Jennifer M. Cermak

Androgens and Dry Eye in Sjögren's Syndromea

ABSTRACT: Sjögrens syndrome is an extremely complex and currently incurable autoimmune disorder, which occurs primarily in females, and is associated with lacrimal gland inflammation, meibomian gland dysfunction, and severe dry eye. We hypothesize that androgen deficiency, which reportedly occurs in primary and secondary Sjögrens syndrome (e.g., systemic lupus erythematosus, rheumatoid arthritis), is a critical etiologic factor in the pathogenesis of dry eye syndromes. We further hypothesize that androgen treatment to the ocular surface will promote both lacrimal and meibomian gland function and alleviate both “aqueous‐deficient” and “evaporative” dry eye. Our results demonstrate that androgens regulate both lacrimal and meibomian gland function, and suggest that topical androgen administration may serve as a safe and effective therapy for the treatment of dry eye in Sjögrens syndrome.

Prenatal availability of choline modifies development of the hippocampal cholinergic system

Choline supplementation during fetal development [embryonic days (E) 11–17] permanently enhances memory performance in rats. To characterize the neurochemical mechanisms that may mediate this effect, we investigated the development of indices of the cholinergic system in the hippocampus: choline acetyltransferase (ChAT), acetylcholinesterase (AChE), synthesis of acetylcholine (ACh) from choline transported by high‐affinity choline uptake (HACU), and potassium‐evoked ACh release. During E11–E17, Sprague‐Dawley pregnant rats consumed 0 [choline‐deficient (ChD)], 1.3 [control (ChC)], and 4.6 [choline‐supplemented (ChS)] mmol/(kg • day) of choline, respectively. On postnatal days 17 and 27, hippocampi of the ChD animals had the highest AChE and ChAT activities, and increased synthesis of ACh from choline transported by HACU, concomitant with reductions of tissue ACh content relative to the ChC and ChS rats and an inability to sustain depolarization‐evoked ACh release relative to the ChS animals. In contrast, AChE and ChAT activities, and ACh synthesized from choline transported by HACU, were lowest in ChS rats whereas depolarization‐evoked ACh release was the highest. This pattern of changes suggests that the hippocampus of the ChD animals is characterized by fast ACh recycling and efficient choline reutilization for ACh synthesis, presumably to maintain adequate ACh release despite the decrease of the ACh pool, whereas in the ChS animals ACh turnover and choline recycling is slower while the evoked release of ACh is high. Together, the data show a complex adaptive response of the hippocampal cholinergic system to prenatal choline availability and provide a novel example of developmental plasticity in the nervous system governed by the supply of a single nutrient.—Cermak, J. M., Holler, T., Jackson, D. A., Blusztajn, J. K. Prenatal availability of choline modifies development of the hippocampal cholinergic system. FASEB J. 12, 349–357 (1998)

Is Complete Androgen Insensitivity Syndrome Associated with Alterations in the Meibomian Gland and Ocular Surface

Purpose. This studys purpose was to determine whether complete androgen insensitivity syndrome (CAIS) is associated with alterations in the meibomian gland and ocular surface. Methods. Individuals with CAIS, as well as age-matched female and male controls, completed questionnaires which assessed dry eye symptoms and underwent slit lamp evaluations of the tear film, tear meniscus, lids and lid margins and conjunctiva. The quality of meibomian gland secretions was also analyzed. Results. Our results demonstrate that CAIS is associated with meibomian gland alterations and a significant increase in dry eye signs and symptoms. Clinical assessment revealed that CAIS women, as compared to controls, had a significant increase in telangiectasia, keratinization, lid erythema and orifice metaplasia of the meibomian glands, and a significant decrease in the tear meniscus and quality of meibomian gland secretions. Questionnaire results showed that dry eye symptoms were increased over twofold in CAIS individuals, as compared to controls, including a significant increase in the sensations of dryness, pain and light sensitivity. Conclusion. Our results suggest that androgen insensitivity may promote meibomian gland dysfunction and an increase in the signs and symptoms of dry eye.

Developmental Periods of Choline Sensitivity Provide an Ontogenetic Mechanism for Regulating Memory Capacity and Age-Related Dementia

In order to determine brain and behavioral sensitivity of nutrients that may serve as inductive signals during early development, we altered choline availability to rats during 7 time frames spanning embryonic day (ED) 6 through postnatal day (PD) 75 and examined spatial memory ability in the perinatally-treated adults. Two sensitive periods were identified, ED 12–17 and PD 16–30, during which choline supplementation facilitated spatial memory and produced increases in dendritic spine density in CA1 and dentate gyrus (DG) regions of the hippocampus while also changing the dendritic fields of DG granule cells. Moreover, choline supplementation during ED 12–17 only, prevented the memory decline normally observed in aged rats. These behavioral changes were strongly correlated with the acetylcholine (ACh) content of hippocampal slices following stimulated release. Our data demonstrate that the availability of choline during critical periods of brain development influences cognitive performance in adulthood and old age, and emphasize the importance of perinatal nutrition for successful cognitive aging.

Seizure-induced memory impairment is reduced by choline supplementation before or after status epilepticus

Prenatal choline supplementation can protect rats against cognitive deficits induced by status epilepticus induced by the cholinergic agent pilocarpine [J. Neurosci. 20 (2000) 1]. In the present day, we have extended this novel finding by investigating the effects of pre- and postnatal choline supplementation in memory deficits associated with status epilepticus induced with kainic acid (KA). In the first experiment pregnant rats received a normal, choline-supplemented, or choline deficient diet starting on the 11th day of gestation and continuing until postnatal (P) 7. At P42, rats were given a convulsant dosage of KA. Two weeks following the KA-induced status epilepticus rats underwent testing of visual-spatial memory using the Morris water maze test. Rats receiving supplemental choline performed better in the water maze than the deficient and control groups. Moreover, the activity of hippocampal choline acetyltransferase was 18% lower in the choline deficient animals as compared with the other two groups. In the second experiment we administered KA to P35 rats that had been given a normal diet. Following the status epilepticus the rats were given a choline-supplemented or control diet for 4 weeks and then tested in the water maze. Rats receiving choline supplementation performed far better than rats receiving a regular diet. This study demonstrates that choline supplementation prior to or following KA-induced status epilepticus can protect rats from memory deficits induced by status epilepticus.

Prenatal Availability of Choline Alters the Development of Acetylcholinesterase in the Rat Hippocampus

Choline (Ch) supplementation during embryonic days (ED) 12–17 enhances spatial and temporal memory in adult and aged rats, whereas prenatal Ch deficiency impairs attention performance and accelerates age-related declines in temporal processing. To characterize the neurochemical and neuroanatomical mechanisms that may mediate these behavioral effects in rats, we studied the development [postnatal days (PD) 1, 3, 7, 17, 27, 35, 90, and 26 months postnatally] of acetylcholinesterase (AChE) activity in hippocampus, neocortex and striatum as a function of prenatal Ch availability. We further measured the density of AChE-positive laminae (PD27 and PD90) and interneurons (PD20) in the hippocampus as a function of prenatal Ch availability. During ED11-ED17 pregnant Sprague-Dawley rats received a Ch-deficient, control or Ch-supplemented diet (average Ch intake 0, 1.3 and 4.6 mmol/kg/day, respectively). Prenatal Ch deficiency increased hippocampal AChE activity as compared to control animals in both males and females from the 2nd to 5th week postnatally. Moreover, prenatal Ch supplementation reduced hippocampal AChE activity as compared to control animals over the same developmental period. There was no effect of prenatal Ch status on either cortical or striatal AChE activity at any age measured, and by PD90 the effect of Ch on hippocampal AChE was no longer observed. In order to localize the early changes in hippocampal AChE activity anatomically, frozen coronal brain sections (PD20, PD27, PD90) were stained histochemically for AChE. Consistent with biochemical results, the AChE staining intensity was reduced in PD27 hippocampal laminae in the Ch-supplemented group and increased in the Ch-deficient group compared to control animals. There was no effect of the diet on hippocampal AChE staining intensity on PD90. In addition, the prenatal Ch availability was found to alter the size and density of AChE-positive PD20 interneurons. These results show that prenatal Ch availability has long-term consequences on the development of the hippocampal cholinergic system.

Dietary choline supplementation in pregnant rats increases hippocampal phospholipase D activity of the offspring.

Supplementation with choline during pregnancy in rats causes a long‐lasting improvement of visuospatial memory of the offspring. The biochemical mechanism of this effect may be related to the function of choline as a precursor of phosphatidylcholine (PC), the substrate of a receptor‐stimulated enzyme, phospholipase D (PLD). PLD activation initiates the sequential formation of two intracellular messengers, phosphatidic acid and l,2‐sn‐diacyl‐ glycerol. We hypothesized that prenatal choline status may cause long‐term modulation of PLD‐catalyzed PC hydrolysis in the hippocampus, a brain region implicated in visuospatial memory functions. PLD activity was determined in hippocampal slices prelabeled with [3H]glycerol or [3H]oleic acid by measuring the PLD‐catalyzed formation of [3H]phosphatidyl‐ propanol in the presence of 1‐propanol. Slices were obtained from male pups born to mothers consuming a control diet, a choline‐supplemented diet, or a choline‐free diet from days 11 to 17 of pregnancy. The radiolabeling of phospholipid classes was unaffected by the treatments. Prenatal choline supplementation significantly increased basal PLD activity in [3H]glyc‐ erol‐labeled slices [by 46% of controls on postnatal day (P) 7 and by 36% on P21 ], and [3H]oleate‐labeled slices (by 91 % on P7), as well as glutamate‐stimulated PLD activity in [3H]oleate‐labeled slices (by 60% on P7). Prenatal choline deficiency failed to alter PLD activity. The actions of choline apparently required intact cells because in vitro assays of PLD activity in hippocampal homogenates, using fluorescent NBD‐ PC as substrate, revealed no differences between groups. The results show that prenatal choline supplementation up‐regulates basal and receptor‐stimulated PLD activity in the hippocampus during postnatal development.—Holler, T., Cermak, J. M., Blusztajn, J. K. Dietary choline supplementation in pregnant rats increases hippocampal phospholipase D activity of the offspring. FASEBJ. 10,1653‐1659(1996)

Sex steroids, the meibomian gland and evaporative dry eye.

Our recent research has led to our hypothesis that gender and sex steroid hormones are critical factors in the regulation of the meibomian gland and pathogenesis of evaporative dry eye. The objective of this article is to briefly summarize the experimental basis for this hypothesis.

Imprinting of hippocampal metabolism of choline by its availability during gestation: Implications for cholinergic neurotransmission

Choline supplementation during the second half of the gestational period in rats permanently improves visuospatial memory. Choline availability during this period also alters the turnover of choline and acetylcholine in the hippocampus in 3-4 week-old animals in a complex pattern consistent with the notion that cholinergic neurotransmission is enhanced by prenatal choline supplementation.

Correlations between nutrient intake and the polar lipid profiles of meibomian gland secretions in women with Sjögren's syndrome.

Very recently, we discovered that women with Sjogren’s syndrome exhibit one of two distinct profiles in the polar lipid fraction of their meibomian gland secretions (Fig. 1). The first pattern is characterized by a single predominant peak eluting early on in the total ion current during HPLC analysis. The second pattern is characterized by multiple peaks spread over time. To begin to explore the mechanism(s) underlying these differences, we sought to determine whether the nutrient intake, and particularly the lipid consumption, of Sjogren’s syndrome patients may vary between those individuals expressing the “single” versus the “multiple” profile.