA (mtDNA) is believed to be both source and target of ROS. mtDNA unlike nuclear DNA is not compactly packed and hence more susceptible to oxidative stress (OS) than nuclear DNA. In the present study, the role of OS in mitochondrial genome changes was studied in men with idiopathic infertility. The study included 33 infertile oligo-asthenozoospermic (OA) men and 30 fertile controls. Semen analyses were performed and OS was measured by estimating the level of malondialdehye (MDA) in the seminal plasma and ROS in the sperm. Sperm mtDNA was sequenced by standard PCR-DNA sequencing protocol for ATPase and nicotinamide adenine dinucleotide dehydrogenase (ND) groups of genes. Sperm count and progressive motility were found to be significantly lower in infertile group than the fertile controls. Semen MDA and ROS levels of infertile group were significantly higher (p<0.0001), when compared to the control group. However, catalase and glutathione peroxidase (GPx) levels were significantly lower in infertile group, compared to controls, but no significant difference in superoxide dismutase (SOD) activity was observed between control and cases. This might be due to higher expression of SOD alone in order to overcome OS in the semen. mtDNA analysis showed significant and high frequency of nucleotide changes in the ATPase (6 and 8), ND (2, 3, 4 and 5) genes of infertile cases compared to the controls. Hence excess ROS and low antioxidant levels in the semen might cause mtDNA mutations and vice versa in OA men that might impair the fertilizing capacity of spermatozoa. Thus, it is important to understand the etiology of mitochondrial genome mutations in idiopathic OA cases for better diagnostic and prognostic value in infertility treatment/assisted reproductive technique.

Effect of Tectona grandis Linn. on dexamethasone-induced insulin resistance in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The bark of Tectona grandis Linn. is traditionally used in the treatment of diabetes.

AIM

The present study was undertaken to investigate the effect of ethanolic extract of bark of Tectona grandis Linn. (TG) in dexamethasone-induced insulin resistance in mice.

MATERIALS AND METHODS

Mice were treated with prestandardised dose of dexamethasone for 22 days and effect of TG at the doses of 50, 100 and 200 mg/kg, p.o. on plasma blood glucose level, serum triglyceride level, glucose uptake in skeletal muscle, levels of hepatic antioxidant enzymes (GSH, SOD, catalase and LPO), and body weight were observed.

RESULTS

TG showed significant decrease in plasma glucose and serum triglyceride levels (p<0.01) at the dose of 100 and 200 mg/kg, p.o. and also stimulated glucose uptake in skeletal muscle. The levels of antioxidant enzymes GSH, SOD, and catalase were significantly increased (p<0.01) and there was significant decrease (p<0.01) in level of LPO.

CONCLUSION

Hence it can be concluded that Tectona grandis may prove to be effective in the treatment of Type-II Diabetes mellitus owing to its ability to decrease insulin resistance.

DNA integrity and semen quality in men with low seminal antioxidant levels

Accurate transmission of information coded in the sperm genome is vital to the pre- and post-natal development of the offspring. Recent advances in reproductive biology have proposed evaluation of sperm DNA integrity as an important assessment tool to infer the presence of DNA strand breaks, numerical abnormalities in sperm chromosome complement, and alterations in the epigenetic regulation of the paternal genome. Oxidative stress (OS), characterized by increased free radicals, may lead to the production of apurine sites, apyrimidine sites, oxidation of nucleotides of sperm genome. This study was performed to assess the impact of OS on DNA integrity in sperms. 52 infertile men [oligozoospermic-13, asthenozoospermic-15, teratozoospermic-19, oligoasthenoteratozoospermic-5] and 20 fertile controls were investigated for products of lipidperoxides as malondialdehyde; antioxidants such as superoxide dismutase, catalase and glutathione in seminal plasma by biochemical methods. DNA integrity of the sperms was analyzed by visual scoring method in which the comets were graded into 4 categories (A-D) on the basis of their tail length indicative of increasing levels of DNA damage. Significant increase in DNA damage (higher number of sperms in group D) in cases (oligozoospermic (O)-20%, asthenozoospermic (A)-24%, teratozoospermic (T)-28%, OAT-43%) as compared to controls (8%) was found. Increased malondialdehyde levels, abnormal sperm morphology and higher DNA damage were observed in the cases. The antioxidants superoxide dismutase, catalase and glutathione had a positive association with sperm count and motility while a negative association with the percentage of dead sperms and abnormal morphology was observed. This study highlights the influence of low antioxidants on sperm genome integrity and indicates sperm DNA integrity as a better and more reliable prognostic tool for infertility evaluation than simple quantitative and morphologic evaluation of spermatozoa.

Rieger syndrome with multiple chromosomal breaks and chromosome 4 deletion

Rieger syndrome (RS) is a rare autosomal dominant disorder with variable expressivity and complete penetrance. Axenfeld-Rieger syndrome (ARS) shows genetic heterogeneity with mutations in several chromosomal loci being implicated including PITX2, FOXC1 and PAX6. Cytogenetic analysis was done in this case. Patient had de novo 46,XY,del(4q25-q27) karyotype with a high percentage (>35%) of chromosomal breaks. The breaks were on different chromosomes and not related to disease phenotype of RS. Such chromosomal breaks are diagnostic of chromosomal instability syndromes. Available literature does not report chromosomal breaks in RS or due to culture condition. Such a high percentage of chromosomal breaks are associated with development of certain cancers. In the present case we did not find any features consistent with any of the chromosomal instability syndromes like Fanconi's anaemia and Blooms syndrome, but such cases need to be under regular follow-up. Thus RS cases with multiple chromosomal breaks need regular follow-up and genetic counselling.

Robertsonian translocation and their role in pathogenesis of recurrent in vitro fertilization failure

BACKGROUND

Chromosomal anomalies have been postulated to be one of the principal genetic factors in reproductive failure. The principal structural anomalies are Robertsonian translocations which occur at a total frequency of rate 1.23 per thousand in newborns. Since most infertile men with Robertsonian translocation are oligospermic, they are good candidates for assisted reproduction like in vitro fertilization and intracytoplasmic sperm injection. However, a large number of such men/couples experience recurrent assisted procreation failure.

MATERIAL/METHODS

The aim of the study was to diagnose the genetic basis of recurrent assisted reproductive failure (in vitro fertilization /intracytoplasmic sperm injection) in infertile men. One hundred twenty infertile men with idiopathic infertility who experienced recurrent assisted procreation techniques failure were recruited into this study after giving informed consent and after ethical clearance had been obtained. Semen and cytogenetic analyses were done to assess the semen status and cytogenetic profile of these men.

RESULTS

Robertsonian translocations were found in 6 of 120 participants (5%). The men with Robertsonian translocation had recurrent assisted procreation techniques failure (>4 failed attempts; 3 in vitro fertilization and at least 1 unsuccessful intracytoplasmic sperm injection). In comparison, the men with a Yq microdeletion and other chromosomal abnormalities conceived after 1 to 2 in vitro fertilization cycles. These chromosomal anomalies may be the basis of failure of these assisted-reproductive procreation techniques.

CONCLUSIONS

These results highlight the need for genetic investigations in all infertile men experiencing recurrent assisted procreation techniques failure.

Genetic screening in couples experiencing recurrent assisted procreation failure

Infertility is a major health problem affecting about 10-20% of couples in the reproductive age group. Male factor is assumed to be responsible in about 50% cases of infertility. The origin of reduced testicular sperm function is unknown in about 50-70% of cases and for such couples assisted reproduction techniques (ART) are a boon. Male infertility is often due to poor semen quality and may be associated with genetic defects. ART has revolutionized management of infertility and intracytoplasmic sperm injection (ICSI) is the ART procedure of choice in 60-80% cases. Despite major technological advancements and professional expertise in ART, the success rate and carry-home live birth rate of ICSI is low (18-25%). This study was aimed to understand the genetic etiopathology of recurrent ART failure. For this, 110 couples with 3 or more failed ART cycles were recruited. A detailed history was taken and only idiopathic ART failure cases were enrolled for this study. They were subjected to cytogenetic and Yq microdeletion analysis. Genetic abnormalities were detected in 19 couples. Since a large number (18.2%) cases harboured genetic abnormalities, it is important for all couples opting for ART to undergo a thorough genetic analysis to prevent recurrent emotional, physical and financial stress.